Sviluppo di un metodo elettrochimico per la determinazione della capacità antiossidante

The aim of the present thesis, carried out at the Analytical Group of the Faculty of Industrial Chemistry in Bologna, is to develop a new electrochemical method for the determination of the Antioxidant Capacity (AOC). The approach is based on the deposition of a non-conducting polymeric film on the working electrode surface and the following exposition to the radicals OH· produced by H2O2 photolysis. The strongly oxidant action of hydroxyl radicals degrades, causing an increase of the Faradic current, relevant to the redox couple [Ru(NH3)6]2+/3+ monitored by cyclic voltammetry(CV); the presence of an antioxidant compound in solution slows down the radical action, thus protecting the polymeric film and blocking the charge transfer. The parameter adopted for the quantification of the AOC, was the induction time, called also lag phase, which is the time when the degradation of the film starts. Five pure compounds, among most commonly antioxidant, were investigated : Trolox®(an analogue water-soluble of vitamin E), (L)-ascorbic acid, gallic acid, pyrogallol and (-)- epicatechin. The AOC of each antioxidant was expressed by TEAC index (Trolox® Equivalent Antioxidant Capacity), calculated from the ratio between the slope of the calibration curve of the target compound and the slope of the calibration curve of Trolox®. The results from the electrochemical method, have been compared with those obtained from some other standardized methods, widely employed. The assays used for the comparison, have been: ORAC, a spectrofluorimetric method based on the decrease of fluorescein emission after the attack of alkylperoxide radicals, ABTS and DPPH that exploit the decoloration of stable nitrogen radicals when they are reduced in presence of an antioxidant compound and, finally, a potentiometric method based on the response of the redox couple [Fe(CN)6]3-/ [Fe(CN)6]4-. From the results obtained from pure compounds, it has been found that ORAC is the methodology showing the best correlation with the developed electrochemical method, maybe since similar radical species are involved. The comparison between the considered assays, was also extended to the analysis of a real sample of fruit juice. In such a case the TEAC value resulting from the electrochemical method is higher than those from standardized assays.

Les conflits et les rapports de force dans la langue. Le dominant et le domine dans le domaine scolaire

La standardisation de la langue française a inévitablement eu des conséquences soit dans l’attitude de défense du français, soit dans l’inquiétude de ceux qui parlent une autre langue. Cette étude veut établir une comparaison entre le rapport langue du pouvoir/langues non officielles et le rapport professeur/élève en milieu scolaire. La distinction entre langue officielle et dites « langues minoritaires » sera mis en relation avec la langue des jeunes, qui, à l’école, se confrontent et entrent en collision avec la langue de leur professeur. En effet, les classes hétérogènes et l’influence de la langue maternelle auprès des élèves, fils d’immigrés, exposent les enseignants à toute une série de difficultés liées aux différences culturelles. Les dénonciations et les cas de violence dans les écoles mettront l’accent également sur l’opinion publique et sur le type de mesures mises en relief par les Institutions publiques. L’aire géographique prise en considération inclut Paris et ses environs même si quelques exemples d’enquêtes menées dans d’autres parties de la France et à l’étranger seront cités.

La traduzione del romanzo per ragazzi Apache - Girl Warrior di Tanya Landman: Un incontro tra storia, genere e culture.

This dissertation deals with the translation into Italian of selected passages from the Young Adult historical novel Apache – Girl Warrior by English author Tanya Landman. The book was chosen after contacting Italian publisher Settenove, dedicated to preventing gender-based violence through children's books and essays. The novel, set in the second half of the Nineteenth Century, tells the story of Siki, a fourteen years old Native American girl who decides to become a warrior in order to avenge her family, killed by the Mexicans. The story also deals with the contact and conflict between Native Americans and white settlers during the so-called Apache Wars. Chapter I deals with Apache's genre; it consists in an overview of the historical novel form and its diffusion, both in Italy and in the English-speaking world. Typical features and themes are also dealt with in this chapter. Chapter II is dedicated to Apache's author. Landman's other works and her mission as a writer are taken into account, as well as the inspirations that led her to writing the novel and the process of research on American history it involved. This chapter also includes a comparison between Tanya Landman's and Louise Erdrich's works. In chapter III, Apache is compared to two well-known novels for children and young adults, The little house on the prairie and Caddie Woodlawn; the aim of this is to demonstrate how widespread misrepresentations about Native Americans are in mainstream literature. Chapter IV analyzes the novel and serves as an introduction to its translation, focusing on its plot, themes, characters and language, while chapter V presents the passages I've chosen to translate; their translation can be found later in the same chapter. In chapter VI, I comment on the choices made during the translation process; translation problems are divided into culture-specific, stylistic, semantic and linguistic.