Transfer matrix approach for the Kerr and Faraday rotation in layered nanostructures

To study the optical rotation of the polarization of light incident on multilayer systems consisting of atomically thin conductors and dielectric multilayers we present a general method based on transfer matrices. The transfer matrix of the atomically thin conducting layer is obtained using the Maxwell equations. We derive expressions for the Kerr (Faraday) rotation angle and for the ellipticity of the reflected (transmitted) light as a function of the incident angle and polarization of the light. The method is demonstrated by calculating the Kerr (Faraday) angle for bilayer graphene in the quantum anomalous Hall state placed on the top of dielectric multilayers. The optical conductivity of the bilayer graphene is calculated in the framework of a four-band model.Comment: 10 pages, 6 figure

QUALITATIVE ASPECTS OF CRIŞUL REPEDE RIVER

Qualitative aspects of Crisul Repede River. The evolution of water quality over the Crişul Repede River is atypical because of natural and anthropic factors. The most significant factors are the geological substrate, and the settlements with their agricultural and industrial activity. The study was performed at three gauging stations for the period 1996-2006, taking into account the annual average values. The considered elements were: the discharge values, temperature, suspensions, oxygen regime, nutrients and phosphorus, taking into consideration their temporal and spatial variation. By comparing them with the admitted limits we could enroll them in various quality classes

Chemomapping of artichoke (cynara scolymus l.) and fenugreek (trigonella foenum-graecum l.) extracts, and analysis of generated biological effects using in vitro and in vivo modell systems

A disszertációmban azokról a kutatásokról számolok be, amelyek az articsóka és a görögszéna beltartalmi értékei, illetve élettani hatásai közötti összefüggésekre irányulnak. Első lépésként vizes és alkoholos extraktumokat készítettem szárított articsókalevélből és görögszénamagból, majd tanulmányoztam azok bioaktív hatóanyagait (UHPLC-ESI-MS), valamint meghatároztam összpolifenol- és összflavonoid-tartalmukat, illetve in vitro antioxidáns kapacitását (UV-VIS spektrofotométer). Az articsóka és görögszéna extraktumok élettani hatásait tanulmányozva megállapítottam, hogy a vizes és alkoholos kivonataim nem befolyásolják kedvezőtlenül a Drosophila melanogaster életképességét, azaz in vivo nem citotoxikusak és nem növelik meg sem a kromoszómatörések sem a pontmutációk gyakoriságát, vagyis nem genotoxikusak (SMART tesztrendszer). Továbbá megállapítottam, hogy a vizes és alkoholos kivonatok eltérő módon befolyásolják a humán emlőkarcinoma sejtvonalak életlépességét (MTT viabilitás/proliferációs teszt). A vizes extraktumok bifázisos hatása egyszerre utal kis koncentráció esetén az adaptív stresszválaszok hatékonyságának növelésére, míg nagy koncentráció esetén a proliferáció gátlásra. Az alkoholos extraktumok erőteljes in vitro citotoxicitása pedig apoptózis által indukált sejthalálra enged következtetni. Mindent egybevetve, a kísérleti eredményeim arra utalnak, hogy mind az articsóka, mind a görögszéna extraktumok genotoxicitás nélküli tumorellenes hatása egy olyan alap, amelyre ráépíthetők ezen növények humán prevenciós és/vagy terápiás alkalmazásai.In my doctoral dissertation the presented experiemental data are meant to correlate the bioactive compounds content and generated biological effects of artichoke- and fenugreek extracts. Therefore, I have prepared aqueous- and alcoholic extracts from artichoke and fenugreek, then by chemomapping I have determined the bioactive compound profile, total polyphenol-, total flavonoid content and the in vitro antioxidant capacity of all extracts. The in vivo studies of generated biological effects have shown that the artichoke- and fenugreek extracts do not reduce viability of Drosophila melanogaster, and are not cytotoxic nor genotoxic since they fail to increase the chromosomal breakage and gene mutation rate. The in vitro studies have revealed that the aqueous- and alcoholic extracts do affect differently the viability of human breast carcinoma cell lines. The aqueous artichoke- and aqueous fenugreek extracts affect viability in biphasic manner, suggesting the concentration-dependent implication of adaptive stress response and cytotoxicity. The alcoholic artichoke- and alcoholic fenugreek extracts feature a pronounced cytotoxic effect across a wide concentration range that seems to be related to apoptosis induced cell death. Taken together, all these data are suggesting that the artichoke and fenugreek extracts non-genotoxic butanti-tumoral effects represent a solid scientific ground in order to prove these plants potential usefulness in preventing and/ortreating human conditions like cancer.d

Jacques Ferron ou la mémoire extérieure

L'Amélanchier de Ferron est un monument à la quête d'identité - pas seulement celle du peuple québécois mais, de façon générale, toute identité collective menacée en sa survie même. Les communautés ont besoin de mémoires extérieures, d'objets et de personnes qui les rappellent chaque jour à elles-mêmes et qui les sauvent de l'amnésie des aliénés. Cependant, c'est rarement à la surface qu'on saisit ces identités et les dangers qui les guettent : les véritables mémoires extérieures remontent l'histoire pour en sublimer l'essentiel et déjouer ainsi les tentatives de la civilisation pétrolière, qui tente de liquider doucement cet essentiel en lui subsitutant de plaisants leurres.Ferron's l'Amélanchier is a monument to the quest for identity - the identity not only of the people of Quebec, but of any collective whose very survival is threatened. Communities need external memories - objects and individuals that will recall them to themselves daily and save them from falling prey to the amnesia of the alienated. But these identities and the dangers that threaten them are seldom grasped at the surface: true external memories retrace history in order to lay hold of its essence and thus counter the attempts of our "petroleum civilization" to liquidate the essential by substituting its own pleasing delusions for it

MONTHLY AVERAGE FLOW IN RÂUL NEGRU HYDROGRAPHIC BASIN

Râul Negru hydrographic basin represents a well individualised and relatively homogenous physical-geographical unity from Braşov Depression. The flow is controlled by six hydrometric stations placed on the main collector and on two of the most powerful tributaries. Our analysis period is represented by the last 25 years (1988 - 2012) and it’s acceptable for make pertinent conclusions. The maximum discharge month is April, that it’s placed in the high flow period: March – June. Minimum discharges appear in November - because of the lack of pluvial precipitations; in January because of high solid precipitations and because of water volume retention in ice. Extreme discharge frequencies vary according to their position: in the mountain area – small basin surface; into a depression – high basin surface. Variation coefficients point out very similar variation principles, showing a relative homogeneity of flow processes

Youth mobilisation as social navigation: reflections on the concept of Dubriagem

Este artigo foca a mobilização para o conflito dos jovens, alegando que a guerra constitui um terreno de possibilidades para a juventude urbana na Guiné‑Bissau e mostrando como estes mesmos jovens navegam através da guerra através de opções tácticas e manobrando os seus laços sociais. Baseando‑se no termo crioulo guineense dubriagem, o artigo propõe o conceito de navegação social enquanto uma perspectiva de análise esclarecedora da práxis em ambientes instáveis. Este conceito foca as formas de actuação em ambientes de mudança social, enquadrando o processo de movimento. O artigo defende uma análise da práxis partindo de uma interpretação Batesoniana e intermorfológica da acção para aprofundar a compreensão dos actos dos jovens em situações de conflito.This article sheds light on the mobilisation of young people into conflict. It argues that warfare constitutes a terrain of possibility for urban youth in Guinea‑Bissau, and shows how they navigate war as an event by tactically manoeuvring within the social ties and options that arise in such situations. Building on the Guinean Creole term of dubriagem, the article proposes the concept of social navigation as an analytical optic able to shed light on praxis in unstable environments. The concept of social navigation makes it possible to focus on the way we move within changing social environments. It is processuality squared, illuminating motion within motion. The article thus advocates an analysis of praxis that takes its point of departure in a Batesonian and intermorphological understanding of action in order to further our understanding of the acts of youth in conflict