Modelling the performance of fluorescent solar collectors

The theoretical power conversion efficiency of a silicon solar cell with a fluorescent solar collector is believed to reach 90% of the maximum efficiency of an ideal silicon solar given by the Shockley-Queisser detailed balance limit, but the practical efficiencies are significantly lower due to several loss mechanisms. This work presents an analytic model which take the non-ideal coupling between the collector and the solar cell mounted at the edge into consideration and it is shown in good agreement with experimental results

Gandhi and the Ethic of Active Non-Violence

This paper argues that Gandhi’s active non-violence is an ethic that (a) resists the use of illegitimate violence to solve conflict and (b) seeks to remove the material and moral conditions that engender conflict. It gets its ultimate strength from “soul-force” as Gandhi calls it. Its effectiveness depends on the deep spiritual life of its practitioners, the respect for human rights and social justice. A society can be governed by non-violent means only if the vast majority of its members are already non-violent in their civic behavior. Gandhi does not advocate radical pacifism as he recognizes the right of self-defense, and the legitimacy of the constitutionally limited state. The reduction, not the elimination, of violence is its general policy

“Izumi” Bijeloga Viteza: kreativnost i “inventivnost” u romanu Through the Looking-Glass

The figure of the White Knight in Lewis Carroll’s Through the Looking-Glass has often been read as part of a tradition of “nonsense literature”. While this is true, I wish to extend that argument and locate the figure of the White Knight in the context of the debates around the Patent Law of 1852. While defining and recognising the role of mechanical labour, the role and function of artistic labour also featured in these debates. The White Knight’s “inventions” are deeply resonant with these debates and prompt us to ask: what is the role of the artist in an industrial society? How can art retain its autonomy and justify itself when confronted with the pervasive discourse of utilitarianism? This paper argues that the anxiety around the role of the artist is palpable in the figure of the White Knight, and through him Carroll enunciates what may be read as his intervention in this debate.Figura Bijeloga Viteza u djelu Što je Alica otkrila iza zrcala Lewisa Carrolla često se interpretira u obzoru tradicije „nonsensne književnosti“. To je prikladno, no namjera je ovoga rada proširiti tu argumentaciju i smjestiti lik Bijeloga Viteza u kontekst rasprava o Zakonu o patentima iz 1852. godine. One određuju i prepoznaju ulogu mehaničkoga rada, ali se također dotiču uloge i funkcije umjetničkoga rada. „Izumi“ Bijeloga Viteza dubinski su povezani s tim raspravama te nas vode k pitanju: koja je uloga umjetnika u industrijskom društvu? Kako umjetnost može zadržati autonomiju i opravdati se kad se suočava sa sveprisutnim diskursom utilitarizma? Ovaj članak pokazuje da je anksioznost koja se povezuje s ulogom umjetnika upravo opipljiva u liku Bijeloga Viteza te da Carroll kroz taj lik artikulira stajalište koje se može tumačiti kao njegov prinos spomenutoj raspravi

Collaboration entre enseignants ordinaires et spécialisés :: principes, pratiques et intégration d’élèves

Ce mémoire s’inscrit dans le domaine de l’enseignement spécialisé et étudie les principes de collaboration mis en place entre enseignants des secteurs de l’enseignement ordinaire et spécialisé, ceci dans le contexte actuel de l’évolution de la mission de l’école qui doit favoriser l’intégration des élèves à besoins éducatifs particuliers. Une première partie théorique explore les différents textes prescriptifs, tant internationaux que nationaux, ainsi que quelques articles de loi. Puis, se référant à l’état des connaissances produites, les différentes terminologies des concepts d’intégration et d’inclusion, ainsi que les paradigmes des notions de collaboration et de coenseignement sont présentés. Les observations menées lors de deux expériences d’intégration de 5 élèves de classe spécialisée dans une classe ordinaire vont permettre d’analyser la pratique enseignante. L’objectif de la recherche est de définir quels sont les principes fondateurs d’une collaboration, quelle forme celle-ci peut prendre et quels en sont les effets sur l’intégration des élèves. Les résultats révèlent que, bien que la collaboration ait un impact positif sur l’intégration des élèves, c’est surtout les interactions et l’entraide entre eux qui provoquent de nouveaux liens entre pairs et ainsi une meilleure intégration

Master of Science

thesisThe purpose of this research is to verify the structural integrity of the AN/FPS-117 Long Range Radar and radar tower. An investigation is performed to understand how the fluctuating loads have an impact on the nucleation of crack-like discontinuities and the service life of the components and what steps should be taken as a result of the analysis. It is hypothesized that the rotation of the radar, in conjunction with the variation in level of the platform, creates fluctuating loads in support members that will decrease the life and reliability of these and other radar components. An analysis is conducted of the changes in stress and strain amplitudes on the structure due to the rotation of the radar. Based on the material type, fatigue properties were determined and a strain-life curve was constructed to approximate the number of cycles to failure. The resulting strain amplitude from the fluctuation of loads was found to be relatively small compared to the strain-life curve. The change in radar level did not have a significant impact on the strain amplitude and calculated cycles to failure based on strain gage measurements. A damage tolerance assessment was completed to estimate the crack growth rate of the cracks found in the radar support plate. The results from this analysis were compared with a failure analysis that was performed on the radar support plate

Photon reabsorption in fluorescent solar collectors

Understanding photon transport losses in fluorescence solar collectors is very important for increasing optical efficiencies. We present an analytical expression to characterize photon reabsorption in fluorescent solar collectors, which represent a major source of photon loss. A particularly useful universal form of this expression is found in the limit of high reabsorption, which gives the photon reabsorption probability in a simple form as a function of the absorption coefficient and the optical étendue of the emitted photon beam. Our mathematical model predicts fluorescence spectra emitted from the collector edge, which are in excellent agreement with experiment and provide an effective characterization tool for photon transport in light absorbing media

Le coût social de l'alcool, du tabac et des drogues illicites en France, 2000

Calcul du coût social de l'alcool, du tabac et des drogues illicites en France 2000Coût social, alcool, tabac, drogues

Strong, specific, monodentate G-C base pair recognition by N7-inosine derivatives in the pyrimidine•purine-pyrimidine triple-helical binding motif

The nucleoside analogs 7-(2′-deoxy-α-D-ribofuranosyl)hypoxanthine (β7H, 1), 7-(2′-deoxy-β-D-ribofuranosyl)hypoxanthine (β7H, 2) and 7-(2′-O-methyl-β-Dribofuranosyl)hypoxanthine (β7HOMe, 3) were prepared and incorporated into triplex forming oligodeoxynucleotides, designed to bind to DNA in the parallel (pyrimidine•purine-pyrimidine) motif. By DNase I footprinting techniques and UV-melting curve analysis it was found that, at pH 7.0, the 15mer oligonucleotides d(TTTTTMeCTXTMeCTMeCTMeCT) (MeC = 5-methyldeoxycytidine, X = β7H, β7HOMe) bind to a DNA target duplex forming a H•G-C base triple with equal to slightly increased (10-fold) stability compared to a control oligodeoxynucleotide in which the hypoxanthine residue is replaced by MeC. Remarkably, triplehelix formation is specific to G-C base pairs and up to 40 µM third strand concentration, no stable triplex exhibiting H•A-T, H•T-A or H•C-G base arrangements could be found (target duplex concentration ∼0.1 nM). Multiply substituted sequences containing β7H residues either in an isolated [d(TTTTTβ7HTβ7HTβ7HTβ7HTβ7HT)] or in a contiguous [d(TTTβ7Hβ7Hβ7Hβ7HTTTTβ7HTTT)] manner still form triplexes with their targets of comparable stability as the control (MeC-containing) sequences at pH 7.0 and high salt or spermine containing buffers. General considerations lead to a structural model in which the recognition of the G-C base pair by hypoxanthine takes place via only one H-bond of the N-H of hypoxanthine to N7 of guanine. This model is supported by a molecular dynamics simulation. A general comparison of the triplex forming properties of oligonucleotides containing β7H with those containing MeC or N7-2′-deoxyguanosine (N7G) reveals that monodentate recognition in the former case can energetically compete with bidentate recognition in the latter two case