Science & Mathematics

The synthesis and crystal structure of the title compound, C 30 H 29 NO, are described. This compound is a member of the chiral dihydroisoquinoline-derived family, used as building blocks for functional materials and as source of chirality in asymmetric synthesis, and was isolated as one of two diastereomeric β- amino alcohols, the title molecule being found to be the ( S,R ) diastereoisomer. In the crystal, molecules are packed in a herringbone manner parallel to (103) and (10\overline{3}) via weak C—H...O and C—H...π(ring) interactions. Hirshfeld surface analysis showed that the surface contacts are predominantly H...H interactions ( ca 75%). The crystal studied was refined as a two-component inversion twin.

This article first distinguishes constraints from rules, and descriptive constraints from prescriptive ones. Both kinds can be used to calculate a constraint-based completenesses (as opposed to a real-world-based completeness), i.e. evaluating how much of a knowledge base is complete with respect to some constraints, e.g. for evaluating how well this base follows given ontology design patterns or best practices. Such evaluations may also guide knowledge elicitation and modelisation. This article explores the ways constraints can be represented via relations between classes, hence via any knowledge representation language (KRL) that has an expressiveness at least equal to RDF or RDFS. Compared to the popular practice of both representing and checking constraints via queries, this approach is as simple, offers more possibilities for exploiting both knowledge and constraints, and permits the selection and use of inference engines adapted to the expressiveness of the exploited knowledge instead of the use of restricted or ad hoc constraint-validation tools. This approach is also modular in the sense it separates content from usage: the represented "content focused constraints" can then be exploited via few "content independent" queries, one for each usage and kind of constraint. This approach provides more possibilities.

Poursuivant la réalisation de méthodes de caractérisation d'un fluide en écoulement par diffusion Rayleigh forcée, nous avons mis au point une technique de marquage d'une figure bidimensionnelle quelconque dans le fluide par imagerie optique. L'impression de ce réseau et la visualisation directe de sa déformation permettent d'obtenir une mesure directe des composantes du gradient de vitesse.

Inverting the gaze initially adopted by scholars of Iran that had been inspired by Said’s Orientalism thesis, a line of academic enquiry that one might call Iranian Occidentalism, i.e. the study of Iranian perceptions, or perhaps better, (re)constructions, of the West, has been gathering considerable momentum in the last decade or so. However, while work has been done on several different facets of this Iranian Occidentalism – e.g. on its manifestations in travelogues, in poetry and prose literature, in the arts, or in academic philosophy – no attention has so far been paid by scholars to the question of how, if at all, Iranian historians have studied the history of the Occident in their academic writings. This essay addresses this desideratum and breaks new ground by analysing the rare instance of one of 20th-century Iran’s most venerated historians – the ‘father of Modern Iranian history’, Fereydun Adamiyat (1920-2008) – writing on a completely non-Iran related, major topic within Modern European history, namely the rise of National-Socialism in Germany and the fall of the Weimar Republic. This analysis starts by explaining Adamiyat’s account of the destruction of Germany’s democracy in the 1930s in its unexpected context – a book on Social-Democratic thought in Iran at the time of the Constitutional Revolution (1906-1911) published in Tehran for the first time in 1975. It then proceeds to assessing Adamiyat’s account of the triumph of National Socialism in 1930s Germany in terms of its merits as a contribution to scholarship before enquiring into the potential of a present-day political agenda on the part of Adamiyat in having chosen to write on this specific topic at the specific time that he did, namely during the mid-1970s, i.e. at a time when Iran seemed to have reached a level of stability and (sudden) wealth that could not have been more different from the troubled final years of the Weimar Republic. In so doing this essay does not only open up an entirely new chapter in the study of Iranian Occidentalism but also makes an original contribution to another burgeoning field, namely the study of the development of history as an academic discipline and as a politically contested body of knowledge in 20th-century Iran.

Er-doped amorphous silicon suboxide thin films were prepared by the coevaporation method. The Er concentration was varied from 0.4 to 6 at. % and the samples were annealed at different temperatures up to 900°C. The samples exhibit a broad photoluminescence band in the visible range. Both energy and intensity of this band were dependent on the annealing temperature. For as-deposited films and samples annealed below 500°C, this band was assigned to defects in the oxide films. For higher annealing temperatures, this photoluminescence band shifted to higher wavelengths and was correlated to the appearance of amorphous silicon clusters. Two narrow bands in the near-infrared range at 0.98 and 1.54 m were also observed for the annealed samples. The intensity of these Er-related luminescence was maximal for an annealing temperature equal to around 700°C. The effective absorption cross section of Er was dependent on the annealing temperature and was equal to 6.6ϫ 10 −16 cm 2 for the sample annealed at 700°C. The strong Er-related photoluminescence is discussed in terms of a coupling phenomenon between Er 3+ ions and spatially confined amorphous silicon clusters which act as sensitizers. The existence of a low annealing temperature to obtain the best Er-related photoluminescence is also discussed.

A free-space microwave nondestructive testing and evaluation module is developed for the low-power, non-ionizing, contactless, and real-time characterization of doped composite thin-film materials in an industrial context. The instrumentation proposed is built up with a handled vector network analyzer interfaced with corrugated horn antennas to measure the near-field complex reflection S11 of planar prepreg composite materials in a roll-to-roll in-line production line. Dedicated modeling and calibrations routines are developed to extract the microwave conductivity from the measured microwave signal. Practical extraction of the radiofrequency (RF) conductivity of thin film prepreg composite materials doped with nano-powders is exemplary shown at the test frequency of 10 GHz.

Un appareil est décrit, destiné au contrôle de l'intensité d'un faisceau d'atomes métastables de gaz rare d'énergie cinétique thermique, provoquant une perturbation négligeable du faisceau. Ionisés par des électrons de faible énergie (Ee < E*), les atomes métastables sont comptés par l'intermédiaire d'un filtre quadrupolaire. Les courbes de section efficace d'ionisation e- + He* → He + + 2 e- sont données en fonction de l'énergie Ee- et comparées aux résultats antérieurs. La mesure du flux d'atomes métastables est décrite; la fidélité, la sensibilité et la précision de l'appareil sont discutés.

In this article, we look at two competing hypotheses to explain IPO underpricing in France when a seasoned offering follows the IPO. The first hypothesis assumes that the initial underpricing is a signal from a high quality firm in the anticipation of a subsequent equity issue at a higher price. The second competing hypothesis assumes that the market transmits to managers their valuation of the company. Our database examines two types of subsequent risky issuances: on the one hand, stocks and on the other hand, hybrid issuances (such as convertible bonds, bonds with attached warrants, and stocks with attached warrants). Further, in the French market, firms may be introduced through different mechanisms, which are not equally compatible with both hypotheses. We show that the initial underpricing is greater if a stock issuance rather than other security offerings of a convertible nature subsequently follow the IPO. We find evidence in favor of the signaling hypothesis in the case of fixed price IPOs. For the auction-like procedures, we show that the initial investors' demand, rather than post-IPO performance, determines the type of security that is issued, but has no effect on the financing decision itself. The market feedback hypothesis is therefore only weakly supported: a poor market message does not keep managers from expanding, but rather encourages them to use stage financing rather than straight equity.

To understand texts written in natural language (LN), we use our knowledge about the norms of the domain. Norms allow to infer more implicit information from the text. This kind of information can, in general, be defeasible, but it remains useful and acceptable while the text do not contradict it explicitly. In this paper we describe a non-monotonic reasoning system based on the norms of the car crash domain. The system infers the cause of an accident from its textual description. The cause of an accident is seen as the most specific norm which has been violated. The predicates and the rules of the system are stratified: organized on layers in order to obtain an efficient reasoning.

24x36 mm, gélatine plan-film.

This first publication on Za:r is part of a work that first started in 1991 in Azare and has now taken the shape of a lifelong enterprise. The general purpose of describing the Za:r language is to help put on the linguistic map a language spoken by about 150 000 speakers in the South of Bauchi State, Nigeria, and mainly in the ogoro Local Government Area. The present work is primarily aimed at Za:r speakers. All of them are bilingual, using Za:r locally and Hausa regionally. English is a prerequisite in the Nigerian system of education. Through the use of Za:r, English and Hausa in the dictionary and collection of texts, this book is meant to develop the readers' competence in the three languages and will help Za:r children become more familiar with English. Finally, the local (Bauchi) Hausa has been chosen for the translation of the collection of texts, and to document a non-standard variety of the language.