Near Edge Fine Structures on Electron Energy Loss Spectroscopy Core Loss Edges

Core edges recorded in Electron Energy Loss Spectroscopy (EELS) display a large variety of profiles. We have investigated several specific aspects concerning Energy Loss Near Edge Structures (ELNES) and emphasize the interest in a careful edge shape analysis to obtain refined microanalytical information, such as local symmetry. After indicating the general impact of EELS fine structures as compared to EDX and Auger spectroscopies we discuss the instrumental conditions required for recording satisfactory spectra and consider the theoretical problems which are involved in data interpretation. The major portion of this paper presents results for selected K, L23, M45 and N45 core excitations in compounds (mainly oxides). In each case the phenomena governing the ELNES distribution are pointed out. In conclusion, we summarize the potential of a careful analysis of ELNES for studying the chemical state of the absorbing atom and the symmetry of it s first coordination shell (molecular description) or longer range effects (projections of solid state density of states as seen by the ejected atom)

Physical investigations on (In2S3)x(In2O3)y and In2S3-xSex thin films processed through In2S3 annealing in air and selenide atmosphere

In2S3-xSex and (In2S3)x(In2O3)y thin films have been prepared on glass substrates using appropriate heat treatments of In evaporatedt hin films. X-ray analysis shows that In thin films which were annealed under sulfur atmosphere at 350°C were mainly formed by In2S3. A heat treatment o fthis binary in air at 400°C during one hour leads to (In2S3)x(In2O3)y ternary material which has a tetragonal structure with a preferred orientation of the crystallites along the (109) direction. Similarly, a heat treatment of In2S3 in selenium atmosphere at 350°C during six hours leads to a new In2S3-xSex ternary material having tetragonal body centered structure with a preferred orientation of the crystallites along the (109) direction.Optical band gap,refractive index and extinction coefficient values of In2S3-xSex and (In2S3)x(In2O3)y thin films have been reached. Moreover, correlations between optical conductivity, XRD, AFM and Urbach energy of such ternary thin films have been discussed. Finally, the recorded formation disparity between the quaternary (In2S3)x(In2O3)y and ternary In2S3-xSex compounds has been discussed in terms of the Simha–Somcynsky and Lattice Compatibility theories

Kyste Amygdaloïde Oropharynge A Propos D\'un Cas

Le kyste amygdaloïde est une tumeur kystique latéro-cervicale haute rare, issue de la 2ème fente branchiale. Il représente 2% des tumeurs latéro-cervicales du cou, et 6,1à 85,2% des anomalies de la deuxième fente. La forme oropharyngée est très rare. Nous rapportons une observation d\'un kyste amygdaloïde oropharyngé, chez une femme de 56 ans. Aucune symptomatologie particulière n\'a été notée. L\'examen clinique a révélé une tuméfaction de la loge amygdalienne droite, refoulant le pilier antérieur. La TDM a objectivé un processus expansif nécrosé de l\'amygdale palatine droite comblant l\'espace parapharyngé droit, en contact avec la base de la langue et le muscle ptérygoïdien médial homolatéral. Une résection complète et sans rupture du kyste a été pratiquée par voie transorale, le geste a été complété par une amygdalectomie droite. L\'histologie a confirmé le diagnostic par la co-existence d\'un revêtement épithélial et d\'une infiltration de tissu lymphoïde. Le recul est de 6 mois sans récidiveSecond branchial cleft cysts are the most common type of branchial abnormalities and usually found high in the neck. Oropharyngeal presence of branchial cleft cyst is very rare. We report a case of oropharyngeal branchial cleft cyst in 56 years women, wich had any specific symptom. Radiologic examination (TDM) revealed an expansive mass of the palatin tonsil. It was removed completely with right palatin tonsil. Cyst had a squamous epithelium-lined wall with lymphoid aggregation in histopathologic study, which was chareacteristic finding of branchial cleft cyst. There was no evidence of recurrence for 6 months for follow-up. We review reported oropharyngeal or nasopharyngeal presentation of these cases in literature and embryologic explanation. Keywords: Oropharyngeal, branchial, cysts Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 49-5

Indium free electrode, highly flexible, transparent and conductive for optoelectronic devices

WO3/Ag/WO3 multilayer structures were used as ITO free transparent electrode, transparent heat mirrors and transparent heaters. WO3/Ag/WO3 stacked layers were deposited by sequential sublimation, evaporation under vacuum. After optimization of Ag thickness (16 nm), they exhibit low sheet resistance (8 Ω/sq), high transmittance in the visible (TMax = 91.5%, averaged T400-700 = 80.6%) and high reflection in the near infrared and infrared regions. These values are optimal when it is used as transparent electrode but, as transparent heat mirrors 18 nm are better due to higher reflection in the NIR and IR. All these properties made possible to use them in different devices. When used as transparent anode in organic photovoltaic cells, they allow achieving performance similar to those obtained with ITO. Their transmission and reflection spectra show that they can also be employed as transparent heat mirrors. Similarly, studies dedicated to heating properties of the WO3/Ag/WO3 multilayer structures show that their performance are comparable to those obtained with another possible substituent to ITO, silver nanowires thin films

Development of scalable and versatile nanomaterial libraries for nanosafety studies: polyvinylpyrrolidone (PVP) capped metal oxide nanoparticles

The potential long-term environmental impact of manufactured nanomaterials (NMs) remains poorly understood, and the need to better predict NM fate and transformations and chronic effects is particularly urgent. Compared to their bulk counterparts, manufactured NMs can have distinct physical and chemical characteristics, which influence their behaviour, stability and toxicity. It is therefore essential to develop standard and reference NM libraries for environmental nanoscience and nano(eco)toxicology, and to facilitate a move towards computational prediction of NM fate, through quantitative structure–activity relationships for example. The aim of this work was to develop and fully characterise one such library, which included comparable NMs with a range of core chemistries, but the same capping agent and size range, for use in future studies to test the hypothesis that the core chemistry is a primary factor in controlling toxicity. The library contained the following NMs: 10k, 40k and 360k PVP capped ceria, zinc oxide and copper oxide (9 NMs in total). The work presented here upholds the underpinning hypothesis that the mechanism of NM formation is the same in all cases, suggesting that the protocol is very robust and has the potential to generate a wide range of comparable metal oxide NMs and potentially expand the library further with doped metal oxide and metal NMs. Characterisation by means of DLS (both size and zeta measurements), UV/Vis, XPS, FT-IR, TEM, STEM, EDX and EELS confirms that the tested synthesis protocol can easily and successfully be used to create stable PVP capped metal oxide NMs of reproducible sizes

Integral and discrete representations of some Hq-semiclassical forms

The aim of this paper is to deduce integral and discrete representations of some Hq-semiclassical forms of class one. These forms were studied by B. Bouras and F. Marcellan in [1], (Quadratic decomposition of a family of Hq-semiclassical orthogonal polynomial sequences, J. Difference Equ. Appl. 18 (2012), 2039{2057), but unfortunately, the above problem of representation remained opened in that work. In this paper, we find the moments investigate the of theses forms to solve this problem.Keywords: q-difference operator, Hq-semi-classical polynomials, integral representation, q-difference equations, q-series representation

Le sport : organisation et enjeux financiers

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