Preparation and optical properties of GA(x)IN(1-x)P alloys

The solution crystallization method was used to obtain Ga(z)In(1-x)P alloys for all values of x desired between zero and 1. The method of preparation makes it possible to crystallize the solid at a constant temperature. The points obtained by cathodoluminescence are nearly in straight lines. The optical absorption thresholds are confirmed in the results and make it possible to define the nature of the transitions except when x is in the neighborhood of 0.65. These determinations agree with those of Hilsum and Porteus (1968), but are not in agreement with those obtained by Lorenz et al, (1968)

Innovative Technologies for District Heating and Cooling: InDeal Project

The paper discusses the outcomes of the conference organized by the InDeal project. The conference took place on 12 December 2018 in Montpellier as part of the EnerGaia energy forum 2018. A holistic interdisciplinary approach for district heating and cooling (DHC) networks is presented that integrates heterogeneous innovative technologies from various scientific sectors. The solution is based on a multi-layer control and modelling framework that has been designed to minimize the total plant production costs and optimize heating/cooling distribution. Artificial intelligence tools are employed to model uncertainties associated with weather and energy demand forecasts, as well as quantify the energy storage capacity. Smart metering devices are utilized to collect information about all the crucial heat substations’ parameters, whereas a web-based platform offers a unique user environment for network operators. Three new technologies have been further developed to improve the efficiency of pipe design of DHC systems: (i) A new sustainable insulation material for reducing heat losses, (ii) a new quick-fit joint for an easy installation, and (iii) a new coating for reducing pressure head losses. The results of a study on the development and optimization of two energy harvesting systems are also provided. The assessment of the environmental, economic and social impact of the proposed holistic approach is performed through a life cycle analysis. The validation methodology of the integrated solution is also described, whereas conclusions and future work are finally given

Successful treatment of fusarium solani ecthyma gangrenosum in a patient affected by leukocyte adhesion deficiency type 1 with granulocytes transfusions

<p>Abstract</p> <p>Background</p> <p>Ecthyma gangrenosum (EG) manifests as a skin lesion affecting patients suffering extreme neutropenia and is commonly associated with <it>Pseudomonas aeruginosa </it>in immunocompromised patients. Leukocyte adhesion deficiency I (LAD I) which count among primary immunodeficiency syndromes of the innate immunity, is an autosomal recessive disorder characterized in its severe phenotype by a complete defect in CD18 expression on neutrophils, delayed cord separation, chronic skin ulcers mainly due to recurrent bacterial and fungal infections, leucocytosis with high numbers of circulating neutrophils and an accumulation of abnormally low number of neutrophils at sites of infection.</p> <p>Case Presentation</p> <p>We report at our knowledge the first case of a child affected by LAD-1, who experienced during her disease course a multi-bacterial and fungal EG lesion caused by <it>fusarium solani</it>. Despite targeted antibiotics and anti-fungi therapy, the lesion extended for as long as 18 months and only massive granulocytes pockets transfusions in association with G-CSF had the capacity to cure this lesion.</p> <p>Conclusion</p> <p>We propose that granulocytes pockets transfusions will be beneficial to heal EG especially in severely immunocompromised patients.</p

LA MICROGRAVITÉ, MOYEN D'ÉTUDE DES FLUIDES ET DES CRISTAUX

L'apesanteur, condition spatiale, permet d'obtenir : la lévitation naturelle des solides et des fluides, l'absence de convections dans les fluides, des phénomènes dus à la prédominance des forces de cohésion, des tensions superficielles ainsi que des forces de capillarité, dans les liquides. Des laboratoires spatiaux (Spacelab, Soyouz) vont permettre l'exploitation de la microgravité, nouveau moyen d'expérimentation dans différents domaines scientifiques, en particulier en Physique des Fluides et en Sciences des Matériaux. On s'attend à obtenir, en dehors de connaissances fondamentales nouvelles, des matériaux aux propriétés nouvelles ou améliorées, ou des matériaux nouveaux qu'il serait impossible de réaliser sur terre.Zero-gravity, a space condition, allows to obtain the solids and fluids natural levitation, convectionless fluids, phenomena due to the predominance of the cohesion forces, superficial tensions, and capillar forces in the liquids. Space Laboratories (Spacelab, Soyouz, ...) will allow the exploitation of microgravity, new experimental possibility for different scientific fields, particularly in the Fluids Physics and in the Materials Sciences. It is expected the obtention, apart from new and fundamental knowledges, of materials with new or improved properties or new materials unrealizable on the ground

Diffusion de la lumière par les monocristaux de tellurure de zinc

We report studies of the phonon spectrum of zinc telluride crystals deduced from measurements of the first-order and second-order light scattering (under laser irradiation). The contribution of the Γ, X and L-point phonons to the two-phonon scattering mechanisms has been evaluated by a group theoretical analysis. Using this analysis we have interpreted all lines of the first- and second-order scattering spectra. The values found for the phonon frequencies at the zone center and zone edges agree well with those given by theory. The theoretical and experimental phonon densities are in good agreement only in the range of small energies.Par des mesures de diffusion de la lumière au premier et au second ordre (sous irradiation laser), nous avons étudié le spectre de phonons de cristaux de tellurure de zinc. Une analyse fondée sur la théorie des groupes a permis d'évaluer la contribution des phonons aux points Γ, X et L aux mécanismes de diffusion à deux phonons. Sur la base de cette analyse ont été interprétées toutes les raies des spectres de diffusion de premier et de second ordre. Les valeurs trouvées pour les fréquences des phonons au centre et en bord de zone de Brillouin correspondent bien à celles données par la théorie. Les densités de phonons théoriques et expérimentales sont en bon accord seulement dans le domaine des petites énergies

Méthode de détermination de l'angle de croissance d'un matériau : application au silicium

An apparatus has been designed for the experimental determination of the growth angle. The growth angle of crystalline silicon has been measured in vacuum and under argon atmosphere. In both cases we find a value of 11° ± 1.5° for { 110 } and { 111 } oriented surfaces of silicon and 9.5° ± 1.5° for polycrystalline silicon. The experimental results are in agreement with a theoretical model based on the thermodynamic equilibrium of the three phases at the solid-liquid-vapour junction.Un nouveau dispositif expérimental pour la détermination de l'angle de croissance sous atmosphère contrôlée a été mis au point. L'angle de croissance du silicium a été mesuré à l'aide de ce dispositif sous vide et sous atmosphère d'argon. Dans les deux cas nous avons trouvé une valeur de 11° ± 1,5° pour les orientations { 111 } et { 110 } de la surface du silicium monocristallin et de 9,5° ± 1,5° pour le silicium polycristallin. Nous montrons que les résultats obtenus sont en accord avec un modèle théorique basé sur l'équilibre thermodynamique des énergies interfaciales à l'intersection des trois phases solide, liquide et gaz

Variation avec la température des propriétés thermoélectriques des solutions solides Bi2Te3/Sb2Te 3

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ÉTUDE DES SPECTRES DE PHOTOLUMINESCENCE DE ZnTe DOPÉ AU LITHIUM. NATURE DES TRANSITIONS

Les spectres de photoluminescence du tellurure de zinc dopé au lithium sont étudiés entre 4,2 K et 300 K. La concentration des porteurs dans les échantillons est vérifiée par mesures électriques. Les spectres de luminescence à 4,2 K sont étudiés en fonction de la concentration en Li entre 1017 et 1019 cm-3. Les variations d'énergie des raies de photoluminescence sont étudiees en fonction de la température. On met en évidence que les deux émissions à 2,336 eV ± 4 meV et 2,362 eV ± 8 meV, caractéristiques de ZnTe dopé au lithium, sont dues à la recombinaison de porteurs libres respectivement sur un niveau accepteur et un niveau donneur. Les variations d'intensité des raies d'émission en fonction de la température sont aussi déterminées. Un modèle des cinétiques de recombinaison basé sur l'interprétation ci-dessus, a permis une analyse semi-quantitative de l'intensité des émissions en fonction de la température. Le modèle a aussi permis de déterminer l'énergie d'ionisation du donneur (15 meV), de l'accepteur (47 meV) et l'énergie d'activation du processus non radiatif.The photoluminescence emission of Li-doped zinc telluride is studied between 4.2 K and 300 K. Concentration of carriers in the samples is also verified by electrical mesurements. The photoluminescence spectrum at 4.2 K is investigated as a function of Li concentration between 1017 and 1019 cm-3. The energy variations of the bands with temperature are studied. Evidences are obtained that the two emission bands at 2.336 eV ± 4meV, and 2.362 eV ± 8 meV, characteristic of Li-doped ZnTe, are due to free carrier recombination on an acceptor and a donor levels respectively. The intensity variations of the bands with temperature are also determined. A recombination kinetics model based on this interpretation has permitted semi-quantitative analysis of the temperature dependence of the two band intensities. The model also allows the determination of the donor ionization energy (15 meV), the acceptor ionization energy (47 meV) and the activation energy of the non radiative process (8 meV)