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Copyright of Revue Française de Géotechnique is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the technical problem of coal roadway supporting with thin-layered argillaceous composite roof, using the background of the #53121 conveyance roadway in Zhaozhuang Coal Mine, the deformation failure law and control technology of coal roadway with thin-layered argillaceous composite roof are explored by combining the research methods of field investigation, laboratory experiment and similar material simulation as well as field tests. The obtained results indicate that the deformation failure of coal roadway is influenced by the surrounding rock structure, ground stress, groundwater and support parameter. The thickness of stratification of immediate roof not only affects the deformation and failure morphology of the surrounding rock, but also plays a positive role in the stability of the main roof. Based on the theory of combination beam, the joint supporting technique with the main body of long anchor + short anchor in the roof, anchor + bolt in roadway ' s sides and the accessory body of steel beam + metal net is proposed, and field test is carried out. The deformation observation results of surrounding rock show that the support technology can effectively control the deformation and failure of surrounding rock with thin-layered argillaceous composite roof, and significantly improve the stability of surrounding rock. [ABSTRACT FROM AUTHOR]

The field of multiferroics has experienced a rapid progress resulting in the discovery of many new physical phenomena. BiFeO 3 (BFO) compound, which is one of the few room-temperature single-phase multiferroics, has contributed subsequently to this progress. As a result, significant review articles have been devoted specifically to this famous system. This chapter is dedicated to the strain effects on the structure stability and property changes of BFO thin films. It is a short and non-exhaustive topical overview that may be seen as an invitation for interested readers to go beyond. There is a very active and prolific research in this field and we apologize to the authors whose relevant work is not cited here. After a short introduction, we will thus review the effect of strain on BFO films by describing the consequences on the structure and the phase transitions as well as on polar, magnetic and magnetoelectric properties. [ABSTRACT FROM AUTHOR]

L’oxyde de zinc est parmi les oxydes transparents et conducteurs les plus prometteurs dans le domaine du photovoltaïque. En effet, il joue le rôle de fenêtre optique permettant de capter plus de photons. Le présent travail consiste à étudier et comprendre le comportement du ZnO déposé par spray pyrolyse, avec le recuit de frittage à hautes températures de la métallisation par sérigraphie. La métallisation par sérigraphie est la technique de fabrication par excellence de cellules solaires à l’échelle industrielle. On se focalise surtout sur les propriétés optiques à partir des spectres de réflexion et de transmission par l’emploi de la méthode de Mueller. Après analyse des résultats, on remarque que l’énergie de gap du ZnO décale vers les basses énergies avec le recuit. Elle démarre de 3,49 eV pour l’échantillon sans recuit à 3,26 eV pour l’échantillon recuit à 900 °C.

Copyright of Matériaux et Techniques is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A multiple thin-layer approach was developed using LabVIEW software to simulate artificial drying of baled hay. The model assumed batch drying of a stack of bales with vertical airflow across the product; simulated controls included air temperature, airflow inversion, exhaust air recirculation and cool air tempering at the end of drying. A laboratory dryer was used to generate new data to estimate empirical equations of moisture transfer coefficient and equilibrium moisture content for grass hay. Total drying cost included variable costs (propane, electricity, labour), fixed costs of dryer, and a weight loss function due to overdrying below the target of 12% final moisture content on a wet basis (wb). For hay initially at a moisture content of 26% wb, the least-cost drying air temperature was 45°C in the range of 40 to 60°C. A single airflow inversion after 3 h improved final moisture homogeneity and reduced the drying cost by $10/t dry matter (DM) compared with no inversion. Partial exhaust airflow recirculation (typical ratio of 0.3) slightly improved the final moisture content homogeneity and energy efficiency but provided little cost reduction due to a longer drying time. A forced-air cooling period at the end of drying recuperated sensible heat in the bales, allowed the reduction of the heating period by about 15 rain, and provided a slight economic gain ($1/t DM). Overall drying costs of hay from 26 to 12% dry basis (db) were decreased from $44 to $30/t DM by selecting improved values for control parameters. Such a predictive model could be integrated into a control system for commercial hay drying to enhance thermal efficiency and to reach the targeted final moisture content at reduced cost. By modifying the empirical equations of moisture transfer coefficient and equilibrium moisture content, other baled biomasses such as corn stover or cereal straw could also be modelled to identify improved drying scenarios. [ABSTRACT FROM AUTHOR]

Deposited titanium oxide thin films are used as optical protector films for several materials and as energy converters for solar cells. In this work, titanium oxide thin films are deposited on c-Si and glass substrates by reactive radiofrequency sputtering. All the deposits are grown at ambient temperature and the sputtering gas is a mixture of oxygen and argon with an overall pressure of 10 -2  mbar. The oxygen partial pressure ratios varies from 5% to 20%. Characterization of deposited films is made by grazing incidence X-ray diffraction (GIXD), grazing incidence X-ray reflection (GIXR), X-ray photoemission spectroscopy (XPS) and optical transmission spectroscopy. The characterization results reveal that deposited films of TiO 2 are polycrystalline and present both rutile and anatase phases. The chemical composition of raw films in Ti : O ratio is equal to 1 : 2.02, and the titanium at surface is completely oxidized. In fact, the Ti2p core level behavior shows that the oxidization state of Ti is equal to +4. The specularily reflected intensity according to incidence angle of the X-ray on TiO 2 /glass structure shows one critical angle attributed to the TiO 2 film equal to 0.283°. This angle value involves film density between rutile and anatase phases. The optical characterization shows that TiO 2 thin films obtained are transparent in visible range, and have a refraction index value equal to 2.45 and when extrapolated to infrared range, it is equal to 2.23. The value of gap energy (3.35 eV) is deduced from variation of absorption coefficient versus incident radiation energy. Dans cet article, nous présentons une étude de caractérisation des couches minces d'oxyde de titane dans les structures TiO 2 /c-Si et TiO 2 /verre, déposées par pulvérisation cathodique radio fréquence réactive. Les spectres de diffraction des rayons X en incidence rasante montrent que nos couches sont constituées d'un mélange polycristallin de deux phases du dioxyde de titane: la rutile et l'anatase. Les mesures de réflectométrie des rayons X mettent en évidence un seul angle limite de réflexion totale égal à 0.283°. Cet angle limite correspond à une densité massique comprise entre celle de la phase rutile et celle de la phase anatase. Les analyses XPS des films à l'état brut indiquent que la composition chimique Ti:O est de 1:2.02. Le niveau de cœur Ti2p montre que l'état d'oxydation du Ti est +4. Les films TiO 2 obtenus sont transparents dans le visible et sont caractérisés par un indice de réfraction extrapolé à l'infini (infrarouge) de 2.23, un indice de réfraction dans le visible de 2.45 et une bande interdite de largeur 3.35 eV. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Telecommunications is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Une méthode originale de préparation de couches minces de matériaux organiques ayant un intérêt pour la fabrication de composants en optique intégrée, est présentée. Ces couches sont obtenues en balayant un compact de pom (3-méthyl 4-nitropyridine 1-oxyde) par le faisceau d'un laser continu à l'argon. L'irradiation provoque l'évaporation des molécules organiques et les cristallise sur un substrat. Les développements et les limites de cette technique sont discutés. An original technique to prepare thin organic films is presented. These materials are of interest for integrated optics. Films are formed after scanning of compacted powder of pom (3-methyl 4-nitropyridine 1-oxyd) with continuous wave Ar ion laser. The action of the laser is to evaporate organic molecules from the compact and cristallize them on a supporting substrate. The developments and limits of this technique are discussed. [ABSTRACT FROM AUTHOR]

Les guides obtenus par diffusion de mercure dans un substrat de tellurure de cadmium sont à gradient d'indice. L'étude des lignes noires permet d'en mesurer le profil d'indice de réfraction. A partir de données bibliographiques reliant l'indice de réfraction à la concentration de cadmium, on déduit le profil de concentration. La précision de la mesure permet de mettre en évidence, sur quelques échantillons, une flèche de fabrication de 10 μm sur 5 mm. Les mesures d'affaiblissement de l'onde infrarouge guidée sur une distance de quelques millimètres permettent d'annoncer un affaiblissement inférieur à 0,5 dB/cm à 10,6 μm. La tenue en puissance des guides a été testée à des densités de l'ordre de 10 kW/cm en continu. Hg-diffusion in a CdTe substrate leads to a graded index waveguide. M-lines analysis gives the refractive index profile of these guides. From published data giving refractive index versus cadmium concentration, we deduce the concentration profile. Measurement accuracy enables to show a fabrication bending on some samples of 10 μm/5 mm. The propagation of a 10.6 μm wave exhibits an exceptionnally low attenuation (<0.5 dB/cm) on all modes. Up to 10 kW/cm - cw power density has been guided without damage. [ABSTRACT FROM AUTHOR]