Effect of electron irradiation on transparent conductive films ZnO:Al deposited at different sputtering power

Transparent conductive oxide thin films of Al-doped ZnO grown by rf magnetron sputtering were irradiated with high energy electrons with the energy 12.6 MeV and fluence 5·10¹⁴ e/cm². The films were produced using different sputtering powers. It has been shown that electron irradiation creates defects that lead to distortions of the crystal lattice, which results in reduced crystallinity of the films. Also, it leads to film heating that results in radiation annealing and relaxation of the lattice

Electroactivity of Al in Al-Doped ZnO Films

The report devoted to study the influence of Al content on its electroactivity in ZnO thin films. Al-doped ZnO thin films were deposited by growth method on silicon substrates. The set of ZnO:Al films with concentrations of Al in the range from 0.2 to 1.2 % were grown. For samples characterization, XRD, EDX analysis, atomic force microscopy and transmittance measurements were used. The temperature dependences of electrical resistivity and Hall coefficient were investigated

A new practical method to evaluate the Joule-Thomson coefficient for natural gases

© 2017, The Author(s). The Joule–Thomson (JT) phenomenon, the study of fluid temperature changes for a given pressure change at constant enthalpy, has great technological and scientific importance for designing, maintenance and prediction of hydrocarbon production. The phenomenon serves vital role in many facets of hydrocarbon production, especially associated with reservoir management such as interpretation of temperature logs of production and injection well, identification of water and gas entry locations in multilayer production scenarios, modelling of thermal response of hydrocarbon reservoirs and prediction of wellbore flowing temperature profile. The purpose of this study is to develop a new method for the evaluation of JT coefficient, as an essential parameter required to account the Joule–Thomson effects while predicting the flowing temperature profile for gas production wells. To do this, a new correction factor, CNM, has been developed through numerical analysis and proposed a practical method to predict CNM which can simplify the prediction of flowing temperature for gas production wells while accounting the Joule–Thomson effect. The developed correlation and methodology were validated through an exhaustive survey which has been conducted with 20 different gas mixture samples. For each sample, the model has been run for a wide range of temperature and pressure conditions, and the model was rigorously verified by comparison of the results estimated throughout the study with the results obtained from HYSYS and Peng–Robinson equation of state. It is observed that model is very simple and robust yet can accurately predict the Joule–Thomson effect

Motion of an Oil Droplet Through a Water-Filled Uneven Pore Déplacement d'une gouttelette d'huile à travers un pore irrégulier rempli d'eau

The need to understand various mechanisms governing fluid-fluid displacements associated with enhanced oil recovery provides the motivation for this study. The observation of apparently linear dependence of flow rates upon pressure gradients during multiphase flow through porous media conceals the true nature of displacement phenomena such as Haine's jumps, droplet break-up, coalescence, etc. Most of these phenomena are understood only qualitatively. This study is on attempt to quantitatively describe them for a specific idealized pore geometry using approximate quasi steady-state calculations. The progress of a non-wetting oil droplet down a periodically convergent-divergent pore, the basic unit of which is a truncated bicone, shows a fluctuating, piecewise continuous track that resembles Haine's jumps. In addition to Haine's jumps, variations in the motion of droplets may also occur due to their break-up, coolescence or the instability of their interfacial configurations. Different parts of a droplet may be required to adjust to different curvatures and sometimes it may fail to maintain a constant mean curvature throughout its interface. Consequently, while flowing through constrictions, a droplet may break-up. Some portions of broken droplets may then travel in the middle of the pore and sometimes may coalesce with each other in different portions of the pore. The droplets become immobilized whevener the pressure gradients available across them are insufficient to overcome the threshold pressure offered by their interfaces. Possible implications of these phenomena in the entrapment of residual oil, hystereses in capillary pressure and relative permeability curves, and fluctuations in the multiphase flovv of fluids through porous media are discussed. <br> Le besoin de comprendre les divers mécanismes régissant les déplacements de certains fluides par d'autres, déplacements rencontrés dans la récupération assistée du pétrole, constitue la motivation de cet article. L'observation de la relation apparemment linéaire entre débits et gradients de pression dans un écoulement polyphasique en milieu poreux, dissimule la vraie nature des phénomènes de déplacement tels que l'écoulement discontinu de Haine, la rupture et la fusion des gouttelettes, etc. La plupart de ces phénomènes ne sont connus que qualitativement. La présente étude constitue une tentative de les décrire quantitativement à partir des calculs approchés admettant un régime quasi stationnaire et pour le cas d'un pore ayant une géométrie idéale donnée. La progression d'une gouttelette d'huile non mouillante le long d'un pore périodiquement convergent-divergent dont l'unité de base est un bicône tronqué, se présente sous un cheminement fluctuant, continu par morceaux et ressemblant à l'écoulement discontinu de Haine. En plus de cet écoulement discontinu, des variations dans le déplacement des gouttelettes peuvent également se produire à cause de leur fragmentation, de leur coalescence ou de l'instabilité de leur configuration interfaciale. Les différentes parties d'une gouttelette peuvent être nécessaires pour s'adapter à diverses courbures et il peut quelquefois arriver qu'elles ne puissent maintenir une courbure moyenne constante partout sur l'interface. Une gouttelette peut donc se fragmenter au passage des étranglements. Certaines parties de gouttelettes éclatées peuvent alors circuler au milieu du pore et parfois fusionner entre elles à certains endroits. Les gouttelettes s'immobilisent chaque fois que les gradients de pression disponibles à travers elles sont insuffisants pour surmonter la pression de seuil présentée par leurs interfaces. Les implications possibles de ces phénomènes dans le piégeage d'huile résiduelle, les hystérésis des courbes de pression capillaire et de perméabilités relatives, et les fluctuations dans les écoulements polyphasiques des fluides en milieu poreux, sont discutés

Mass transfer in liquid-phase epitaxy of two-layer systems

A liquid phase epitaxy diffusion model of a two-layer system at instable cooling speed of the solution-melt has been developed. It was discovered that the transition process continues even after the termination of cooling, due to which the layer growth continues as well. This effect is connected with to the hypothetical inertia of the diffusion process. The practical application of this phenomenon is shown