Effect of indium doping on the electrical and structural properties of TiO2 thin films used in MOS devices

We investigated the effect of Indium (In) doping on the structural and electrical properties of Ti/Au/ TiO2:In/n-Si metal-oxide-semiconductor (MOS) devices. Sputtering grown TiO2 thin films on Si substrate were doped using two In-films with 15 nm and 50 nm thicknesses leading to two structures named Low Indium Doped (LID) sample and High Indium Doped (HID) sample, respectively. XRD analysis shows no diffraction pattern related to Indium indicating that In has been incorporated into the TiO2 lattice. Current-Voltage (I-V) characteristics show that rectification ratio at 2V is higher for HID sample than for LID sample. Evaluated barrier height, ϕB0 , decreased while the ideality factor, n, increased with decreasing temperature. Such behavior is ascribed to barrier inhomogeneity that was assumed to have a Gaussian Distribution (GD) of barrier heights at interface. Evidence of such GD was confirmed by plotting ϕB0versus n. High value of mean barrier ϕ̅B0 and lower value of standard deviation (σ) of HID structure are due to indium doping which increases the barrier homogeneities. Finally, estimated Richardson constants A* are in good agreement with theoretic values (112 A/cm2K2), particularly, for the HID structure

L'évolution de la conception des espaces extérieurs hôteliers en Tunisie. Le cas de la région de Hammamet

This research has for object to study, the apartment hotels of the region of Hammamet created from 1959 till 2009. It has for object to verify the hypothesis that the conception of hotels was dependent on the nature of the touristic offer and demand and that it followed an evolution parallel to that of their functional and spatial relation with the hinterland. This work attempts to present the results stemming from the application of a landscape method of analysis to verify the hypothesis of the existence of three landscape models illustrating the evolution of the conception of the outer spaces of the hotels of the region of Hammamet ( Tunisia). The followed approach is similar to a process corresponding to three stages of approach of the landscape where it is a question of reading (all the formal characteristics), to understanding (elaboration of the landscape models) and to explain (by the political, socioeconomic context which gave him birth. She allowed to bring to light three landscape models reflecting the evolution of the touristic landscape of the Tunisian coast. It is about the vernacular model, the international model and about the neo-vernacular model defining three historic periods. The first historic period is illustrated by hotel units, registered with a lot of consideration on their site of implantation reproducing the architecture and the spatial organization of the residences of Hammamet. In the second historic period, were established hotels indifferent to their territory of implantation. The third period was marked by hotel units which highlight an originality inspired by the vernacular model.Ce sujet de recherche a pour objet d'études, les résidences hôtelières de la région de Hammamet créées de 1959 à 2009. Il a pour objet de vérifier l'hypothèse que la conception des hôtels a été tributaire de la nature de l'offre et de la demande touristiques et qu'elle a suivi une évolution parallèle à celle de leur relation fonctionnelle et spatiale avec l'arrière-pays. Ce travail s'attache à présenter les résultats issus de l'application d'une méthode d'analyse paysagère pour vérifier l'hypothèse de l'existence de trois modèles paysagers illustrant l'évolution de la conception des espaces extérieurs des hôtels de la région de Hammamet (Tunisie). La démarche suivie s'apparente à un processus correspondant aux trois stades d'approche du paysage où il s'agit de lire (l'ensemble des caractéristiques formelles), de comprendre ( élaboration du modèle paysager) et d'expliquer (par le contexte politique, socio-économique qui lui a donné naissance). Elle a permis de mettre en évidence trois modèles paysagers reflétant l'évolution du paysage touristique du littoral tunisien. Il s'agit du modèle vernaculaire, du modèle international et du modèle néo-vernaculaire définissant trois périodes historiques. La première période historique est ainsi illustrée par des unités hôtelières, inscrites avec beaucoup d'égards à leur site d'accueil reproduisant l'architecture et l'organisation spatiale des résidences de villégiature et des maisons de Hammamet. Dans la deuxième période historique, ont été instaurés des hôtels indifférents à leur territoire d'accueil. La troisième période a été marquée par des unités hôtelières qui mettent en exergue une originalité inspirée du modèle vernaculaire et qui renouent de la sorte avec les formes paysagères locales

State of the art of greenway concept application in Tunisian green policy. A case study of an urban landscape in Sousse city

This paper is about the concept of the greenways in Tunisia, defined as a structure allowing to connect the green spaces between them. Two steps have been applied to assess the use of greenway concept in Tunisia and especially in Sousse city. The first one shows Tunisian administrative documents recount and the second one explains the spatial distribution of Sousse city greenways using GIS software. The examination of the planning of the green spaces in Tunisia, either through the documents of town planning or through the specific programs, allowed us to reveal the place of this notion in the Tunisian political speech and to conclude that the notion of greenways and its foundations, is missing in the documents of town planning, in the Tunisian environmental policy (Green Plan of Grand Sousse) even if the use of the term "greenways" is not really explicit. Then, it is our belief that there is a great potential in Tunisia for the adoption of greenways as a planning alternative, and tools such as the GIS environment can contribute significantly to this effort