Lyon 2016, Capitale de la terre

Bérengère Perello et David Gandreau. « Lyon 2016 Capitale de la terre », ArchéOrient - Le Blog, 24 juin 2016, [En ligne] http://archeorient.hypotheses.org/6299La ville de Lyon a été nommée en 2016 « Capitale de la terre ». « Lyon 2016, Capitale de la terre » est piloté par CRAterre-ENSAG et réalisé avec le soutien de la Ville de Lyon. Il s’agit d’une contribution au programme WHEAP (World Heritage Earthen Architecture Programme) du Centre du patrimoine mondial de l’UNESCO

Lyon 2016, Capitale de la terre

Bérengère Perello et David Gandreau. « Lyon 2016 Capitale de la terre », ArchéOrient - Le Blog, 24 juin 2016, [En ligne] http://archeorient.hypotheses.org/6299La ville de Lyon a été nommée en 2016 « Capitale de la terre ». « Lyon 2016, Capitale de la terre » est piloté par CRAterre-ENSAG et réalisé avec le soutien de la Ville de Lyon. Il s’agit d’une contribution au programme WHEAP (World Heritage Earthen Architecture Programme) du Centre du patrimoine mondial de l’UNESCO

Contact Metal-Dependent Electrical Transport in Carbon Nanotubes and Fabrication of Graphene Nanoribbons

In this thesis, we fabricate and characterize carbon nanotube (CNT) and graphene-based field effect transistor devices. The CNT-based work centers on the physics of metal contacts to CNT, particularly relating the work function of contact metals to carrier transport across the junction. The graphene work is motivated by the desire to utilize the high carrier mobility of graphene in field effect transistors. We introduce a surface-inversion channel (SIC) model based on low temperature and electrical measurements of a distinct single-walled semiconducting CNT contacted by Hf, Cr, Ti and Pd electrodes. Anomalous barrier heights and metal-contact dependent band-to-band tunneling phenomena are utilized to show that dependent upon contact work function and gate field, transport occurs either directly between the metal and CNT channel or indirectly via injection of carriers from the metal-covered CNT region to the CNT channel. The model is consistent with previously contradictory experimental results, and the methodology is simple enough to apply in other contact-dominant systems. We further develop a model explain Isd-Vsd tendencies in CNT FETs. Using experimental and analytical analysis, we demonstrate a relationship between the contact metal work function and electrical transport properties saturation current (Isat) and differential conductance in ambient exposed CNT. A single chemical vapor deposition (CVD)-grown 6 millimeter long semiconducting single-walled CNT is electrically contacted with a statistically significant number of Hf, Cr, Ti, Pd, and Ti, Au electrodes, respectively. The observed exponentially increasing relationship of Isat and with metal-contact work function that is explained by a theoretical model derived from thermionic field emission. Next, a performance analysis on CNT Schottky diodes using source-drain current anisotropy is explored. An analytical model is derived based on thermionic field emission and used to correlate experimental data from Pd-Hf, Ti-Hf, Cr-Hf, Ti-Cr, and Pd-Au mixed metal devices fabricated on one single 6 mm-long CNT. Results suggest that the difference in work functions of the two contact-metals, and not a dominant Schottky contact, determines diode performance. Results are further applied and demonstrated in a reversible polarity diode. Lastly, we investigate the effect of UV irradiation of graphene, CNT, and graphene/CNT hybrids in an oxygen environment. Samples were irradiated by 254/185 nm UV light in an oxygen environment for up to two hours. Results suggest a unique method to generate graphene nanoribbons using aligned carbon nanotubes (CNT) as a graphene etch mask. Ambient and cryogenic Gsd-Vg measurements of resulting ultra-thin graphene nanoribbons show p-type character and field effect GOn/GOff > 10^4

Characterization of Contact mechanisms and Effect of Electron Irradiation on Conductance Mechanisms in Carbon Nanotube Field Effect Transistors

We have fabricated electrical devices based on thermal chemical vapor deposition (TCVD) grown single walled carbon nanotubes (SWCNTs). Long SWCNT are utilized to analyze electrical transport properties and extract contact data including Schottky Barrier heights (SBHs) and contact resistance. For all studies performed, multiple contact metals were used, and tens to hundreds of devices were fabricated on single CNT. This mass production method allows comparison of results, as well as greater options in device analysis.To analyze SBHs at carbon nanotube - metal contacts, field effect transistor (FET) devices were examined using AFM, low temperature measurements in closed - cycle refrigerator (CCR), and electrical characterization. SBH is measured on carbon nanotubes with multiple metal contacts for comparison purposes, with barriers extracted via low temperature activation energy measurements and nonlinear curve fitting using the program Origin. Two methods were utilized in the fabrication of carbon nanotube devices for the SB study. The first incorporated both electron beam lithography (EBL) for exposures and focused ion beam (FIB) for deposition of lead lines between CNT contacts and large probe pads. The second method used only EBL to prevent the ionic exposure common in FIB.The effect of using EBL with devices incorporating CNT has also been investigated. The effect on metallic and semiconducting CNT exposure in the channel of the transistor devices was examined and a physical mechanism for the variations discussed. We show that the subsequent generation of trap states along the CNT channel varies the conduction mechanism of the nanotube and has a significant effect on device performance. Metallic and Semiconducting CNT react very differently, with an apparent increased localization in the metallic tubes responsible for dramatic decreases in conductance

Maximization of fitness by phenological and phenotypic plasticity in range expanding rabbitfishes (Siganidae)

Global warming is modifying the phenology, life-history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades; however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems.publishedVersio

Datos para el conocimiento del patrimonio minero de la comarca valenciana del Valle de Cofrentes – Ayora (Valencia, Comunidad Valenciana, Sistema Ibérico)

En este artículo, nos centraremos en el Patrimonio Minero de la comarca valenciana del Valle de Cofrentes - Ayora. Se trata de una comarca interior de la provincia de Valencia., situada cerca de la provincia de Albacete Por otra parte se halla de un territorio plenamente ubicado dentro del Sistema Ibérico, entre afloramientos de materiales mesozoicos, que fundamentalmente pertenecen al Cretácico y al Jurásico; aunque los afloramientos Triásicos son también muy abundantes. Dentro de esta comarca existen diversos elementos del Patrimonio Minero de la Comunidad Valenciana, aunque las actividades mineras no han gozado nunca de gran desarrollo. Estos elementos se hallan relacionados fundamentalmente con las Salinas y con los Hornos de Yeso. En esta comunicación, nos centraremos fundamentalmente en estos elementos del patrimonio minero.Postprint (published version

Datos para el conocimiento del patrimonio minero de la comarca valenciana de Los Serranos

En este artículo, nos centraremos en el Patrimonio Minero de la comarca valenciana de los Serranos / els Serrans. Se trata de una comarca situada casi en el centro de la Comunidad Valenciana, ubicada totalmente dentro del Sistema Ibérico, entre afloramientos de materiales mesozoicos, fundamentalmente del Cretácico y del Jurásico. Dentro de esta comarca existen interesantes elementos del Patrimonio Minero de la Comunidad Valenciana, aunque las actividades mineras no han gozado de gran desarrollo. Estos elementos se hallan relacionados fundamentalmente con Tejeras y con Hornos de Yeso. En esta comunicación, nos centraremos especialmente en los diferentes elementos, de los dos grupos acabados de mencionar. This article will focus on mining heritage in the valencian region of Los Serranos / Els Serrans. This county is located almost in the middle of the Valencian Community. It is located entirely within the Iberian System, surrounded by Mesozoic materials, mainly from the Cretaceous and Jurassic. Within this region there are many elements of the mining heritage of Valencian Community, although mining activities have not ever been so important. These elements are mainly related with tile furnaces and gypsum kilns. This paper is focused on these two types of elements of the mining heritage.Postprint (published version

Datos para el conocimiento del patrimonio minero de la comarca valenciana de la Plana de Utiel

En este artículo, nos centraremos en el Patrimonio Minero de la comarca valenciana de la Plana de Utiel. Se trata de una comarca interior de la provincia de Valencia, situada junto a la provincia de Cuenca, a la que antaño perteneció. Por otra parte se halla de un territorio plenamente ubicado dentro del Sistema Ibérico, entre afloramientos de materiales mesozoicos, que fundamentalmente pertenecen al Cretácico y al Jurásico; aunque los afloramientos Triásicos son también muy abundantes. Dentro de esta comarca existen diversos elementos del Patrimonio Minero de la Comunidad Valenciana, aunque las actividades mineras no han gozado nunca de gran desarrollo. Estos elementos se hallan relacionados fundamentalmente con las Salinas y con los Hornos de Yeso. En esta comunicación, nos centraremos fundamentalmente en estos elementos del patrimonio minero. This article will focus on mining heritage in the valencian region of Plana de Utiel. It’s a county of the Valencia province, located by the Cuenca province, where it belonged in the past. Moreover, it is located entirely within the Iberian System, surrounded by Mesozoic materials, mainly from the Cretaceous and Jurassic, although triassic outcrops are also abundant. Within this region there are many elements of the mining heritage of Valencian Community, although mining activities have not ever been so important. These elements are mainly related with salines and gypsum kilns. This paper is focused primarily on these elements of the mining heritage.Postprint (published version

Visualizing Poiseuille flow of hydrodynamic electrons

Hydrodynamics is a general description for the flow of a fluid, and is expected to hold even for fundamental particles such as electrons when inter-particle interactions dominate. While various aspects of electron hydrodynamics were revealed in recent experiments, the fundamental spatial structure of hydrodynamic electrons, the Poiseuille flow profile, has remained elusive. In this work, we provide the first real-space imaging of Poiseuille flow of an electronic fluid, as well as visualization of its evolution from ballistic flow. Utilizing a scanning nanotube single electron transistor, we image the Hall voltage of electronic flow through channels of high-mobility graphene. We find that the profile of the Hall field across the channel is a key physical quantity for distinguishing ballistic from hydrodynamic flow. We image the transition from flat, ballistic field profiles at low temperature into parabolic field profiles at elevated temperatures, which is the hallmark of Poiseuille flow. The curvature of the imaged profiles is qualitatively reproduced by Boltzmann calculations, which allow us to create a 'phase diagram' that characterizes the electron flow regimes. Our results provide long-sought, direct confirmation of Poiseuille flow in the solid state, and enable a new approach for exploring the rich physics of interacting electrons in real space

Datos para el conocimiento del patrimonio minero de la comarca aragonesa del Somontano. II Salinas, Hornos de Yeso, Balnearios

En este artículo, nos centraremos en el Patrimonio Minero de la comarca aragonesa del Somontano. Se trata de una comarca situada en el centro de Aragón, repartida entre la Depresión Geológica del Ebro (entre afloramientos de materiales cenozoicos) y el Sistema Pirenaico (entre afloramientos de materiales mesozoicos). Dentro de esta comarca existen interesantes elementos del Patrimonio Minero de la Comunidad Aragonesa. En este caso nos centraremos en el patrimonio minero relacionado con las salinas, los hornos de yeso y los establecimientos balnearios.Postprint (published version