Respect My Authority: The Past, Present, and Future of the Public Authority

This comment synthesizes various historical aspects of motor vehicle infrastructure in the United States. The network of issues at play involves centuries of public policy decisions made at the local, state, and federal level, which twentieth century legal innovations hastened and curdled into the car culture we are all a part of today. The public authority is the paradigm of these legal innovations, but it has outlived its usefulness in the face climate change and burgeoning issues relating to urbanism

Cocoa Butter Saturated with Supercritical Carbon Dioxide: Measurements and Modelling of Solubility, Volumetric Expansion, Density and Viscosity

International audienceThe use of supercritical carbon dioxide technology for lipid processing has recently developed at the expense of traditional processes. For designing new processes the knowledge of thermophysical properties is a prerequisite. This work is focused on the characterization of physical and thermodynamic properties of CO2-cocoa butter (CB) saturated mixture. Measurements of density, volumetric expansion, viscosity and CO2 solubility were carried out on CB-rich phase at 313 and 353 K and pressures up to 40 MPa. The experimental techniques have previously been compared and validated. Density measurements of CB and CB saturated with CO2, were performed using the vibrating tube technology at pressures ranging from 0.1 to 25 MPa. Experimental values correlated well with the modified Tait equation. CO2 solubility measurements were coupled to those of density in the same pressures ranges. At 25 MPa, the solubility of CO2 is 31.4 % and 28.7 % at 313 and 353 K. Phase behaviour was investigated using a view cell in order to follow the expansion of the CB-rich phase with the rise in pressure. Volumetric expansion up to 47 % was measured and correlated to the CO2 solubility. Phase inversion was observed at 313 K and 40 MPa. Lastly, we developed an innovative falling ball viscometer for high pressure measurements. Viscosity measurements were carried out up to 25 MPa showing a viscosity reduction up to 90 % upon CO2 dissolution. These results were correlated with two empirical models. A new model here presented, was favourably compared with the Grunberg and Nissan model. All the experimental results are consistent with the available literature data for the CB-CO2 mixture and other fat systems. This work is a new contribution to the characterization of physical and thermodynamic behaviour of fats in contact with CO2 which is necessary to design supercritical fluid processes for fats processing

Development of Characterization Techniques of Thermodynamic and Physical Properties Applied to the CO2-DMSO Mixture

International audienceThis work is focused on the development of new characterization techniques of physical and thermodynamic properties. These techniques have been validated using the binary system DMSO-CO2 for which several studies of characterization have been well documented. We focused on the DMSO-rich phase and we carried out measurements of volumetric expansion, density, viscosity and CO2 solubility at 298.15, 308.15 and 313.15 K and pressures up to 9 MPa. The experimental procedures were compared and validated with the available literature data on SC-CO2-DMSO system. We made density and CO2 solubility measurements, using respectively the vibrating tube technology and two static analytical methods. Lastly, we developed an innovative falling body viscosimeter for high pressure measurements. All the measurements made are in good agreement with the already published data in spite of very different experimental techniques. This work is a contribution to the understanding of the DMSO-CO2 binary as it implements new viscosity data. Moreover, it opens new perspectives about the determination of the properties of other systems such as polymers-CO2 and fats-CO2, which are essential for supercritical process design such as extraction, crystallization, chromatography and synthesis reaction

Implications of a comparison of the stratigraphy and depositional environments of the Argana (Morocco) and Fundy (Nova Scotia, Canada) Permian-Jurassic basins

The Argana rift basin of Morocco and the Fundy rift basin of the Maritime Provinces of Eastern Canada are on the conjugate margins of the central Atlantic Ocean. In the Late Triassic and Early Jurassic these basins lie at similar paleolatitudes within the same great rift system. A comparison of the depositional- and tectono-stratigraphy reveal strong similarities, much greater that those shared between the Fundy basin and other rifts in eastern North America. Both the Argana and Fundy basins are comprised of four, mostly unconformity-bound, tectonostratigraphic sequences (TS I-IV) probably controlled by pulses of extension: TS I, is Permian in age and the depositional facies of the Argana basin looks more humid than the age equivalent in the Fundy basin and the latter may not be a rift sequence; TS II, is early Late Triassic (Carnian) in age and is the most humid looking facies in both basins; TS III, is late Late Triassic (Norian and Rhaetian) in age and is much more arid in both basins with abundant aeolianites and evaporites; TS IV, is latest Triassic and earliest Jurassic (late Rhaetian - early Hettangian) and shows an increase in the range of variability in climate-sensitive facies - its basal part contains the Triassic-Jurassic boundary an overlying basalt flow sequence and additional fluvial and lacustrine strata on top. The dramatic similarity in both facies and sequence stratigraphy between the Argana and Fundy basins, at least during the Triassic, argues for similar tectonic control, restricted to that latitudinal swath of Pangea, as well as similar paleoclimate