Search results for "Faces"
showing 10 items of 3167 documents
Triggering a transient organo-gelation system in a chemically active solvent
2021
A transient organo-gelation system with spatiotemporal dynamic properties is described. Here, the solvent actively controls a complex set of equilibria that underpin the dynamic assembly event. The observed metastability is due to the in situ formation of a secondary solvent, acting as an antagonist against the primary solvent of the organogel. peerReviewed
Oligonucleotides-decorated-poly(N-vinyl pyrrolidone) nanogels for gene delivery
2013
Pulsed electron-beam irradiation of a semi-dilute poly(N-vinyl pyrrolidone) (PVP) aqueous solution in the presence of acrylic acid has led to a carboxyl functionalized nanogel system. Nanoparticles hydrodynamic size and surface charge density, in water and as a function of pH, were investigated by dynamic light scattering and laser doppler velocimetry, respectively. Nanogels (NGs) were proved not to be cytotoxic at the cellular level. Indeed, they rapidly bypass the cellular membrane to accumulate in specific cell portions of the cytoplasm, in the perinuclear area. The availability of pendant carboxyl groups on the crosslinked PVP NGs core prompted us to attempt their decoration with a sing…
The adsorption of water vapor on super absorbent product at low temperatures and low mass.
2006
The adsorption isotherms of water vapor on super absorbent product have the same form of type III isotherm at ambient temperature with the hysteresis phenomena. For temperatures lower than ambient, the isotherms become deformed because of the chains effect. The polymer is characterized by a multilayer adsorption, which occurs before a full-course is complete. During adsorption reactions, the polymer undergoes rearrangement polymeric network, which results from a cooperative diffusion of the water molecules and from a chain spacing followed by an expansion of the polymeric network. Three types of water molecules adsorbed on polymer were identified: strongly dependent water, adsorbed water, a…
Positron Studies of Subsurface Zone in Titanium Created in Sliding Wear
2014
Positron annihilation studies of the subsurface zone constituted during dry sliding in pure titanium are reported. A new type of defect depth profile in this zone, which is not an exponential decay usually reported for other metals and alloys, is observed. Two layers in the subsurface zone are present in this metal. In the layer adjacent to the worn surface, the characteristic plateau of the mean positron lifetime that extends to a depth of 60–70 μm was observed. Small vacancy clusters and dislocations were recognized in this layer. At deeper zone, the mean positron lifetime decreased exponentially in the manner typical for the other metals. In this zone, vacancy clusters increase in size a…
Late Paleozoic Ice Age glaciers shaped East Antarctica landscape
2019
International audience; The erosion history of Antarctica is fundamental to our understanding of interlinks between climate and glacier dynamics. However, because of the vast polar ice sheet covering more than 99% of Antarctica land mass, the continental surface response to glacial erosion remains largely unknown. Over the last decade the subglacial topography of Antarctica has been imaged by airborne radar surveys. These studies revealed high and complex sub-glacial relief in the core of the East Antarctic shield, interpreted as resulting from rifting episodes and low long-term erosion rates, or repeated large-scale glacial retreats and advances. In East Antarctica, thermochronology studie…
Impact of Holocene climate variability on lacustrine records and human settlements in South Greenland
2015
Due to its sensitivity to climate changes, south Greenland is a particularly suitable area to study past global climate changes and their influence on locale Human settlements. A paleohydrological investigation was therefore carried out on two river-fed lakes: Lake Qallimiut and Little Kangerluluup, both located close to the Labrador Sea in the historic farming center of Greenland. Two sediment cores (QAL-2011 and LKG-2011), spanning the last four millennia, were retrieved and showed similar thin laminae, described by high magnetic susceptibility and density, high titanium and TOC / TN atomic ratio, and coarse grain size. They are also characterized either by inverse grading followed by nor…
Pullout Force and Inlet Oscillation in Telescopic Carbon Nanotubes: A Quantum Study
2021
The noncovalent interaction energy as a function of the core extension in double-walled carbon nanotubes (DWCNT) was accurately calculated in the frame of density functional theory, considering dis...
Sketching Sound with Voice and Gesture
2015
Voice and gestures are natural sketching tools that can be exploited to communicate sonic interactions. In product and interaction design, sounds should be included in the early stages of the design process. Scientists of human motion have shown that auditory stimuli are important in the performance of difficult tasks and can elicit anticipatory postural adjustments in athletes. These findings justify the attention given to sound in interaction design for gaming, especially in action and sports games that afford the development of levels of virtuosity. The sonic manifestations of objects can be designed by acting on their mechanical qualities and by augmenting the objects with synthetic and…
From Dupin cyclides to scaled cyclides
2003
Dupin cyclides are algebraic surfaces introduced for the first time in 1822 by the French mathematician Pierre-Charles Dupin. They have a low algebraic degree and have been proposed as a solution to a variety of geometric modeling problems. The circular curvature line’s property facilitates the construction of the cyclide (or the portion of a cyclide) that blends two circular quadric primitives. In this context of blending, the only drawback of cyclides is that they are not suitable for the blending of elliptic quadric primitives. This problem requires the use of non circular curvature blending surfaces. In this paper, we present another formulation of cyclides: Scaled cyclides. A scaled cy…
Enhancing values of roofs albedo for lowering cities’ air temperature and electric demand of buildings: a simple economic evaluation
2019
Abstract In cities vegetated roofs are becoming more popular because they can mitigate Urban Heat Island phenomena by decreasing the outdoor air temperature in summer. This decrease reduces the electric energy demand for climatization of buildings, which, in front of a milder climate, will recur less to mechanical tools for guaranteeing thermal comfort conditions to occupants. Cities can registered another indirect positive effect: the reduced cooling energy demand, limits the heat released by the climatization systems’ external unities toward the urban open spaces, thus lowering the outdoor air temperature. Therefore, the outdoor surface temperature of green, as well as cool roofs, can be …