Search results for "interfaces"
showing 10 items of 1258 documents
Control of Corona Composition and Morphology in Aggregates of Mixtures of PS-b-PAA and PS-b-P4VP Diblock Copolymers: Effects of pH and Block Length
2014
The corona compositions and morphologies in aggregates of mixtures of amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA) and polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymers are influenced by controllable assembly parameters such as the hydrophilic block length and solution pH. The morphologies and corona compositions of the aggregates were investigated by transmission electron microscopy and electrophoretic mobility, respectively. When mineral acids or bases are present during aggregate formation, they can exert a strong influence on the corona composition. Morphology changes were also seen with changing pH, as well as changes in corona composition, specifica…
Unrest at the Nevados de Chillán volcanic complex: a failed or yet to unfold magmatic eruption?
2018
Resuming erupting activity at volcanoes that have been long quiescent poses a significant challenge to hazard assessment, as it require assessment of whether the change in activity is an isolated event or the beginning of a new eruptive sequence. Such inception is often poorly characterised as quiescent volcanoes tend to be poorly equipped and not extensively monitored, especially with respect to gas geochemistry. Here, we report gas composition and flux measurements from a newly opened vent at the very onset of eruptive activity at the Nevados de Chillán volcanic complex (Chile) in January-February 2016. The molar proportions of H2O, CO2, SO2, H2S and H2 gases are found to be 98.4, 0.97, 0…
Electron Irradiation Effects on Single‐Layer MoS 2 Obtained by Gold‐Assisted Exfoliation
2022
International audience; Mechanical exfoliation assisted by gold is applied to obtain good quality large lateral size single-layer MoS2. The effects of 2.5 MeV electron irradiation are investigated at room temperature on structural and electronic features by Raman and microluminescence spectroscopy. The exciton recombination emission in the direct bandgap of single-layer MoS2 is affected during irradiation starting from the minimum explored dose of 1 kGy. At higher doses, Raman bands show no relevant modifications whereas the exciton emission is quenched, suggesting that irradiation-induced point defects affect exciton dynamics.
Analyzing online search patterns of music festival tourists
2020
Music festivals, as cultural events that induce tourism flows, intermediate both the cultural and travel experience. The present study analyzes online search behavior of potential attenders to a music festival. We hypothesize that the search process reveals latent patterns of behavior of cultural tourists planning to attend music festivals. To this end, information from Google Trends on queries related to three popular music festivals is used to build a network of search topics. Based on it, alternative exponential random graph model specifications are estimated. Findings support the general result of mediated information flows: music festivals induce planning and traveling queries. Howeve…
Liposomes modified by mono- and bis-phthalocyanines: A comprehensive EPR study.
2016
The impact of selected metallophthalocyanines, featuring diverse molecular structure, upon the fluidity of liposome membranes was studied using the spin label EPR technique. The “mono”-type MPc’s (M = Zn, Sn; Pc = C32H16N8 is the phthalocyanine ligand) and sandwich LnPc2 complexes (Ln = Nd, Sm, Gd) were explored. Liposomes were obtained in a sonication process, from egg yolk lecithin (EYL) in water. TEMPO and 16-DOXYL spin labels were used to monitor the peripheral and central part of the lipid double layer, respectively, which allowed to localize the phthalocyanine additive within the bilayer, as well as to perform independent measurements of changes in fluidity upon addition thereof. All …
Adsorption of gelatin during electrodeposition of copper and tin-copper alloys from acid sulfate electrolyte
2014
International audience; An acid Cu–Sn deposition bath was developed, and copper and copper–tin coatings were electrodeposited on polycrystalline platinum. The effect of gelatin on copper and copper–tin electrodeposition from acid sulfate solutions has been investigated by a variety of electrochemical methods (voltammetric studies and electrochemical quartz crystal microbalance) as well as by morphologic technique (scanning electron microscopy). The electrochemical results have shown that the overpotential is required when gelatin is added, indicating the presence of interaction between the additive and the coating. From the results of X-ray photoelectron spectroscopy, PM-IRRAS and cyclic vo…
Development of antibiotic loaded biodegradable matrices to prevent superficial infections associated to total knee arthroplasty.
2019
Abstract Development of a pharmaceutical form for the superficial infections related with arthroplasties would be helpful for clinical practice. In this context, we set out to evaluate ciprofloxacin and gentamicin elution from systems based on chitosan. Films and semisolid hydrogels containing chitosan alone (2%) or in combination with gelatin (6%) or different proportions (from 12% to 36%) of tetrakis-(hydroxymethyl)-phosphonium-chloride (THPC) were tested as delivery systems. Different antibiotic doses were assayed (0.5 mg/cm2,1 mg/cm2 and 2 mg/cm2). Antibiotic release was studied for each formulation. In vitro cytocompatibility studies and a simulation exercise for bioactivity evaluation…
An exploratory study of gazing behavior during live performance
2009
It is known that the visual information given by performers during a performance works as a useful channel of communication to the audience. In my previous studies, many performers referred to the importance of gazing behavior or eye contact. The purpose of this research is to explore the role of gaze during live performance by measuring the timing and direction of gazing. The hypotheses are as follows: [1] Gazing behavior depends on the musical structure. [2] Gazing behavior is used for the communication between performers which is necessary during performance. [3] Performers set their gazing direction in order to contribute to the audience’s understanding of the music. This research was e…
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…