Controlled release of poly(vinyl sulfonate) scale inhibitor to extend reservoir treatment lifetime

Precipitate scale formation is a major issue for the oil industry, plugging equipment, and reservoirs and resulting in increased operational costs. Poly(vinyl sulfonate) (PVS) is often used as a scale inhibitor to prevent the formation of barium sulfate scale. However, PVS effectiveness is limited by its short lifetime in reservoir. In this article, PVS has been entrapped in polyelectrolyte complex nanoparticles (PECNPs), altering its charge and thus enabling improved adsorption on the rock surface. As the ionic strength of the surrounding brine increases, the PVS is then released from the PECNPs, making it available to inhibit scale formation gradually. Positively charged PECNPs were made using a combination of poly(ethyleneimine) (PEI) and PVS. After NPs optimization, static adsorption tests were performed, which confirm the nanoparticles' rapid and strong adsorption. An increase in the ionic strength of the displacing fluid was used to decompose the PECNPs structure and release the PVS into solution. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47225.     

Large flexibility of high aspect ratio carbon nanostructures fabricated by electron-beam-induced deposition

The mechanical properties of free-standing electron beam deposited amorphous carbon structures have been studied using atomic force microscopy. The fabricated carbon blades are found to be extraordinarily flexible, capable of undergoing vertical deflection up to ～ 75% of their total length without inelastic deformation. The elastic bending modulus of these structures was calculated to be 28 ± 10 GPa.     

Priming and habituation for faces: Individual differences and inversion effects.

Immediate repetition priming for faces was examined across a range of prime durations in a threshold identification task. Similar to word repetition priming results, short duration face primes produced positive priming whereas long duration face primes eliminated or reversed this effect. A habituation model of such priming effects predicted that the speed of identification should relate to the prime duration needed to achieve negative priming. We used face priming to test this prediction in two ways. First, we examined the relationship between priming effects and individual differences in the target duration needed for threshold performance. Second, we compared priming of upright and inverted faces. As predicted, the transition from positive to negative priming as a function of prime duration occurred more slowly for inverted faces and for individuals with longer threshold target durations. Additional experiments ruled out alternative explanations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maximizing miniature aerial vehicles

Despite the tremendous potential demonstrated by miniature aerial vehicles (MAV) in numerous applications, they are currently limited to operations in open air space, far away from obstacles and terrain. To broaden the range of applications for MAVs, methods to enable operation in environments of increased complexity must be developed. In this article, we presented two strategies for obstacle and terrain avoidance that provide a means for avoiding obstacles in the flight path and for staying centered in a winding corridor. Flight tests have validated the feasibility of these approaches and demonstrated promise for further refinement.     

The Electrodeacidification of Blood

The design parameters for blood electrodeacidification were determined experimentally with due consideration of the physical properties of the diffusion of hydrogen through palladium (Pd) membrane electrodes, along with the physiological aspects of hemodialysis and electrohemodialysis for acidosis. Several models of an electrodeacidifier for extracorporeally circulating blood were built. Initial designs showed difficulties with clotting of heparinized blood and excessive hemolysis, but no evidence of membrane fouling. In subsequent experiments the clotting problem was eliminated by the interposition of anion exchange membranes between the blood and the Pd black surface.