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A catalytic strategy is presented for the selective conversion of OH groups in polyols, such as EVOH, while preserving the carbon backbone with applications for the recycling and compatibilization of multilayered polymer films.

 

In the last decade, there has been a surge in development and mainstream adoption of Artificial Intelligence (AI) systems that can generate textual image descriptions from images. However, only a few of these, such as Microsoft’s SeeingAI, are specifically tailored to needs of people who are blind screen reader users, and none of these have been brought to bear on the particular challenges faced by parents who desire image descriptions of children’s picture books. Such images have distinct qualities, but there exists no research to explore the current state of the art and opportunities to improve image-to-text AI systems for this problem domain. We conducted a content analysis of the image descriptions generated for a sample of 20 images selected from 17 recently published children’s picture books, using five AI systems: asticaVision, BLIP, SeeingAI, TapTapSee, and VertexAI. We found that descriptions varied widely in their accuracy and completeness, with only 13% meeting both criteria. Overall, our findings suggest a need for AI image-to-text generation systems that are trained on the types, contents, styles, and layouts characteristic of children’s picture book images, towards increased accessibility for blind parents. 

We combine computational and experimental methods to study the acid-catalyzed conversion of polyalcohols to provide insights into the selective functionalization and conversion of multi-layered plastic films.

 

Monitoring the frictional behavior of rock discontinuities is essential for the identification of potential natural hazards caused by mechanical instability. Active seismic monitoring of changes in transmitted and/or reflected compressional (P) and shear (S) waves has been used as a non-destructive method to assess the degree of damage inside rock and to monitor slip along a discontinuity. The objective of this study is to explore the geophysical response of a saturated rock joint undergoing shear. Laboratory shear tests are conducted on prismatic Indiana limestone specimens. Induced tension fractures resulted in specimens composed of two blocks (152.4 mm  127.0 mm  50.8 mm) with rough contact surfaces. Direct shear experiments were performed inside a metal confinement chamber under an effective normal stress of 2 MPa on water-saturated specimens. During the experiments, the chamber pressure, the total normal load, the shear load and the slip displacement were monitored. During the tests, continuous pulses of P- and S-waves were transmitted through the specimen and the amplitudes of the transmitted and reflected waves were recorded. The paper provides results of the mechanical and geophysical response of saturated joints and compares them with those obtained from similar, but dry, joints. For dry joints, both transmitted and reflected P- and S-waves show a distinct peak wave amplitude prior to shear failure. However, for saturated joints, a distinct peak in amplitude is only observed in both transmitted and reflected S-waves. Transmitted and reflected P-waves, propagated through saturated rock, displayed a continuous decrease and increase in amplitude, respectively, but had a sudden change in the rate of amplitude change that can be taken as a seismic precursor to joint shear failure. 

We suggest a technique to amplify a train of attosecond pulses, produced via high-harmonic generation of an infrared laser field, in active medium of a plasma-based X-ray laser driven by a replica of the same IR field as used to produce high harmonics forming a train of attosecond pulses.