Interlaboratory study of ice adhesion using different techniques

Low ice adhesion surfaces are a promising anti-icing strategy. However, reported ice adhesion strengths cannot be directly compared between research groups. This study compares results obtained from testing the ice adhesion strength on two types of surfaces at two different laboratories, testing two different types of ice with different ice adhesion test methods at temperatures of −10 and −18 °C. One laboratory used the centrifuge adhesion test and tested precipitation ice and bulk water ice, while the other laboratory used a vertical shear test and tested only bulk water ice. The surfaces tested were bare aluminum and a commercial icephobic coating, with all samples prepared in the same manner. The results showed comparability in the general trends, surprisingly, with the greatest differences for bare aluminum surfaces at −10 °C. For bulk water ice, the vertical shear test resulted in systematically higher ice adhesion strength than the centrifugal adhesion test. The standard deviation depends on the surface type and seems to scale with the absolute value of the ice adhesion strength. The experiments capture the overall trends in which the ice adhesion strength surprisingly decreases from −10 to −18 °C for aluminum and is almost independent of temperature for a commercial icephobic coating. In addition, the study captures similar trends in the effect of ice type on ice adhesion strength as previously reported and substantiates that ice formation is a key parameter for ice adhesion mechanisms. Repeatability should be considered a key parameter in determining the ideal ice adhesion test method

LyricWhiz: Robust Multilingual Zero-shot Lyrics Transcription by Whispering to ChatGPT

We introduce LyricWhiz, a robust, multilingual, and zero-shot automatic lyrics transcription method achieving state-of-the-art performance on various lyrics transcription datasets, even in challenging genres such as rock and metal. Our novel, training-free approach utilizes Whisper, a weakly supervised robust speech recognition model, and GPT-4, today's most performant chat-based large language model. In the proposed method, Whisper functions as the "ear" by transcribing the audio, while GPT-4 serves as the "brain," acting as an annotator with a strong performance for contextualized output selection and correction. Our experiments show that LyricWhiz significantly reduces Word Error Rate compared to existing methods in English and can effectively transcribe lyrics across multiple languages. Furthermore, we use LyricWhiz to create the first publicly available, large-scale, multilingual lyrics transcription dataset with a CC-BY-NC-SA copyright license, based on MTG-Jamendo, and offer a human-annotated subset for noise level estimation and evaluation. We anticipate that our proposed method and dataset will advance the development of multilingual lyrics transcription, a challenging and emerging task.Comment: 9 pages, 2 figures, 5 tables, accepted by ISMIR 202

Comparative genomics and DNA methylation analysis of Pseudomonas aeruginosa clinical isolate PA3 by single-molecule real-time sequencing reveals new targets for antimicrobials

IntroductionPseudomonas aeruginosa (P.aeruginosa) is an important opportunistic pathogen with broad environmental adaptability and complex drug resistance. Single-molecule real-time (SMRT) sequencing technique has longer read-length sequences, more accuracy, and the ability to identify epigenetic DNA alterations.MethodsThis study applied SMRT technology to sequence a clinical strain P. aeruginosa PA3 to obtain its genome sequence and methylation modification information. Genomic, comparative, pan-genomic, and epigenetic analyses of PA3 were conducted.ResultsGeneral genome annotations of PA3 were discovered, as well as information about virulence factors, regulatory proteins (RPs), secreted proteins, type II toxin-antitoxin (TA) pairs, and genomic islands. A genome-wide comparison revealed that PA3 was comparable to other P. aeruginosa strains in terms of identity, but varied in areas of horizontal gene transfer (HGT). Phylogenetic analysis showed that PA3 was closely related to P. aeruginosa 60503 and P. aeruginosa 8380. P. aeruginosa's pan-genome consists of a core genome of roughly 4,300 genes and an accessory genome of at least 5,500 genes. The results of the epigenetic analysis identified one main methylation sites, N6-methyladenosine (m6A) and 1 motif (CATNNNNNNNTCCT/AGGANNNNNNNATG). 16 meaningful methylated sites were picked. Among these, purH, phaZ, and lexA are of great significance playing an important role in the drug resistance and biological environment adaptability of PA3, and the targeting of these genes may benefit further antibacterial studies.DisucssionThis study provided a detailed visualization and DNA methylation information of the PA3 genome and set a foundation for subsequent research into the molecular mechanism of DNA methyltransferase-controlled P. aeruginosa pathogenicity

Design and Preparation of Sandwich-Like Polydimethylsiloxane (PDMS) Sponges with Super-Low Ice Adhesion

The mitigation of ice on exposed surfaces is of great importance to many aspects of life. Ice accretion, however, is unavoidable as time elapses and temperature lowers sufficiently. One practical solution is to reduce ice adhesion strength on a surface as low as possible, by either decreasing substrate elastic modulus, lowering surface energy or increasing the length of cracks at ice-solid interface. Herein, we present a facile preparation of polydimethylsiloxane (PDMS) based sandwich-like sponges with super-low ice adhesion. The weight ratio of the PDMS prepolymer to the curing agent is tuned to lower surface energy and elastic modulus. The introduction of PDMS sponge structures combined the advantages of both reduced apparent elastic modulus and most importantly, the macroscopic crack initiators at ice-solid interface, resulting in dramatic reduction of ice adhesion strength. Our design of sandwich-like sponges achieved a low ice adhesion strength as low as 0.9 kPa for pure PDMS materials without any additives. The super-low ice adhesion strength remains constant after 25 icing and deicing cycles. We thus provided a new and low-cost approach to realize durable super-low ice adhesion surfaces

Design of Icephobic Surfaces by Lowering Ice Adhesion Strength: A Mini Review

Ice accretion can lead to severe consequences in daily life and sometimes catastrophic events. To mitigate the hazard of icing, passive icephobic surfaces have drawn widespread attentions because of their abilities in repelling incoming water droplets, suppressing ice nucleation and/or lowering ice adhesion strength. As time elapses and temperature lowers sufficiently, ice accretion becomes inevitable, and a realistic roadmap to surface icephobicity for various outdoor anti-icing applications is to live with ice but with the lowest ice adhesion strength. In this review, surfaces with icephobicity are critically categorized into smooth surfaces, textured surfaces, slippery surfaces and sub-surface textured surfaces, and discussed in terms of theoretical limit, current status and perspectives. Particular attention is paid to multiple passive anti-icing strategies combined approaches as proposed on the basis of icephobic surfaces. Correlating the current strategies with one another will promote understanding of the key parameters in lowering ice adhesion strength. Finally, we provide remarks on the rational design of state-of-the-art icephobic surfaces with low ice adhesion strength

Design and Preparation of Sandwich-Like Polydimethylsiloxane (PDMS) Sponges with Super-Low Ice Adhesion

The mitigation of ice on exposed surfaces is of great importance to many aspects of life. Ice accretion, however, is unavoidable as time elapses and temperature lowers sufficiently. One practical solution is to reduce ice adhesion strength on a surface as low as possible, by either decreasing substrate elastic modulus, lowering surface energy or increasing the length of cracks at ice-solid interface. Herein, we present a facile preparation of polydimethylsiloxane (PDMS) based sandwich-like sponges with super-low ice adhesion. The weight ratio of the PDMS prepolymer to the curing agent is tuned to lower surface energy and elastic modulus. The introduction of PDMS sponge structures combined the advantages of both reduced apparent elastic modulus and most importantly, the macroscopic crack initiators at ice-solid interface, resulting in dramatic reduction of ice adhesion strength. Our design of sandwich-like sponges achieved a low ice adhesion strength as low as 0.9 kPa for pure PDMS materials without any additives. The super-low ice adhesion strength remains constant after 25 icing and deicing cycles. We thus provided a new and low-cost approach to realize durable super-low ice adhesion surfaces.submittedVersionThis is a submitted manuscript of an article published by Elsevier Ltd in Soft Matter, 11 May 2018

Design and preparation of icephobic PDMS-based coatings by introducing an aqueous lubricating layer and macro-crack initiators at the ice-substrate interface

Preventing ice accretion on exposed surfaces is important to the operational performance of various facilities and devices. As time elapses and temperature lowers sufficiently, ice accretion becomes inevitable. Herein, we present a new approach to prepare icephobic coatings by incorporating two strategies towards lowering ice adhesion strength, i.e. introducing an aqueous lubricating layer and maximizing macro-crack initiators at the ice-substrate interface. The aqueous lubricating layer is realized by grafting poly(acrylic acid) (PAA) onto polydimethylsiloxane (PDMS) coatings, and the macro-crack initiators are induced by introducing macro-scale hollow sub-surface structures into PDMS coatings. By using vertical shear tests, ice adhesion strengths of PAA-g-PDMS (10:1), PDMS coatings with macro-scale hollow sub-surface structures (hPDMS) (10:1), PAA-g-hPDMS (10:1), PAA-g-PDMS (10:10), hPDMS (10:10), and PAA-g-hPDMS (10:10) coatings are obtained as 178.5 ± 22 kPa, 153.1 ± 19 kPa, 122.7 ± 18 kPa, 24.6 ± 4 kPa, 20.3 ± 3.4 kPa and 17.6 ± 3.2 kPa, respectively, showing a reduction of 37.2 %, 46.1 %, 56.8 %, 32.8 %, 44.5 % and 51.9 % when compared with corresponding pure PDMS coatings. These results indicate that ice adhesion strength can be further reduced by simultaneously introducing two strategies. The principle of designing icephobic coatings by combining two or more strategies to reduce ice adhesion to as low as possible provides a new avenue to the preparation of icephobic coatings, and makes practical applications possible under extremely severe conditions

Polysiloxane as icephobic materials – the past, present and the future

Polysiloxane is one of the most favorite polymeric materials used in the emerging field of passive surface icephobicity; This is due to its tailorable softness, hydrophobicity, and relatively high durability. Given the state-of-the-art ice adhesion strength of polysiloxane surfaces has reached a threshold below 1 kPa, a timely survey on the published polysiloxane icephobic surfaces can serve as a valuable reference concerning how far the research field has already progressed and how much potential remains to be exploited for the future development of polymeric icephobic materials. This review categorizes the use of polysiloxane materials for icephobic strategies into three classes according to their surface stiffness. The advantages and shortcomings of each polysiloxane material group are assessed. By scrutinizing the current ice adhesion strength theory, a reference coating thickness is identified, which can be used for optimizing icephobic coating design. A surface icephobicity diagram is also presented, where a lower bound of ice adhesion on a smooth surface is derived, depicting the needs of incorporating different mechanisms to break the theoretical low ice adhesion limit. Finally, the challenges in applying the polysiloxane icephobic materials are discussed, and the possible key research directions are highlighted

Understanding the role of hollow sub-surface structures in reducing ice adhesion strength

The accretion of ice on exposed surfaces infers detrimental effects on many aspects of life and technology. Passive icephobic coatings, designed by strategies towards lowering ice adhesion to mitigate the icing problems, have recently received wide attention. In our previous studies, the incorporation of hollow sub-surface structures which act as macro-scale crack initiators has been shown to dratically lower the ice adhesion on PDMS surfaces. In this study, the effects of hollow sub-surface structure geometry, such as the heights, shapes, and distributions, as well as directions of the applied shear force, are experimentally investigated. Our results show that the number of potential macro-scale crack initiation sites dictates ice adhesion strength. Directions of the applied shear force also influence ice adhesion strength when the potential crack length is dependent on the applied shear force direction. The inter-locking effect between ice and the coating, caused by the pre-deformation, needs to be considered if one of the dimensions of the hollow sub-surface structures approaches millimeter scale. These results improve the understanding of the role of hollow sub-surface structures in reducing ice adhesion, providing new insights on the design principles for multi-scale crack initiators promoted icephobic surfaces

Durable low ice adhesion foams modulated by submicron pores

Ice accretion is a severe challenge for both production and livelihood in cold regions. Previously reported high-performance icephobic surfaces by infusing lubricants are either temporarily icephobic, chemically unstable or mechanically weak. Herein, we report the design and fabrication of submicron porous polydimethylsiloxane (PDMS, Sylgard 184 with weight ratio 10:1) foams based chemically stable and mechanically robust icephobic materials. The relationship between the ice adhesion strength and porosity is revealed. Without any surface additives and lubricants as well as sacrificing the crosslinking density of elastomeric foam, the stable ice adhesion strength of the submicron porous foam reaches 16.8 ± 5.8 kPa after 50 icing/deicing cycles. In addition, the icephobic foams show excellent chemical stability and mechanical robustness, and the ice adhesion strengths are all less than 30.0 kPa after acid/base/salt/organic solvent corrosion and 1000 abrasion cycles. The submicron porous elastomeric strategy opens up a new avenue for high-performance durable icephobic materials with excellent stability and robustness