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1. Chemical abrasion: the mechanics of zircon dissolution

   https://doi.org/10.5194/gchron-5-127-2023  

   McKanna, Alyssa J.; Koran, Isabel; Schoene, Blair; Ketcham, Richard A. (January 2023, Geochronology)

   Abstract. Chemical abrasion is a technique that combines thermal annealing and partialdissolution in hydrofluoric acid (HF) to selectively removeradiation-damaged portions of zircon crystals prior to U–Pb isotopicanalysis, and it is applied ubiquitously to zircon prior to U–Pb isotopedilution thermal ionization mass spectrometry (ID-TIMS). The mechanics ofzircon dissolution in HF and the impact of different leaching conditions onthe zircon structure, however, are poorly resolved. We present amicrostructural investigation that integrates microscale X-ray computedtomography (µCT), scanning electron microscopy, and Ramanspectroscopy to evaluate zircon dissolution in HF. We show that µCTis an effective tool for imaging metamictization and complex dissolutionnetworks in three dimensions. Acid frequently reaches crystal interiors viafractures spatially associated with radiation damage zoning and inclusionsto dissolve soluble high-U zones, some inclusions, and material aroundfractures, leaving behind a more crystalline zircon residue. Other acid pathsto crystal cores include the dissolution of surface-reaching inclusions andthe percolation of acid across zones with high defect densities. In highlycrystalline samples dissolution is crystallographically controlled withdissolution proceeding almost exclusively along the c axis. Increasing theleaching temperature from 180 to 210 ∘C results indeeper etching textures, wider acid paths, more complex internal dissolutionnetworks, and greater volume losses. How a grain dissolves strongly dependson its initial radiation damage content and defect distribution as well asthe size and position of inclusions. As such, the effectiveness of anychemical abrasion protocol for ID-TIMS U–Pb geochronology is likelysample-dependent. We also briefly discuss the implications of our findingsfor deep-time (U-Th)/He thermochronology. 

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2. Periodicity in the Electrochemical Dissolution of Transition Metals

   https://doi.org/10.1002/anie.202100337  

   Speck, Florian D.; Zagalskaya, Alexandra; Alexandrov, Vitaly; Cherevko, Serhiy (May 2021, Angewandte Chemie International Edition)

   Abstract Extensive research efforts are currently dedicated to the search for new electrocatalyst materials in which expensive and rare noble metals are replaced with cheaper and more abundant transition metals. Recently, numerous alloys, oxides, and composites with such metals have been identified as highly active electrocatalysts through the use of high‐throughput screening methods with the help of activity descriptors. Up to this point, stability has lacked such descriptors. Hence, we elucidate the role of intrinsic metal/oxide properties on the corrosion behavior of representative 3d, 4d, and 5d transition metals. Electrochemical dissolution of nine transition metals is quantified using online inductively coupled plasma mass spectrometry (ICP‐MS). Based on the obtained dissolution data in alkaline and acidic media, we establish clear periodic correlations between the amount of dissolved metal, the cohesive energy of the metal atoms (E_coh), and the energy of oxygen adsorption on the metal (ΔH_O,ads). Such correlations can support the knowledge‐driven search for more stable electrocatalysts. 

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3. Computational Modeling of Drug Dissolution in the Human Stomach

   https://doi.org/10.3389/fphys.2021.755997  

   Seo, Jung Hee; Mittal, Rajat (January 2022, Frontiers in Physiology)

   A computational model of drug dissolution in the human stomach is developed to investigate the interaction between gastric flow and orally administrated drug in the form of a solid tablet. The stomach model is derived from the anatomical imaging data and the motion and dissolution of the drug in the stomach are modeled via fluid-structure interaction combined with mass transport simulations. The effects of gastric motility and the associated fluid dynamics on the dissolution characteristics are investigated. Two different pill densities are considered to study the effects of the gastric flow as well as the gravitational force on the motion of the pill. The average mass transfer coefficient and the spatial distributions of the dissolved drug concentration are analyzed in detail. The results show that the retropulsive jet and recirculating flow in the antrum generated by the antral contraction wave play an important role in the motion of the pill as well as the transport and mixing of the dissolved drug concentration. It is also found that the gastric flow can increase the dissolution mass flux, especially when there is substantial relative motion between the gastric flow and the pill. 

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4. The dual role of dissolution at a crack tip

   https://doi.org/10.1038/s41529-024-00513-2  

   Zhao, Mingjie; Gu, Wenjia; Warner, Derek_H (September 2024, npj Materials Degradation)
5. Effect of cleaning methods on the dissolution of diatom frustules

   https://doi.org/10.1016/j.marchem.2020.103826  

   Saad, Emily M.; Pickering, Rebecca A.; Shoji, Kanaha; Hossain, Mohammad I.; Glover, T. Grant; Krause, Jeffrey W.; Tang, Yuanzhi (August 2020, Marine Chemistry)

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