Report on catalyst synthesis and testing

<p>In this public report, we present the main results obtained with the best identified tandem system for the direct conversion of CO2 into propane, from the initial synthesis at lab-scale to the catalyst upscaling. The PdZn/ZrO2 + SAPO-34 catalyst combination was found to provide the highest combined CO2 conversion (40%) and propane selectivity (50%, with 20% CO, 6% C1, 13% C2, 10% C4, and 1% C5), achieving two of the three key performance indicators (KPIs) defined in the COZMOS project for catalyst performance.</p><p>This catalyst combination was selected as our 1st generation catalyst in the project, and different strategies for catalyst production upscaling have been investigated. The physical mixture of the upscaled version of PdZn/ZrO2 and SAPO-34 achieved 90% of the catalytic performance previously observed for the lab-scale catalyst, also meeting the established KPI. Otherwise, the formulation of technical catalyst in tablet or extrudate shapes demonstrated the migration of Zn from the ZrO2 matrix to the Al-containing binder and the SAPO-34 function. The significant loss of activity in these cases suggested the impracticality of using these shapes for this catalyst combination.</p><p>The upscaled catalyst mixture was extensively tested for tandem CO2 hydrogenation and a detailed kinetic model was developed. The versatility of the models allowed the prediction of product distribution using different reaction (temperature, pressure and space velocity) and operation conditions (CO2 feeds, CO feeds and CO2/CO feeds).</p><p>These kinetic rate expressions were communicated from WP1 (catalyst development) to WP2 (plant design), WP3 (pilot-plant testing) and WP4 (Life Cycle Assessment), enabling the project's industrial partners to design an industrial plant and perform techno-economic and life cycle assessments (TEA and LCA, WP2 and WP4, respectively). Moreover, this catalyst combination is currently in pilot-plant testing within the COZMOS activities of WP3.</p&gt

Supplementary material 4 from: Pearman JK, Casas L, Michell C, Aldanondo N, Mojib N, Holtermann K, Georgakakis I, Curdia J, Carvalho S, Gusti A, Irigoien X (2022) Comparative metagenomics of phytoplankton blooms after nutrient enrichment of oligotrophic marine waters. Metabarcoding and Metagenomics 6: e79208. https://doi.org/10.3897/mbmg.6.79208

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Supplementary material 9 from: Pearman JK, Casas L, Michell C, Aldanondo N, Mojib N, Holtermann K, Georgakakis I, Curdia J, Carvalho S, Gusti A, Irigoien X (2022) Comparative metagenomics of phytoplankton blooms after nutrient enrichment of oligotrophic marine waters. Metabarcoding and Metagenomics 6: e79208. https://doi.org/10.3897/mbmg.6.79208

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Supplementary material 5 from: Pearman JK, Casas L, Michell C, Aldanondo N, Mojib N, Holtermann K, Georgakakis I, Curdia J, Carvalho S, Gusti A, Irigoien X (2022) Comparative metagenomics of phytoplankton blooms after nutrient enrichment of oligotrophic marine waters. Metabarcoding and Metagenomics 6: e79208. https://doi.org/10.3897/mbmg.6.79208

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Supplementary material 8 from: Pearman JK, Casas L, Michell C, Aldanondo N, Mojib N, Holtermann K, Georgakakis I, Curdia J, Carvalho S, Gusti A, Irigoien X (2022) Comparative metagenomics of phytoplankton blooms after nutrient enrichment of oligotrophic marine waters. Metabarcoding and Metagenomics 6: e79208. https://doi.org/10.3897/mbmg.6.79208

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Supplementary material 6 from: Pearman JK, Casas L, Michell C, Aldanondo N, Mojib N, Holtermann K, Georgakakis I, Curdia J, Carvalho S, Gusti A, Irigoien X (2022) Comparative metagenomics of phytoplankton blooms after nutrient enrichment of oligotrophic marine waters. Metabarcoding and Metagenomics 6: e79208. https://doi.org/10.3897/mbmg.6.79208

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NIST certified secure key generation via deep learning of physical unclonable functions in silica aerogels (dataset)

Physical unclonable functions (PUFs) are complex physical objects that aim at overcoming the vulnerabilities of traditional cryptographic keys, promising a robust class of security primitives for different applications. Optical PUFs present advantages over traditional electronic realizations, namely a stronger unclonability, but suffer from problems of reliability and weak unpredictability of the key. We here develop a two-step PUF generation strategy based on deep-learning, which associates reliable keys verified against the NIST certification standards of true random generators for cryptography. The idea explored in this work is to decouple the design of the PUFs from the key generation and train a neural architecture to learn the mapping algorithm between the key and the PUF. We report experimental results with all-optical PUFs realized in silica aerogels and analyzed a population of 100 generated keys, each of 10000 bit length. The key generated passed all tests required by the NIST standard, with proportion outcomes well beyond NIST’s recommended threshold. The two-step key generation strategy studied in this work can be generalized to any PUF based on either optical or electronic implementations. It can help the design of robust PUFs for both secure authentications and encrypted communications

Practical splitting methods for the adaptive integration of nonlinear evolution equations. Part I: Construction of optimized schemes and pairs of schemes

We present a number of new contributions to the topic of const ructing efficient higher-order splitting methods for the numerical integration of evolution equations. Particular schemes are constructed via setup and solution of polynomial systems for the splitting coefficients. To this end we use and modify a recent approach for generating these systems for a large class of splittings. In particular, various types of pairs of schemes intended for use in adaptive integrators are constructed

Negative allometric growth during ontogeny in the large pelagic filter-feeding basking shark

Many pelagic shark species change body and fin shape isometrically or by positive allometry during ontogeny. But some large apex predators such as the white shark Carcharodon carcharias or the tiger shark Galeocerdo cuvier show distinct negative allometry, especially in traits related to feeding (head) or propulsion (caudal fin). In particular, changes in propulsion are attributed to a shift in swimming mode. The more heterocercal caudal fin of younger individuals with its large caudal fin span seemingly aids in hunting small, agile prey. In contrast, the less heterocercal caudal fin with a larger fin area in larger individuals aids a long-distance slow swimming mode. We were interested if negative allometric effects can be observed in a planktivorous shark, the basking shark Cetorhinus maximus, a large species adapted to long-distance slow swimming. To address this question, we compared three size classes, specifically  541 cm total length. Comparing literature data, we found negative allometric growth of the head and of the caudal fin, but a more rapid decrease of relative caudal fin size than of relative head length. Hereby, we provide the first evidence for early negative allometric growth of the caudal fin in a large pelagic filter-feeding shark. Our study further demonstrates that ecomorphological approaches may add valuable insight into the life history of animals that are challenging to study in their natural habitat, including large roving sharks such as the basking shark.© The Author(s) 201