Notes from the 4th Meeting of International Panel of Mesoscience
The 4th meeting of International Panel of Mesoscience (IPM) was held online via Zoom on 28 September 2021. Due to the time difference in the various countries where the panel members are located, two sessions in series were held (the times reported refer to Beijing time). Details about the two sessions can be found in the meeting agenda circulated prior to the meeting. Meanwhile, two annual reports on "Mesoscale/Meso-scale in 2020" and "Variational Studies in 2020" were circulated.
In the following, the outcomes from the two sessions are summarised:
Session 1: 8:00am-10:00am Chaired by Robin Batterham and Richard Zare
Opening Introduction: Activities Overview of IPM by Jinghai Li
Prof. Jinghai Li emphasized the necessity of paradigm shift in science as we face the global challenges, and the common difficulties of understanding complex systems which usually consist of multiple levels each exhibiting characteristic multiscale structure. Complexity usually emerges at mesoscales in mesoregimes under a certain range of specified conditions, taking the form of spatiotemporal structures where order and disorder coexist normally with nonequilibrium features. He introduced that the IPM was approved by China Association of Science & Technology in 2017 to focus on these common complexities, and three consecutive IPM meetings were held from 2018 to 2020, all with fruitful outcomes. He suggested that the 4th meeting should discuss how to identify case studies, how to translate a complex physical problem into a multi-objective variational problem, and how to transform a multi-objective problem into a single-objective problem, etc. He proposed some next actions of a joint perspective article, an international conference and an IPM meeting in 2022.
Presentation 1: Literature Survey on “Mesoscale/Meso-scale” in 2020 by Jianhua Chen and Yu Zhang
This presentation introduced the annual literature survey on the explicit and implicit mesoscale research and a special survey on catalysis. For the explicit studies, there are more than 2,500 papers, and the hotspots are still meteorology, oceanography, materials science and so on. Typically, they fall into three categories, namely geophysical, material, engineering and computing. Several examples are reported to show their linkage to mesoscience, indicating that mesoscale structures, competition, and regimes are very common and closely interrelated, and this also happens in the implicit research. The examples of biological systems indicate that mesoscience can be applied to both animate or inanimate systems. The special survey introduced the mesoscience study in catalysis in the past years and recent progress on revealing the spatiotemporal structures at different scales. In the catalysis field, researchers have put great effort on revealing the dynamic structures, controlling mechanisms, as well as the regulation directions, however, the word “mesoscience” is rarely mentioned. Apart from the recent progress on revealing the spatiotemporal structures, the oscillating catalytic activity deserves special attentions because it might play as a typical mesoregime. The summary emphasized several keywords of mesoscale interactions, collective behavior, mesoregimes, complexity and networks for further studies, and called for efforts on exploring how to correlate the large span of scales and quantifying the mesoscale complexities.
Prof. Richard Zare and Prof. Robin Batterham paid special attention on whether the researchers had mentioned the word “mesoscience”. Prof. Robin Batterham commented that it is a good way of drawing out what is the difference between activity that is happening at the mesoscale and with competing mechanism and those that are starting to treat this as an area of a discipline in the turning light. More detailed discussion about how we could collaborate with some of these authors to take their work further was postponed to the discussion session.
Presentation 2: Literature Survey on “Vibrational studies” in 2020 by Lin Zhang
This presentation introduced the annual literature survey on “variational” in the core collection of Web of Science (WOS) in the year of 2020, including 6555 papers but only a few relevant to this topic. Following the characteristic of mesoscience, such as the three-regime, the multi-objective, and the mesoscale, the above related papers are classified into three categories, that is, the three-regime related, the multi-objective related and the mesoscale related. The three-regime characteristic exists in several physical phenomena, such as the cuprate high-temperature superconductor, the HgBa2CuO4+y, the hole-doped 2D Hubbard model on the square lattice, and so on. Meanwhile, it is noted that these papers are mainly in the field of solid state physics, especially related to superconduction. For the multi-objective related, several systems have been identified for their dominant mechanisms, such as the qualitative characterization of the motions of robots, the joint-angle drift problem of dual redundant manipulators, the premium-product supply chain optimization, the load-bearing capacity of a deformable solid, the speech, and so on. It is noted that these papers are mainly in the field of social science. Further, we note that for mesoscience the physics and the math do not coincide with each other, because in physics a single optimal solution is needed while in math a lot of Pareto-optimal solutions are found for multi-objective optimization/variational problem. The reason is due to the missing information of decision maker preference, which can be obtained with the support of physics. For the mesoscale related, researchers have noticed the importance of mesoscale of mesoscience. To sum up, more and more physical and social systems are found to be mesoscience’s problems, and more and more researchers pay their attention to mesoscience, though not using the term of mesoscience.
Dr. Bernd Sachweh presented a short comment as that for catalyst and battery materials et al., researchers are never aware of using mesoscience in their study, and we should discuss how to reach these people and introduce mesoscience to them. Prof. Robin Batterham agreed this suggestion, and proposed to discuss whether it is possible to reach out and foster a direct collaboration with these people who work in an area of mesoscale.
Presentation 3: Mesoscience Applied to Early Prediction of Catastrophic Failure: From Bench to Field, from Earth to Space by Antoinette Tordesillas
A transdisciplinary approach which integrates network flow theory of granular failure and mesoscience is employed to develop a holistic framework for spatiotemporal slope stability analytics for failure estimation (SSSAFE). SSSAFE is physics-based and bears explicit connections to the micromechanics and dynamics of ductile to brittle failure in granular solids. This framework has been tested on four data sets: one at the laboratory scale using individual grain displacement data; three at the field scale using line-of-sight displacement of a slope surface, from ground-based radar in two mines and from space-borne radar for the 2017 Xinmo landslide. A key finding is that emergent kinematic clusters manifest generic dynamics ('gedy's') which deliver an early prediction of the geometry, location and time of failure -- across vastly different system scales -- from laboratory to field -- and from slope level to regional level.
Presentation 4: Sustainability – Different Aspects from Chemical Industry by Bernd Sachweh
Dr. Bernd Sachweh talked about the strategic changes at BASF to meet the requirements of sustainable development, in terms of the products, processes and R&D orientations. One of the focuses is on the replacement of fossil fuels by green renewable energies and another is on chemical cycling of the production processes. In both cases, multi-scale problems are involved and understanding the meso-scales is important. Optimization of the energy systems at the unit, plant and site scales, with plant at the meso-scale was discussed as a typical example.
Chairs’ Summary of Discussion
The panelists have emphasized the importance of putting mesoscience into action in a soaring number of mesoscale problems. While common principles, mathematical tools and methodological guidelines are desired for practical applications, further case studies in areas of typical mesoscale phenomena and board impact are highly recommended. Such areas include geological catastrophe (finding early signs for monitoring and prediction), climate change (e.g., the switching between EI Nino and La Nina phenomena, which may be related to the interaction between the solar activities and the geomagnetic field), energy systems (multi-objective optimization for less carbon footprint and higher efficiency, etc.), and catalysis (the coupling of the reaction and diffusion and the effect of the substrate and atmosphere). The formation of clouds and the dynamics of traffic networks were also mentioned as more concentrated examples. To bring more and more people in the study of mesoscale phenomena to the realm of mesoscience and be aware of its power for elucidating the complexity and emergence that are otherwise puzzling for traditional approaches, workshops on these specific topics with wider range of people participating could be a forceful propeller.
Session 2: 16:00-18:00 Chaired by Raffaella Ocone
Remarks by Richard Williams via Raffaella
I see “natural processing” in geology, biology and insects/animals to be foundational examples. They are important as we wish to understand the underlying processes and their interactions and we wish to predict and control outcomes from these processes.
These systems are important to life and my proposal is that future meetings or sub-meetings may wish to focus on these under a banner of using natural processes to assure and accelerate sustainable economies.
In particular, understanding of predicting climate adaptation (at global and local scale) and in the adoption and control of sustainable and smart nature inspired (autogenous) manufacturing and re-manufacturing processes and pathways.
My supposition is that by focusing on globally needed approaches to wicked problems we may drive funding to and understanding of the importance of mesoscience methodologies. The conference group have expertise (e.g. Prof. Marc-Olivier Coppens) in some of these areas.
Presentation 1: Multiscale, Multiphysics Modeling of the Electrochemical Reduction of CO2 by Alexis Bell
Prof. Alexis Bell talked about the electrochemical reduction of CO2, a big issue belonging to the big field of reutilizing C. He introduced firstly the current challenges, especially in activity and selectivity. Then he described the detailed complex processes involved, and analyzed the relevant factors. Several couples of competing tendencies have been well revealed, signifying the multiple dominant mechanisms governing the relevant mesoscale behaviors. Many efforts have already been made to improve the overall performance, concerning optimizing the cell geometry, the fed phase, the cation size, etc. If mesoscale models can be developed through the mesoscience methodology, they might be helpful in improving the simulations and thus better guiding the optimization.
Presentation 2: Representation Learning Unravels Compromise-in-competition in a Complex System by Shuo Zhou
A new metric called s-LID based on the concept of Local Intrinsic Dimensionality is developed to identify and quantify hierarchies of kinematic patterns in heterogeneous media. s-LID measures how outlying a grain's motion is relative to its nearest neighbors in displacement state space. s-LID reveals a hierarchy of concurrent deformation bands. The novel patterns uncovered from s-LID contradict the common belief of a causal sequence where a subset of microbands coalesce and/or grow to form shearbands. Instead, s-LID suggests that the deformation of the sample in the lead-up to failure is governed by a compromise-in-competition among different coexisting structures, which amplifies and promotes the progressive dominance of the embryonic-shearbands over microbands. In a manner consistent with mesoscience, the microbands dominate the early stages of the prefailure regime (A-dominated) while the shearbands dominate the failure regime (B-dominated).
Presentation 3: Photochemistry and Complexity Science to Promote Sustainability by Pier Luigi Gentili
Prof. Pier Luigi Gentili gave a speech entitled “Complexity science and mesoscience allied together to promote sustainability”. The fulfilment of the 2030 Agenda goals entails dealing with world economy, human societies, and various other Complex Systems. Facing such a global challenge requires developing complexity science by merging it with mesoscience. To this end, he summarized the features of Complex Systems, including the networks with diverse and variable nodes and links and high degree nonlinearity, out-of-equilibrium in thermodynamic sense, emergent properties and so on. Then he presented the difficulties in describing and predicting Complex Systems, thereon proposed several strategies, including Interdisciplinary dialogue and course, combination of reductionist, systemic and even mesoscience approaches, natural computing and chemical artificial intelligence.
Presentation 4: On the Importance of the Mesoscale Regime for Microwave-initiated Catalysis by Xiangyu Jie
Dr. Xiangyu Jie reported recent work from their group in Microwave initiated catalysis which originates from a mesoscience concept called “Size-Induced Metal-Insulator Transition (SIMIT). Using microwave-initiated catalysis (nanosized FeAlOx as catalyst) to convert the low-value plastic waste to high purity hydrogen and carbon nanomaterials was shown as an example for the utilization of this technology to solve real challenges in the world. Microwave has the advantage of only heating the catalyst which lead to big temperature gradient between the catalyst and the waste particles. This selective heating ensures the striping out of only hydrogen molecule from the waste structure and formation of carbon nanotube without other side reactions. Prof. Alexis Bell commented that this is an interesting talk and concerned about the cost of using microwave power as well as the economy efficiency of the process. This had also been taken into good consideration by the group, Dr. Xiangyu Jie introduced that the preliminary lab-scale study had found that the energy efficiency of microwave-initiated process is 120 times higher than the conventional one due to the advantage of selective heating ability of microwave as well as the high demanding fact in carbon nanotube in the market. Dr. Xiangyu Jie emphasized that this is a newly developed technique and is promising in both academic and industrial aspects.
Presentation 5: Approaching Sustainability Through Chemistry by David Cole-Hamilton
Prof. David Cole-Hamilton talked on “Approaching Sustainability Through Chemistry”, which is mainly prepared based on his paper published in Chem. Eur. J. 2020 (26) 1894-1899. Facing the 2030 Agenda goals, chemistry over the mesoscale can contribute to resolve the relevant issues. The Haber Bosch process for ammonia, which consumes 1.4% world energy supply and allows an extra 2 billion people to be fed, is exemplified to this end. To realize a green process with low temperature catalysis, magnetic heating of catalyst over the mesoscale is recommended to realize green hydrogen production. Covid-19 vaccination and periodic elements table with their resources availability are further given as two examples. In summary, the life is believed to be bright and lies with meso-chemistry.
Chair’s Summary of Discussion
The presentations focused on the role of mesoscience in extremely relevant scientific problems at the interface between chemistry and chemical engineering, and were followed by a very lively discussion focusing on the future work of the IPM. It was noted that, whilst it is relatively simple to recognise the existence of the mesoscale, it is more complex to unveil the role of mesoscience. Prof. Jinghai Li clearly identified the role of the principle of “compromise in competition,” which is at the basis of mesoscience.
Clearly mesoscience is a general concept which is often applied in very diverse fields, despite the fact that authors do not call such an approach mesoscience, but mesoscience permeates most of the scientific and technological fields that we study. Those fields, where a mesoscale can be identified are generally characterised by phenomena that compete and compromise to exist.
The panelists agreed that case studies should be devised and analysed through the “compromise in competition” principle. It was unanimously decided that the Panel should start by developing, under the auspices of the principles of mesoscience, a case study on “Catalysis”. It was agreed that a sub-group will be formed to ignite the work and all committee members interested will be invited to contribute.
Prof. Raffaella Ocone’s concluding remarks stressed once again the high importance of mesoscience and the need for devising case studies supported by the development and formalisation of the mathematical and scientific frameworks that will raise mesoscience to the status of a proper science.