ACS Engineering AuPub Date : 2024-03-27DOI: 10.1021/acsengineeringau.3c0006910.1021/acsengineeringau.3c00069
Vitor Gama, Beatriz Dantas, Oishi Sanyal* and Fernando V. Lima*,
{"title":"Process Operability Analysis of Membrane-Based Direct Air Capture for Low-Purity CO2 Production","authors":"Vitor Gama, Beatriz Dantas, Oishi Sanyal* and Fernando V. Lima*, ","doi":"10.1021/acsengineeringau.3c0006910.1021/acsengineeringau.3c00069","DOIUrl":"https://doi.org/10.1021/acsengineeringau.3c00069https://doi.org/10.1021/acsengineeringau.3c00069","url":null,"abstract":"<p >Addressing climate change constitutes one of the major scientific challenges of this century, and it is widely acknowledged that anthropogenic CO<sub>2</sub> emissions largely contribute to this issue. To achieve the “net-zero” target and keep the rise in global average temperature below 1.5 °C, negative emission technologies must be developed and deployed at a large scale. This study investigates the feasibility of using membranes as direct air capture (DAC) technology to extract CO<sub>2</sub> from atmospheric air to produce low-purity CO<sub>2</sub>. In this work, a two-stage hollow fiber membrane module process is designed and modeled using the AVEVA Process Simulation platform to produce a low-purity (≈5%) CO<sub>2</sub> permeate stream. Such low-purity CO<sub>2</sub> streams could have several possible applications such as algae growth, catalytic oxidation, and enhanced oil recovery. An operability analysis is performed by mapping a feasible range of input parameters, which include membrane surface area and membrane performance metrics, to an output set, which consists of CO<sub>2</sub> purity, recovery, and net energy consumption. The base case for this simulation study is generated considering a facilitated transport membrane with high CO<sub>2</sub>/N<sub>2</sub> separation performance (CO<sub>2</sub> permeance = 2100 GPU and CO<sub>2</sub>/N<sub>2</sub> selectivity = 1100), when tested under DAC conditions. With a constant membrane area, both membranes’ intrinsic performances are found to have a considerable impact on the purity, recovery, and energy consumption. The area of the first module plays a dominant role in determining the recovery, purity, and energy demands, and in fact, increasing the area of the second membrane has a negative impact on the overall energy consumption, without improving the overall purities. The CO<sub>2</sub> capture capacity of DAC units is important for implementation and scale-up. In this context, the performed analysis showed that the m-DAC process could be appropriate as a small-capacity system (0.1–1 Mt/year of air), with reasonable recoveries and overall purity. Finally, a preliminary CO<sub>2</sub> emissions analysis is carried out for the membrane-based DAC process, which leads to the conclusion that the overall energy grid must be powered by renewable sources for the technology to qualify within the negative emissions category.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00069","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142010491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-03-27DOI: 10.1021/acsengineeringau.3c00069
Vitor Gama, Beatriz Dantas, Oishi Sanyal, Fernando V. Lima
{"title":"Process Operability Analysis of Membrane-Based Direct Air Capture for Low-Purity CO2 Production","authors":"Vitor Gama, Beatriz Dantas, Oishi Sanyal, Fernando V. Lima","doi":"10.1021/acsengineeringau.3c00069","DOIUrl":"https://doi.org/10.1021/acsengineeringau.3c00069","url":null,"abstract":"Addressing climate change constitutes one of the major scientific challenges of this century, and it is widely acknowledged that anthropogenic CO<sub>2</sub> emissions largely contribute to this issue. To achieve the “net-zero” target and keep the rise in global average temperature below 1.5 °C, negative emission technologies must be developed and deployed at a large scale. This study investigates the feasibility of using membranes as direct air capture (DAC) technology to extract CO<sub>2</sub> from atmospheric air to produce low-purity CO<sub>2</sub>. In this work, a two-stage hollow fiber membrane module process is designed and modeled using the AVEVA Process Simulation platform to produce a low-purity (≈5%) CO<sub>2</sub> permeate stream. Such low-purity CO<sub>2</sub> streams could have several possible applications such as algae growth, catalytic oxidation, and enhanced oil recovery. An operability analysis is performed by mapping a feasible range of input parameters, which include membrane surface area and membrane performance metrics, to an output set, which consists of CO<sub>2</sub> purity, recovery, and net energy consumption. The base case for this simulation study is generated considering a facilitated transport membrane with high CO<sub>2</sub>/N<sub>2</sub> separation performance (CO<sub>2</sub> permeance = 2100 GPU and CO<sub>2</sub>/N<sub>2</sub> selectivity = 1100), when tested under DAC conditions. With a constant membrane area, both membranes’ intrinsic performances are found to have a considerable impact on the purity, recovery, and energy consumption. The area of the first module plays a dominant role in determining the recovery, purity, and energy demands, and in fact, increasing the area of the second membrane has a negative impact on the overall energy consumption, without improving the overall purities. The CO<sub>2</sub> capture capacity of DAC units is important for implementation and scale-up. In this context, the performed analysis showed that the m-DAC process could be appropriate as a small-capacity system (0.1–1 Mt/year of air), with reasonable recoveries and overall purity. Finally, a preliminary CO<sub>2</sub> emissions analysis is carried out for the membrane-based DAC process, which leads to the conclusion that the overall energy grid must be powered by renewable sources for the technology to qualify within the negative emissions category.","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140325124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-02-29DOI: 10.1021/acsengineeringau.3c00072
B. Ruşen Argun, and , Antonia Statt*,
{"title":"Interplay of Spatial and Topological Defects in Polymer Networks","authors":"B. Ruşen Argun, and , Antonia Statt*, ","doi":"10.1021/acsengineeringau.3c00072","DOIUrl":"10.1021/acsengineeringau.3c00072","url":null,"abstract":"<p >Polymer networks are widely used in applications, and the formation of a network and its gel point can be predicted. However, the effects of spatial and topological heterogeneity on the resulting network structure and ultimately the mechanical properties, are less understood. To address this challenge, we generate in silico random networks of cross-linked polymer chains with controlled spatial and topological defects. While all fully reacted networks investigated in this study have the same number of end-functionalized polymer strands and cross-linkers, we vary the degree of spatial and topological heterogeneities systematically. We find that spatially heterogeneous cross-linker distributions result in a reduction in the network’s primary loops with increased spatial heterogeneity, the opposite trend as observed in homogeneous networks. By performing molecular dynamics simulations, we investigated the mechanical properties of the networks. Even though spatially heterogeneous networks have more elastically active strands and cross-linkers, they break at lower extensions than the homogeneous networks and sustain slightly lower maximum stresses. Their shear moduli are higher, i.e., stiffer, than theoretically predicted, and higher than their homogeneous gel counterparts. Our results highlight that topological loop defects and spatial heterogeneities result in significantly different network structures and, ultimately, different mechanical properties.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-02-22DOI: 10.1021/acsengineeringau.3c00071
Gouri Sankar Das, K. Sandeep Raju, Nisha Dhiman and Kumud Malika Tripathi*,
{"title":"Removal of Anthropogenic Toxic Gaseous Compounds from Indoor using Biomass-based Graphene Aerogels","authors":"Gouri Sankar Das, K. Sandeep Raju, Nisha Dhiman and Kumud Malika Tripathi*, ","doi":"10.1021/acsengineeringau.3c00071","DOIUrl":"10.1021/acsengineeringau.3c00071","url":null,"abstract":"<p >The efficient capture of HCHO, tobacco smoke, and anthropogenic toxic pollutants is of paramount importance to mitigate indoor air pollution and protect the general population. Ultralight N-doped graphene aerogel (N-GA) with a three-dimensional (3D) honeycomb-like coarse-pore structure is synthesized from biomass (pear). By taking advantage of the micrometer-sized honeycomb pores, 3D interconnected porous structure, hierarchical pores, large pore volume (0.81 cm<sup>3</sup> g<sup>–1</sup>), highly accessible surface area (1582 m<sup>2</sup> g<sup>–1</sup>), and heteroatom-enriched (1.89% of N and 9.88% of O) nature, the N-GA offered high adsorption of the toxic gaseous compounds (TGCs). The as-synthesized N-GA without any further chemical/physical treatment exhibits an excellent adsorption-based capture of TGCs such as HCHO (996.7 mg g<sup>–1</sup>), ethanol (611 mg g<sup>–1</sup>), tobacco smoke (523.8 mg g<sup>–1</sup>), benzene (482.3 mg g<sup>–1</sup>), toluene (392 mg g<sup>–1</sup>), and carbon dioxide (365.3 mg g<sup>–1</sup>). Moreover, N-GA, as a low-cost and renewable adsorbent, exhibits high recyclability and long-term adsorption efficiency. These results demonstrate the potential of N-GA as an unprecedented candidate to design high-performance adsorbents for TGCs, suggesting a great application potential in air filters to control both indoor and outdoor air pollution.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139955962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-02-21DOI: 10.1021/acsengineeringau.4c00002
Vivek V. Ranade*, and , Linda J. Broadbelt*,
{"title":"Celebrating ACS Engineering Au’s 2023 Rising Stars in Chemical Engineering","authors":"Vivek V. Ranade*, and , Linda J. Broadbelt*, ","doi":"10.1021/acsengineeringau.4c00002","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00002","url":null,"abstract":"","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139914422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-02-14DOI: 10.1021/acsengineeringau.3c00067
Colin O’Modhrain, Georgi Trenchev, Yury Gorbanev* and Annemie Bogaerts,
{"title":"Upscaling Plasma-Based CO2 Conversion: Case Study of a Multi-Reactor Gliding Arc Plasmatron","authors":"Colin O’Modhrain, Georgi Trenchev, Yury Gorbanev* and Annemie Bogaerts, ","doi":"10.1021/acsengineeringau.3c00067","DOIUrl":"10.1021/acsengineeringau.3c00067","url":null,"abstract":"<p >Atmospheric pressure plasmas have shifted in recent years from being a burgeoning research field in the academic setting to an actively investigated technology in the chemical, oil, and environmental industries. This is largely driven by the climate change mitigation efforts, as well as the evident pathways of value creation by converting greenhouse gases (such as CO<sub>2</sub>) into useful chemical feedstock. Currently, most high technology readiness level (TRL) plasma-based technologies are based on volumetric and power-based scaling of thermal plasma systems, which results in large capital investment and regular maintenance costs. This work investigates bringing a quasi-thermal (so-called “warm”) plasma setup, namely, a gliding arc plasmatron, from a lab-scale to a pilot-scale capacity with an increase in throughput capacity by a factor of 10. The method of scaling is the parallelization of plasmatron reactors within a single housing, with the aim of maintaining a warm plasma regime while simultaneously improving build cost and efficiency (compared to separate reactors operating in parallel). Special attention is also given to the safety and control features implemented in the setup, a key component required for integration into industrial systems. The performance of the multi-reactor gliding arc plasmatron (MRGAP) reactor is investigated, focusing on the influence of flow rate and the number of active reactors. The location of active reactors was deemed to have a negligible effect on the monitored metrics of conversion, energy efficiency, and energy cost. The optimum operating conditions were found to be with the most active reactors (five) at the highest investigated flow rate (80 L/min). Analysis of results suggests that an optimum conversion (9%) and plug power-based energy efficiency (19%) can be maintained at a specific energy input (SEI) around 5.3 kJ/L (or 1 eV/molecule). The concept of parallelization of plasmatron reactors within a singular housing was demonstrated to be a viable method for scaling up from a lab-scale to a prototype-scale device, with performance analysis suggesting that increasing the power (through adding more reactor channels) and total flow rate, while maintaining an SEI around 5.3 or 4.2 kJ/L, i.e., 1.3 or 1 eV/molecule (based on plug power and plasma-deposited power, respectively), can result in increased conversion rate without sacrificing absolute conversion or energy efficiency.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139771948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-02-12DOI: 10.1021/acsengineeringau.3c00047
Helge Sören Stein*,
{"title":"Nonlinear Potentiodynamic Battery Charging Protocols for Fun, Education, and Application","authors":"Helge Sören Stein*, ","doi":"10.1021/acsengineeringau.3c00047","DOIUrl":"10.1021/acsengineeringau.3c00047","url":null,"abstract":"<p >Most secondary batteries in academia are (dis)charged by applying a constant current (CC) followed by a constant voltage (CV), i.e., a CCCV procedure. The usual concept is then to condense data for interpretation into representations such as differential capacity, or d<i>Q</i>/d<i>V</i>, graphs. This is done to extract information related to phenomena such as the growth of the solid electrolyte interphase or, more broadly, degradation. Typically, these measurements take several months because measurements for differential capacity analysis need to be performed at relatively low C-rates. An alternate charging schedule to CCCV is pulsed charging, where CC sections are interrupted by an open-circuit measurement on a second time scale. These and similar partially constant current strategies primarily target diffusive effects during charging and broadly fall into a linear charging category, where the time derivative for the actuated property is mostly zero. Herein, the author explores nonlinear charging, i.e., the process of actively applying a potential with a nontrivial time derivate and a resulting nontrivial current time derivative, to engineer (dis)charge cycles with enhanced information density. This method of nonlinear charging is then used to charge a cell such that some potential ranges in the differential capacity diagram are omitted. This study is purely a simulative endeavor and not backed by experimentation owing mainly to the lack of facile implementation of arbitrary function inputs for battery cyclers and might point to limitations of the underlying theory. If found to be confirmed through an experiment, then this technique would, however, motivate a new roadmap to better understand secondary battery degradation inspired by electrocatalyst degradation.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139771755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-01-24DOI: 10.1021/acsengineeringau.3c00060
Marcello B. Solomon, Swapna S. Rabha, Gustavo Fimbres-Weihs, Himanshu Goyal, Firouzeh R. Taghikhah, Jithin J. Varghese, Samuel R. Wenger, Weibin Liang, Eleanor R. Kearns, Jun Huang, Niket S. Kaisare* and Deanna M. D’Alessandro*,
{"title":"Decarbonization in Australia and India: Bilateral Opportunities and Challenges for the Net Zero Transformation","authors":"Marcello B. Solomon, Swapna S. Rabha, Gustavo Fimbres-Weihs, Himanshu Goyal, Firouzeh R. Taghikhah, Jithin J. Varghese, Samuel R. Wenger, Weibin Liang, Eleanor R. Kearns, Jun Huang, Niket S. Kaisare* and Deanna M. D’Alessandro*, ","doi":"10.1021/acsengineeringau.3c00060","DOIUrl":"10.1021/acsengineeringau.3c00060","url":null,"abstract":"<p >The global Net Zero transformation is a vital response to the climate change crisis. Australia and India face similar challenges due to their reliance on fossil resources, growing energy demand, and agricultural emissions. However, differences exist in the population, industry, and development. This perspective explores these comparisons between Australia and India’s Net Zero aspirations and current sociopolitical and economic drivers. As part of the portfolio of options needed to address net zero goals, Carbon Capture, Utilization, and Storage (CCUS) and Carbon Dioxide Removal (CDR) solutions are specifically discussed. The perspective concludes with opportunities for the nations to engage in knowledge sharing and bilateral partnerships to help accelerate the world’s transformation to Net Zero.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139560604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-01-19DOI: 10.1021/acsengineeringau.3c00066
Daniele Micale, Mauro Bracconi* and Matteo Maestri,
{"title":"Increasing Computational Efficiency of CFD Simulations of Reactive Flows at Catalyst Surfaces through Dynamic Load Balancing","authors":"Daniele Micale, Mauro Bracconi* and Matteo Maestri, ","doi":"10.1021/acsengineeringau.3c00066","DOIUrl":"10.1021/acsengineeringau.3c00066","url":null,"abstract":"<p >We propose a numerical strategy based on dynamic load balancing (DLB) aimed at enhancing the computational efficiency of multiscale CFD simulation of reactive flows at catalyst surfaces. Our approach employs DLB combined with a hybrid parallelization technique, integrating both MPI and OpenMP protocols. This results in an optimized distribution of the computational load associated with the chemistry solution across processors, thereby minimizing computational overheads. Through assessments conducted on fixed and fluidized bed reactor simulations, we demonstrated a remarkable improvement of the parallel efficiency from 19 to 87% and from 19 to 91% for the fixed and fluidized bed, respectively. Owing to this improved parallel efficiency, we observe a significant computational speed-up of 1.9 and 2.1 in the fixed and fluidized bed reactor simulations, respectively, compared to simulations without DLB. All in all, the proposed approach is able to improve the computational efficiency of multiscale CFD simulations paving the way for a more efficient exploitation of high-performance computing resources and expanding the current boundaries of feasible simulations.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Engineering AuPub Date : 2024-01-12DOI: 10.1021/acsengineeringau.3c00058
Markus J. Buehler*,
{"title":"Generative Retrieval-Augmented Ontologic Graph and Multiagent Strategies for Interpretive Large Language Model-Based Materials Design","authors":"Markus J. Buehler*, ","doi":"10.1021/acsengineeringau.3c00058","DOIUrl":"10.1021/acsengineeringau.3c00058","url":null,"abstract":"<p >Transformer neural networks show promising capabilities, in particular for uses in materials analysis, design, and manufacturing, including their capacity to work effectively with human language, symbols, code, and numerical data. Here, we explore the use of large language models (LLMs) as a tool that can support engineering analysis of materials, applied to retrieving key information about subject areas, developing research hypotheses, discovery of mechanistic relationships across disparate areas of knowledge, and writing and executing simulation codes for active knowledge generation based on physical ground truths. Moreover, when used as sets of AI agents with specific features, capabilities, and instructions, LLMs can provide powerful problem-solution strategies for applications in analysis and design problems. Our experiments focus on using a fine-tuned model, MechGPT, developed based on training data in the mechanics of materials domain. We first affirm how fine-tuning endows LLMs with a reasonable understanding of subject area knowledge. However, when queried outside the context of learned matter, LLMs can have difficulty recalling correct information and may hallucinate. We show how this can be addressed using retrieval-augmented Ontological Knowledge Graph strategies. The graph-based strategy helps us not only to discern how the model understands what concepts are important but also how they are related, which significantly improves generative performance and also naturally allows for injection of new and augmented data sources into generative AI algorithms. We find that the additional feature of relatedness provides advantages over regular retrieval augmentation approaches and not only improves LLM performance but also provides mechanistic insights for exploration of a material design process. Illustrated for a use case of relating distinct areas of knowledge, here, music and proteins, such strategies can also provide an interpretable graph structure with rich information at the node, edge, and subgraph level that provides specific insights into mechanisms and relationships. We discuss other approaches to improve generative qualities, including nonlinear sampling strategies and agent-based modeling that offer enhancements over single-shot generations, whereby LLMs are used to both generate content and assess content against an objective target. Examples provided include complex question answering, code generation, and execution in the context of automated force-field development from actively learned density functional theory (DFT) modeling and data analysis.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.3c00058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}