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TH-C-204-00: Medical Physics Workshop: An Update On the Journal’s Improvement Activities and Guidance On Writing and Reviewing Papers

In this presentation, the Editors will outline our vision for the future of Medical Physics and review recent work-in-progress initiatives to implement this vision. Finally, we will close with guidance to authors on how to write a good Medical Physics paper. A major focus will be the transition to a new publisher in 2017 following a more than 40-year association with American Institute of Physics Publishing (AIPP). Vision for Medical Physics and status of current initiatives: Jeff Williamson, Editor-in-Chief The broad vision of Medical Physics is “to continue the Journal’s tradition of publishing the very best science that propels our discipline forward and improves our contribution to patient care.” More concretely, the Journal should be the preeminent forum for exchange of cutting edge medical physics science. We seek to identify the best contributions in (a) high impact clinical physics innovations; (b) clinical translation and validation of basic science innovations; and (c) cutting edge basic science developments with potential for patient care improvements. Among the challenges and opportunities, we face are: electronic-only and open access publishing; competition from new radiological science journals; trends towards more interactive, social-media based scientific communities; and diversification of the medical physics research, authorship, and readership domains, including clinical applications quite foreign to core ABR clinical competencies. Recently implemented and ongoing initiatives include: Revised Table of Contents (TOC) and more contemporary topical submission categories Structured review template in HTML format Comprehensive hierarchical taxonomy for identifying reviewer expertise Formal process for soliciting high quality and impact Review and Vision 20/20 Articles We have recruited four Review Article Co-editors: John Rowlands and Ingrid Reiser (imaging physics) and Joao Seco and Tim Zhu (therapy physics). The Co-Editors will identify timely topics and solicit high profile authors to submit review manuscripts. To submit an article, authors will need to work with an assigned Co-Editor to develop a mutually acceptable outline and abstract. 5) A new and exciting class of articles: Medical Physics Dataset Articles (MPDAs) MPDAs describe scientifically or clinically valuable open-access datasets with high potential for contributing to the research of medical physicists working on related problems. In contrast to Research Articles, MPDAs should not include hypothesis testing; or data analyses supporting generalizable conclusions. The publically accessible dataset must be permanently archived before the MPDA can be published. This initiative is being led by Joe Deasy. Update on new publisher transition: The transition of AAPM scientific publishing operations to a major publishing house is a major opportunity to expand Medical Physics readership and its scholarly impact. The advantages include: (a) common manuscript management and web hosting platforms for Medical Physics and its sister journal, JACMP; (b) greater than 4-fold expansion of subscribing institutions; and (c) resources to mount data-driven, highly targeted marketing campaigns to enhance citation and download rates. A transition update of this epochal development, which has only begun as of this writing (3/31/16), will be given. Improving manuscript quality via structured reviews, enhanced scientific category taxonomy, and outreach: Shiva Das, Therapy Physics Editor Medical Physics is committed to continuous improvement with the ultimate goal of improving the potential impact of accepted manuscripts. In order to do so, Medical Physics must be able to tap into important/emerging areas and be able to select high quality contributions consistently via discerning reviews. Improving the quality of reviews is crucial to selecting high quality manuscripts and also to improving manuscript impact via feedback in the review process. With this in mind, Medical Physics is in the process of: (a) fostering outreach to important areas that are currently underrepresented in Medical Physics; (b) implementing a structured template review form; and (c) implementing a comprehensive scientific category taxonomy to identify reviewers who are best suited to an article. Outreach efforts have begun to various scientific areas. Strategies to increase submissions from these areas will be discussed. As a consequence of this effort, a special issue on particle therapy is under development. A review template was implemented in late 2014 on a limited test basis. Based on reviewer feedback, the template was restructured and shortened to capture essential review elements. The restructured template is due to be released shortly. The new scientific category taxonomy is in the process of being deployed to reviewers and associate editors. Salient aspects of the structured review template and scientific category taxonomy will be discussed in this talk. Writing good scientific papers and responding to critiques: Mitch Goodsitt, Imaging Physics Editor The essential components of the abstract, introduction, methods, discussion and conclusion sections of manuscripts, as well as the desired writing style and style of the figures and tables will be reviewed. Publishable Medical Physics manuscripts must include clear and concise statements of the novelty and clinical and/or scientific importance of the authors’ work. Examples of novelty include: new technical solution to an important clinical problem; new generalizable knowledge; and first demonstration that an existing engineering solution solves a clinical problem. Please note that we encourage authors of recently published conference proceedings (e.g., SPIE, IEEE) papers on novel medical physics related work to submit more substantial versions of that work to our journal. All submissions must include: sufficient background information and rationale; enough detail for others to reproduce the authors’ work; sufficient statistical analysis to refute or validate the authors’ hypotheses; a description of how the present work compares to, is distinct from, and improves upon others’ work; and sections devoted to the limitations of the study and future directions. Writing should be polished. Poor wording, grammar and composition frustrate the review process. Our journal does not have copyeditors for revising manuscripts. When authors receive critiques from the referees and associate editor, the authors should provide a detailed point-by-point response to each comment. The authors’ rebuttal should include the text of the original criticism, the authors’ response, and a pasted copy of the modified text along with the line numbers in the revised article. The new text should be highlighted in a different font color in the revised submission. Following these recommendations will improve submissions and facilitate the review process.

60 APPLIED LIFE SCIENCES↗

TH-C-204-01: Vision for Medical Physics and Status of Current Initiatives

In this presentation, the Editors will outline our vision for the future of Medical Physics and review recent work-in-progress initiatives to implement this vision. Finally, we will close with guidance to authors on how to write a good Medical Physics paper. A major focus will be the transition to a new publisher in 2017 following a more than 40-year association with American Institute of Physics Publishing (AIPP). Vision for Medical Physics and status of current initiatives: Jeff Williamson, Editor-in-Chief The broad vision of Medical Physics is “to continue the Journal’s tradition of publishing the very best science that propels our discipline forward and improves our contribution to patient care.” More concretely, the Journal should be the preeminent forum for exchange of cutting edge medical physics science. We seek to identify the best contributions in (a) high impact clinical physics innovations; (b) clinical translation and validation of basic science innovations; and (c) cutting edge basic science developments with potential for patient care improvements. Among the challenges and opportunities, we face are: electronic-only and open access publishing; competition from new radiological science journals; trends towards more interactive, social-media based scientific communities; and diversification of the medical physics research, authorship, and readership domains, including clinical applications quite foreign to core ABR clinical competencies. Recently implemented and ongoing initiatives include: Revised Table of Contents (TOC) and more contemporary topical submission categories Structured review template in HTML format Comprehensive hierarchical taxonomy for identifying reviewer expertise Formal process for soliciting high quality and impact Review and Vision 20/20 Articles We have recruited four Review Article Co-editors: John Rowlands and Ingrid Reiser (imaging physics) and Joao Seco and Tim Zhu (therapy physics). The Co-Editors will identify timely topics and solicit high profile authors to submit review manuscripts. To submit an article, authors will need to work with an assigned Co-Editor to develop a mutually acceptable outline and abstract. 5) A new and exciting class of articles: Medical Physics Dataset Articles (MPDAs) MPDAs describe scientifically or clinically valuable open-access datasets with high potential for contributing to the research of medical physicists working on related problems. In contrast to Research Articles, MPDAs should not include hypothesis testing; or data analyses supporting generalizable conclusions. The publically accessible dataset must be permanently archived before the MPDA can be published. This initiative is being led by Joe Deasy. Update on new publisher transition: The transition of AAPM scientific publishing operations to a major publishing house is a major opportunity to expand Medical Physics readership and its scholarly impact. The advantages include: (a) common manuscript management and web hosting platforms for Medical Physics and its sister journal, JACMP; (b) greater than 4-fold expansion of subscribing institutions; and (c) resources to mount data-driven, highly targeted marketing campaigns to enhance citation and download rates. A transition update of this epochal development, which has only begun as of this writing (3/31/16), will be given. Improving manuscript quality via structured reviews, enhanced scientific category taxonomy, and outreach: Shiva Das, Therapy Physics Editor Medical Physics is committed to continuous improvement with the ultimate goal of improving the potential impact of accepted manuscripts. In order to do so, Medical Physics must be able to tap into important/emerging areas and be able to select high quality contributions consistently via discerning reviews. Improving the quality of reviews is crucial to selecting high quality manuscripts and also to improving manuscript impact via feedback in the review process. With this in mind, Medical Physics is in the process of: (a) fostering outreach to important areas that are currently underrepresented in Medical Physics; (b) implementing a structured template review form; and (c) implementing a comprehensive scientific category taxonomy to identify reviewers who are best suited to an article. Outreach efforts have begun to various scientific areas. Strategies to increase submissions from these areas will be discussed. As a consequence of this effort, a special issue on particle therapy is under development. A review template was implemented in late 2014 on a limited test basis. Based on reviewer feedback, the template was restructured and shortened to capture essential review elements. The restructured template is due to be released shortly. The new scientific category taxonomy is in the process of being deployed to reviewers and associate editors. Salient aspects of the structured review template and scientific category taxonomy will be discussed in this talk. Writing good scientific papers and responding to critiques: Mitch Goodsitt, Imaging Physics Editor The essential components of the abstract, introduction, methods, discussion and conclusion sections of manuscripts, as well as the desired writing style and style of the figures and tables will be reviewed. Publishable Medical Physics manuscripts must include clear and concise statements of the novelty and clinical and/or scientific importance of the authors’ work. Examples of novelty include: new technical solution to an important clinical problem; new generalizable knowledge; and first demonstration that an existing engineering solution solves a clinical problem. Please note that we encourage authors of recently published conference proceedings (e.g., SPIE, IEEE) papers on novel medical physics related work to submit more substantial versions of that work to our journal. All submissions must include: sufficient background information and rationale; enough detail for others to reproduce the authors’ work; sufficient statistical analysis to refute or validate the authors’ hypotheses; a description of how the present work compares to, is distinct from, and improves upon others’ work; and sections devoted to the limitations of the study and future directions. Writing should be polished. Poor wording, grammar and composition frustrate the review process. Our journal does not have copyeditors for revising manuscripts. When authors receive critiques from the referees and associate editor, the authors should provide a detailed point-by-point response to each comment. The authors’ rebuttal should include the text of the original criticism, the authors’ response, and a pasted copy of the modified text along with the line numbers in the revised article. The new text should be highlighted in a different font color in the revised submission. Following these recommendations will improve submissions and facilitate the review process.

60 APPLIED LIFE SCIENCES↗

TH-C-204-02: Improving Manuscript Quality Via Structured Reviews, Enhanced Scientific Category Taxonomy, and Outreach

In this presentation, the Editors will outline our vision for the future of Medical Physics and review recent work-in-progress initiatives to implement this vision. Finally, we will close with guidance to authors on how to write a good Medical Physics paper. A major focus will be the transition to a new publisher in 2017 following a more than 40-year association with American Institute of Physics Publishing (AIPP). Vision for Medical Physics and status of current initiatives: Jeff Williamson, Editor-in-Chief The broad vision of Medical Physics is “to continue the Journal’s tradition of publishing the very best science that propels our discipline forward and improves our contribution to patient care.” More concretely, the Journal should be the preeminent forum for exchange of cutting edge medical physics science. We seek to identify the best contributions in (a) high impact clinical physics innovations; (b) clinical translation and validation of basic science innovations; and (c) cutting edge basic science developments with potential for patient care improvements. Among the challenges and opportunities, we face are: electronic-only and open access publishing; competition from new radiological science journals; trends towards more interactive, social-media based scientific communities; and diversification of the medical physics research, authorship, and readership domains, including clinical applications quite foreign to core ABR clinical competencies. Recently implemented and ongoing initiatives include: Revised Table of Contents (TOC) and more contemporary topical submission categories Structured review template in HTML format Comprehensive hierarchical taxonomy for identifying reviewer expertise Formal process for soliciting high quality and impact Review and Vision 20/20 Articles We have recruited four Review Article Co-editors: John Rowlands and Ingrid Reiser (imaging physics) and Joao Seco and Tim Zhu (therapy physics). The Co-Editors will identify timely topics and solicit high profile authors to submit review manuscripts. To submit an article, authors will need to work with an assigned Co-Editor to develop a mutually acceptable outline and abstract. 5) A new and exciting class of articles: Medical Physics Dataset Articles (MPDAs) MPDAs describe scientifically or clinically valuable open-access datasets with high potential for contributing to the research of medical physicists working on related problems. In contrast to Research Articles, MPDAs should not include hypothesis testing; or data analyses supporting generalizable conclusions. The publically accessible dataset must be permanently archived before the MPDA can be published. This initiative is being led by Joe Deasy. Update on new publisher transition: The transition of AAPM scientific publishing operations to a major publishing house is a major opportunity to expand Medical Physics readership and its scholarly impact. The advantages include: (a) common manuscript management and web hosting platforms for Medical Physics and its sister journal, JACMP; (b) greater than 4-fold expansion of subscribing institutions; and (c) resources to mount data-driven, highly targeted marketing campaigns to enhance citation and download rates. A transition update of this epochal development, which has only begun as of this writing (3/31/16), will be given. Improving manuscript quality via structured reviews, enhanced scientific category taxonomy, and outreach: Shiva Das, Therapy Physics Editor Medical Physics is committed to continuous improvement with the ultimate goal of improving the potential impact of accepted manuscripts. In order to do so, Medical Physics must be able to tap into important/emerging areas and be able to select high quality contributions consistently via discerning reviews. Improving the quality of reviews is crucial to selecting high quality manuscripts and also to improving manuscript impact via feedback in the review process. With this in mind, Medical Physics is in the process of: (a) fostering outreach to important areas that are currently underrepresented in Medical Physics; (b) implementing a structured template review form; and (c) implementing a comprehensive scientific category taxonomy to identify reviewers who are best suited to an article. Outreach efforts have begun to various scientific areas. Strategies to increase submissions from these areas will be discussed. As a consequence of this effort, a special issue on particle therapy is under development. A review template was implemented in late 2014 on a limited test basis. Based on reviewer feedback, the template was restructured and shortened to capture essential review elements. The restructured template is due to be released shortly. The new scientific category taxonomy is in the process of being deployed to reviewers and associate editors. Salient aspects of the structured review template and scientific category taxonomy will be discussed in this talk. Writing good scientific papers and responding to critiques: Mitch Goodsitt, Imaging Physics Editor The essential components of the abstract, introduction, methods, discussion and conclusion sections of manuscripts, as well as the desired writing style and style of the figures and tables will be reviewed. Publishable Medical Physics manuscripts must include clear and concise statements of the novelty and clinical and/or scientific importance of the authors’ work. Examples of novelty include: new technical solution to an important clinical problem; new generalizable knowledge; and first demonstration that an existing engineering solution solves a clinical problem. Please note that we encourage authors of recently published conference proceedings (e.g., SPIE, IEEE) papers on novel medical physics related work to submit more substantial versions of that work to our journal. All submissions must include: sufficient background information and rationale; enough detail for others to reproduce the authors’ work; sufficient statistical analysis to refute or validate the authors’ hypotheses; a description of how the present work compares to, is distinct from, and improves upon others’ work; and sections devoted to the limitations of the study and future directions. Writing should be polished. Poor wording, grammar and composition frustrate the review process. Our journal does not have copyeditors for revising manuscripts. When authors receive critiques from the referees and associate editor, the authors should provide a detailed point-by-point response to each comment. The authors’ rebuttal should include the text of the original criticism, the authors’ response, and a pasted copy of the modified text along with the line numbers in the revised article. The new text should be highlighted in a different font color in the revised submission. Following these recommendations will improve submissions and facilitate the review process.

60 APPLIED LIFE SCIENCES↗

TH-C-204-03: Writing Good Scientific Papers and Responding to Critiques

In this presentation, the Editors will outline our vision for the future of Medical Physics and review recent work-in-progress initiatives to implement this vision. Finally, we will close with guidance to authors on how to write a good Medical Physics paper. A major focus will be the transition to a new publisher in 2017 following a more than 40-year association with American Institute of Physics Publishing (AIPP). Vision for Medical Physics and status of current initiatives: Jeff Williamson, Editor-in-Chief The broad vision of Medical Physics is “to continue the Journal’s tradition of publishing the very best science that propels our discipline forward and improves our contribution to patient care.” More concretely, the Journal should be the preeminent forum for exchange of cutting edge medical physics science. We seek to identify the best contributions in (a) high impact clinical physics innovations; (b) clinical translation and validation of basic science innovations; and (c) cutting edge basic science developments with potential for patient care improvements. Among the challenges and opportunities, we face are: electronic-only and open access publishing; competition from new radiological science journals; trends towards more interactive, social-media based scientific communities; and diversification of the medical physics research, authorship, and readership domains, including clinical applications quite foreign to core ABR clinical competencies. Recently implemented and ongoing initiatives include: Revised Table of Contents (TOC) and more contemporary topical submission categories Structured review template in HTML format Comprehensive hierarchical taxonomy for identifying reviewer expertise Formal process for soliciting high quality and impact Review and Vision 20/20 Articles We have recruited four Review Article Co-editors: John Rowlands and Ingrid Reiser (imaging physics) and Joao Seco and Tim Zhu (therapy physics). The Co-Editors will identify timely topics and solicit high profile authors to submit review manuscripts. To submit an article, authors will need to work with an assigned Co-Editor to develop a mutually acceptable outline and abstract. 5) A new and exciting class of articles: Medical Physics Dataset Articles (MPDAs) MPDAs describe scientifically or clinically valuable open-access datasets with high potential for contributing to the research of medical physicists working on related problems. In contrast to Research Articles, MPDAs should not include hypothesis testing; or data analyses supporting generalizable conclusions. The publically accessible dataset must be permanently archived before the MPDA can be published. This initiative is being led by Joe Deasy. Update on new publisher transition: The transition of AAPM scientific publishing operations to a major publishing house is a major opportunity to expand Medical Physics readership and its scholarly impact. The advantages include: (a) common manuscript management and web hosting platforms for Medical Physics and its sister journal, JACMP; (b) greater than 4-fold expansion of subscribing institutions; and (c) resources to mount data-driven, highly targeted marketing campaigns to enhance citation and download rates. A transition update of this epochal development, which has only begun as of this writing (3/31/16), will be given. Improving manuscript quality via structured reviews, enhanced scientific category taxonomy, and outreach: Shiva Das, Therapy Physics Editor Medical Physics is committed to continuous improvement with the ultimate goal of improving the potential impact of accepted manuscripts. In order to do so, Medical Physics must be able to tap into important/emerging areas and be able to select high quality contributions consistently via discerning reviews. Improving the quality of reviews is crucial to selecting high quality manuscripts and also to improving manuscript impact via feedback in the review process. With this in mind, Medical Physics is in the process of: (a) fostering outreach to important areas that are currently underrepresented in Medical Physics; (b) implementing a structured template review form; and (c) implementing a comprehensive scientific category taxonomy to identify reviewers who are best suited to an article. Outreach efforts have begun to various scientific areas. Strategies to increase submissions from these areas will be discussed. As a consequence of this effort, a special issue on particle therapy is under development. A review template was implemented in late 2014 on a limited test basis. Based on reviewer feedback, the template was restructured and shortened to capture essential review elements. The restructured template is due to be released shortly. The new scientific category taxonomy is in the process of being deployed to reviewers and associate editors. Salient aspects of the structured review template and scientific category taxonomy will be discussed in this talk. Writing good scientific papers and responding to critiques: Mitch Goodsitt, Imaging Physics Editor The essential components of the abstract, introduction, methods, discussion and conclusion sections of manuscripts, as well as the desired writing style and style of the figures and tables will be reviewed. Publishable Medical Physics manuscripts must include clear and concise statements of the novelty and clinical and/or scientific importance of the authors’ work. Examples of novelty include: new technical solution to an important clinical problem; new generalizable knowledge; and first demonstration that an existing engineering solution solves a clinical problem. Please note that we encourage authors of recently published conference proceedings (e.g., SPIE, IEEE) papers on novel medical physics related work to submit more substantial versions of that work to our journal. All submissions must include: sufficient background information and rationale; enough detail for others to reproduce the authors’ work; sufficient statistical analysis to refute or validate the authors’ hypotheses; a description of how the present work compares to, is distinct from, and improves upon others’ work; and sections devoted to the limitations of the study and future directions. Writing should be polished. Poor wording, grammar and composition frustrate the review process. Our journal does not have copyeditors for revising manuscripts. When authors receive critiques from the referees and associate editor, the authors should provide a detailed point-by-point response to each comment. The authors’ rebuttal should include the text of the original criticism, the authors’ response, and a pasted copy of the modified text along with the line numbers in the revised article. The new text should be highlighted in a different font color in the revised submission. Following these recommendations will improve submissions and facilitate the review process.

60 APPLIED LIFE SCIENCES↗

Addressing the characterisation challenge to understand catalysis in MOFs: the case of nanoscale Cu supported in NU-1000

Here, we explore the dynamic structure and reactivity of Cu species supported on NU-1000. By combining pair distribution function (PDF) analysis and difference envelope density (DED) analysis of in situ synchrotron-based X-ray scattering data, we simultaneously probe the local structure of supported Cu-species, their distribution within NU-1000 and distortions of the NU-1000 lattice under conditions relevant to catalysis and catalyst activation. Our analyses show that atomic layer deposition (ALD) of Cu in NU-1000 (Cu-AIM) leads to the formation of Cu-oxo clusters within the small pores that connect the triangular and hexagonal channels. Exposure of Cu-AIM to a reducing atmosphere at 200 °C produces metallic Cu 0 of two distinct particle sizes: ~4 nm nanoparticles and small sub-nanometer clusters. The size of these nanoparticles appears to be constrained by NU-1000 pore dimensions, with evidence of the sub-nanometer clusters being bound within the triangular channels flanked by pyrene rings. This supported Cu 0 –NU-1000 system is catalytically active for gas-phase ethylene hydrogenation. Exposure of the catalyst to oxidative atmosphere re-oxidises the Cu species to a Cu 2 O cuprite phase. The dynamic restructuring of the system in different chemical environments underscores the importance of probing these systems in situ .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Compare predictions of transient fission gas release by empirical and mechanistic models to experiments in high burnup UO 2 fuel

Understanding and predicting fuel performance at high burnup require improving our understanding of transient fission gas release. High-burnup operations enable new mechanisms of fission gas release, which affect fuel performance. The Nuclear Regulatory Commission has recently published its interpretation of existing fuel fragmentation, relocation, and dispersal data in a research information letter. There, transient fission gas release was identified as one of the main factors that contributes to fuel fragmentation, relocation, and dispersal, and therefore limits fuel extension to high burnup. However, transient fission gas release is a complex phenomenon that cannot be fully described by simple empirical descriptions. This report summarizes the development of a mechanistic model for high-burnup transient fission gas release in the fuel performance code BISON. This research was supported by the Nuclear Energy Advanced Modeling and Simulation program during fiscal year 2023 to improve our understanding of high-burnup transient fission gas release and ability to predict it as a function of operation history. To support the development of a mechanistic transient fission gas release model, the existing Simple Integrated Fission Gas Release and Swelling (Sifgrs) model in BISON has been completely refactored to make it more modular and extensible. This effort supports the model's application to high-burnup conditions, its extension to other fuel forms, and the continuous improvement of its current features. Once refactoring was completed, models for high-burnup structure formation, fission gas transfer from non-restructured fuel to high-burnup structure, high-burnup structure intragranular and intergranular fission gas behavior, high-burnup structure bubble evolution, fuel pulverization, and the resulting transient fission gas release were tested and implemented in the Simple Integrated Fission Gas Release and Swelling (Sifgrs) model or tightly coupled to it. The new mechanistic model was then compared to an empirical model developed in parallel by a Nuclear Energy University Program project using a Studsvik high-burnup loss-of-coolant-accident assessment case. Finally, the report details the preliminary BISON results for a benchmark activity organized by the Nuclear Energy Agency to evaluate fuel performance codes' predictive capabilities for burst fission gas release. This work represents an important step toward a mechanistic understanding of fission gas release in high-burnup conditions.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

xSDK: Building an ecosystem of highly efficient math libraries for exascale

Current efforts to build increasingly powerful computer architectures are opening up new avenues for more complex and higher fidelity simulations coupled with data analytics and learning, leading to new scientific insights and deeper understanding. At one extreme, exascale computers will be much faster than previous computer generations (performing 10 18 operations per second—that is, 1,000 times faster than petascale). To achieve these performance improvements, computer architectures are becoming increasingly complex, with deep memory hierarchies, very high node and core counts, and heterogeneous features such as graphics processing units (GPUs). Such architectural changes impact the full breadth of computing scales, as heterogeneity pervades even current-generation laptops, workstations, and moderate-sized clusters. While emerging advanced architectures provide unprecedented opportunities, they also present significant challenges for developers of scientific applications, such as multiphysics and multiscale codes, who must adapt their software to handle disruptive changes in architectures and new programming models that have not yet stabilized. Developers must consider increasing concurrency while reducing communication and synchronization, and other complexities such as the potential for using mixed precision to leverage the compute power available in low-precision tensor cores. On one hand, developers must implement new scientific capabilities, which in turn increase code complexity. On the other hand, the codes must be ported to new architectures, requiring the inclusion of new programming models and the restructuring of code to achieve good performance. Addressing these issues is beyond the capability of any single person or team—leading to the need for collaboration among many teams, who encapsulate their expertise in reusable software and work together to create sustainable software ecosystems.

97 MATHEMATICS AND COMPUTING↗

Introduction to Space Station Freedom

NASA field centers and contractors are organized to develop 'work packages' for Space Station Freedom. Marshall Space Flight Center and Boeing are building the U.S. laboratory and habitation modules, nodes, and environmental control and life support system; Johnson Space Center and McDonnell Douglas are responsible for truss structure, data management, propulsion systems, thermal control, and communications and guidance; Lewis Research Center and Rocketdyne are developing the power system. The Canadian Space Agency (CSA) is contributing a Mobile Servicing Center, Special Dextrous Manipulator, and Mobile Servicing Center Maintenance Depot. The National Space Development Agency of Japan (NASDA) is contributing a Japanese Experiment Module (JEM), which includes a pressurized module, logistics module, and exposed experiment facility. The European Space Agency (ESA) is contributing the Columbus laboratory module. NASA ground facilities, now in various stages of development to support Space Station Freedom, include: Marshall Space Flight Center's Payload Operations Integration Center and Payload Training Complex (Alabama), Johnson Space Center's Space Station Control Center and Space Station Training Facility (Texas), Lewis Research Center's Power System Facility (Ohio), and Kennedy Space Center's Space Station Processing Facility (Florida). Budget appropriations impact the development of the Space Station. In Fiscal Year 1988, Congress appropriated only half of the funds that NASA requested for the space station program ($393 million vs. $767 million). In FY 89, NASA sought $967 million for the program, and Congress appropriated $900 million. NASA's FY 90 request was $2.05 billion compared to an appropriation of $1.75 billion; the FY 91 request was $2.45 billion, and the appropriation was $1.9 billion. After NASA restructured the Space Station Freedom program in response to directions from Congress, the agency's full budget request of $2.029 billion for Space Station Freedom in FY 92 was appropriated. For FY 93, NASA is seeking $2.25 billion for the program; the planned budget for FY 94 is $2.5 billion. Further alterations to the hardware configuration for Freedom would be a serious setback; NASA intends 'to stick with the current baseline' and continue planning for utilization.

Kohrs, Richard↗

Towards the Structure Determination of a Modulated Protein Crystal: The Semicrystalline State of Profilin:Actin

One of the remaining challenges to structural biology is the solution of modulated structures. While small molecule crystallographers have championed this type of structure, to date, no modulated macromolecular structures have been determined. Modulation of the molecular structures within the crystal can produce satellite reflections or a superlattice of reflections in reciprocal space. We have developed the data collection methods and strategies that are needed to collect and analyze these data. If the macromolecule's crystal lattice is composed of physiologically relevant packing contacts, structural changes induced under physiological conditions can cause distortion relevant to the function and biophysical processes of the molecule making up the crystal. By careful measurement of the distortion, and the corresponding three-dimensional structure of the distorted molecule, we will visualize the motion and mechanism of the biological macromolecule(s). We have measured the modulated diffraction pattern produced by the semicrystalline state of profilin:actin crystals using highly parallel and highly monochromatic synchrotron radiation coupled with fine phi slicing (0.001-0.010 degrees) for structure determination. These crystals present these crystals present a unique opportunity to address an important question in structural biology. The modulation is believed to be due to the formation of actin helical filaments from the actin beta ribbon upon the pH-induced dissociation of profilin. To date, the filamentous state of actin has resisted crystallization and no detailed structures are available. The semicrystalline state profilin:actin crystals provides a unique opportunity to understand the many conformational states of actin. This knowledge is essential for understanding the dynamics underlying shape changes and motility of eukaryotic cells. Many essential processes, such as cytokinesis, phagocytosis, and cellular migration depend upon the capacity of the actin microfilament system to be restructured in a controlled manner via polymerization, depolymerization, severing, cross-linking, and anchorage. The structure the semicrystalline state of profilin:actin will challenge and validate current models of muscle contraction and cell motility. The methodology and theory under development will be easily extendable to other systems.

Borgstahl, G.↗

Current Sheet Evolution In The Aftermath Of A CME Event

We report on SOHO UVCS observations of the coronal restructuring following a coronal mass ejection (CME) on 2002 November 26, at the time of a SOHO-Ulysses quadrature campaign. Starting about 1.5 hr after a CME in the northwest quadrant, UVCS began taking spectra at 1.7 R, covering emission from both cool and hot plasma. Observations continued, with occasional gaps, for more than 2 days. Emission in the 974.8 A line of [Fe XVIII], indicating temperatures above 6 x 10(exp 6) K, was observed throughout the campaign in a spatially limited location. Comparison with EIT images shows the [Fe XVIII] emission to overlie a growing post-flare loop system formed in the aftermath of the CME. The emission most likely originates in a current sheet overlying the arcade. Analysis of the [Fe XVIII] emission allows us to infer the evolution of physical parameters in the current sheet over the entire span of our observations: in particular, we give the temperature versus time in the current sheet and estimate its density. At the time of the quadrature, Ulysses was directly above the location of the CME and intercepted the ejecta. High ionization state Fe was detected by the Ulysses SWICS throughout the magnetic cloud associated with the CME, although its rapid temporal variation suggests bursty, rather than smooth, reconnection in the coronal current sheet. The SOHO-Ulysses data set provided us with the unique opportunity of analyzing a current sheet structure from its lowest coronal levels out to its in situ properties. Both the remote and in situ observations are compared with predictions of theoretical CME models.

Bemporad, A.↗

Radiation and Nuclear Technology in Planetary Cave Environments

Many technological and environmental challenges must be resolved to enable successful lunar habitation and exploration, and to maximize scientific return. This presentation is intended as a preliminary discussion on three such areas of interest with the intent to identify likely areas of mutual benefit for collaboration and data sharing between the space nuclear and radiological disciplines with the planetary cave community. First is the previously identified and studied possible application of lunar lava tubes or pits to reduce the solar and cosmic radiation environment burden on crew health and hardware reliability. This is an area of continued interest, and should be kept in the forefront of discussion during the selection of sites for potential exploration or long-term habitation. In theory, the prospect of using existing morphology presents an enticing opportunity to reduce the requirements on landed mass or construction while also reducing dose or fluence of harmful natural radiation. However, such discussions should also include the practical implications of relocating habitation hardware and personnel from a landing site to a subsurface location. Inherent risks associated with landing in proximity to the relevant terrain must also be considered and weighed against those imposed by the natural radiation environment. Second is a discussion on the means by which a long-term habitation module or base of operations may be powered throughout the lunar day-night cycle. Fission surface power presents an opportunity to establish round-the-clock power in any lunar surface environment, including permanently shadowed regions where solar panels cannot operate, or in any other non-polar region where solar radiation is available for no more than two weeks per four-week cycle. Among the drawbacks of fission surface power is the need to either land and co-locate a heavy shield to minimize radiological consequences to personnel or equipment, land and operate construction equipment capable of restructuring the in-situ regolith to provide appropriate shielding, or to make use of existing topology features (e.g. craters or pits) to serve as pre-formed radiation barriers. A realistic assessment of the practicality of this third option should involve the selection of candidate features from existing surveys, and assess the effectiveness of the approach using modern radiation transport methodologies. Consideration must be made for the needs to reject waste heat in the thermal power conversion process, which typically requires the use of large area radiators. Energy must be exchanged from the reactor and power conversion system to such radiators, and the impacts on thermal efficiency and secondary scatter of nuclear radiation must be considered. Further consideration should be made for the implications of placement of a power source such that it does not sacrifice valuable scientific opportunity. Placement of a reactor is likely to thereafter prevent personnel access within that feature. Third is a discussion on the use of portable radioisotope power systems (RPS) within confined spaces, both with respect to the dose effects of emitted nuclear radiation and also performance associated with emitted thermal radiation. Radioisotope power systems provide a unique capability to power objects with no reliance upon solar radiance. However, their useable power production relies upon the flow of heat from ‘hot side’ (decaying radioisotope) to ‘cold side’ (radiators emitting heat to space). In the case of a confined volume in vacuum such as a lunar lava tube, that radiated energy will absorb into the wall, which is already above the ‘cold background’ temperature of dark space, and then gradually rises in temperature. That temperature rise, and its implications on availability of useable electrical power, will depend upon factors such as enclosure volume, thermal emissivity/absorptivity, and thermal conductivity through the depth of absorbing media. The advantages of nuclear technology may prove to enable unique scientific exploration opportunities, both above the lunar surface and below. In turn, the unique advantages of lunar lava tubes or pits may present unique opportunities to enhance the application of these technologies and to mitigate the effects of radiation from both natural and technological sources. A discussion on these pairings may prove to be valuable to all, in our endeavor to explore our neighboring worlds.

Radiation↗

Elucidating Abnormal Grain Growth in Thermomagnetic Processed Materials with Transfer Learning and Reinforcement Learning

The goal of this research program is to establish the mechanism governing local grain boundary motion, which is needed to design and process desirable microstructures for better performance, by identifying the relative contributions of grain boundary (GB) energy and mobility to grain growth. Classical models for grain growth assume that the primary mechanism for reducing the total interfacial energy is area reduction and that GB restructuring is not significant. This assumption implies that grain growth is locally driven by curvature. However, recent experimental observations using new non-destructive 3D x-ray diffraction microscopy techniques (3D-XRM) reveal that classic descriptors (i.e., curvature, number of neighbors, grain size) do not predict real grain growth. Instead, local GB motion appears to be governed by its energy relative to its neighbors such that low-energy boundaries replace those of higher energy. However, simulations that incorporate GB energy anisotropy still fail to reproduce these observations. These discrepancies suggest that the common assumption for grain growth theory must be re-examined to predict and, thus, control microstructure evolution in real polycrystals. A significant challenge to testing this assumption is due to anisotropic GB mobility. Mobility may cause abnormal grain growth or affect the final grain shapes or growth rate but its true contributions are unknown because it is difficult to measure. For example, observations in Fe have found that grains associated with high energy and high mobility boundaries tend to experience abnormal grain growth, whereas abnormal grain growth is associated with low energy and high mobility boundaries in alumina. As mobility and energy both control GB motion, it is challenging to isolate the local driving forces necessary to test the common assumption that the primary mechanism is area reduction. The novelty of this work is the use of machine learning tools to capture GB mobility and energy from 3D-XRM measurements in polycrystals to test the common assumption used in grain growth models. Machine learning can capture high-order correlations in dynamic systems like those found in the evolving GB topology. The PIs have developed a physics-regularized interpretable machine learning microstructure evolution (PRIMME) model that accurately replicates the grain growth behavior of its trained data set.

36 MATERIALS SCIENCE↗

Transportation Hub Infrastructure Expansion: Decision Support Under Uncertainty

The Athena project (www.athena-mobility.org) has worked to investigate the relationship between the Dallas-Fort Worth Airport (DFW) and the greater Dallas area in order to better understand and therefore better inform future decision-making regarding the critical infrastructure that influence mobility between the airport and the city. Through this work, infrastructure related to curbside pickup and drop-off, parking, public transit, and the road network congestion were identified as critical to the operation of the DFW transportation hub. The infrastructure analysis and expansion aspect of the Athena project is focused on the restructuring of the CTA curb as a hierarchical curb and the building or repurposing of parking infrastructure as the interplay between these two areas. Many sources of uncertainty exist that may impact future airport and transportation hub operations, such as passenger volume growth, population demographic changes over time, electric vehicle (EV) adoption rates, and autonomous vehicle (AV) adoption rates. Due to these sources of uncertainty, we have selected for our research a modeling framework that can capture various types of uncertainty and hedge against those uncertainties in the optimization process. We analyze road network and curb congestion, the rise of transportation networking companies, trends in parking usage, existing policies around this infrastructure, airport revenue streams, and other contributing factors to enable infrastructure decision making with less uncertainty. To accomplish this wholistic analysis, we have developed a novel multi-stage, multi-period stochastic optimization model which considers the airport's decisions from 2025-2045 under different possible future macro trajectories and day-to-day variations in operational conditions captured as "annual representation of operations" scenarios with respective probabilities. This model has also been designed to leverage the outputs of various efforts under the Athena project to create a combined decision framework for infrastructure decisions. These various efforts include the route optimization model, the ASPIRES simulation, the mode choice model, and the SUMO traffic simulation. Our computational experiments of this system at scale have resulted in a working version of our infrastructure model which enables the explicit representation and consideration of various sources of uncertainty in the decision process to enable robust, flexible decision-making. This model has been effectively run on NREL's HPC system, Eagle, with large numbers of stochastic scenarios and shows promise as a scalable tool for robust consideration of uncertainties in airport planning. We have tested our model using 30,240 operational circumstances in total, resulting in a problem with more 200 million variables. This model was solved in several different configurations, and a workflow to simulate the performance of the infrastructure model results was developed and deployed. In general, our results indicate that a combination of remote parking, remote curb infrastructure, and dynamic pricing can generate revenue, reduce emissions, accommodate emerging technologies such as AVs and EVs, and manage airport passenger growth over time. We note the success of the proposed strategy depends on the data collection and forecasting abilities of DFW. We have also seen that the AV adoption by TNCs might necessitate larger amounts of remote curb. The results of this work inform strategies for airport infrastructure decision making, as well as demonstrate the value of an adaptable model, but also indicate that there are avenues remaining where further research would be of value.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗