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At least 1,189 records · Page 66

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DOE OSTI2014

Prenatal caffeine ingestion induces transgenerational neuroendocrine metabolic programming alteration in second generation rats

Our previous studies have demonstrated that prenatal caffeine ingestion induces an increased susceptibility to metabolic syndrome with alterations of glucose and lipid metabolic phenotypes in adult first generation (F1) of intrauterine growth retardation (IUGR) rats, and the underlying mechanism is originated from a hypothalamic–pituitary–adrenal (HPA) axis-associated neuroendocrine metabolic programming alteration in utero. This study aims to investigate the transgenerational effects of this programming alteration in adult second generation (F2). Pregnant Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. Four groups in F2 were set according to the cross-mating between control and caffeine-induced IUGR rats. F2 were subjected to a fortnight ice water swimming stimulus on postnatal month 4, and blood samples were collected before and after stress. Results showed that the majority of the activities of HPA axis and phenotypes of glucose and lipid metabolism were altered in F2. Particularly, comparing with the control group, caffeine groups had an enhanced corticosterone levels after chronic stress. Compared with before stress, the serum glucose levels were increased in some groups whereas the triglyceride levels were decreased. Furthermore, total cholesterol gain rates were enhanced but the high-density lipoprotein-cholesterol gain rates were decreased in most caffeine groups after stress. These transgenerational effects were characterized partially with gender and parental differences. Taken together, these results indicate that the reproductive and developmental toxicities and the neuroendocrine metabolic programming mechanism by prenatal caffeine ingestion have transgenerational effects in rats, which may help to explain the susceptibility to metabolic syndrome and associated diseases in F2. - Highlights: • Caffeine-induced neuroendocrine metabolic programming of HPA has hereditary effect. • Caffeine-induced reproductive and developmental toxicities in F1 have hereditary effect. • Caffeine-induced programming of HPA axis in F2 has gender and parental differences.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2014

An expert computer program for classifying stars on the MK spectral classification system

This paper describes an expert computer program (MKCLASS) designed to classify stellar spectra on the MK Spectral Classification system in a way similar to humans—by direct comparison with the MK classification standards. Like an expert human classifier, the program first comes up with a rough spectral type, and then refines that spectral type by direct comparison with MK standards drawn from a standards library. A number of spectral peculiarities, including barium stars, Ap and Am stars, λ Bootis stars, carbon-rich giants, etc., can be detected and classified by the program. The program also evaluates the quality of the delivered spectral type. The program currently is capable of classifying spectra in the violet-green region in either the rectified or flux-calibrated format, although the accuracy of the flux calibration is not important. We report on tests of MKCLASS on spectra classified by human classifiers; those tests suggest that over the entire HR diagram, MKCLASS will classify in the temperature dimension with a precision of 0.6 spectral subclass, and in the luminosity dimension with a precision of about one half of a luminosity class. These results compare well with human classifiers.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

NCRP Program Area Committee 2: Operational Radiation Safety

Program Area Committee 2 of the National Council on Radiation Protection and Measurements provides guidance for radiation safety in occupational settings in a variety of industries and activities. The committee completed three reports in recent years covering recommendations for the development and administration of radiation safety programs for smaller educational institutions, requirements for self-assessment programs that improve radiation safety and identify and correct deficiencies, and a comprehensive process for effective investigation of radiological incidents. Ongoing work includes a report on sealed radioactive source controls and oversight of a report on radioactive nanomaterials focusing on gaps within current radiation safety programs. Future efforts may deal with operational radiation safety programs in fields such as the safe use of handheld and portable X-Ray fluorescence analyzers, occupational airborne radioactive contamination, unsealed radioactive sources, or industrial accelerators.

Operational Radiation Safety↗

DOE OSTI2015

Understanding Portability of a High-Level Programming Model on Contemporary Heterogeneous Architectures

Accelerator-based heterogeneous computing is gaining momentum in the high-performance computing arena. However, the increased complexity of heterogeneous architectures demands more generic, high-level programming models. OpenACC is one such attempt to tackle this problem. Although the abstraction provided by OpenACC offers productivity, it raises questions concerning both functional and performance portability. In this article, the authors propose HeteroIR, a high-level, architecture-independent intermediate representation, to map high-level programming models, such as OpenACC, to heterogeneous architectures. They present a compiler approach that translates OpenACC programs into HeteroIR and accelerator kernels to obtain OpenACC functional portability. They then evaluate the performance portability obtained by OpenACC with their approach on 12 OpenACC programs on Nvidia CUDA, AMD GCN, and Intel Xeon Phi architectures. They study the effects of various compiler optimizations and OpenACC program settings on these architectures to provide insights into the achieved performance portability.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2017

Estimating the Impacts of Direct Load Control Programs Using GridPIQ, a Web-Based Screening Tool

In direct load control (DLC) programs, utilities can curtail the demand of participating loads to contractually agreed-upon levels during periods of critical peak load, thereby reducing stress on the system, generation cost, and required transmission and generation capacity. Participating customers receive financial incentives. The impacts of implementing DLC programs extend well beyond peak shaving. There may be a shift of load proportional to the interrupted load to the times before or after a DLC event, and different load shifts have different consequences. Tools that can quantify the impacts of such programs on load curves, peak demand, emissions, and fossil fuel costs are currently lacking. The Grid Project Impact Quantification (GridPIQ) screening tool includes a Direct Load Control module, which takes into account project-specific inputs as well as the larger system context in order to quantify the impacts of a given DLC program. This allows users (utilities, researchers, etc.) to test and compare different program specifications and their impacts.

Demand Reponse↗

DOE OSTI2018

Long‐term evaluation of fitness and demographic effects of a Chinook Salmon supplementation program

Abstract While the goal of supplementation programs is to provide positive, population‐level effects for species of conservation concern, these programs can also present an inherent fitness risk when captive‐born individuals are fully integrated into the natural population. In order to evaluate the long‐term effects of a supplementation program and estimate the demographic and phenotypic factors influencing the fitness of a threatened population of Chinook Salmon ( Oncorhynchus tshawytscha ), we genotyped tissue samples spanning a 19‐year period (1998–2016) to generate pedigrees from adult fish returning to Johnson Creek, Idaho, USA. We expanded upon previous estimates of relative reproductive success (RRS) to include grandparentage analyses and used generalized linear models to determine whether origin (hatchery or natural) or phenotypic traits (timing of arrival to spawning grounds, body length, and age) significantly predicted reproductive success (RS) across multiple years. Our results provide evidence that this supplementation program with 100% natural‐origin broodstock provided a long‐term demographic boost to the population (mean of 4.56 times in the first generation and mean of 2.52 times in the second generation). Overall, when spawning in nature, hatchery‐origin fish demonstrated a trend toward lower RS compared to natural‐origin fish ( p < 0.05). However, when hatchery‐origin fish successfully spawned with natural‐origin fish, they had similar RS compared to natural by natural crosses (first‐generation mean hatchery by natural cross RRS = 1.11 females, 1.13 males; second‐generation mean hatchery by natural cross RRS = 1.03 females, 1.08 males). While origin, return year, and body length were significant predictors of fitness for both males and females ( p < 0.05), return day was significant for males but not females ( p > 0.05). These results indicate that supplementation programs that reduce the potential for genetic adaptation to captivity can be effective at increasing population abundance while limiting long‐term fitness effects on wild populations.

Janowitz‐Koch, Ilana↗

DOE OSTI2015

Scalable control program for multiprecursor flow-type atomic layer deposition system

The authors report the development and implementation of a scalable control program to control flow type atomic layer deposition (ALD) reactor with multiple precursor delivery lines. The program logic is written and tested in LABVIEW environment to control ALD reactor with four precursor delivery lines to deposit up to four layers of different materials in cyclic manner. The programming logic is conceived such that to facilitate scale up for depositing more layers with multiple precursors and scale down for using single layer with any one precursor in the ALD reactor. The program takes precursor and oxidizer exposure and purging times as input and controls the sequential opening and closing of the valves to facilitate the complex ALD process in cyclic manner. The program could be used to deposit materials from any single line or in tandem with other lines in any combination and in any sequence.

42 ENGINEERING↗

DOE OSTI2015

SU-B-213-03: Evaluation of Graduate Programs

The North American medical physics community validates the education received by medical physicists and the clinical qualifications for medical physicists through accreditation of educational programs and certification of medical physicists. Medical physics educational programs (graduate education and residency education) are accredited by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP), whereas medical physicists are certified by several organizations, the most familiar of which is the American Board of Radiology (ABR). In order for an educational program to become accredited or a medical physicist to become certified, the applicant must meet certain specified standards set by the appropriate organization. In this Symposium, representatives from both CAMPEP and the ABR will describe the process by which standards are established as well as the process by which qualifications of candidates for accreditation or certification are shown to be compliant with these standards. The Symposium will conclude with a panel discussion. Learning Objectives: Recognize the difference between accreditation of an educational program and certification of an individual Identify the two organizations primarily responsible for these tasks Describe the development of educational standards Describe the process by which examination questions are developed GS is Executive Secretary of CAMPEP.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2015

SU-B-213-04: Evaluation of Residency Programs

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2015

MO-DE-BRA-02: From Teaching to Learning: Systems-Based-Practice and Practice-Based-Learning Innovations in Medical Physics Education Programs

Purpose: The increasing complexity in the field of radiation medicine and concomitant rise in patient safety concerns call for enhanced systems-level training for future medical physicists and thus commensurate innovations in existing educational program curricula. In this work we report on the introduction of three learning opportunities to augment medical physics educational programs towards building systems-based practice and practice-based learning competencies. Methods: All initiatives were introduced for senior -level graduate students and physics residents in an institution with a newly established medical-physics graduate program and therapeutic-physics residency program. The first, centered on incident learning, was based on a spreadsheet tool that incorporated the reporting structure of the Radiation Oncology-incident Learning System (ROILS), included 120 narratives of published incidents and enabled inter-rater variability calculations. The second, centered on best-practices, was a zero-credit seminar course, where students summarized select presentations from the AAPM virtual library on a weekly basis and moderated class discussions using a point/counterpoint approach. Presentation styles were critiqued. The third; centered on learning-by-teaching, required physics residents to regularly explain fundamental concepts in radiological physics from standard textbooks to board certified physics faculty members. Results: Use of the incident-learning system spreadsheet provided a platform to recast known accidents into the framework of ROILS, thereby increasing awareness of factors contributing to unsafe practice and appreciation for inter-rater variability. The seminar course enhanced awareness of best practices, the effectiveness of presentation styles and encouraged critical thinking. The learn-by-teaching rotation allowed residents to stay abreast of and deepen their knowledge of relevant subjects. Conclusion: The incorporation of systems-driven initiatives broadens comprehension of the wider systems context of medical physics, enhances awareness of resources for innovation, communication and sustained learning while maintaining a metric-driven focus on patient safety within the formative phase of student careers. The initiatives were well-received, feasible, and utilized available or shared-resources translatable across educational programs.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-G-TeP4-11: Implementation of a Non-Measurement-Based Patient-Specific IMRT QA Program

Purpose: To implement a comprehensive non-measurement-based verification program for patient-specific IMRT QA Methods: Based on published guidelines, a robust IMRT QA program should assess the following components: 1) accuracy of dose calculation, 2) accuracy of data transfer from the treatment planning system (TPS) to the record-and-verify (RV) system, 3) treatment plan deliverability, and 4) accuracy of plan delivery. Results: We have implemented an IMRT QA program that consist of four components: 1) an independent re-calculation of the dose distribution in the patient anatomy with a commercial secondary dose calculation program: Mobius3D (Mobius Medical Systems, Houston, TX), with dose accuracy evaluation using gamma analysis, PTV mean dose, PTV coverage to 95%, and organ-at-risk mean dose; 2) an automated in-house-developed plan comparison system that compares all relevant plan parameters such as MU, MLC position, beam iso-center position, collimator, gantry, couch, field size settings, and bolus placement, etc. between the plan and the RV system; 3) use of the RV system to check the plan deliverability and further confirm using “mode-up” function on treatment console for plans receiving warning; and 4) implementation of a comprehensive weekly MLC QA, in addition to routine accelerator monthly and daily QA. Among 1200 verifications, there were 9 cases of suspicious calculations, 5 cases of delivery failure, no data transfer errors, and no failure of weekly MLC QA. These 9 suspicious cases were due to the PTV extending to the skin or to heterogeneity correction effects, which would not have been caught using phantom measurement-based QA. The delivery failure was due to the rounding variation of MLC position between the planning system and RV system. Conclusion: A very efficient, yet comprehensive, non-measurement-based patient-specific QA program has been implemented and used clinically for about 18 months with excellent results.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

A Programming Framework for Neuromorphic Systems with Emerging Technologies

Neuromorphic computing is a promising post-Moore's law era technology. A wide variety of neuromorphic computer (NC) architectures have emerged in recent years, ranging from traditional fully digital CMOS to nanoscale implementations with novel, beyond CMOS components. There are already major questions associated with how we are going to program and use NCs simply because of how radically different their architecture is as compared with the von Neumann architecture. When coupled with the implementations using emerging device technologies, which add additional issues associated with programming devices, it is clear that we must define a new way to program and develop for NC devices. In this work, we discuss a programming framework for NC devices implemented with emerging technologies. We discuss how we have applied this framework to program a NC system implemented with metal oxide memristors. We utilize the framework to develop two applications for the memristive NC device: a simple multiplexer and a simple control task (the cart-pole problem). Finally, we discuss how this framework can be extended to NC systems implemented with a variety of novel device components and materials.

Schuman, Catherine↗

DOE OSTI2023

A MultiGPU Performance-Portable Solution for Array Programming Based on Kokkos

Today, multiGPU nodes are widely used in high-performance computing and data centers. However, current programming models do not provide simple, transparent, and portable support for automatically targeting multiple GPUs within a node on application areas of array programming. In this paper, we describe a new application programming interface based on the Kokkos programming model to enable array computation on multiple GPUs in a transparent and portable way across both NVIDIA and AMD GPUs. We implement different variations of this technique to accommodate the exchange of stencils (array boundaries) among different GPU memory spaces, and we provide autotuning to select the proper number of GPUs, depending on the computational cost of the operations to be computed on arrays, that is completely transparent to the programmer. We evaluate our multiGPU extension on Summit (#5 TOP500), with six NVIDIA V100 Volta GPUs per node, and Crusher that contains identical hardware/software as Frontier (#1 TOP500), with four AMD MI250X GPUs, each with 2 Graphics Compute Dies (GCDs)for a total of 8 GCDs per node. We also compare the performance of this solution against the use of MPI + Kokkos, which is the cur-rent de facto solution for multiple GPUs in Kokkos. Our evaluation shows that the new Kokkos solution provides good scalability for many GPUs and a faster and simpler solution (from a programming productivity perspective) than MPI + Kokkos.

Valero Lara, Pedro↗

DOE OSTI2023

CHARM-SYCL: New Unified Programming Environment for Multiple Accelerator Types

Addressing performance portability across diverse accelerator architectures has emerged as a major challenge in the development of application and programming systems for high-performance computing environments. Although recent programming systems that focus on performance portability have significantly improved productivity in an effort to meet this challenge, the problem becomes notably more complex when compute nodes are equipped with multiple accelerator types—each with unique performance attributes, optimal data layout, and binary formats. To navigate the intricacies of multi-accelerator programming, we propose CHARM-SYCL as an extension of our CHARM multi-accelerator execution environment [27]. This environment will combine our SYCL-based performance-portability programming front end with a back end for extremely heterogeneous architectures as implemented with the IRIS runtime from Oak Ridge National Laboratory. Our preliminary evaluation indicates potential productivity boost and reasonable performance compared to vendor-specific programming system and runtimes.

Fujita, Norihisa↗

DOE OSTI2019

DaCe - Data Centric Parallel Programming

DaCe is a parallel programming framework that takes code in Python/NumPy and other programming languages, and maps it to high-performance CPU, GPU, and FPGA programs, which can be optimized to achieve state-of-the-art. Internally, DaCe uses the Stateful DataFlow multiGraph (SDFG) data-centric intermediate representation: A transformable, interactive representation of code based on data movement. Since the input code and the SDFG are separate, it is possible to optimize a program without changing its source, so that it stays readable. On the other hand, transformations are customizable and user-extensible, so they can be written once and reused in many applications. With data-centric parallel programming, we enable direct knowledge transfer of performance optimization, regardless of the application or the target processor.

Ben-Nun, Tal↗

DOE OSTI2023

The Benefits of a Software Bill of Materials Program at Nuclear Facilities

Software supply chain attacks are becoming increasingly more prevalent in both information communications technology and operational technology environments. Often, a supplier or other entity discloses vulnerability information about software components and subcomponents used in a digital asset, but an asset owner is unable to quickly ascertain if the vulnerable component is installed in their facility. The generation and use of a software bill of materials (SBOM) for installed digital assets can enable an asset owner to quickly identify if and where a component is used, allowing them to evaluate the risk and determine necessary risk treatments. The integration of an SBOM program into a nuclear facility not only improves vulnerability management and risk management processes, it also benefits asset and configuration management, cybersecurity, and supply chain programs. This paper reviews the U.S. Department of Energy Office of Nuclear Energy Cybersecurity Crosscutting Technology Development program’s work on integrating an SBOM program into a nuclear facility. It also provides a discussion on the benefits of such a program.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2025

Business Models for Scaling Demand Flexibility Volume III – Stakeholder ecosystem management challenges, and lessons learned from U.S. programs

Load growth at the grid edge is driving increased attention to the distribution system and its ability to enable customer technology adoption in an affordable and timely manner. Key industry stakeholders, including electric utilities and regulators, can benefit from strategies to manage and balance customer needs with infrastructure investments, such as demand flexibility. This report focuses on demand flexibility—the ability to reduce, shift, shed, generate, or modulate loads in response to building and grid needs—to reduce the need for costly grid upgrades by deferring investment needs and increase system reliability by shifting electricity usage during periods of high risk. Specifically, we focus on the emerging characteristics of business models for demand flexibility as a framework to understand how demand flexibility programs generate value. In this report, we focus on demand flexibility program stakeholder ecosystem management strategies, which provide information on value delivery and describe how program implementers leverage partner capabilities and collaborate to deliver customer and grid benefits. This report discusses the role of stakeholder ecosystem management in demand flexibility programs, identifies existing challenges to effective stakeholder management, and describes lessons learned. This report is part of a series that includes reports on value propositions, customer relationship management strategies, and program life cycle.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2014

HTR-PROTEUS pebble bed experimental program cores 9 & 10: columnar hexagonal point-on-point packing with a 1:1 moderator-to-fuel pebble ratio

PROTEUS is a zero-power research reactor based on a cylindrical graphite annulus with a central cylindrical cavity. The graphite annulus remains basically the same for all experimental programs, but the contents of the central cavity are changed according to the type of reactor being investigated. Through most of its service history, PROTEUS has represented light-water reactors, but from 1992 to 1996 PROTEUS was configured as a pebble-bed reactor (PBR) critical facility and designated as HTR-PROTEUS. The nomenclature was used to indicate that this series consisted of High Temperature Reactor experiments performed in the PROTEUS assembly. During this period, seventeen critical configurations were assembled and various reactor physics experiments were conducted. These experiments included measurements of criticality, differential and integral control rod and safety rod worths, kinetics, reaction rates, water ingress effects, and small sample reactivity effects (Ref. 3). HTR-PROTEUS was constructed, and the experimental program was conducted, for the purpose of providing experimental benchmark data for assessment of reactor physics computer codes. Considerable effort was devoted to benchmark calculations as a part of the HTR-PROTEUS program. References 1 and 2 provide detailed data for use in constructing models for codes to be assessed. Reference 3 is a comprehensive summary of the HTR-PROTEUS experiments and the associated benchmark program. This document draws freely from these references. Only Cores 9 and 10 are evaluated in this benchmark report due to similarities in their construction. The other core configurations of the HTR-PROTEUS program are evaluated in their respective reports as outlined in Section 1.0. Cores 9 and 10 were evaluated and determined to be acceptable benchmark experiments.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗