Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “challenges”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,639 records · Page 91
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

De-starring Challenging Cygnus Data: A Comparison of Three Methods

This report addresses recent questions concerning the RadPro de-starring process. Ultimately, the issues that gave rise to the questions proved to be unrelated to the de-starring process. However, the nature of the questions exposed some misunderstanding on how to evaluate de-starring results. A fundamental of the de-starring process is that not every data point that is extracted as a star is actually a star. This work applies and compares three different methods to very challenging data to illustrate how to evaluate de-starring results. These three methods include (1) the procedure in RadPro, (2) a version of StarStats8, and (3) a method found in the literature by Abel Diaz (L.A. Cosmic), that was developed for astrophysical applications by Pieter G. van Dokkum. In L.A. Cosmic the radiation stars are generated by cosmic-ray hits and the data of interest are true physical stars and galaxies. Dokkum’s work is heavily referenced and appears in over 1,000 citations; a scholarly article on the topic describes it. The term de-starring will include removing cosmic-ray hits from such data. Another de-starring application, developed by Archambault et al. at the M. D. Anderson Cancer Center at the University of Texas in Houston is reviewed in this work but no comparison is made, as the algorithm is very similar to that of RadPro. This process was not named in their paper, and we will refer to it as MDACC. The focus of this report is on identifying stars. Computing replacement values, a different topic, is not covered in this report.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Meeting Growing Energy Efficiency Challenges by Supporting the Program Administrator Industry

The Consortium for Energy Efficiency (CEE) received #DE-EE0006367 to assist local energy efficiency programs to work together to meet the growing energy efficiency challenges by supporting the program administrator industry covering the period August 1, 2014 through December 31, 2017, amendments 1-3 inclusive. CEE is a 501c (3) organization promoting voluntary alignment of local, ratepayer-funded energy efficiency programs to increase the energy savings and environmental benefits from their combined efforts. These efficiency programs are typically mandated by state regulatory or legislative bodies and administered by electric and gas utilities or designated state agencies. More than 100 program administrator organizations, representing efforts in 40 states, participated as US members in CEE. In addition, CEE's membership also includes 8 program administrator organizations from 5 Canadian provinces.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2018

Born Qualified Grand Challenge LDRD Final Report

This SAND report fulfills the final report requirement for the Born Qualified Grand Challenge LDRD. Born Qualified was funded from FY16-FY18 with a total budget of ~$13M over the 3 years of funding. Overall 70+ staff, Post Docs, and students supported this project over its lifetime. The driver for Born Qualified was using Additive Manufacturing (AM) to change the qualification paradigm for low volume, high value, high consequence, complex parts that are common in high-risk industries such as ND, defense, energy, aerospace, and medical. AM offers the opportunity to transform design, manufacturing, and qualification with its unique capabilities. AM is a disruptive technology, allowing the capability to simultaneously create part and material while tightly controlling and monitoring the manufacturing process at the voxel level, with the inherent flexibility and agility in printing layer-by-layer. AM enables the possibility of measuring critical material and part parameters during manufacturing, thus changing the way we collect data, assess performance, and accept or qualify parts. It provides an opportunity to shift from the current iterative design-build-test qualification paradigm using traditional manufacturing processes to design-by-predictivity where requirements are addressed concurrently and rapidly. The new qualification paradigm driven by AM provides the opportunity to predict performance probabilistically, to optimally control the manufacturing process, and to implement accelerated cycles of learning. Exploiting these capabilities to realize a new uncertainty quantification-driven qualification that is rapid, flexible, and practical is the focus of this effort.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Community Choice Aggregation: Challenges, Opportunities, and Impacts on Renewable Energy Markets

Community choice aggregations (CCAs) are local governmental entities that procure electricity on behalf of retail electricity customers within some geographic area. CCAs are expanding in seven states that allow CCAs through enabling legislation. In 2017, we estimate that about 750 CCAs procured about 42 million MWh of electricity on behalf of about 5 million customers in 2017. In this report, we seek to summarize the current status of CCAs in the United States. We quantify CCA sales and customer bases in terms of both renewable and non-renewable energy. We summarize trends in CCA renewable energy power procurement. Based on 12 interviews with CCAs and other stakeholders, we identify key factors that could improve or reduce the potential of CCAs to support renewable energy markets. Last, we identify the challenges created and faced by the expansion of CCAs.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2014

Issue Paper: Electricity System Adequacy - Challenges Facing the Nuclear Power Industry

One in a series of Issue Papers addressing Electricity System Adequacy, this report focuses on Challenges Facing the Nuclear Power Industry. Early proclamations of a nuclear renaissance yield to predictions of the industry's decline, while proposed carbon regulations offer potential optimism to use nuclear as a clean energy source. Yet, nuclear plants are currently 'at-risk' of early retirement (for economic reasons) due to electricity market design issues and competition with low priced natural gas. Concerns are identified as baseload generation shifts from coal and nuclear to increasing natural gas and renewables which may impact on the reliability of the power system.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2019

Transformational Challenge Reactor Autonomous Control System Framework and Key Enabling Technologies

Autonomous operation of nuclear plants has the potential for significantly improving the economics of existing plants while maintaining operation within the safety envelope of the reactor. Autonomous operation technology, if developed and deployed, may enable deployment of small reactors at remote sites while requiring minimal operator support. In addition to reducing costs, the technology can add additional layers of safety through rapid decision making and actuation in off-normal situations. Within the context of the Transformational Challenge Reactor (TCR), autonomous control along with the other unique characteristics of the reactor (advanced manufacturing) is expected to enable rapid deployment. On the other hand, technology for autonomy can add risk to the system if not properly developed. There is therefore a need for systematic development and demonstration of autonomy technology for TCR. This document describes a framework for autonomy for the TCR. It defines autonomous operation and examines whether autonomy is possible for nuclear systems. The report also describes enabling sensing technologies for autonomy and describes a framework to facilitate autonomy.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2019

"Compete, Deter, and Win" in a Trans-Regional Perspective: On Meeting the New Challenges of Extended Deterrence

On February 26-27, the Center for Global Security Research (CGSR) at Lawrence Livermore National Laboratory (LLNL) hosted a workshop to examine extended deterrence in a transregional perspective the challenges of the “compete, deter, and win” strategy set out in the U.S. National Defense Strategy. This was the Center’s third annual workshop on extended deterrence. This session brought together participants drawn across the policy, military, and technical communities. Among the 65 participants, 10 were from allied countries in Europe and 12 from allied countries in the Asia-Pacific region.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2019

Expanding the Photovoltaic Supply Chain in the United States: Opportunities and Challenges

Growth in U.S. manufacturing of solar-grade polysilicon, photovoltaic (PV) cells, and PV modules has not kept pace with global growth in these industries, and in some cases has even decreased. As a result, the United States has lost approximately 80% of its global market share in these industries over the past decade. However, projections of strong PV demand growth continuing in the United States and globally—along with significant announced U.S. cell and module plant expansions—suggest that PV could have important near-term impacts on related U.S. manufacturing sectors. This report primarily considers the infrastructure availability in the United States to meet demand for industries upstream of PV manufacturing if all U.S. PV installations were manufactured domestically from domestically sourced materials and components. It does not evaluate economic factors such as cost-competitiveness with other countries, policy incentives, shipping costs, and so forth, which are important factors to evaluate but are outside the scope of this work. Our goal is to delineate the infrastructure challenges and opportunities that upstream U.S. manufacturing sectors could encounter if the U.S. PV manufacturing sector grows. This analysis could be used in future discussions of the feasibility of creating a domestic PV supply chain that relies on domestic sourcing for upstream materials.

14 SOLAR ENERGY↗
DOE OSTI2019

Key Material Properties for Thermo-Structural Analysis of Transformational Challenge Reactor Core Components

This report presents thermo-structural (Williamson 2012) constitutive relationships and models pertaining to Transformational Challenge Reactor (TCR) core components using BISON. The material correlations for TCR core candidate materials include 316L stainless steel, uranium dioxide, and Chemical Vapor Infiltrated (CVI) silicon carbide were compiled. Preliminary, sensitivity analyses were performed on a simple cylindrical geometry by parametrically varying material properties. The sensitivity analyses elucidate the impact of material properties on the induced stresses in the TCR core structures. The results of the sensitivity studies for the SiC concept showed that the swelling is expected to be the largest source of uncertainty, followed by the elastic modulus. In the SS316L and UO 2 concept, the thermal conductivity of the can was the dominate effect, and a temperature dependent correlation or tabulated data would be advisable. The geometry and modeling method simulations showed that the inclusion of the heat generation is the SiC can does alter the stress and temperature magnitudes. However, the stress concentrations and profiles remain consistent.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2019

An Initial Investigation of the Design Challenges Associated with Reliable 100GigE Packet Capture

Network security researchers often rely on Emulytics TM to provide a way to evaluate the safety and security of real world systems. This work involves running a large number of virtual machines on a distributed platform to observe how software and hardware will respond to different types of attacks. While Emulytics TM software such as minimega provide a scalable system for conducting experiments, the sheer volume of network traffic produced in an experiment can easily exceed the rate at which data can be recorded for offline analysis. As such, researchers must perform live analytics, narrow their monitoring scope or accept that they must run an experiment multiple times to capture all the information they require. In support of Sandia's commitment to Emulytics TM , we are developing new storage components for the Carlin cluster that will enable researchers to capture significantly more network traffic from their experiments. This report provides a summary of Haoda Wang's initial investigation of how new AMD Epyc storage nodes can be adapted to perform packet capture at 100Gbps speeds with minimal loss. This work found that the NVMe storage capabilities of the Epyc architecture are suitable for capturing 100Gbps Ethernet traffic. While capturing traffic with existing libraries was surprisingly challenging, we were able to develop a DPDK-based software tool that recorded network traffic to disk with minimal packet loss.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Progress in Overcoming Materials Challenges with Supercritical CO 2 Recompression Closed Brayton Cycles

The supercritical carbon dioxide (S-CO2) Brayton Cycle has gained significant attention in the last decade as an advanced power cycle capable of achieving high efficiency power conversion. Sandia National Laboratories, with support from the U.S. Department of Energy Office of Nuclear Energy (US DOE-NE), has been conducting research and development in order to deliver a technology that is ready for commercialization. There are a wide range of materials related challenges that must be overcome for the success of this technology. At Sandia, recent work has focused on the following main areas: (1) Investigating the potential for system cost re duction through the introduction of low cost alloys in low temperature loop sections, (2) Identifying material options for 10MW RCBC systems, (3) Understanding and resolving turbine degradation, (4) Identifying gas foil bearing behavior in CO 2 , and (5) Identifying the influence of gas chemistry on alloy corrosion. Progress in each of these areas is provided in this report.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Safeguards by Design Challenge (Final Report- FY19)

This University Engagement project challenged engineering students at universities, without nuclear engineering degrees but with research reactors, to incorporate Safeguards by Design concepts into their Senior Capstone Design Project. This University Engagement project was part of the U. S. Department of Energy’s (DOE) National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation, Office of International Nuclear Safeguards, Next Generation Safeguards Initiative, Human Capital Development: University Engagement Program. This program exposed university students with Mechanical Engineering major and Nuclear Engineering minors to the concepts of international nuclear safeguards. FY19, three teams at the University of Rhode Island and one team at the University of Texas - Austin participated in researching, designing, building, and testing projects to support international nuclear safeguards measurements or verification. The projects involved engaging in activities at the university’s research reactors. All the projects engaged students with prototyping a design and/or tool for application at the Universities’ Research Reactor. At the end of the course, most of the students expressed the experience was a positive and they learned more about international nuclear safeguards and applying requirements than they had previously encountered.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2019

Grid-Interactive Efficient Buildings Technical Report Series: Overview of Research Challenges and Gaps

These reports evaluate state-of-the-art and emerging building technologies that have significant potential to provide grid services. The reports also identify major research challenges and gaps facing the technologies as well as opportunities for technology-specific R&D. The GEB Technical Report Series will help inform and guide BTO's portfolio and serve as a foundational resource for the larger building research community. On-site behind-the-meter generation, battery storage, and electric vehicles are also an important part of the distributed energy resource (DER) optimization strategy for buildings. In general, the component technology reports do not focus on distributed generation or battery storage, but the Whole-Building Controls, Sensors, Modeling, and Analytics report discusses how a building can optimize across all DERs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Best Practices for Electric Vehicle Supply Equipment Installations in the National Parks: Challenges, Lessons Learned, Installation Best Practices, and Recommendations for the National Park Service

In recent years, the National Renewable Energy Laboratory (NREL) and the National Park Service (NPS) have partnered to undertake a variety of projects intended to provide electric vehicle supply equipment (EVSE) to park visitors. Efforts to install charging infrastructure in the national parks have been underway for almost a decade, with installation projects as part of NPS partnerships with several organizations. These projects have been initiated through a variety of funding sources, such as coordinated donations and agreements with other governmental agencies including the U.S. Department of Energy (DOE). This report captures challenges, lessons learned, and best practices from recent NPS EVSE projects based on interviews with NPS employees and stakeholders involved in the projects. The report summarizes notable takeaways and makes recommendations to help ensure the success of future charging installation projects. Preserving this information will be valuable for informing and ensuring the success of future charging installation efforts at national parks, as well as for organizations outside of NPS. Note that this report focuses on light-duty plug-in electric vehicle (EV) projects, though NPS is also pursuing medium- and heavy-duty EV efforts.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

Strategic Competition In Cyberspace: Challenges And Implications Workshop Summary

On July 10th and 11th 2019, the Center for Global Security Research (CGSR) at Lawrence Livermore National Laboratory convened a workshop to examine the nature of strategic competition in cyberspace and the challenges facing current United States cyber domain strategy. The event aimed to situate the discussion of cyber strategy within the broader context of national defense strategy, also taking account of the complex dual-use nature of cyberspace and the variety of stakeholders involved. This was the second workshop that CGSR has hosted on cyber domain strategy and its implications. This event focused specifically on cyber domain military strategy, but with an eye to the implications also for civilian cyberspace, economic and technical interdependence, and democratic Internet governance.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗