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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.

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At least 1,495 records · Page 83

Potential Energy Savings Due to Phase Change Material in a Building Wall Assembly: An Examination of Two Climates

Phase change material (PCM), placed in an exterior wall, alters the temperature profile within the wall and thus influences the heat transport through the wall. This may reduce the net energy transport through the wall via interactions with diurnal temperature swings in the external environment or reduce the electricity needed to meet the net load through the wall by shifting the time of the peak load to a time when the cooling system operates more efficiently. This study covers a broad range of parameters that can influence the effectiveness of such a merged thermal storage-thermal insulation system. These parameters included climate, PCM location within the wall, amount of PCM, midpoint of the PCM melting and freezing range relative to the indoor setpoint temperature, temperature range over which phase change occurs, and the wall orientation. Two climates are investigated using finite difference and optimization analyses: Phoenix and Baltimore, with two utility rate schedules. Although potential savings for a PCM with optimized properties were greater when the PCM was concentrated near the inside wall surface, other considerations described here lead to a recommendation for a full-thickness application. An examination of the temperature distribution within the walls also revealed the potential for this system to reduce the amount of energy transported through the wall framing. Finally, economic benefits can exceed energy savings when time-of-day utility rates are in effect, reflecting the value of peak load reductions for the utility grid.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Generating Sequential PV Deployment Scenarios for High Renewable Distribution Grid Planning: Preprint

This paper introduces a novel approach for generating solar photovoltaic (PV) plant deployment scenarios for grid integration planning. The approach guarantees consistency among scenarios of the same deployment by ensuring that higher penetration scenarios contain PV units deployed in lower penetration scenarios. It also constrains the size and spatial distribution of the PV plants and considers three placement types. A case study on a real-world distribution system proves that the precepts of scenario consistency, deployment diversity, and placement are met. The study further investigates the impact of the resulting scenarios via a stochastic hosting capacity analysis. Results indicate that the ratio between PV and load sizes, referred to as the nodal PV penetration factor (NPPF), is a key driver of the grid integration impact. By reducing the NPPF from 5 to 2, the maximum hosting capacity increased by at least 112%. The study also reveals that scenarios under random placement can lead to higher hosting capacity values.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗

ANALYSIS TOOLS FOR SIZING AND PLACEMENT OF ENERGY STORAGE IN GRID APPLICATIONS

The purpose of this report was to review pertinent literature and studies to identify current state-of-the-art models and analytical tools that optimize the siting, sizing, and economic value of energy storage in a smart grid infrastructure. In recent decades, research and development has significantly improved the cost and reliability of energy storage systems. However, a relatively small percentage of that work has focused on engineering tools for integrating energy storage into existing or future electric grids. This literature review revealed that only a small number of software tools exist, and that those tools only partially address the needs for placement, sizing, and overall control strategies of stationary energy storage within a smart grid infrastructure. None of the tools comprehensively captures the benefits of energy storage, which would reveal all of the potential values. None of the tools or models provides optimization features that identify optimal placement and sizing options within a transmission or distribution system context. This review identifies a need for tool development to fill the gap in the grid analytics and provides some recommendations of guiding principles for advancing the analytical capabilities needed for the engineering and grid planning communities.

energy storage↗

SU-E-T-476: Quality Assurance for Gamma Knife Perfexion Using the Exradin W1 Plastic Scintillation Detector

Purpose: To perform dose profile and output factor measurements for the Exradin W1 plastic scintillation detector (PSD) for the Gamma Knife Perfexion (GKP) collimators in a Lucy phantom and to compare these values to an Exradin A16 ion chamber, EBT3 radiochromic film and treatment planning system (TPS) data. Methods: We used the Exradin W1 PSD which has a small volume, near-water equivalent sensitive element. It has also been shown to be energy independent. This new detector is manufactured and distributed by Standard Imaging, Inc. Measurements were performed for all three collimators (4 mm, 8 mm and 16 mm) for the GKP. The Lucy phantom with the PSD inserted was moved in small steps to acquire profiles in all three directions. EBT3 film was inserted in the Lucy phantom and exposed to a single shot for each collimator. Relative output factors were measured using the three detectors while profiles acquired with the PSD were compared to the ones measured with EBT3 radiochromic film. Results: Measured output factors relative to the largest collimator are as followsCollimator PS EBT3 A1616mm 1.000 1.000 1.0008mm 0.892 0.881 0.8834mm 0.795 0.793 0.727 The nominal (vendor) OFs for GKP are 1.000, 0.900, and 0.814, for collimators 16 mm, 8 mm and 4 mm, respectively. There is excellent agreement between all profiles measured with the PSD and EBT3 as well as with the TPS data provided by the vendor. Conclusion: Output factors measured with the W1 were consistent with the ones measured with EBT3 and A16 ion chamber. Measured profiles are in excellent agreement. The W1 detector seems well suited for beam QA for Gamma Knife due to its dosimetric characteristics. Sam Beddar would like to disclose a NIH/NCI SBIR Phase II grant (2R44CA153824-02A1) with Standard Imaging, Title: “Water-Equivalent Plastic Scintillation Detectors for Small Field Radiotherapy”.

07 ISOTOPE AND RADIATION SOURCES↗

SU-F-T-145: Modeling of a Proton Pencil Beam Partially Blocked by a Collimator

Purpose: To develop a mathematical model of the fluence distribution of a proton pencil beam that is partially blocked by a collimator. Methods: In one dimension, an exact analytical solution of the proton distribution behind a collimator edge was derived, taking the beam’s phase space, the edge position, and the scattering downstream of the collimator as input. Extension to two dimensions was achieved using a Clarkson-like Method: determine the radial distances from each calculation point to the collimator outline, calculate the beam’s phase space in the direction of each radial line, apply the one-dimensional model along each radial line, and sum the contributions. A Matlab implementation of the full model produced high-resolution distributions with relatively short calculation times (of about 2 ms per calculation point). The model was validated by comparison to Monte Carlo simulations for select pencil beam phase space distributions and collimator shapes. Results: Agreement between model and simulation confirm the exact mathematical solution of the one-dimensional model. In two dimensions the agreement is reasonable, but not exact, due to the approximations introduced in the Clarkson-like method. Conclusion: A model has been developed and validated that gives the lateral fluence distribution of a pencil beam beyond a collimator. Notably, this model does not include free parameters and the final fluence is completely determined by the phase space parameters of the beam, already existing in the treatment planning system, as well as both axial and lateral position of the aperture edge. As such, it can be incorporated in a full pencil-beam dose calculation algorithm allowing for the modeling of field-specific collimators in proton pencil beam scanning and, potentially, the optimization of collimator shape and/or pencil phase space in addition to the customary spot weight optimization.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

MO-FG-CAMPUS-JeP3-01: A Statistical Model for Analyzing the Rotational Error of Single Iso-Center Technique

Purpose: To develop a generalized statistical model that incorporates the treatment uncertainty from the rotational error of single iso-center technique, and calculate the additional PTV (planning target volume) margin required to compensate for this error. Methods: The random vectors for setup and additional rotation errors in the three-dimensional (3D) patient coordinate system were assumed to follow the 3D independent normal distribution with zero mean, and standard deviations σx, σy, σz, for setup error and a uniform σR for rotational error. Both random vectors were summed, normalized and transformed to the spherical coordinates to derive the chi distribution with 3 degrees of freedom for the radical distance ρ. PTV margin was determined using the critical value of this distribution for 0.05 significant level so that 95% of the time the treatment target would be covered by ρ. The additional PTV margin required to compensate for the rotational error was calculated as a function of σx, σy, σz and σR. Results: The effect of the rotational error is more pronounced for treatments that requires high accuracy/precision like stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT). With a uniform 2mm PTV margin (or σx =σy=σz=0.7mm), a σR=0.32mm will decrease the PTV coverage from 95% to 90% of the time, or an additional 0.2mm PTV margin is needed to prevent this loss of coverage. If we choose 0.2 mm as the threshold, any σR>0.3mm will lead to an additional PTV margin that cannot be ignored, and the maximal σR that can be ignored is 0.0064 rad (or 0.37°) for iso-to-target distance=5cm, or 0.0032 rad (or 0.18°) for iso-to-target distance=10cm. Conclusions: The rotational error cannot be ignored for high-accuracy/-precision treatments like SRS/SBRT, particularly when the distance between the iso-center and target is large.

60 APPLIED LIFE SCIENCES↗

LA100 Equity Strategies: Executive Summary

LA100 Equity Strategies is a collaborative effort between LADWP, NREL, UCLA, and Kearns & West that employs an interdisciplinary approach utilizing distinct - but connected - research efforts informed and guided by the project Steering Committee, which met monthly through the duration of the project. Chapters 1 through 4 address recognition and procedural justice through recognition, process, and community strategies, while Chapters 5 through 12 address distributional justice through program and infrastructure strategies. Chapters 13 through 17 provide policy and program strategies. Each chapter provides data, methods, tools, insights, and strategies to help LADWP make data-driven, community- informed decisions for equitable investments and program development.

14 SOLAR ENERGY↗

A method for modeling battery-temperature-aware EV power profiles utilizing Next-Gen Profile data

With the expected increase in the number of electric vehicles (EVs) on the road in the coming years, it is important that analysis tools are capable of modeling and predicting the expected load on the power grid due to both individual EV charging sessions as well as large populations of vehicles. To do this accurately, the power profile of an EV charge session must be accurately modeled, including for scenarios where the temperature is above or below the ideal, and also take into account the nuances of manufacturer charging preferences. This paper introduces a method that utilizes the data in the Next-Gen Profile (NGP) data collection project to build a model of EV charging that takes into account the variations in charging power that occur due to off-nominal battery temperature and manufacturer preferences that limit power due to cold temperatures or high battery state-of-charge.

24 - POWER TRANSMISSION AND DISTRIBUTION↗

Assessing the Impacts of Hydrologic and Land Use Alterations on Water Temperature in the Farmington River Basin in Connecticut

Aquatic ecosystems can be significantly altered by the construction of dams and modification of riparian buffers and the effects are often reflected in spatial and temporal changes to water temperature. To investigate the implications for water temperature of spatially and temporally varying riparian buffers and dam-induced hydrologic alterations, we have implemented a modeling system (DHSVM-RBM) that couples a spatially distributed land surface hydrologic model, DHSVM, with the distributed stream temperature model, RBM. The basic modeling system has been applied previously to several similar-sized watersheds. However, we have made enhancements to DHSVM-RBM that simulate spatial heterogeneity and temporal variation (i.e. seasonal changes in canopy cover) in riparian vegetation, and we included additional features in DHSVM-RBM that provide the capability for simulating the impacts of reservoirs that may develop thermal stratification. We have tested the modeling system in the Farmington River basin in the Connecticut River system that includes varying types of watershed development (e.g. deforestation and reservoirs) that can alter the streams’ hydrologic regime and thermal energy budget. We evaluated streamflow and stream temperature simulations against all available observations distributed along the Farmington River basin. Results based on metrics recommended for model evaluation compare well to those obtained in similar studies. We demonstrate the way in which the model system can provide decision support for watershed planning by simulating a limited number of scenarios associated with hydrologic and land use alterations.

Freshwater Ecosystem, Water Temperature, Riparian ↗

Flight management - Pilot procedures and system interfaces for the 1980-1990's

In the air transportation system of the 1980-1990's, aircraft must perform with greater precision in time and position than is possible today. Rapid development in electronics technology makes renovation in airborne-system concepts feasible. The Ames Research Center is conducting research on pilot procedures and pilot-system interfaces for such systems. Research on various pilot-system interface devices and manned simulations was conducted to study rules of distributed decision making authority among pilots and controllers with various airborne display concepts, and a pilot-oriented command logic for the control of avionic systems was studied. Results are summarized, and ongoing work and future research plans described.

Wempe, T. E.↗

The NASA space power technology program

The objective and planning of the NASA space power research and technology program are reviewed. The areas of research covered include photovoltaic energy conversion, chemical energy conversion and storage, thermal to electric conversion, environmental interactions and power systems management of distribution.

Mullin, J. P.↗

Pilot land data system

During the fall of 1983, the Information Systems Office of NASA's Office of Space Science and Applications assembled a Working Group to develop initial plans for a Pilot Land Data System (PLDS). Workshops coordinated planning and concept development activities between land-related and computer science disciplines, and examined land research requirements, information science technology requirements, PLDS architecture, and methodologies for system evaluation. The PLDS will be a limited-scale distributed information system to explore scientific, technical and management approaches to satisfy land science research needs. PLDS will pave the way for a Land Data System to improve data access, processing, transfer and analysis, fostering an environment in which land science information synthesis can occur on a scale not previously possible owing to limits to data assembly and access and efficiency of processing.

Cressy, P. J.↗

Evaluation of DVD-R for Archival Applications

For more than a decade, CD-ROM and CD-R have provided an unprecedented level of reliability, low cost and cross-platform compatibility to support federal data archiving and distribution efforts. However, it should be remembered that years of effort were required to achieve the standardization that has supported the growth of the CD industry. Incompatibilities in the interpretation of the ISO-9660 standard on different operating systems had to be dealt with, and the imprecise specifications in the Orange Book Part n and Part Hi led to incompatibilities between CD-R media and CD-R recorders. Some of these issues were presented by the authors at Optical Data Storage '95. The major current problem with the use of CD technology is the growing volume of digital data that needs to be stored. CD-ROM collections of hundreds of volumes and CD-R collections of several thousand volumes are becoming almost too cumbersome to be useful. The emergence of Digital Video Disks Recorder (DVD-R) technology promises to reduce the number of discs required for archive applications by a factor of seven while providing improved reliability. It is important to identify problem areas for DVD-R media and provide guidelines to manufacturers, file system developers and users in order to provide reliable data storage and interchange. The Data Distribution Laboratory (DDL) at NASA's Jet Propulsion Laboratory began its evaluation of DVD-R technology in early 1998. The initial plan was to obtain a DVD-Recorder for preliminary testing, deploy reader hardware to user sites for compatibility testing, evaluate the quality and longevity of DVD-R media and develop proof-of-concept archive collections to test the reliability and usability of DVD-R media and jukebox hardware.

Martin, Michael D.↗

Security for Multimedia Space Data Distribution over the Internet

Distribution of interactive multimedia to remote investigators will be required for high quality science on the International Space Station (ISS). The Internet with the World Wide Web (WWW) and the JAVA environment are a good match for distribution of data, video and voice to remote science centers. Utilizing the "open" Internet in a secure manner is the major hurdle in making use of this cost effective, off-the-shelf, universal resource. This paper examines the major security threats to an Internet distribution system for payload data and the mitigation of these threats. A proposed security environment for the Space Station Biological Research Facility (SSBRP) is presented with a short description of the tools that have been implemented or planned. Formulating and implementing a security policy, firewalls, host hardware and software security are also discussed in this paper. Security is a vast topic and this paper can only give an overview of important issues. This paper postulates that a structured approach is required and stresses that security must be built into a network from the start. Ignoring security issues or putting them off until late in the development cycle can be disastrous.

Stone, Thom↗

Manual Asset Inventory: NASA Kennedy Space Center

The National Aeronautics and Aerospace Administration (NASA) relies in the security and protection of the information and information systems to know the devices that are connected to the Agency networks whether these are business, mission, research, or engineering devices. The Agency uses different Information Technology resources in order to do this process automatically, however, there are some devices that need to be reported manually. As a result of this, every month the Agency distributes among its Information System Owners (ISOs) the Manual Asset Inventory, a document that consists of a Microsoft Excel spreadsheet with twenty field descriptions cells that has to be filled out by the ISO of every Security Plan in the Center [fifty three in total] and uploaded into the IT Security Enterprise Data Warehouse (ITSEC-EDW).

Presentation↗

Transactive Energy Simulation Platform

TESP combines existing domain simulators in the electric power grid, with new transactive agents, growth models and evaluation scripts. The existing domain simulators include GridLAB-D for the distribution grid and single-family residential buildings, MATPOWER for transmission and bulk generation, and EnergyPlus for large buildings. More are planned for subsequent versions of TESP. The new elements are: TEAgents - simulate market participants and transactive systems for market clearing. Some of this functionality was extracted from GridLAB-D and implemented in Python for customization by PNNL and others; Growth Model - a means for simulating system changes over a multiyear period, including both normal load growth and specific investment decisions. Customizable in Python code; and Evaluation Script - a means of evaluating different transactive systems through customizable post-processing in Python code. TESP provides a method for other researchers and vendors to design transactive systems, and test them in a virtual environment. It allows customization of the key components by modifying Python code.

Source record↗

Advanced Research on Integrated Energy Systems Cyber Range

As digital technologies expand to meet the needs of a more autonomous, interconnected, and advanced power system, new cybersecurity complexities and vulnerabilities arise. The ARIES Cyber Range enables the energy sector to evaluate these evolutions and validate cybersecurity solutions without impacting live systems. Combining power grid-scale hardware with emulation and simulation approaches, the ARIES Cyber Range can faithfully replicate modern energy systems - from grid physics to communication networks, and everything in between - with real-world fidelity. At NLR, researchers and partners are answering complex power system cybersecurity questions, examining emerging threats to the electric sector, and de risking new security technologies, all at a mission-relevant speed that keeps pace with rapidly evolving systems and hazards.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Generating Sequential PV Deployment Scenarios for High Renewable Distribution Grid Planning

This paper introduces a novel approach for generating solar photovoltaic (PV) plant deployment scenarios for grid integration planning. The approach guarantees consistency among scenarios of the same deployment by ensuring that higher penetration scenarios contain PV units deployed in lower penetration scenarios. It also constrains the size and spatial distribution of the PV plants and considers three placement types. A case study on a real-world distribution system proves that the precepts of scenario consistency, deployment diversity, and placement are met. The study further investigates the impact of the resulting scenarios via a stochastic hosting capacity analysis. Results indicate that the ratio between PV and load sizes, referred to as the nodal PV penetration factor (NPPF), is a key driver of the grid integration impact. By reducing the NPPF from 5 to 2, the maximum hosting capacity increased by at least 112%. The study also reveals that scenarios under random placement can lead to higher hosting capacity values.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗