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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 37 records · Page 2

The DREAM approach to demand-side emissions reductions in Indonesia, 2020–2060

Indonesia’s current energy system modeling is heavily focused on the supply side, but emissions reductions in the demand sector have a significant impact on advancing Indonesia’s ambitious emissions reductions goals. To address the gap, we develop a new modeling tool DREAM Indonesia based on a bottom-up, technology-rich demand side framework and formulate projections of demand-side emissions reductions in Indonesia in 2020–2060. We find that demand-side energy efficiency and electrification can halve the growth rate of final energy demand to 1.4% annually over 2020–2060 and reverse the growing trend of emissions. The feasibility of full electrification by 2060, coupled with rapid adoption of existing technologies, positions the building sector as a model for achievable decarbonization and a cornerstone of Indonesia’s emissions reductions ambitions. In the industrial sector, extensive emissions reductions of 87% by 2060 (compared to business-as-usual) are achievable through energy efficiency improvements, alongside enhanced material efficiency measures including optimized material usage, low-carbon substitutions, innovative technologies, and increased circularity. In the transportation sector, balancing final energy demand by incorporating energy efficiency improvements across all transport modes, along with electrification particularly in road transportation, could decrease the emissions by up to 82% in 2060 compared to business-as-usual. This study provides insights and modeling approaches for rapidly growing Asian economies as well as other developing countries facing combined development and decarbonization challenges.

DREAM Indonesia↗

DC-Ripple-Energy Adaptive-Minimization (DREAM) Modulation Scheme for a High Power Density Inverter

The DC bus capacitor is one of the major power-density and reliability hurdles of electric drive systems. It is hard to shrink because it is constrained by the DC bus RMS ripple current, which is only load dependent. A dual-inverter based segmented drive can reduce the ripple current by ~50% compared to a non-segmented case. This paper analyzes the origin of this ripple current and points out the path for minimization. An optimal DC-ripple-energy adaptive-minimization (DREAM) modulation method is proposed to further reduce the ripple current. It is observed in experimental results that the proposed method can achieve additional 38% reduction over the traditional segmented drive system.

Xue, Lincoln↗

Implementation of a Campuswide Distributed Mass Storage Service: the Dream Versus Reality

In 1990, a technical team at NASA Lewis Research Center, Cleveland, Ohio, began defining a Mass Storage Service to pro- wide long-term archival storage, short-term storage for very large files, distributed Network File System access, and backup services for critical data dw resides on workstations and personal computers. Because of software availability and budgets, the total service was phased in over dm years. During the process of building the service from the commercial technologies available, our Mass Storage Team refined the original vision and learned from the problems and mistakes that occurred. We also enhanced some technologies to better meet the needs of users and system administrators. This report describes our team's journey from dream to reality, outlines some of the problem areas that still exist, and suggests some solutions.

Prahst, Stephen↗

Kennedy Space Center: Creating a Spaceport Reality from the Dreams of Many

On December 17, 1903, Orville Wright piloted the first powered airplane only 20 feet above the ground near Kitty Hawk, North Carolina. The flight lasted 12 seconds and covered 120 feet. Who would have guessed that the bizarre looking contraption developed by brothers in the bicycle business would lay the ground work eventually resulting in over a million passengers moved daily in a sky filled with the contrails of jets flying at over 30,000 feet in elevation and over 500 miles per hour. Similarly, who would have guessed that the destructive nature of V-2 rockets of Germany would spark the genesis of spaceflight to explore our solar system and beyond? Yet the interest in using the Kennedy Space Center (KSC) continues to grow. Potential customers have expressed interest in KSC as a location for testing new rocket engines, servicing the world's largest airborne launching platform for drop-launch rockets, developing multi-use launch platforms that permit diverse customers to use the same launch platform, developing new spacecraft, and implementing advanced modifications for lifting 150 metric ton payloads to low earth orbit. The multitude of customers has grown and with this growth comes a need to provide a command, control, communication, and range infrastructure that maximizes flexibility and reconfigurability to address a much more frequent launch rate of diverse vehicles and spacecraft. The Ground Systems Development and Operations (GSDO) Program Office at KSC is embarking upon these developments to realize the dream of a robust spaceport. Many unique technical trade studies have been completed or are underway to successfully transition KSC into a multi-user customer focused spaceport. Like the evolution of the airplane, GSDO is working to transform KSC infrastructures that will turn once unthinkable space opportunities into a reality for today.

Gray, James A.↗

Coupled Material Response Simulations of Dragonfly Capsule and DrEAM Reconstruction

Icarus is a three-dimensional, unstructured, finite-volume material response solver developed at NASA Ames Research Center and has been recently used to analyze the material response of the Dragonfly capsule for a variety of problems. Since the Dragonfly capsule will be instrumented in a similar manner to the Mars 2020 and MSL capsules, it is important to assess how our current simulation tools can aid in understanding Dragonfly Entry Aerosciences Measurements (DrEAM). In this presentation, the Ares multi-physics tool that couples Icarus to the flow and radiation physics of the aerothermal environment will be used to better understand how modeling sensitivities might affect environment reconstructions and our understanding of measured data. Ares couples Icarus to the US3D flow solver and NERO, a reduced-order, finite-volume radiation transport solver and uses a customized time-scale management to enable coupled simulations for a large portion of the Dragonfly trajectory. As a result of the coupling, a more accurate and consistent assessment of modelling sensitivities to aerothermal reconstruction can be assessed. For example, the radiometer is sensitive to the quantity of CN in the flow, which is a byproduct of the free-stream methane but also the pyrolysis gas products injected into the boundary layer due to ablation of the heatshield. Ares will be used to conduct a simulation of the full Dragonfly capsule for 50 seconds of the trajectory. The different aerothermal and material response models will be discussed and the key results will be presented in terms of the simulated thermocouple and radiometer measurements on the backshell.

Ablation↗

A million persons, a million dreams: a vision for a national center of radiation epidemiology and biology

Epidemiologic studies of radiation-exposed populations form the basis for human safety standards. Furthermore, they also help shape public health policy and evidence-based health practices by identifying and quantifying health risks of exposure in defined populations. For more than a century, epidemiologists have studied the consequences of radiation exposures, yet the health effects of low levels delivered at a low-dose rate remain equivocal.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗