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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 1,117 records · Page 62

Digital Engineering and Cybersecurity Decision Analysis in Early Phases of SMR-Driven IES Projects

Considerable efforts are underway to ensure cybersecurity is integrated into the systems engineering lifecycle. Cyber-informed engineering and security-by-design frameworks are intended to identify and engineer out cybersecurity risks throughout the lifecycle. While these approaches are valuable for promoting the need to include cybersecurity considerations in early design phases to create more secure systems, they may not consider the entirety of digital risks. Digital risks in a digital instrumentation and control system include adversarial and unintentional risks from internal and external factors, such as human performance errors, design flaws, environmental conditions, and equipment degradation or failure. This report provides a detailed discussion on digital risk prior to describing the background and concept of operations for a small modular reactor-driven integrated energy system connected to industrial applications. The challenges of competing objectives and competing stakeholder requirements are discussed and the impacts on digital engineering, security considerations, and interdependencies are evaluated for mission-level, facility-level, and system-level decisions.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Task 12 PV Sustainability - Status of PV Module Recycling in Selected IEA PVPS Task 12 Countries

Photovoltaic (PV) deployment has accelerated in recent years compared to projections in the early 2010s. This means that PV end of life (EOL) waste streams will also increase at a higher pace than anticipated. To meet and optimise PV EOL management, appropriate regulatory and technological approaches must be implemented in the near term, ensuring that available options are adapted to the conditions of each country or region. This report aims to review the current regulatory and industrial landscape for selected countries belonging to the International Energy Agency's PV Power Systems technology collaboration programme, to assess status of PV EOL management, allow for comparison and cross-fertilization, and establish a foundation for future tracking of progress. Although volumes of EOL PV modules are still small, EOL PV is treated and recycled in a proper manner in the countries and regions that have EOL regulations in place. However, the current low volumes, limited available recycling technologies, logistics challenges, and undeveloped markets for recovered materials result in a high-cost, low-revenue scenario for PV module recycling globally. Nevertheless, the implementation of PV EOL regulations in more countries and R&D investment in PV recycling is expected to accelerate further improvements to meet future demand and to achieve high-value, low-cost recycling. We hope this report contributes to understanding the global status of PV recycling and to accelerating its development as a promising option for the proper EOL management of PV modules in the coming decades.

14 SOLAR ENERGY↗

SHASTA: Task 2.2: Sensor Development for Subsurface Hydrogen Storage Monitoring Technology Maturation and Commercialization Plan (TMCP)

In Task 2.2 under the SHASTA program, NETL is developing in-situ optical fiber sensors for real-time monitoring of hydrogen, methane, and chemical parameters such as pH at subsurface hydrogen storage conditions. This Technology Maturation and Commercialization Plan report will provide the summary of NETL sensor development and test results under the SHASTA program to meet the subsurface application requirements and proposed technology maturation and deployment plan, and commercialization potential.

08 HYDROGEN↗

Measurement of Boron by 3 He Nuclear Reaction Analysis

Reference samples with known boron coverage are needed for calibrating measurements of boron deposition in tokamaks where boron is used for wall conditioning to improve fusion plasma performance. This report summarizes recent work at the Sandia Ion Beam Laboratory to fabricate such reference samples. Rutherford backscattering and nuclear reaction analysis were used to determine the boron coverage on reference samples consisting of a thin layer of boron on a silicon substrate.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Drive turbine systems for 20-inch turbofan simulators. 1: Duct turbine design

A study was made to evolve the turbine drive systems for 20-inch turbofan engine simulators. The fan designs used in the simulators included single-stage and two-stage configurations that covered a wide range of rotative speed and power requirement. The objective assumed for the study was to evolve one core turbine design that could drive all of the single-stage fans and, when operated in combination with one duct turbine design, drive all of the two-stage fans. The duct turbine power output is then needed to determine the make-up power required of the core turbine over the range of two-stage fan operating conditions. The duct turbine design analysis is reported and includes the selection of the duct turbine velocity diagram, a description of the blade design, and a determination of its off-design performance. Adjustable stators were found to be quite advantageous to the duct turbine off-design operation. The use of adjustable stators enabled the duct turbine to accommodate fan mass flow at all operating points and caused the duct turbine power output to increase as the total power requirement increased. This in turn resulted in a core turbine make-up power requirement that was not significantly greater than that required for driving the single-stage fans.

Whitney, W. J.↗

Experimental investigation of transient stimulated Raman scattering in a linearly dispersionless medium.

The results of numerical calculations of the transient stimulated Raman scattering reported previously have been verified experimentally under conditions where both linear dispersion and self-focusing effects were negligible. The existence of a delay between maxima of the laser and Stokes pulses is experimentally demonstrated for the first time, while the pulse shortening in time via Raman scattering is established more firmly than in previous work. The incident-laser-pulse duration, generated-Stokes-pulse duration, and delay between intensity maxima for the laser and Stokes pulses were measured with the two-photon absorption-fluorescence technique. The effective phonon-dephasing time is determined via spontaneous Raman scattering. By using these measured quantities, inferences are made as to the magnitude of the transient gain and the shape of the exciting picosecond laser pulse.

Carman, R. L.↗

Small step tracking - Implications for the oculomotor 'dead zone'

Recently Timberlake, Wyman, Skavenski, and Steinman (1972) concluded in a study of the oculomotor error signal in the fovea that 'the oculomotor dead zone is surely smaller than 10 min and may even be less than 5 min (smaller than the 0.25 to 0.5 deg dead zone reported by Rashbass (1961) with similar stimulus conditions).' The Timberlake et al. speculation is confirmed by demonstrating that the fixating eye consistently and accurately corrects target displacements as small as 3.4 min. The contact lens optical lever technique was used to study the manner in which the oculomotor system responds to small step displacements of the fixation target. Subjects did, without prior practice, use saccades to correct step displacements of the fixation target just as they correct small position errors during maintained fixation.

Wyman, D.↗

Adhesive fracture mechanics

In studies of fracture mechanics the adhesive fracture energy is regarded as a fundamental property of the adhesive system. It is pointed out that the value of the adhesive fracture energy depends on surface preparation, curing conditions, and absorbed monolayers. A test method reported makes use of a disk whose peripheral part is bonded to a substrate material. Pressure is injected into the unbonded central part of the disk. At a certain critical pressure value adhesive failure can be observed. A numerical stress analysis involving arbitrary geometries is conducted.

Bennett, S. J.↗

The effects of exposure to LN2 temperatures and 2.5 suns solar radiation on 30-cm ion thruster performance

An experimental test program was developed to demonstrate all 30 cm Hg-ion bombardment thruster functions over the thermal environment of several proposed missions. A 30 cm thruster with grids dished 1.25 cm and instrumented with 31 thermocouples, was placed in a vacuum tank equipped with minus 196 C walls. Cold storage of a thruster was simulated and temperatures as low as minus 100 C were attained on the thruster. The thruster started successfully from these cold conditions. The thruster operating at both half and full beam power was exposed to 2.5 suns on axis solar simulation. Various thruster thermal configurations, used to simulate multiple thruster operation, were tested at the above conditions. The results of these tests are reported herein.

Mirtich, M. J.↗

The effects of exposure to LN2 temperatures and 2.5 suns solar radiation on 30-cm ion thruster performance

An experimental test program was developed to demonstrate all 30 cm Hg-ion bombardment thruster functions over the thermal environment of several proposed missions. A 30 cm thruster with grids dished 1.25 cm and instrumented with 31 thermocouples, was placed in a vacuum tank equipped with -196 C walls. Cold storage of a thruster was simulated and temperatures as low as -100 C were attained on the thruster. The thruster started successfully from these cold conditions. The thruster operating at both half and full beam power was exposed to 2.5 suns on axis solar simulation. Various thruster thermal configurations, used to simulate multiple thruster operation, were tested at the above conditions. The results of these tests are reported herein.

Mirtich, M. J.↗

Experimental study of the constituents of space wash water

This report presents experimental data, obtained under controlled conditions, which quantify the various constituents of human origin that may be expected in space wash water. The experiments were conducted with a simulated crew of two male and two female subjects. The data show that the expected wash water contaminants originating from human secretions are substantially lower than theoretical projections indicated. The data presented are immediately useful and may have considerable impact on the tradeoff comparisons among various unit processes and systems under consideration by NASA for recycling space wash water.

Putnam, D. F.↗

Characteristics of fragments

Methods used to estimate initial fragment velocities from various types of accidental explosions, geometry of vessel, or explosion source are reported. In addition, fragmentation ranges and impact conditions, using initial velocities as inputs, are discussed. Several classes of accidental explosions and fragment mass distribution predicted by statistical methods are included. Computer program techniques are summarized.

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