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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

ASME Code Activities

U.S. Nuclear Regulatory Commission (NRC) is currently assessing ASME Section III, Division 5 (2017 Edition) and accompanying Code Cases for endorsement Draft Regulatory Guide (DG-1380) and draft NUREG (2245) on the endorsement of Division 5 were issued and public comment phase completed DG-1380 places conditions in the areas of general requirements, mechanical design, metallic materials allowable stresses, and graphite materials/design of Division 5 DG-1380 is a revision to Regulatory Guide 1.87, Revision 1, 1975 (which endorsed the 159X series of ASME Code Cases, with conditions) NRC staff is currently reviewing the low-temperature and elevated temperature Alloy 617 code cases for endorsement Results of the review will be incorporated into DG-1380 and changes will be announced publicly The formal endorsement of Section III, Division 5 and accompanying code cases, with conditions, will be made through Regulatory Guide 1.87, Revision 2

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

GUI Control System for the Mu2e Electrostatic Septum High Voltage at Fermilab

The Mu2e Experiment has stringent beam structure requirements; namely, its proton bunches with a time structure of 1.7 $\mu$s in the Fermilab Delivery Ring. This beam structure will be delivered using the Fermilab 8-GeV Booster, the 8-GeV Recycler Ring, and the Delivery Ring. The 1.7-$\mu$s period of the Delivery Ring will generate the required beam structure by means of a third order resonant extraction system operating on a single circulating bunch. The electrostatic septum (ESS) for this system is particularly challenging, requiring mechanical precision in a ultra high vacuum of 1 x 10$^-8$ Torr to generate 100 kV across 15 mm. This paper describes a graphical user interface that has been developed to automate the conditioning and commissioning process for the electrostatic septa. It is based on an interface to the Fermilab ACNET system using the ACSys Python Data Pool Manager (DPM) Client produced and maintained by Fermilab Accelerator Controls. Network interfacing between data pool managers made by the application and ACNET devices introduce an inherent (approximately 1 s) latency in throughput of the readouts. This delay is utilized to process and graph incoming data events of devices crucial to conditioning of a electrostatic septum (ESS). 'Ramping' and 'Monitoring' modes adjust settings of the power supply based on internal logic to efficaciously increase and maintain the high voltage (HV) in the ESS, easing the voltage setting on incidence of sparking or other possibly damaging events. A timestamped log file is produced as the application runs.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Additive manufacturing of power poles using bamboo-polymer composites: A quick solution for power grid restoration

Polymer additive manufacturing (AM) technology is rapidly growing and its transition to become an advanced manufacturing technique now offers possibilities for unconventional applications. One of these potential applications is on site additive manufacturing of power poles. During natural incidents such as storms and hurricanes, power lines can be severely damaged and there may not be sufficient spare power poles to replace. In such situations, additive manufacturing of power poles on site can offer a fast, temporary solution during emergencies. The ability of freeform manufacturing of parts with complex geometries makes large scale AM attractive for various applications; however, due to residual stress build up and need for different mechanical requirements for different applications, reinforcement of the AM feedstock is necessary. In addition to carbon and glass fibers, bio-derived fibers can also be used as a reinforcing phase, both to utilize the natural resources at the emergency area and in terms of long-term sustainability. In this project, design and additive manufacturing of a 13.1 m power pole was demonstrated. Three different feedstock material options (polystyrene, cellulose ester and polycarbonate reinforced with glass and bamboo fibers) and two different pole designs were investigated. As-printed part tensile properties both in printing and interlayer directions were measured and a power pole was printed as six pieces and put together successfully. Finally, a conceptual design of a portable power pole manufacturing approach was proposed.

Tekinalp, Halil↗
NASA NTRSDate not supplied

Hold Down and Release Mechanism Hardware Simulator for Ground Deployment Testing

Hold Down and Release Mechanisms (HDRMs) are a common piece of spacecraft hardware which restrain components during launch, transit, and later allow them to be extended, jettisoned, separated, etc. at the spacecraft’s destination. Due to prohibitively high cost, long lead times, and limited reset capability, testing of mechanisms that require HDRMs is often difficult. This project explored the possibility of designing HDRM-analogue devices that would replicate the function of flight HDRMs during ground-based testing for a fraction of the cost of a flight HDRM. These devices were designed with the requirements of the Spin Eject Mechanism to be used on the Mars Sample Return (MSR) Capture, Containment, and Return System (CCRS) in mind. A trade study was conducted to determine the optimal internal mechanism design of the device, comparing several mechanisms from existing HDRMs to several simpler, more novel mechanisms. CAD software was used to create a preliminary design of the device utilizing a mix of commercial off-the-shelf parts and custom-manufactured parts. Several straightforward analyses were conducted to determine the most effective models for the off-the-shelf parts. A prototype largely composed of 3D-printed components was also created to proof the design concept. Although this HDRM simulator was designed for a particular mechanism for the CCRS mission, its general design is useful for ground testing of a variety of mechanisms requiring similar HDRM simulators.

Kian Vilhauer↗
NASA NTRS1993

Optimal design of a composite structure

This paper presents a design methodology for a laminated composite stiffened panel, subjected to multiple in-plane loads and bending moments. Design variables include the skin and stiffener ply orientation angles and stiffener geometry variables. Optimum designs are sought which minimize structural weight and satisfy mechanical performance requirements. Two types of mechanical performance requirements are placed on the panel, maximum strain and minimum strength. Minimum weight designs are presented which document that the choice of mechanical performance requirements cause changes in the optimum design. The effects of lay-up constraints which limit the ply angles to user specified values, such as symmetric or quasi-isotropic laminates, are also investigated.

Graesser, D. L.↗
DOE OSTI2024

Mechanisms and site requirements for NO and NH 3 oxidation on Cu/SSZ-13

Two series of Cu/SSZ-13 catalysts were synthesized via aqueous solution and solid-state ion exchange using SSZ-13 supports of varying Si/Al ratios. The isolated and multinuclear Cu content of these catalysts were determined by H 2 temperature programmed reduction (H 2 -TPR). Multinuclear Cu in these catalysts, including in situ Cu- dimers formed from ZCu II OH coupling and permanent CuO clusters, are active species for dry NO oxidation. NH 3 oxidation on these catalysts follows an internal SCR (i-SCR) mechanism, i.e., a portion of NH 3 is first oxidized to NO, then NO is selectively reduced by the remaining NH 3 to N 2 . NH 3 oxidation displays distinct kinetic behavior below ~300 °C and above ~400 °C. At low temperature the results indicate that NH 3 -solvated mobile Cu-ions are the active centers. CuO clusters, when present, also contribute to the low temperature activity by catalyzing NH 3 oxidation to NO. At high temperature, in situ Cu-dimers and CuO clusters catalyze NH 3 oxidation to NO, and isolated Cu-ions catalyze SCR to realize the cascade turnovers. For both NO and NH 3 oxidation, Cu-dimers balanced by framework charges of close proximity appear to be more active than Cu-dimers balanced by distant framework charges. However, the former Cu-dimers are less stable than the latter and tend to split into monomers in the presence of vicinal Brønsted acid sites. Via density functional theory (DFT) calculations, the i-SCR mechanism for low temperature NH 3 oxidation, i.e., the energetic favorability for the involvement of the NO intermediate, is justified. Furthermore, the DFT results also agree with experimental data that the formation of Cu-dimers from ZCu II OH dimerization is essential for NH 3 oxidation at high temperature.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1992

SOHO MAMA openable cover/vacuum seal mechanism

The requirements, design, and test results of an openable cover mechanism with a high-vacuum seal developed for the Multi-Anode Microchannel Array (MAMA) Detectors, aboard the Solar and Heliospheric Observatory (SOHO) spacecraft. The mechanism, tested in summer/fall of 1991, has completed 1000 test cycles in an inert atmosphere at room temperature and pressure. Measured mechanism performance included: vacuum seal less than 5 x 10 exp -10 torr-liter/second, 103 degree angular range of travel, 20-minute cycle time, and successful latching functions. An openable cover mechanism that provides a clean, high-vacuum seal is vital to the success of a MAMA Detector operating over a full wavelength coverage from 500 to 1600 A.

Wiens, Mitchell T.↗
NASA NTRS1995

Requirements for energy based constitutive modeling in tire mechanics

The history, requirements, and theoretical basis of a new energy based constitutive model for (rubber) material elasticity, hysteresis, and failure are presented. Energy based elasticity is handled by many constitutive models, both in one dimension and in three dimensions. Conversion of mechanical energy to heat can be modeled with viscoelasticity or as structural hysteresis. We are seeking unification of elasticity, hysteresis, and failure mechanisms such as fatigue and wear. An energy state characterization for failure criteria of (rubber) materials may provide this unification and also help explain the interaction of temperature effects with failure mechanisms which are described as creation of growth of internal crack surface. Improved structural modeling of tires with FEM should result from such a unified constitutive theory. The theory will also guide experimental work and should enable better interpretation of the results of computational stress analyses.

Luchini, John R.↗
NASA NTRS1983

Space telescope: Solar array primary deployment mechanism

The requirements, the design, and the test program which were carried out in producing the Space Telescope Solar Array (STSA) primary deployment mechanisms (PDM) are described. The PDM will be used to rotate the rolled solar array supporting boom from its launch position alongside the telescope housing, through 90 deg to its use position. After five years in space the array is to be rerolled and by use of the PDM swung back to its stowed position alongside the telescope housing for capture and return to Earth via the Space Shuttle.

Chandler, D. P.↗
NASA NTRS1981

ATS-6 engineering performance report. Volume:Program and systems summaries: Mechanical and thermal details

The overall mission and spacecraft systems, testing, and operations are summarized. The mechanical subsystems are reviewed, encompassing mechanical design requirements; separation and deployment mechanisms; design and performance evaluation; and the television camera reflector monitor. Thermal control and contamination are discussed in terms of thermal control subsystems, design validation, subsystems performance, the advanced flight experiment, and the quartz-crystal microbalance contamination monitor.

Wales, R. O.↗
NASA NTRS1998

Arabidopsis thaliana responses to mechanical stimulation do not require ETR1 or EIN2

Plants exposed to repetitive touch or wind are generally shorter and stockier than sheltered plants. These mechanostimulus-induced developmental changes are termed thigmomorphogenesis and may confer resistance to subsequent stresses. An early response of Arabidopsis thaliana to touch or wind is the up-regulation of TCH (touch) gene expression. The signal transduction pathway that leads to mechanostimulus responses is not well defined. A role for ethylene has been proposed based on the observation that mechanostimulation of plants leads to ethylene evolution and exogenous ethylene leads to thigmomorphogenetic-like changes. To determine whether ethylene has a role in plant responses to mechanostimulation, we assessed the ability of two ethylene-insensitive mutants, etr1-3 and ein2-1, to undergo thigmomorphogenesis and TCH gene up-regulation of expression. The ethylene-insensitive mutants responded to wind similarly to the wild type, with a delay in flowering, decrease in inflorescence elongation rate, shorter mature primary inflorescences, more rosette paraclades, and appropriate TCH gene expression changes. Also, wild-type and mutant Arabidopsis responded to vibrational stimulation, with an increase in hypocotyl elongation and up-regulation of TCH gene expression. We conclude that the ETR1 and EIN2 protein functions are not required for the developmental and molecular responses to mechanical stimulation.

Non-NASA Center↗
NASA NTRS2013

Elusive Ethylene Detected in Saturns Northern Storm Region

The massive eruption at 40 deg. N (planetographic latitude) on Saturn in 2010 December has produced significant and lasting effects in the northern hemisphere on temperature and species abundances. The northern storm region was observed on many occasions in 2011 by Cassini's Composite Infrared Spectrometer (CIRS). In 2011 May, temperatures in the stratosphere greater than 200 K were derived from CIRS spectra in the regions referred to as "beacons" (warm regions in the stratosphere). Ethylene has been detected in the beacon region in Saturn's northern storm region using CIRS. Ground-based observations using the high-resolution spectrometer Celeste on the McMath-Pierce Telescope on 2011 May 15 were used to confirm the detection and improve the altitude resolution in the retrieved profile. The derived ethylene profile from the CIRS data gives a C2H4 mole fraction of 5.9 +/- 4.5 x 10(exp -7) at 0.5 mbar, and from Celeste data it gives 2.7 +/- 0.45 x 10(exp -6) at 0.1 mbar. This is two orders of magnitude higher than the amount measured in the ultraviolet at other latitudes prior to the storm. It is also much higher than predicted by photochemical models, indicating that perhaps another production mechanism is required or a loss mechanism is being inhibited.

Hesman, B. E.↗
NASA NTRS2014

Deployable Greenhouse for Food Production

The X-HAB team in the CU Graduate Projects course was tasked with developing a Distributed Robotic Plant Production System (DRoPPS) that provided remote food production capability for long-duration space missions. The system consists of a Remotely Operated Gardening Robot (ROGR) and a Smart Pot (SPOT). SPOT was designed to grow a plant in a hydroponic system, while also providing multiple sensor data feedback to a remote user. ROGR was designed to give a remote user a method of moving SPOT and caring for the plant. A User Interface (UI) was created to provide a means by which a remote user could interact with the system. At the conclusion of the semester, ROGR was 95% complete, and only required minor mechanical fixes. SPOT was 85% complete, and required additional machining of mechanical parts. The UI was 75% complete, and required additional functionality and user testing. The project was not fully completed due to the scope of the project. Regardless, multiple team members have agreed to continue working on the project to finish by the June 1st presentation day at NASA.

Nikolaus Correll↗
NASA NTRS1988

Integrated resource scheduling in a distributed scheduling environment

The Space Station era presents a highly-complex multi-mission planning and scheduling environment exercised over a highly distributed system. In order to automate the scheduling process, customers require a mechanism for communicating their scheduling requirements to NASA. A request language that a remotely-located customer can use to specify his scheduling requirements to a NASA scheduler, thus automating the customer-scheduler interface, is described. This notation, Flexible Envelope-Request Notation (FERN), allows the user to completely specify his scheduling requirements such as resource usage, temporal constraints, and scheduling preferences and options. The FERN also contains mechanisms for representing schedule and resource availability information, which are used in the inter-scheduler inconsistency resolution process. Additionally, a scheduler is described that can accept these requests, process them, generate schedules, and return schedule and resource availability information to the requester. The Request-Oriented Scheduling Engine (ROSE) was designed to function either as an independent scheduler or as a scheduling element in a network of schedulers. When used in a network of schedulers, each ROSE communicates schedule and resource usage information to other schedulers via the FERN notation, enabling inconsistencies to be resolved between schedulers. Individual ROSE schedules are created by viewing the problem as a constraint satisfaction problem with a heuristically guided search strategy.

Zoch, David↗
NASA NTRS2014

Fundamental Property Requirements for Thermal and Mechanical Response Analysis of Thermal Protection Materials and Systems

Spacecraft that are designed to reenter the Earth's atmosphere, or enter the atmosphere of another planet, require Thermal Protection Systems (TPS) in order to survive the extreme thermal environments during the atmospheric flight. Analytical modeling of thermal and mechanical response is a fundamental aspect of the design of TPS and development of TPS materials. The analyses are used to understand the response of the materials and systems under representative environments. Performing these analyses, and evaluating the results, requires a variety of fundamental inputs, including: thermal and mechanical material properties; predicted or measured ground test and flight environments; and information about adjacent structure or attachments. We explain the nature of the analyses, highlight the essential fundamental data that are required, and describe the impact of the accuracy in the input data on the final results. We also describe the important priorities in material characterization testing in support of analyses.

Squire, Thomas↗