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At least 145 records · Page 8

Occupant Preference-Aware Load Scheduling for Resilient Communities

The load scheduling of resilient communities in the islanded mode is subject to many uncertainties such as weather forecast errors and occupant behavior stochasticity. To date, it remains unclear how occupant preferences affect the effectiveness of the load scheduling of resilient communities. This paper proposes an occupant thermal preference-aware load scheduler for resilient communities operating in the islanded mode. First, key resilience indicators are selected to quantify its impacts on the load scheduling of a resilient community. A deterministic model predictive control-based load scheduling framework is adopted as the baseline. Then, a chance-constrained controller is proposed to address the occupant-induced uncertainty in room temperature setpoints. Finally, the chance-constrained controller is compared with the deterministic controller on a virtual community testbed based on a real-world net-zero energy community in Florida, U.S. Results have shown that the proposed chance-constrained controller performs better in terms of serving occupants’ thermal preference and the required battery sizes compared to the deterministic controller with the presence of the assumed stochastic occupant behavior. This work indicates that it is necessary to consider the stochasticity of the occupant behavior when designing optimal load schedulers for resilient communities.

Wang, Jing↗

Implementation of Statistical Process Control: Evaluating the Mechanical Performance of a Candidate Silicone Elastomer Docking Seal

The National Aeronautics and Space Administration has been developing a novel docking system to meet the requirements of future exploration missions to low-Earth orbit and beyond. A dynamic gas pressure seal is located at the main interface between the active and passive mating components of the new docking system. This seal is designed to operate in the harsh space environment, but is also to perform within strict loading requirements while maintaining an acceptable level of leak rate. In this study, a candidate silicone elastomer seal was designed, and multiple subscale test articles were manufactured for evaluation purposes. The force required to fully compress each test article at room temperature was quantified and found to be below the maximum allowable load for the docking system. However, a significant amount of scatter was observed in the test results. Due to the stochastic nature of the mechanical performance of this candidate docking seal, a statistical process control technique was implemented to isolate unusual compression behavior from typical mechanical performance. The results of this statistical analysis indicated a lack of process control, suggesting a variation in the manufacturing phase of the process. Further investigation revealed that changes in the manufacturing molding process had occurred which may have influenced the mechanical performance of the seal. This knowledge improves the chance of this and future space seals to satisfy or exceed design specifications.

docking seal↗

Radio frequency mixing modules for superconducting qubit room temperature control systems

As the number of qubits in nascent quantum processing units increases, the connectorized RF (radio frequency) analog circuits used in first generation experiments become exceedingly complex. The physical size, cost, and electrical failure rate all become limiting factors in the extensibility of control systems. We have developed a series of compact RF mixing boards to address this challenge by integrating I/Q quadrature mixing, intermediate frequency/LO (local oscillator)/RF power level adjustments, and direct current bias fine tuning on a 40 × 80 mm 2 four-layer printed circuit board with electromagnetic interference shielding. The RF mixing module is designed to work with RF and LO frequencies between 2.5 and 8.5 GHz. The typical image rejection and adjacent channel isolation are measured to be ~27 dBc and ~50 dB. By scanning the drive phase in a loopback test, the module short-term amplitude and phase linearity are typically measured to be 5 ×10 -4 (V pp /V mean ) and 1 ×10 -3 radian (pk-pk). The operation of the RF mixing board was validated by integrating it into the room temperature control system of a superconducting quantum processor and executing randomized benchmarking characterization of single and two qubit gates. We measured a single-qubit process infidelity of 9.3(3) × 10 -4 and a two-qubit process infidelity of 2.7(1) × 10 -2 .

47 OTHER INSTRUMENTATION↗

DAQExpert the service to increase CMS data-taking efficiency

The Data Acquisition (DAQ) system of the Compact Muon Solenoid (CMS) experiment at the LHC is a complex system responsible for the data readout, event building and recording of accepted events. Its proper functioning plays a critical role in the data-taking efficiency of the CMS experiment. In order to ensure high availability and recover promptly in the event of hardware or software failure of the subsystems, an expert system, the DAQ Expert, has been developed. It aims at improving the data taking efficiency, reducing the human error in the operations and minimising the on-call expert demand. Introduced in the beginning of 2017, it assists the shift crew and the system experts in recovering from operational faults, streamlining the post mortem analysis and, at the end of Run 2, triggering fully automatic recovery without human intervention. DAQ Expert analyses the real-time monitoring data originating from the DAQ components and the high-level trigger updated every few seconds. It pinpoints data flow problems, and recovers them automatically or after given operator approval. We analyse the CMS downtime in the 2018 run focusing on what was improved with the introduction of automated recovery; present challenges and design of encoding the expert knowledge into automated recovery jobs. Furthermore, we demonstrate the web-based, ReactJS interfaces that ensure an effective cooperation between the human operators in the control room and the automated recovery system. We report on the operational experience with automated recovery.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Steric and Electronic Influence of Excited-State Decay in Cu(I) MLCT Chromophores

For the past eleven years, a dedicated effort in our research group focused on fundamentally advancing the photophysical properties of cuprous bis-phenanthroline-based metal-to-ligand charge transfer (MLCT) excited states. We rationalized that by gaining control over the numerous factors limiting the more widespread use of Cu I MLCT photosensitizers, they would be readily adopted in numerous light-activated applications given the earth-abundance of copper and the extensive library of 1,10-phenanthrolines developed over the last century. Significant progress has been achieved by recognizing valuable structure-property concepts developed by other researchers in tandem with detailed ultrafast and conventional time-scale investigations, in-silico-inspired molecular designs to predict spectroscopic properties, and applying novel synthetic methodologies. Ultimately, we achieved a plateau in exerting cooperative steric influence to control Cu I MLCT excited state decay. This led to combining sterics with π-conjugation and/or inductive electronic effects to further exert control over molecular photophysical properties. The lessons gleaned from our studies of homoleptic complexes were recently extended to heteroleptic bis(phenanthrolines) featuring enhanced visible light absorption properties and long-lived room-temperature photoluminescence. Furthermore, this Account navigates the reader through our intellectual journey of decision-making, molecular and experimental design, and data interpretation in parallel with appropriate background information related to the quantitative characterization of molecular photophysics using Cu I MLCT chromophores as prototypical examples.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Space vehicle thermal testing: Principles, practices and effectiveness

Component qualification and acceptance temperatures are derived from worst case thermal analyses and analytic uncertainty margin subject to certain specified temperature extremes. Temperature requirements are shown for equipment operation within specification and for survival and turn-on (need not operate within specification, but must not experience any degradation when returned to operational range). Temperature excursions for most equipment are seen to be 20 to 50 C above and below room temperature. Components without active electronics which are mounted outboard, such as solar arrays and antennas, are usually designed to withstand wider temperature excursions, particularly at the cold end. Batteries are tightly controlled at cold temperatures to increase life. Payload components such as extremely accurate clocks for precise navigation are controlled over a relatively narrow temperature range.

Gluck, Donald F.↗

Development of magnetostrictive active members for control of space structures

The goal of this Phase 2 Small Business Innovative Research (SBIR) project was to determine the technical feasibility of developing magnetostrictive active members for use as truss elements in space structures. Active members control elastic vibrations of truss-based space structures and integrate the functions of truss structure element, actively controlled actuator, and sensor. The active members must control structural motion to the sub-micron level and, for many proposed space applications, work at cryogenic temperatures. Under this program both room temperature and cryogenic temperature magnetostrictive active members were designed, fabricated, and tested. The results of these performance tests indicated that room temperature magnetostrictive actuators feature higher strain, stiffness, and force capability with lower amplifier requirements than similarly sized piezoelectric or electrostrictive active members, at the cost of higher mass. Two different cryogenic temperature magnetostrictive materials were tested at liquid nitrogen temperatures, both with larger strain capability than the room temperature magnetostrictive materials. The cryogenic active member development included the design and fabrication of a cryostat that allows operation of the cryogenic active member in a space structure testbed.

Johnson, Bruce G.↗

End-Use Savings Shapes Measure Documentation: Demand Control Ventilation

This documentation focuses on a single end-use savings shape measure - Demand Control Ventilation (DCV). DCV can save energy by reducing the rate at which outdoor air (OA) is delivered during periods of less-than-design occupancy. This measure will enable DCV for air loops using applicable HVAC system types (all except dedicated outdoor air systems [DOAS], packaged systems, or that have an energy recovery ventilator [ERV]) and serving applicable space types (all except kitchens, dining areas, patient spaces, mechanical rooms, stairwells and corridors, or high exhaust space types) using model occupancy schedules to control the DCV. The measure is applicable to 72.7% of the stock floor area. As office buildings outside of California in ComStock are modeled using a single, whole-building space type, DCV is not applied to these building types. The DCV measure demonstrates 2.6% total site energy savings (119 trillion British thermal units [TBtu]) for the U.S. commercial building stock modeled in ComStock.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Role of Fast Dynamics in Conductivity of Polymerized Ionic Liquids

Polymerized ionic liquids (PolyILs) are promising candidates for a broad range of technologies. However, the relatively low conductivity of PolyILs at room temperature has strongly limited their applications. In this work, we provide new insights into the roles of various microscopic parameters controlling ion transport in these polymers, which are crucial for their rational design and practical applications. Using broadband dielectric spectroscopy and neutron and light scattering techniques, we found a clear connection between the activation energy for conductivity, fast dynamics, and high-frequency shear modulus in PolyILs at their glass transition temperature (T g ). In particular, our analysis reveals a correlation between conductivity and the amplitude of fast picosecond fluctuations at T g , suggesting the possible involvement of fast dynamics in lowering the energy barrier for ion conductivity. We also demonstrate that both the activation energy for ion transport and the amplitude of the fast fluctuations depend on the high-frequency shear moduli of PolyILs, thus identifying a practically important parameter for tuning conductivity. Finally, the parameters recognized in this work and their connection to the ionic conductivity of PolyILs set the stage for a deeper understanding of the mechanism of ion transport in PolyILs in the glassy state.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Man-machine interfaces in health care

The surgeon, like the pilot, is confronted with an ever increasing volume of voice, data, and image input. Simultaneously, the surgeon must control a rapidly growing number of devices to deliver care to the patient. The broad disciplines of man-machine interface design, systems integration, and teleoperation will play a role in the operating room of the future. The purpose of this communication is to report the incorporation of these design concepts into new surgical and laser delivery systems. A review of each general problem area and the systems under development to solve the problems are presented.

Charles, Steve↗

Toll-Booth Purification

NASA's Technology Application Team at Stanford Research Institute searched available information and suggested a transfer of clean-room technology employing the use of the same laminar flow techniques found in environmental control systems of clean rooms used for contamination-free assembly of precision aerospace equipment. That information, from technology originally developed by NASA and the Energy Research & Development Administration was incorporated in the design of a prototype toll booth purifier. The draft-free design includes a "diffusor", which blows clean air out the toll booth doorway, thus retarding the infiltration of contaminated air. The net effect is a decrease in the toll collector's inhalation of exhaust fumes. The Washington Department of Highways installed the prototype system in a toll booth at the Evergreen Point Bridge near Seattle. After a successful two-year test, the department now has equipped all 10 of the bridge's toll booths with the air purifiers.

Source record↗

Dyes in dye aggregate systems—engineering J, K, and dye packing

The present disclosure is directed to designing dyes and methods to alter the parameters controlling the dipole-dipole coupling of dyes bound to a nucleotide oligomer architecture, which are used to propagate excitons for use in next generation room temperature quantum information systems. The disclosed dyes and methods are directed to changing the dye stability, symmetry, overlap, and steric hindrance of the dyes to fine tune aggregate systems.

Knowlton, William B.↗

Dynamic Human-in-the-Loop Simulated Nuclear Power Plant Thermal Dispatch System Demonstration and Evaluation Study

An Idaho National Laboratory research team performed a human-in-the-loop study with two formerly licensed retired operators to evaluate thermal power dispatch operations supported by the modified GSE Systems GPWR plant simulator. Virtual representations of the analog control panels were presented on touch-screen bays configured to mimic the control room layout in the newly renovated Human Systems Simulation Laboratory. The operators performed 15 scenarios covering normal evolutions to transition the plant from full turbine operation to joint turbine and thermal power dispatch operations in addition to transient response scenarios induced with simulated faults to evaluate the impact of thermal power dispatch system on operator and plant responses. A prototype human-system interface (HSI) was developed and displayed in tandem with the virtual analog panels to support the operators executing the procedurally drive evolutions and transient responses. An interdisciplinary team of operations experts, nuclear engineers, and human factors experts observed the operators performing the scenarios to evaluate the operations. Only a preliminary analysis of the results has been performed. The full analysis will be shared in a milestone report scheduled for release at the end of September; however, some high-level conclusions were readily available. Two high level findings for the system design were captured in the study. The manual control supported by the HSI to transition from standard operations to thermal power dispatch operation imposed a considerable amount of workload on the operators due to tedious manual valve manipulations and system monitoring required to verify their intended effect. An additional operator would be required in the control room to support the daily evolution. Automatic control for the transition was deemed a requirement for plant adoption without imposing additional staffing costs. The second finding was the necessity for an automatic thermal power dispatch system trip isolation function linked to a turbine and reactor trip signal. The operators completed scenarios with automatic isolation functionality and manually required actuation of the thermal power dispatch system. The operator response was sufficiently slower in the manual trip condition, such that operators were unable to manually actuate key post trip safety functions an indicate a degraded control capability that should be avoided. With an automatic trip signal little to no impact of the thermal power dispatch system was identified on the primary plant response and therefore the system could be readily and safely adopted. Together these two findings represent the need to support the adoption of thermal power dispatch capability into existing operations by leveraging automation to augment any additional operator tasking required to control and monitor an additional system beyond existing operations.

99 GENERAL AND MISCELLANEOUS↗

Clean is not Sterile: A Planetary Science and Planetary Protection Perspective on Cleanroom Microbiology at NASA

The Astromaterials Acquisition and Curation Office at NASA is responsible for the curation of extraterrestrial samples from NASA’s past and future sample return missions. Our office curates samples from the moon, meteorites, comets, asteroids, cosmic dust and solar wind particles. All these samples are kept in cleanrooms to limit particulate and trace metal contamination, but none of these cleanrooms are specifically designed to control microbial contamination. During the early Apollo missions NASA scientists were very concerned with protecting the Earth from potential microbial contamination from the moon and with protecting the lunar samples from terrestrial microbes. NASA developed specialized equipment and clean rooms to keep these collections pristine. However, as we learned more about the lunar environment our concerns about microbial contamination lessened. Today none of the existing collections have microbial contamination requirements because they are not considered susceptible to microbial alteration under curation conditions (e.g. solar wind samples, and lunar samples) or have already been contaminated by terrestrial biology (meteorites collected in Antarctica). However, NASA’s OSIRIS-REx mission will land in 2023 with samples from a carbon rich asteroid that will be susceptible to microbial alteration. The Perseverance rover on Mars will begin to collect and cache samples that will be returned to Earth as soon as 2031. Martian samples may contain signs of extraterrestrial life and will have to be treated like the early Apollo samples. Martian samples will be isolated to protect the Earth, and must also be protected from terrestrial contamination. I will present microbial monitoring data from existing NASA cleanrooms and discuss how NASA is planning to use techniques from the pharmaceutical industry and academia to design new laboratories and equipment that will protect astromaterials and the earth from unwanted microbial contamination. I will also discuss a project to sample the external microbiome of the International Space Station. Results from this research will be used to design facilities for use on Mars that limit the amount of contamination associated with crewed missions.

Aaron B Regberg↗

Human factors dimensions in the evolution of increasingly automated control rooms for near-earth satellites

The NASA-Goddard Space Flight Center is responsible for the control and ground support for all of NASA's unmanned near-earth satellites. Traditionally, each satellite had its own dedicated mission operations room. In the mid-seventies, an integration of some of these dedicated facilities was begun with the primary objective to reduce costs. In this connection, the Multi-Satellite Operations Control Center (MSOCC) was designed. MSOCC represents currently a labor intensive operation. Recently, Goddard has become increasingly aware of human factors and human-machine interface issues. A summary is provided of some of the attempts to apply human factors considerations in the design of command and control environments. Current and future activities with respect to human factors and systems design are discussed, giving attention to the allocation of tasks between human and computer, and the interface for the human-computer dialogue.

Mitchell, C. M.↗

A Custom Robotic System for Inspecting HEPA Filters in the Payload Changeout Room at the NASA Kennedy Space Center

In this paper, the prime objective is to describe a custom 4-dof (degree-of-freedom) robotic arm capable of autonomously or telerobotically performing systematic HEPA filter inspection and certification in the Shuttle Launch Pad Payload Changeout Rooms (PCR's) on pads A and B at the Kennedy Space Center, Florida. This HEPA filter inspection robot (HFIR) has been designed to be easily deployable and is equipped with the necessary sensory devices, control hardware, software and man-machine interfaces needed to implement HEPA filter inspection reliably and efficiently without damaging the filters or colliding with existing PCR structures or filters. The main purpose of the HFIR is to implement an automated positioning system to move special inspection sensors in pre-defined or manual patterns for the purpose of verifying filter integrity and efficiency. This will ultimately relieve NASA Payload Operations from significant problems associated with time, cost and personnel safety, impacts realized during non-automated PCR HFIR filter certification.

Spencer, James E., Jr.↗

On-board Optical Spectrometry for Detection of Mixture Ratio and Eroded Materials in Rocket Engine Exhaust Plume

Optical spectrometry can provide means to characterize rocket engine exhaust plume impurities due to eroded materials, as well as combustion mixture ratio without any interference with plume. Fiberoptic probes and cables were designed, fabricated and installed on Space Shuttle Main Engines (SSME), allowing monitoring of the plume spectra in real time with a Commercial of the Shelf (COTS) fiberoptic spectrometer, located in a test-stand control room. The probes and the cables survived the harsh engine environments for numerous hot-fire tests. When the plume was seeded with a nickel alloy powder, the spectrometer was able to successfully detect all the metallic and OH radical spectra from 300 to 800 nanometers.

Barkhoudarian, Sarkis↗

Room Temperature Electrorefining of Rare Earth Metals from End-of-use Nd-Fe-B Magnets

Recovering rare earth elements (REE) from used permanent magnets, which contains about 30 wt.% of rare earth elements, has been persistent technological challenge. Current recycling methods relies on pyrometallurgical or hydrometallurgical processes which are energy- and chemical- intensive and not economically and environmentally viable for rare earth containing magnets. Enabling efficient and simplistic recovery and refining of REEs contained in End-of-Use (EoU) products, such as Neodymium-Iron-Boron (Nd-Fe-B) based magnets will play an important and complementary role in the total supply of REEs in the future. We designed a new electrochemical method and demonstrated a room temperature one-pot process that concurrently separates and electroplates REE from commercial Nd-Fe-B magnets. By establishing selective oxidation and reductive potential as electrochemical control parameter along with electrochemically compatible non-aqueous electrolyte system, we demonstrated selective electroleaching of lanthanides (Nd and Preseodymium (Pr)) from anode and concurrent plating as alloy at Pt cathode. The morphological and chemical evolution of the Nd-Fe-B magnets during electroleaching reveals the electrochemical stimuli and rate of dissolution depends on microstructural complexities of the Nd-Fe-B magnet. The concomitant electroplating process leads to Nd-Pr based alloy which can be used as raw metallic alloy for manufacturing new permanent magnet and other devices. Our study demonstrates a scalable separation and refining methodology, based on widely available organic electrolyte system and without any consumptive chemical use, for selective lanthanide recovery from waste magnets.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗