Results for “Interface” — Page 75

DOE OSTI2020

An energy-based coupling approach to nonlocal interface problems.

Nonlocal models provide accurate representations of physical phenomena ranging from fracture mechanics to complex subsurface flows, settings in which traditional partial differential equation models fail to capture effects caused by long-range forces at the microscale and mesoscale. However, the application of nonlocal models to problems involving interfaces, such as multimaterial simulations and fluid-structure interaction, is hampered by the lack of a physically consistent interface theory which is needed to support numerical developments and, among other features, reduces to classical models in the limit as the extent of nonlocal interactions vanish. In this paper, we use an energy-based approach to develop a formulation of a nonlocal interface problem which provides a physically consistent extension of the classical perfect interface formulation for partial differential equations. Numerical examples in one and two dimensions validate the proposed framework and demonstrate the scope of our theory.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2020

Human-System Interface Design Review Guidelines

The U.S. Nuclear Regulatory Commission (NRC) staff reviews the human factors engineering (HFE) aspects of nuclear power plants in accordance with the Standard Review Plan (NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition). The Human Factors Engineering Program Review Model (NUREG-0711, Revision 3, issued November 2012) contains detailed design review procedures. As part of the review process, the interfaces between plant personnel and the plant's systems and components are evaluated for conformance with HFE guidelines. This document, Human-System Interface Design Review Guidelines (NUREG-0700, Revision 3), provides the guidelines necessary to perform this evaluation. The review guidelines address the physical and functional characteristics of human-system interfaces (HSIs). Because these guidelines only address the HFE aspects of design and not other related considerations, such as instrumentation and control and structural design, they are referred to as HFE guidelines. In addition to the review of actual HSIs, the NRC staff can use the NUREG-0700 guidelines to evaluate a design-specific HFE guidelines document or style guide. The HFE guidelines are organized into four basic parts, which are divided into sections. Part I contains guidelines for the basic HSI elements: information displays, user-interface interaction and management, and analog displays and controls. These elements are used as building blocks to develop HSI systems to serve specific functions. Part II contains the guidelines for reviewing the following HSI systems: alarm system, safety parameter display system, group-view display system, soft control system, computer-based procedure system, automation system, and communication system. Part III provides guidelines for the review of workstations and workplaces. Part IV provides guidelines for the review of HSI support (i.e., maintainability of digital systems and degraded HSI and instrumentation and control conditions).

42 ENGINEERING↗

DOE OSTI2024

A versatile approach to stabilize liquid-liquid interfaces using surfactant self-assembly

Stabilizing liquid–liquid interfaces, whether between miscible or immiscible liquids, is crucial for a wide range of applications, including energy storage, microreactors, and biomimetic structures. In this study, a versatile approach for stabilizing the water-oil interface is presented using the morphological transitions that occur during the self-assembly of anionic, cationic, and nonionic surfactants mixed with fatty acid oils. The morphological transitions underlying this approach are characterized and extensively studied through small-angle X-ray scattering (SAXS), rheometry, and microscopy techniques. Dissipative particle dynamics (DPD) as a simulation tool is adopted to investigate these morphological transitions both in the equilibrium ternary system as well as in the dynamic condition of the water-oil interface. Such a versatile strategy holds promise for enhancing applications such as liquid-in-liquid 3D printing. Moreover, it has the potential to revolutionize a wide range of fields where stabilizing liquid–liquid interfaces not only offers unprecedented opportunities for fine-tuning nanostructural morphologies but also imparts interesting practical features to the resulting liquid shapes. These features include perfusion capabilities, self-healing, and porosity, which could have significant implications for various industries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRSDate not supplied

Creating an Interface to view Multi-Spacecraft Swarm Telemetry

Distributed Spacecraft Systems are a type of multi-spacecraft mission architecture that can not only provide improved resolution, coverage, and availability of existing missions, but also enable missions that would be previously infeasible using traditional approaches. Distributed Spacecraft Autonomy (DSA) is a project developed by the National Aeronautics and Space Administration that enables distributed spacecraft systems. In previous science swarm missions, the spacecraft involved have not been able to communicate with each other without utilizing a ground station. Now that the spacecraft can perform inter-satellite communication, the spacecraft can be treated as a collective. Swarm autonomy is critical for a growing number of satellites which means novel ways of displaying swarm data needs to be implemented. Such systems introduce unique challenges to traditional approaches for command and control of these spacecraft, due to the large number of spacecraft and the complexity of the interactions between them. The ground data system for DSA addresses these challenges through the creation of a custom user interface that allows a single operator to orchestrate a multi-spacecraft swarm in a scalable way. This plenary describes the details of the autonomy demonstration being performed, the requirements of those using the interface to analyze the spacecraft telemetry to assess demonstration success, and the approach taken by the ground systems team to create an interface that satisfies these requirements. This approach involves the creation of several distinct components that correspond to the level of detail presented to the user. These components are based on conventional user roles in human-robot interaction, including supervisor, operator, and mechanic, extended to accommodate the additional overhead of coordinating actions between agents. One main feature of the interface is the listenability matrix component which will represent inter-satellite communications in a heat mapped matrix. The above work described will enable users to command and interact with the spacecraft as a collective.

human-swarm interaction↗

NASA NTRSDate not supplied

Establishing Trust in NASA’s Artemis Program Computer-Human Interface (CHI) Implementation

The NASA Artemis program will return humans to the moon. This time, with the help of commercial and international partners, the program’s objective is a permanent moon base. The moon base infrastructure, including an orbiting moon station and moon surface assets, will be developed for astronauts to stay for the long haul to learn to live and work on another planet in preparation for an eventual Humans-to-Mars mission. As the roundtrip communication delays increase in deep space exploration, more onboard systems autonomy and functionality will be needed to maintain and control the vehicle or habitat. These mission constraints will change the current Earth-based spacecraft ground control support approach that will demand more safe, efficient, and effective Computer-Human Interface (CHI) control. For Artemis, CHI is defined as the elements that the crew interfaces with-audio, video, lighting, and crew controls. Understanding how CHI will need to evolve to support deep space missions will be critical for the Artemis program-especially crew controls which is the focus of this paper. How does NASA ensure crew controls are reliable to control complex systems and prevent a catastrophic event due to human error-especially when the astronauts could be physiologically and/or psychologically impaired? NASA’s approach to mitigating catastrophic hazards in human spaceflight system development such as crew controls is through a holistic system engineering and Human System Integration methodology that embraces NASA’s Human-Rating Requirements-ensuring human performance characteristics to control/safely recover the crew from hazardous situations within the human interface design are considered. This paper discusses, at a high level, CHI for the Artemis program. Next, a discussion of what it means to human-rate a space system crew controls and how trust in the human-computer interface begins with the NASA human rating requirements. Finally, a discussion on how systems engineering, and the human system integration process ensures that crew control implementation incorporates the NASA human-rating requirements.

Human-Rating↗

NASA NTRSDate not supplied

Establishing Trust in NASA’s Artemis Campaign Computer-Human Interface (CHI) Implementation

The NASA Artemis program will return humans to the Moon. This time, with the help of commercial and international partners, the program's objective is a permanent moon base. The moon base infrastructure, including an orbiting moon station and moon surface assets, will be developed for astronauts to stay for the long haul to learn to live and work on another planet in preparation for an eventual Humans-to-Mars mission. As the roundtrip communication delays increase in deep space exploration, the crew will need more onboard systems autonomy and functionality to maintain and control the vehicle or habitat. These mission constraints will change the current Earth-based spacecraft to ground control support approach that will demand more safe, efficient, and effective Computer-Human Interface (CHI) control. For Artemis, CHI is defined as the elements that the crew interfaces with: audio, video, lighting, and crew controls subsystems. Understanding how CHI will need to evolve to support deep space missions will be critical for the Artemis program--especially crew controls, which is the focus of this paper. How does NASA ensure crew controls are reliable enough to control complex systems and prevent a catastrophic event due to human error--especially when the astronauts could be physiologically and/or psychologically impaired? NASA's approach to mitigating catastrophic hazards in human spaceflight system development such as crew controls, is through a holistic system engineering and Human System Integration methodology that focuses on incorporating NASA's Human-Rating Requirements-that ensures human performance characteristics to control/safely recover the crew from hazardous situations within the human interface design are considered. This paper discusses, at a high level, CHI for the Artemis program. Next, a discussion of what it means to human-rate a space system crew controls and how trust in the human-computer interface begins with the NASA human rating requirements. Finally, a discussion on how systems engineering and the human system integration process ensures that crew control implementation incorporates the NASA human-rating requirements.

artemis↗

NASA NTRSDate not supplied

Developing and Testing Two Interfaces for Supplemental Data Service Provider (SDSP) Tools to Support UAS Traffic Management (UTM)

Researchers conducted a usability study using two graphical user interfaces (GUIs) to explore how individuals interpret and interact with different preflight information displays, and to inform the development of Uncrewed Aircraft System (UAS) preflight planning predictive support tools to assess and mitigate flight hazards and risks. A series of preflight risk-assessment tasks were developed to evaluate participant performance using the Supplemental Data Service Provider-Consolidated Dashboard (SDSP-CD) and the Human Automation Team Interface System (HATIS) GUIs. Participants were trained to use both interfaces and their performance was evaluated. These evaluations focused on participants’ preflight planning activities. Objective data on performance tasks across different scenarios involving multi-UASs, as well as self-reports of interactions and subjective experiences using the GUIs were collected. Scores on the system usability scale (SUS) and on a simple task set were examined, as well as user feedback on open-ended questions, to inform development and identify potential improvements to the interfaces.

sUAAV interfaces↗

NASA NTRSDate not supplied

Developing and Testing Two Interfaces for Supplemental Data Service Provider (SDSP) Tools to Support UAS Traffic Management (UTM)

Researchers conducted a usability study using two graphical user interfaces (GUIs) to explore how individuals interpret and interact with different preflight information displays, and to inform the development of Uncrewed Aircraft System (UAS) preflight planning predictive support tools to assess and mitigate flight hazards and risks. A series of preflight risk-assessment tasks were developed to evaluate participant performance using the Supplemental Data Service Provider-Consolidated Dashboard (SDSP-CD) and the Human Automation Team Interface System (HATIS) GUIs. Participants were trained to use both interfaces and their performance was evaluated. These evaluations focused on participants’ preflight planning activities. Objective data on performance tasks across different scenarios involving multi-UASs, as well as self-reports of interactions and subjective experiences using the GUIs were collected. Scores on the system usability scale (SUS) and on a simple task set were examined, as well as user feedback on open-ended questions, to inform development and identify potential improvements to the interfaces.

sUAAV interfaces↗

NASA NTRSDate not supplied

Establishing Trust in NASA’s Artemis Campaign Computer-Human Interface (CHI) Implementation

The NASA Artemis program will return humans to the Moon. This time, with the help of commercial and international partners, the program's objective is a permanent moon base. The moon base infrastructure, including an orbiting moon station and moon surface assets, will be developed for astronauts to stay for the long haul to learn to live and work on another planet in preparation for an eventual Humans-to-Mars mission. As the roundtrip communication delays increase in deep space exploration, the crew will need more onboard systems autonomy and functionality to maintain and control the vehicle or habitat. These mission constraints will change the current Earth-based spacecraft to ground control support approach that will demand more safe, efficient, and effective Computer-Human Interface (CHI) control. For Artemis, CHI is defined as the elements that the crew interfaces with: audio, video, lighting, and crew controls subsystems. Understanding how CHI will need to evolve to support deep space missions will be critical for the Artemis program--especially crew controls, which is the focus of this paper. How does NASA ensure crew controls are reliable enough to control complex systems and prevent a catastrophic event due to human error--especially when the astronauts could be physiologically and/or psychologically impaired? NASA's approach to mitigating catastrophic hazards in human spaceflight system development such as crew controls, is through a holistic system engineering and Human System Integration methodology that focuses on incorporating NASA's Human-Rating Requirements-that ensures human performance characteristics to control/safely recover the crew from hazardous situations within the human interface design are considered. This paper discusses, at a high level, CHI for the Artemis program. Next, a discussion of what it means to human-rate a space system crew controls and how trust in the human-computer interface begins with the NASA human rating requirements. Finally, a discussion on how systems engineering and the human system integration process ensures that crew control implementation incorporates the NASA human-rating requirements.

artemis↗

DOE OSTI2013

Interaction of Thermal Phonons with Interfaces

In this chapter we will first explore the connection between interface scattering and thermal transport using the Boltzmann transport equation (BTE). It will be shown that Boltzmann transport provides a convenient method for considering boundary scattering in nanochannel structures. For internal interfaces such as grain boundaries found in polycrystals, it is more natural to consider transmission and reflection across a single boundary. In this regard we will discuss theories related to interface thermal resistance. Our qualitative discussion of the theories of phonon transport will be followed by a discussion of experimental techniques for measuring thermal transport. We end this chapter by giving a detailed description of two complimentary experimental techniques for measuring the influence of interfaces on thermal phonon transport.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Investigation of radiation damage tolerance in interface-containing metallic nano structures

The proposed work seeks to conduct a basic study by applying experimental and computational methods to obtain quantitative influence of helium sink strength and proximity on He bubble nucleation and growth in He-irradiated nano-scale metallic structures, and the ensuing deformation mechanisms and mechanical properties. We utilized a combination of nano-scale in-situ tension and compression experiments on low-energy He-irradiated samples combined with site-specific microstructural characterization and modeling efforts. We also investigated the mechanical deformation of nano-architected materials, i.e. nanolattices which are comprised of 3-dimensional interwoven networks of hollow tubes, with the wall thickness in the nanometer range. This systematic approach will provide us with critical information for identifying key factors that govern He bubble nucleation and growth upon irradiation as a function of both sink strength and sink proximity through an experimentally-confirmed physical understanding. As an outgrowth of these efforts, we performed irradiations with self-ions (Ni 2+ ) on Ni-Al-Zr metallic glass nanolattices to assess their resilience against radiation damage rather than He-ion implantation. We focused our attention on studying individual bcc/fcc interfaces within a single nano structure (nano-pillar or a hollow tube): a single Fe (bcc)-Cu (fcc) boundary per pillar oriented perpendicular to the pillar axes, as well as pure bcc and fcc nano structures. Additional interfaces of interest include bcc/bcc and metal/metallic glass all within a single nano-structure volume. The model material systems are: (1) pure single crystalline Fe and Cu, (2) a single Fe (bcc)-Cu (fcc) boundary per nano structure (3) a single metal–metallic glass, all oriented non-parallel to the loading direction so that their fracture strength can be tested. A nano-fabrication approach, which involves e-beam lithography and templated electroplating, as well as two-photon lithography, was utilized, which enabled precise control of the initial microstructure control. Experimentally determined stress-strain relationships were enhanced by in-situ SEM observations coupled with TEM microstructural characterization of the same samples before and after deformation (irradiated and as-fabricated) and atomistic (MD) modeling. A comprehensive suite of experiments was conducted to quantitatively assess the key parameters for He bubble nucleation and growth by independently varying the sink strength, sink proximity, and He implantation temperature and dose. The implantations were conducted at Sandia and Los Alamos National Labs (CINT). Nano structuress containing He-enriched interfaces and irradiation-damaged microstructure were tested under uniaxial tension to assess embrittlement, resulting boundary strength, and deformation mechanisms. Results of this work helped identify which types of interfaces are particularly resilient against radiation damage.

36 MATERIALS SCIENCE↗

DOE OSTI2023

PHIL Interface Design for Use With a Voltage-Regulated Amplifier: Preprint

As inverter controls have become increasingly complex, power hardware-in-the-loop (PHIL) has emerged as a leading strategy to thoroughly assess the impact of proprietary inverter controls on a specific power system. The development of a PHIL test bed typically involves the desired inverter, a power amplifier, and a digital real-time simulator (DRTS) to control the simulated power system. As a result of PHIL nonidealities, a form of digital compensation within the DRTS is used, which is commonly referred to as a PHIL interface. The interface design for PHIL test beds has been previously examined in the literature, but many existing methods use older power amplifiers that do not contain internal voltage regulation. These existing interface methods are based around a voltage regulator within the DRTS rather than one preexisting in hardware. In this study, a three-step approach of PHIL interface development for modern power amplifiers with built-in voltage regulation is introduced and validated in hardware with a single 30-kW grid-following inverter.

DRTS↗

DOE OSTI2013

Recent Improvements in Interface Management for Hanford's Waste Treatment and Immobilization Plant - 13263

The U.S. Department of Energy (DOE), Office of River Protection (ORP) is responsible for management and completion of the River Protection Project (RPP) mission, which includes the Hanford Site tank farms operations and the Waste Treatment and Immobilization Plant (WTP). The RPP mission is to store, retrieve and treat Hanford's tank waste; store and dispose of treated wastes; and close the tank farm waste management areas and treatment facilities by 2047. The WTP is currently being designed and constructed by Bechtel National Inc. (BNI) for DOE-ORP. BNI relies on a number of technical services from other Hanford contractors for WTP's construction and commissioning. These same services will be required of the future WTP operations contractor. Partly in response to a DNFSB recommendation, the WTP interface management process managing these technical services has recently been improved through changes in organization and issue management. The changes are documented in an Interface Management Plan. The organizational improvement is embodied in the One System Integrated Project Team that was formed by integrating WTP and tank farms staff representing interfacing functional areas into a single organization. A number of improvements were made to the issue management process but most notable was the formal appointment of technical, regulatory and safety subject matter experts to ensure accurate identification of issues and open items. Ten of the thirteen active WTP Interface Control Documents have been revised in 2012 using the improved process with the remaining three in progress. The value of the process improvements is reflected by the ability to issue these documents on schedule and accurately identify technical, regulatory and safety issues and open items. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

Performance and Reliability of Interface Materials for Automotive Power Electronics (Presentation)

Thermal management and reliability are important because excessive temperature can degrade the performance, life, and reliability of power electronics and electric motors. Advanced thermal management technologies enable keeping temperature within limits; higher power densities; and lower cost materials, configurations and systems. Thermal interface materials, bonded interface materials and the reliability of bonded interfaces are discussed in this presentation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

Chemo‐Mechanics Interplay Dictates Interface Instability and Asymmetry in Plating and Stripping of Sodium Metal Electrodes

Abstract The development of practical sodium (Na) metal batteries is hindered by key challenges including dendrite growth, dead metal formation, and unstable solid electrolyte interphase (SEI) growth. A fundamental understanding of the chemo‐mechanical interactions at the Na/SEI interface is critical for designing stable Na metal electrodes. In this work, the coupled electrochemical‐mechanical processes governing the morphological evolution and stability of Na metal during plating and stripping are investigated. The heterogeneous nature of transport and morphological interactions at the Na/SEI interface is revealed to result in nonuniform mechanical overpotentials and reaction fronts, eventually leading to Na filaments or pits. The spatio‐temporal evolution of stress heterogeneities during Na plating and stripping is shown to be asymmetric, manifesting in varying morphological nonuniformities and instability modes. The crucial role of external pressure in modulating the electrochemical‐transport interactions, the mechanical response of Na, and the localized reaction currents and stresses at the Na/SEI interface is demonstrated. At different external pressure conditions, the correlation between transport heterogeneities in the SEI and the onset and propagation of interface instability has been delineated. This work highlights the need for synergistic tailoring of external pressure and SEI heterogeneity toward achieving stable electrodeposition and dissolution in Na metal electrodes.

Singla, Aditya [School of Mechanical Engineering P↗

DOE OSTI2019

Building Reconfigurable Devices Using Complex Liquid–Fluid Interfaces

Liquid-fluid interfaces provide a platform both for structuring liquids into complex shapes and assembling dimensionally confined, functional nanomaterials. Historically, attention in this area has focused on simple emulsions and foams, in which surface-active materials such as surfactants or colloids stabilize structures against coalescence and alter the mechanical properties of the interface. In recent decades, however, a growing body of work has begun to demonstrate the full potential of the assembly of nanomaterials at liquid-fluid interfaces to generate functionally advanced, biomimetic systems. In this work, a broad overview is given, from fundamentals to applications, of the use of liquid-fluid interfaces to generate complex, all-liquid devices with a myriad of potential applications.

36 MATERIALS SCIENCE↗

DOE OSTI2019

Surface and Interface Properties in Thin‐Film Solar Cells: Using Soft X‐rays and Electrons to Unravel the Electronic and Chemical Structure

Abstract Thin‐film solar cells have great potential to overtake the currently dominant silicon‐based solar cell technologies in a strongly growing market. Such thin‐film devices consist of a multilayer structure, for which charge‐carrier transport across interfaces plays a crucial role in minimizing the associated recombination losses and achieving high solar conversion efficiencies. Further development can strongly profit from a high‐level characterization that gives a local, electronic, and chemical picture of the interface properties, which allows for an insight‐driven optimization. Herein, the authors' recent progress of applying a “toolbox” of high‐level laboratory‐ and synchrotron‐based electron and soft X‐ray spectroscopies to characterize the chemical and electronic properties of such applied interfaces is provided. With this toolbox in hand, the activities are paired with those of experts in thin‐film solar cell preparation at the cutting edge of current developments to obtain a deeper understanding of the recent improvements in the field, e.g., by studying the influence of so‐called “post‐deposition treatments”, as well as characterizing the properties of interfaces with alternative buffer layer materials that give superior efficiencies on large, module‐sized areas.

Weinhardt, Lothar↗

DOE OSTI2021

A Morphologically Stable Li/Electrolyte Interface for All-Solid-State Batteries Enabled by 3D-Micropatterned Garnet

Morphological degradation at the Li/solid-state electrolyte (SSE) interface is a prevalent issue causing performance fading of all-solid-state batteries (ASSBs). To maintain the interfacial integrity, most ASSBs are operated under low current density with considerable stack pressure, which significantly limits their widespread usage. In this work, a novel 3D-micropatterned SSE (3D-SSE) that can stabilize the morphology of the Li/SSE interface even under relatively high current density and limited stack pressure is reported. Under the pressure of 1.0 MPa, the Li symmetric cell using a garnet-type 3D-SSE fabricated by laser machining shows a high critical current density of 0.7 mA cm –2 and stable cycling over 500 h under 0.5 mA cm –2 . This excellent performance is attributed to the reduced local current density and amplified mechanical stress at the Li/3D-SSE interface. These two effects can benefit the flux balance between Li stripping and creep at the interface, thereby pre-venting interfacial degradation such as void formation and dendrite growth.

3D-micropatterned garnet↗