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At least 775 records · Page 43

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NASA NTRSDate not supplied

Enabling Simulation Interoperability between International Standards in the Space Domain

Today, the design and development of space systems are conducted cooperatively by historical space agencies in this area such as NASA, ESA, Roscosmos, and JAXA together with their industrial partners. The space system lifecycle is characterized by high costs, uncertain conditions, and dangerous scenarios. To mitigate these issues, space agencies rely heavily on Modelling and Simulation as a key technology to support the analysis, design, and operation of space systems. To support large-scale distributed simulations, the scientific community has developed several standards to support the reuse and interoperability of simulation models such as IEEE 1516 High-Level Architecture (HLA), Real-time Platform Reference Federation Object Model (RPR FOM), Simulation Model Portability (SMP), and the novel Space Reference Federation Object Model (SpaceFOM). While the SpaceFOM standard has been specifically conceptualized for handling space systems, the other ones are more general-purpose and can be used to design and simulate generic complex systems. As a consequence, there is a lake of rules and guidelines to enable interoperability among these standards. The paper presents solutions and experiences for enabling interoperability and transferability of HLA, RPR FOM, and SMP simulation models with SpaceFOM.

Simulation↗

NASA NTRS2022

Preliminary Analysis of Separation Standards for Urban Air Mobility using Unmitigated Fast-Time Simulation

This research provides a preliminary analysis of various separation standards for Urban Air Mobility (UAM) operations. This study focuses on understanding and analyzing potential conflicts between UAM flights and conflicts between UAM and conventional aircraft. Fast-time simulations are conducted with a projected high-density of UAM traffic scenario and historical conventional non-UAM traffic flying under Instrument Flight Rules (IFR) or Visual Flight Rules (VFR) in Dallas Fort Worth (DFW) airspace. The conflicts are analyzed by examining losses of separation and near mid-air collisions of UAM flights and unmitigated risk of collision. A set of varied separation standards are used to investigate the impact of the new UAM operations on safety. The preliminary conflict analysis results will help inform separation standards development and in airspace and route design activities for future UAM operations.

Urban air mobility↗

NASA NTRSDate not supplied

Preliminary Analysis of Separation Standards for Urban Air Mobility using Unmitigated Fast-Time Simulation

Urban Air Mobility↗

NASA NTRS2022

Guidebook for the Design and Analysis of a NASA Standard Nondestructive Evaluation (NDE) Probability of Detection (POD) Study

Purpose: This document provides guidance on the design and analysis of a NASA Standard nondestructive evaluation (NDE) probability of detection (POD) study. A Standard NDE flaw size is considered to be conservative such that most inspectors, trained and certified in the specific NDE method, are expected to provide at least 90/95 POD for that flaw size to inspect fracture-critical hardware. Scope: This document is specifically applicable to NASA Technical Standards that establish the NDE requirements for any NASA system or component, flight or ground, where fracture control and a quantitative demonstration of POD is a requirement, including NASA-STD-5009B, Nondestructive Evaluation Requirements for Fracture-Critical Metallic Components, and NASA-STD-5019A,Fracture Control Requirements for Spaceflight Hardware.

Probability of Detection↗

DOE OSTI2014

Agent-Based Modleing of Power Plants Placement to Evaluate the Clean Energy Standard Goal

There is a political push for utilities to supply a specified share of their electricity sales from clean energy resources under the clean energy standard (CES). The goal is to achieve 80% clean energy by 2035. However, there are uncertainties about the ability of the utility industry to ramp up quickly even with the incentives that will be provided. Water availability from the streams is one of the major factors. The contiguous United States is divided into eighteen water regions, and multiple states share water from a single water region. Consequently, water usage decisions made in one state (located upstream of a water region that crosses multiple states) will greatly impact what is available downstream in another state. In this paper, an agent-based modeling approach is proposed to evaluate the clean energy standard goal for water-dependent energy resources. Specifically, using a water region rather than a state boundary as a bounding envelope for the modeling and starting at the headwaters, virtual power plants are placed based on the conditions that there is: (i) suitable land to site a particular power plant, (ii) enough water that meet regulatory guidelines within 20 miles of the suitable land, and (iii) a 20-mile buffer zone from an existing or a virtual power plant. The results obtained are discussed in the context of the proposed clean energy standard goal for states that overlap with one water region.

agent-based modeling↗

DOE OSTI2015

Tips and Tricks of Incorporating Industry Standards into a Library Collection

Professional literature on the incorporation of industry standards into a library collection is somewhat limited. The objective of this presentation is to discuss the intricate details of acquiring, managing, and delivering electronic industry standards to library patrons in a seamless manner. Lessons learned regarding vendor selection and license agreements will also be discussed. Results from a survey administer at the National Renewable Energy Laboratory will be used to analyze how collection policies can properly be developed to incorporate industry standards into a library setting. The key points of acquisition decisions, avoidance of liability issues, and cost will be addressed.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2016

Comparison of Standard Wind Turbine Models with Vendor Models for Power System Stability Analysis: Preprint

The International Electrotechnical Commission Standard 61400-27-1 was published in February 2015. This standard deals with the development of generic terms and parameters to specify the electrical characteristics of wind turbines. Generic models of very complex technological systems, such as wind turbines, are thus defined based on the four common configurations available in the market. Due to its recent publication, the comparison of the response of generic models with specific vendor models plays a key role in ensuring the widespread use of this standard. This paper compares the response of a specific Gamesa dynamic wind turbine model to the corresponding generic IEC Type III wind turbine model response when the wind turbine is subjected to a three-phase voltage dip. This Type III model represents the doubly-fed induction generator wind turbine, which is not only one of the most commonly sold and installed technologies in the current market but also a complex variable-speed operation implementation. In fact, active and reactive power transients are observed due to the voltage reduction. Special attention is given to the reactive power injection provided by the wind turbine models because it is a requirement of current grid codes. Further, the boundaries of the generic models associated with transient events that cannot be represented exactly are included in the paper.

17 WIND ENERGY↗

DOE OSTI2016

The effect of the NERC CIP standards on the reliability of the North American Bulk Electric System

Considerable money and effort has been expended by generation, transmission, and distribution entities in North America to implement the North American Electric Reliability Corporation (NERC) Critical Infrastructure Protection (CIP) standards for the bulk electric system. Assumptions have been made that as a result of the implementation of the standards, the grid is more cyber secure than it was pre-NERC CIP, but are there data supporting these claims, or only speculation? Has the implementation of the standards had an effect on the grid? Furthermore, developing a research study to address these and other questions provided surprising results.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2022

Cybersecurity Certification Standard for Distributed Energy and Inverter Based Resources

NREL and UL co-presented on their joint effort to develop a cybersecurity certification standard for distributed energy resources (DERs) at a meeting of the Cybersecurity Advisory Team for State Solar (CATSS). The advisory team is hosted by NASEO & NARUC. The presentation outlined the benefits of a cybersecurity certification standard, the outcomes of previous initiatives, how this effort reflects the evolving electric grid, and the role of state energy offices. UL explained their role as a trusted third party with expertise to lead this effort and the process from Outline of Investigation (OOI) to a certification standard.

BPS↗

DOE OSTI2023

Offshore Wind Workforce Safety Standards and Training Resource

The standardization of safety training requirements for people working at sea to build and operate offshore wind energy projects, adoption of those standards, and alignment with offshore safety training curriculum development was identified as a high-priority workforce gap in the U.S. Offshore Wind Workforce Assessment (Stefek, 2022). Safety is a top priority for the offshore wind industry; however, there has been uncertainty surrounding what unique safety standards and training will be needed and how various offshore wind safety stakeholders will be involved. The scope of safety training for this resource includes workers who build and operate offshore wind energy projects at sea and defines the stakeholders in the complex ecosystem. This fact sheet aims to help reduce these uncertainties by: 1) Delineating jurisdictional lines, while clarifying roles and responsibilities amongst stakeholders; 2) Identifying key actions or partnerships that can encourage further success with safety training and workforce development.

offshore wind↗

DOE OSTI2024

Creating a Universal PV Plug and Socket Standard

Photovoltaic connectors are designed to be quick and easy to install. Current connector qualification standards, such as UL 6703 and IEC 62852, are only intended to evaluate connectors from the same manufacturer and were recently changed to explicitly proscribe the mating of connectors from different manufacturers. Unfortunately, the industry has chosen to design connectors that will commonly connect together with those from other manufacturers. This is done to simplify installation avoiding the situations such as when the connectors on a microinverter, or other module level power electronics, do not match the connectors on the modules in the system. This rampant violation of electrical codes worldwide indicates that there is a strong desire and need to develop a universal connector standard. Here we present the initial approach and philosophy behind the formation of an IEC subgroup under TC82 WG2 looking at this problem. We intend to develop a standard where the materials and geometry of construction are specified to ensure compatibility and the design is intended to be of the highest quality. We expect that this connector will be more costly but especially in rooftop installations where power electronics requires matching components from several manufacturers, that this may still result in a net cost savings. These connectors must be of the highest quality because we wouldn’t want to develop a connector that precluded the manufacturing of a higher quality product, and because these will most commonly be used on rooftop installations where safety is more of a concern. Additionally, because we do not know which brands of connectors will be used together, we cannot simply rely on test results to ensure safety but must create a design that is as inherently safe as possible.

connectors↗

DOE OSTI2024

Reducing Risk With ASHRAE Standard 241

ASHRAE Standard 241’s requirements can make indoor spaces more resilient to the spread of airborne infectious diseases. Buildings that comply with ASHRAE Standard 241-2023, Control of Infectious Aerosols,1 will have the capacity to respond during times of elevated risk with systems that provide the necessary equivalent clean airflow for infection control (VECAi). To reduce risk effectively, these systems need to operate properly. This column explores Standard 241’s requirements for operations and maintenance in high-risk times (infection risk management mode or IRMM) and the importance of creating a Building Readiness Plan.

ashrae standard 241, Operations and Maintenance, b↗

DOE OSTI2025

Domestic and international consensus standards for nuclear criticality safety – overview & status [Abstract]

The domestic and international consensus standards for nuclear criticality safety (NCS) were developed as the lessons-learned from process criticality accidents. These consensus standards were developed to reduce the rate of process criticality accidents in facilities that process, store, handle or transport fissionable materials by hand. After a significant increase in criticality accidents through the mid-1960’s, the rate of criticality accidents decreased due to these standards and the criticality accident rate is extremely low from an industrial safety perspective.

ANS↗

DOE OSTI2019

Design standardization of unit operations for reducing the capital intensity and cost of small‐scale chemical processes

Abstract A methodology is proposed to reduce the cost and capital intensity of small‐scale chemical processes by creating new opportunities for economies of numbers through standardizing the equipment designs across multiple processes. We depart from asynchronous design of single‐processes and adopt a common‐functionality based simultaneous design of multiple processes that use similar unit operations. A generalized cost function is used to appropriately balance the trade‐offs between economies of scale and economies of numbers. An optimization‐based framework for design standardization is developed and illustrated using two case studies. The first involves the simultaneous synthesis of methanol and ammonia processes, and the second addresses the optimal synthesis of multi‐column natural gas liquid (NGL) fractionation processes for different natural gas sources. We observe that considerable reduction in capital intensity of small‐scale processes is possible through equipment standardization.

Arora, Akhil↗

DOE OSTI2014

Impersonating the Standard Model Higgs boson: Alignment without decoupling

In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the Z boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to “alignment without decoupling”, therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of tan β for which this happens are derived in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. In addition, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the m A – tan β parameter space.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2017

Weak gravity conjecture, multiple point principle and the standard model landscape

The requirement for an ultraviolet completable theory to be well-behaved upon compactification has been suggested as a guiding principle for distinguishing the landscape from the swampland. Motivated by the weak gravity conjecture and the multiple point principle, we investigate the vacuum structure of the standard model compactified on S 1 and T 2 . The measured value of the Higgs mass implies, in addition to the electroweak vacuum, the existence of a new vacuum where the Higgs field value is around the Planck scale. We explore two- and three-dimensional critical points of the moduli potential arising from compactifications of the electroweak vacuum as well as this high scale vacuum, in the presence of Majorana/Dirac neutrinos and/or axions. We point out potential sources of instability for these lower dimensional critical points in the standard model landscape. We also point out that a high scale AdS 4 vacuum of the Standard Model, if exists, would be at odd with the conjecture that all non-supersymmetric AdS vacua are unstable. We argue that, if we require a degeneracy between three- and four-dimensional vacua as suggested by the multiple point principle, the neutrinos are predicted to be Dirac, with the mass of the lightest neutrino ≈O(1–10) meV, which may be tested by future CMB, large scale structure and 21cm line observations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2019

The Randomized Freeway Stent Study: Drug-Eluting Balloons Outperform Standard Balloon Angioplasty for Postdilatation of Nitinol Stents in the SFA and PI Segment

Purpose: The prospective randomized multicenter Freeway study evaluated the possible hemodynamic and clinical benefits of primary stent insertion followed by percutaneous transluminal angioplasty (PTA) with drug-eluting balloons (DEB) over post-stent insertion PTA with standard balloons in the treatment of symptomatic femoropopliteal arteriosclerotic lesions. Methods: In total, 204 patients in 13 centers in Germany and Austria were enrolled and randomized to primary stenting followed by either FREEWAY™ drug-eluting balloon or standard PTA balloon angioplasty. The primary endpoint was the rate of clinically driven target lesion revascularization (TLR) at 6 months; the secondary endpoints include TLR rate at 12 months and primary patency, shift in Rutherford classification, ankle–brachial index (ABI) and major adverse events (MAE) at 6 and 12 months. Lesion characteristics and vessel patency were analyzed by an independent and blinded corelab. Results: At 6-month and 12-month follow-up, TLR rate was lower in the DEB arm compared to standard PTA but did not reach statistical significance (4.1% vs. 9.0% p = 0.234 and 7.9% vs. 17.7% p = 0.064, respectively). Primary patency was significantly better for patients treated with the DEB at 6 months (90.3% vs. 69.8% p = 0.001) and 12 months (77.4% vs. 61.0% p = 0.027). Improvement in Rutherford classifications was likewise significantly better for patients in the DEB group at 6 (94.9% vs. 84.3% p = 0.027) and 12 months (95.5% vs. 79.9% p = 0.003). The percentage of patients with an improved ABI of 1.0–1.2 was significantly higher in the DEB group compared to the PTA group at 6 months (55.3% vs. 35.3%; p = 0.015) but without significant difference at 12 months (48.2% vs. 32.9%; p = 0.055). At 6 months, rate of major adverse events (MAE) was 1% in both arms, and at 12 months 2.2% for the DEB and 3.8% for the PTA group. Conclusion: The Freeway Stent Study shows that the usage of DEB as a restenosis prophylaxis seems to be safe and feasible. The 12-month follow-up results give a clear sign in favor of the DEB group.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2018

Testing Fluorescence Lifetime Standards using Two-Photon Excitation and Time-Domain Instrumentation: Fluorescein, Quinine Sulfate and Green Fluorescent Protein

It is essential for everyone working with experimental science to be certain that their instruments produce reliable results, and for fluorescence lifetime experiments, information about fluorescence lifetime standards is crucial. A large part of the literature on lifetime standards dates back to the 1970s and 1980s, and the use of newer and faster measuring devices may deem these results unreliable. We have tested the three commonly used fluorophores fluorescein, quinine sulfate and green fluorescent protein for their suitability to serve as lifetime standards, especially to be used with two-photon excitation measurements in the time-domain. We measured absorption and emission spectra for the fluorophores to determine optimal wavelengths to use for excitation and detector settings. Fluorescence lifetimes were measured for different concentrations, ranging from 10{sup − 3} − 10{sup − 5} M, as well as for various solvents. Fluorescein was soluble in both ethanol, methanol and sulfuric acid, while quinine sulfate was only soluble in sulfuric acid. Green fluorescent protein was prepared in a commercial Tris-HCl, EDTA solution, and all three fluorophores produced stable lifetime results with low uncertainties. No siginificant variation with concentration was measured for any of the fluorophores, and all showed single-exponential decays. All lifetime measurements were carried out using two-photon excitation and lifetime data was obtained in the time-domain using time-correlated single-photon counting.

74 ATOMIC AND MOLECULAR PHYSICS↗