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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Simple Acceptance Decisions and Acceptance Risk

Acceptance risk may be estimated using cumulative probability distribution functions applied to populations of measurands and test measurement values. “Simple acceptance” is a decision rule that sets the acceptance range of a test result equal to the tolerance range specification. While acceptance risk is comprised of both consumer risk and producer risk, this paper compares the effects of simple acceptance decision rules and guardbanding decision rules on consumer risk. Consumer risk is also known as the probability of false acceptance. The terms describe the risk of accepting test results as passing when the actual values exceed specification limits. False acceptance is only possible when the true value of a measurand is out of tolerance and the test result indicates that the measurand is within tolerance. Metrologists generally have some information about the test uncertainty regarding a specific acceptance test result. Along with a general lack of knowledge regarding the measurand population parameters, the complicated interplay between risk, dispersion, and central values generally prevents calibration laboratories from fully characterizing acceptance probabilities. Organizations that model the measurand populations can reduce consumer risk by avoiding certification of items whose measurand populations are not well centered. The models in this paper present a recurring trend: guardbanding reduces nonnegligible risks of false acceptance when compared to simple acceptance. However, guardbanding is not the most effective means of acceptance risk mitigation. Systematic characterization of measurand populations can provide the information a calibration laboratory needs to reliably control acceptance risk.

42 ENGINEERING↗
DOE OSTI2015

The structure of PccH from Geobactersulfurreducens-a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode

The structure of cytochrome c (GSU3274) designated as PccH from Geobactersulfurreducens was determined at a resolution of 2.0 angstrom. PccH is a small (15kDa) cytochrome containing one c-type heme, found to be essential for the growth of G.sulfurreducens with respect to accepting electrons from graphite electrodes poised at -300mV versus standard hydrogen electrode. with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH has a low reduction potential of -24mV at pH7, which is unusual for monoheme cytochromes. Based on difference in structure, together with sequence phylogenetic analysis, we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by G. sulfurreducens. Because PccH is predicted to be located in the periplasm of this bacterium, it could not be involved in the first step of accepting electrons from the electrode but is very likely involved in the downstream electron transport events in the periplasm.

Dantas, Joana↗
DOE OSTI2024

Pathways to IEC Standards for Heliostat Design Qualification and Site Acceptance in Central Receiver CSP Applications

This paper surveys the existing landscape of standards relevant to heliostats, identifies their gaps, and proposes a path forward to a comprehensive set of heliostat guidelines, technical specifications, and standards under the framework of International Electrotechnical Commission (IEC) TC 117. Gaps in existing guidelines and standards are surveyed using a three-tiered taxonomy: component-level, heliostat-level, and field-level. At each level, the gap analysis is followed by a proposal for a coordinated path forward on the development of standards. At the component level, advances in the understanding of wind loading should inform a technical specification for drives and structures. Reflectors require consolidation of measurement guidelines into existing standards documents. Communications & controls require technical standards to inform their selection and secure implementation. At the heliostat level, IEC 62817 (solar trackers) adequately characterizes drive systems, structures, and electronics, but requires adaptation to heliostats' use patterns, operating modes, and expected life cycles. IEC 62817 does not address heliostat beam quality and pointing accuracy, but the process for determining both is elaborated in the SolarPACES Guideline for Heliostat Performance Testing. This SolarPACES document requires two main modifications: adaptation to IEC language and inclusion of testing after heliostats which have undergone accelerated weathering and mechanical cycling (to understand performance degradation). At the field level, IEC 62862-4-2 addresses the function and control of heliostat fields but does not cover the statistically rigorous testing of heliostat groups, or field performance factors like security and soiling. The addition of documents under IEC-62862-4 is proposed to address this gap.

beam↗
DOE OSTI2025

User Acceptance of Shared Autonomous Vehicles

A dissertation is proposed to explore user acceptance of shared autonomous vehicles (SAVs). SAVs are facing limited user acceptance. To systematically tackle the user acceptance barriers of SAVs, the main problem can be disintegrated into two sub-problems of user acceptance of autonomous vehicles (AVs) and ridesharing. The comfort of the ride experience in AVs is a determinant of user acceptance. Understanding the influential factors and developing methodologies to quantify human comfort in AVs are essential to facilitating future research to improve human comfort in AVs. The current pooled rideshare (PR) service closely resembles the anticipated future of SAVs. Understanding why users prefer or refuse to use PR at the current stage prepares SAVs for broader acceptance in the future. Until now, a series of peer-reviewed publications have been published to achieve the technical goals. Two simulator-based user studies were conducted to instrument the research on human comfort in AVs. Statistical analysis was performed to identify the crucial vehicular behavioral factors of human comfort in AVs. The influential factors of human comfort in AVs and methodologies to quantify and detect human comfort in AVs were investigated. Two survey-based studies were deployed to facilitate the investigation of user acceptance of rideshare services. The influential factors of users' willingness to consider PR were explored and identified, and the choice behaviors in ridesharing services were comprehensively modeled and analyzed. The proposed research answers a series of fundamental questions regarding the user acceptance of SAVs. For the branch of user acceptance of AVs, the research generated guidelines for improving passenger comfort in AVs by identifying a series of autonomous driving factors of passenger comfort. The research also provides fundamental tools to estimate human comfort levels for future research and in-AV applications. For the branch of user acceptance of PR, the research provided user acceptance-aware vehicle, service, and policy design insights that can promote the usage of PR.

Su, Haotian↗
DOE OSTI2015

Development and Structure/Property Relationship of New Electron Accepting Polymers Based on Thieno[2',3':4,5]pyrido[2,3- g ]thieno[3,2- c ]quinoline-4,10-dione for All-Polymer Solar Cells

Several electron accepting polymers having weak accepting–strong accepting (WA-SA) and strong accepting–strong accepting (SA-SA) monomer alternation were synthesized for studies of structure/property relationship in all-polymer solar cells. Two kinds of cyclic amide monomers, 4,10-bis(2-butyloctyl)-thieno[2',3':5,6]pyrido[3,4-g]thieno-[3,2-c]isoquinoline-5,11-dione (TPTI) and 5,11-bis(2-butyloctyl)-thieno[2',3':4,5]pyrido[2,3-g]thieno[3,2-c]quinoline-4,10-dione (TPTQ), were synthesized as weak accepting monomers (WA). Difluorinated TPTQ (FTPTQ) and well-known perylene diimide (PDI) monomers were synthesized as strong electron accepting monomers (SA). By using 1-chloronaphthalene (CN) as a cosolvent, the morphology of the polymer blended films can be finely tuned to achieve better ordering toward face-on mode and favorable phase separation between electron donor and acceptor, resulting in significant enhancement of short circuit current (Jsc) and fill factor (FF). The fluorination in the TPTQ unit reduced the dipole moment of the D–A complex and gave a negative effect on a polymer system. PFP showed worse electron accepting property with lower electron mobility than PQP. It is reasoned that the internal polarization plays an important role in the design of electron accepting polymers. As a result, PQP having TPTQ monomer exhibited the best photovoltaic performance with power conversion efficiency (PCE) of 3.52% (Voc = 0.71 V, Jsc = 8.57 mA/cm2, FF = 0.58) at a weight ratio of PTB7-Th:PQP = 1:1, under AM 1.5G.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Impact of community engagement on public acceptance towards waste-to-energy incineration projects: Empirical evidence from China

Highlights: • How community engagement affects public acceptance towards WTE projects is studied. • Public acceptance is affected by demographic variables. • Public trust positively affects public acceptance both directly and indirectly. • Community engagement can effectively enhance public trust in WTE authorities. - Abstract: As one of the most popular methods for the treatment of municipal solid waste (MSW), waste-to-energy (WTE) incineration offers effective solutions to deal with the MSW surge and globe energy issues. Nevertheless, the construction of WTE facilities faces considerable and strong opposition from local communities due to the perceived potential risks. The present study aims to understand whether, and how, community engagement improves local residents’ public acceptance towards waste-to-energy (WTE) incineration facilities using a questionnaire survey conducted with nearby residents of two selected WTE incineration plants located in Zhejiang province, China. The results of data analysis using Structural Equation Modeling (SEM) reveal that firstly, a lower level of public acceptance exists among local residents of over the age of 35, of lower education levels, living within 3 km from the WTE Plant and from WTE incineration Plants which are under construction. Secondly, the public trust of local government and other authorities was positively associated with the public acceptance of the WTE incineration project, both directly and indirectly based on perceived risk. Thirdly, community engagement can effectively enhance public trust in local government and other authorities related to the WTE incineration project. The findings contribute to the literature on MSW treatment policy-making and potentially hazardous facility siting, by exploring the determinants of public acceptance towards WTE incineration projects.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2014

Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans

Purpose: The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. Methods: The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Results: Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference in the performance of any device between gamma criteria of 2%/2 mm, 3%/3 mm, and 5%/3 mm. Finally, optimal cutoffs (e.g., percent of pixels passing gamma) were determined for each device and while clinical practice commonly uses a threshold of 90% of pixels passing for most cases, these results showed variability in the optimal cutoff among devices. Conclusions: IMRT QA devices have differences in their ability to accurately detect dosimetrically acceptable and unacceptable plans. Field-by-field analysis with a MapCheck device and use of the MapCheck with a MapPhan phantom while delivering at planned rotational gantry angles resulted in a significantly poorer ability to accurately sort acceptable and unacceptable plans compared with the other techniques examined. Patient-specific IMRT QA techniques in general should be thoroughly evaluated for their ability to correctly differentiate acceptable and unacceptable plans. Additionally, optimal agreement thresholds should be identified and used as common clinical thresholds typically worked very poorly to identify unacceptable plans.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

SU-F-T-475: An Evaluation of the Overlap Between the Acceptance Testing and Commissioning Processes for Conventional Medical Linear Accelerators

Purpose: This work’s objective is to determine the overlap of processes, in terms of sub-processes and time, between acceptance testing and commissioning of a conventional medical linear accelerator and to evaluate the time saved by consolidating the two processes. Method: A process map for acceptance testing for medical linear accelerators was created from vendor documentation (Varian and Elekta). Using AAPM TG-106 and inhouse commissioning procedures, a process map was created for commissioning of said accelerators. The time to complete each sub-process in each process map was evaluated. Redundancies in the processes were found and the time spent on each were calculated. Results: Mechanical testing significantly overlaps between the two processes - redundant work here amounts to 9.5 hours. Many beam non-scanning dosimetry tests overlap resulting in another 6 hours of overlap. Beam scanning overlaps somewhat - acceptance tests include evaluating PDDs and multiple profiles but for only one field size while commissioning beam scanning includes multiple field sizes and depths of profiles. This overlap results in another 6 hours of rework. Absolute dosimetry, field outputs, and end to end tests are not done at all in acceptance testing. Finally, all imaging tests done in acceptance are repeated in commissioning, resulting in about 8 hours of rework. The total time overlap between the two processes is about 30 hours. Conclusion: The process mapping done in this study shows that there are no tests done in acceptance testing that are not also recommended to do for commissioning. This results in about 30 hours of redundant work when preparing a conventional linear accelerator for clinical use. Considering these findings in the context of the 5000 linacs in the United states, consolidating acceptance testing and commissioning would have allowed for the treatment of an additional 25000 patients using no additional resources.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Scholarship for Nuclear Communications and Methods for Evaluation of Nuclear Project Acceptability

This project aims to go beyond effective communication in understanding how to design nuclear enterprise projects that will gain stakeholder acceptability. Much of what we are studying is generally applicable to controversial projects, and we expect our results to be of broad value beyond the nuclear arena. Acceptability is more than effective communication; it also requires varying degrees of engagement with a disparate number of stakeholder groups. In the nuclear enterprise, previous attempts have been well designed physically (i.e., technologically sound), but have floundered by being insensitive concerning acceptance. Though effective communication is a necessary, but insufficient, condition for such success, there is a lack of scholarship regarding how to gain stakeholder acceptance for new controversial projects, including nuclear ones. Our work is building a model for use in assessing the performance of a project in the area of acceptability. In the nuclear-social nexus, gaining acceptance requires a clear understanding of factors regarded as being important by the many stakeholders that are common to new nuclear project (many of whom hold an effective veto power). Projects tend to become socially controversial when public beliefs, expert opinion and decision-maker understanding are misaligned. As such, stakeholder acceptance is hypothesized as both an ongoing process and an initial project design parameter comprised of complex, social, cognitive and technical components. Controversial projects may be defined as aspects of modern technologies that some people question, or are cautious about. They could range from genetic modifications, biological hazards, effects of chemical agents, nuclear radiation or hydraulic fracturing operations. We intend that our work will result in a model likely to be valuable for refining project design and implementation to increase the knowledge needed for successful management of stakeholder relationships.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Improved Fireset Acceptance Using Established Evaluation Measurements

As new insight is gained into the relationship between firesets and detonators, tighter control of the circuit parameters is desired to maintain consistent and optimum system performance. An analysis of the established acceptance method reveals that it has insufficient precision to guarantee a uniform population of units. While the production has been historically very uniform, the uniformity has been primarily due to the quality and consistency of the manufacturing process rather than to the stringency of the acceptance criteria. The established method of evaluating and accepting firesets for the stockpile has been to discharge the units into a representative load and to record the output current waveform. Three characteristics of the output waveform (Peak Current, Rise Time, and Pulse Width) are then analyzed and an acceptance window is applied directly to these measurements. The purpose of this paper is to introduce a new approach that incorporates these same established measurements. However, instead of applying acceptance criteria to the three measurements directly, rather these measurements are used to evaluate the circuit values of capacitance, inductance and resistance to provide a more stringent and uniform acceptance criteria.

42 ENGINEERING↗
DOE OSTI2018

Commercial SNF Pickup Queue Under the Standard Contact and Analysis of Hypothetical Alternate Acceptance Strategies

The Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (Standard Contract) (10 CFR Part 961) establishes the terms and conditions under which the U.S. Department of Energy (DOE) will make available nuclear waste disposal services to the owners and generators of spent nuclear fuel (SNF) and high-level radioactive waste (HLW), as provided in section 302 of the Nuclear Waste Policy Act of 1982 (NWPA) as amended, and by which DOE will take title to, transport, and dispose of SNF and/or HLW delivered to DOE by those owners or generators who execute the contract. The Standard Contract establishes the process for allocating the federal government’s finite waste acceptance capacity among those various owners/generators. This acceptance allocation, also known as the acceptance queue, orders acceptance and transportation priority in accordance with the principle of “oldest fuel first” (OFF). Under the OFF methodology, the oldest SNF, as measured from the date of permanent discharge from the reactor, is given the highest priority in the acceptance queue. While the date of discharge of spent fuel forms the basis of allocations, the owner/generator can send an equivalent Metric Tons of Uranium (MTU) of SNF that the owner/generator owns in its place, as long as it meets the “Standard Fuel” specifications in Appendix E of the Standard Contract. This is a technical paper that does not take into account the contractual limitations under the Standard Contract. This paper also does not specify the party or parties responsible for any costs discussed herein. This paper provides analysis of hypothetical strategies for accepting SNF and no inferences should be drawn from this paper regarding future actions by DOE. To the extent that discussions or recommendations in this paper conflict with the provisions of the Standard Contract, the Standard Contract provisions prevail.

Joseph III, Robby↗
DOE OSTI2015

The evolution of the Nevada National Security site waste acceptance criteria - 15312

The Nevada National Security Site Waste Acceptance Criteria (DOE/NV--325) is an evolution of requirements spanning almost three decades of waste acceptance at the Nevada National Security Site (NNSS). The original waste acceptance criteria (WAC) document was written in 1978 (document NVO-185) and underwent multiple revisions as time passed and disposal experience was gained. This document came into being when the NNSS first started receiving significant quantities of low-level radioactive waste (LLW) from offsite U.S. Department of Energy (DOE) generators, such as the Mound and Rocky Flats Plants. The original WAC was far less prescriptive and rigorous than the current criteria since many of the current DOE order directives, Federal/State laws, and regulations did not exist. The current WAC reflects the results of numerous revisions in order to address the nuances of the varied waste streams and package configurations accepted for disposal at the NNSS. This includes waste streams that exhibit challenges not previously faced or covered by the WAC and therefore, from time to time, require new information and or changes to be made to the WAC. These wastes now represent a growing percentage of the remaining waste at cleanup sites across the DOE Complex. These waste streams present challenges, such as the technical basis for ensuring safe transportation to and disposal at the NNSS. The current WAC (Rev. 10 dated June 2013), is Available online at: http://www.nv.energy.gov/library/publications/Environmental/DOENV{sub 3}25.pdf). Other challenges for the NNSS include incorporating new and emerging technologies and addressing stakeholder concerns. Addressing these challenges sometimes results in changes to the NNSS WAC. Drivers for revising the NNSS WAC over the years have included operating experience improvements, the need to specify waste origin/ownership, and identifying preferred transportation routing. This paper will discuss various aspects of the NNSS WAC, and how it has evolved based upon DOE orders and requirements, acceptance of offsite mixed wastes, acceptance of non-radioactive classified wastes, stakeholder concerns and agreements, and the changing face of the remaining legacy waste at DOE sites across the United States. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Determinants of debit cards acceptance: An empirical investigation

These days, most of the Malaysians realize that the consumption of debit card will help them to reduce the household debt. Thus, it is important to analyse the acceptance of debit cards for further enhancement and expanding its market share in Malaysia. In addition, there is lacked of research being conducted on the determinants affecting the acceptance of debit cards among Malaysians. Thus, the study aimed to investigate the factors affecting the acceptance of debit cards. This study focuses on payment methods, consumer attitude, and safety of debit card in acceptance of debit cards. Questionnaires were distributed to the 300 respondents. The sampling procedure adopted was stratified random sampling. The data obtained were analysed using SPSS 20.0 which involves scale reliability, descriptive and regression analysis. The result indicates that payment methods, consumer attitude and safety are the determinants of debit cards acceptance. Safety is the best predictor as most of the customers are confidents to use debit cards because of the security being developed around these debit card transactions. The analyses presented in this study can be used by policymakers and managers as a guide to promote banking products and services. The findings achieved in this study will be of interest for practitioners and academics concerned with developments of the Malaysian banking industry.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

A design study for a compact two stage in-flight separator with a high mass resolution and large acceptance

The rare isotope beam separator with a large angular acceptance and energy acceptance is essential for examining the characteristics of unstable nuclei and exotic nuclear reactions. Careful design, however, is required to compensate for the effects of high order aberrations induced by large aperture magnets, which are used to collect rare isotopes obtained from a high energy primary heavy-ion beam hitting a target. In order to minimize the effect of the high order aberration, the optics was based on the mirror symmetry optics, which provides smaller high order aberrations, for the separation of {sup 132}Sn produced by a fission reaction between the primary beam of {sup 238}U and a relatively thick Pb target. The designed optics provides energy acceptance (full), horizontal angular acceptance, and vertical acceptance of approximately 8%, 60 mrad, and 130 mrad, respectively.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Validation of clinical acceptability of an atlas-based segmentation algorithm for the delineation of organs at risk in head and neck cancer

Purpose: The aim of this study was to assess whether clinically acceptable segmentations of organs at risk (OARs) in head and neck cancer can be obtained automatically and efficiently using the novel “similarity and truth estimation for propagated segmentations” (STEPS) compared to the traditional “simultaneous truth and performance level estimation” (STAPLE) algorithm. Methods: First, 6 OARs were contoured by 2 radiation oncologists in a dataset of 100 patients with head and neck cancer on planning computed tomography images. Each image in the dataset was then automatically segmented with STAPLE and STEPS using those manual contours. Dice similarity coefficient (DSC) was then used to compare the accuracy of these automatic methods. Second, in a blind experiment, three separate and distinct trained physicians graded manual and automatic segmentations into one of the following three grades: clinically acceptable as determined by universal delineation guidelines (grade A), reasonably acceptable for clinical practice upon manual editing (grade B), and not acceptable (grade C). Finally, STEPS segmentations graded B were selected and one of the physicians manually edited them to grade A. Editing time was recorded. Results: Significant improvements in DSC can be seen when using the STEPS algorithm on large structures such as the brainstem, spinal canal, and left/right parotid compared to the STAPLE algorithm (all p < 0.001). In addition, across all three trained physicians, manual and STEPS segmentation grades were not significantly different for the brainstem, spinal canal, parotid (right/left), and optic chiasm (all p > 0.100). In contrast, STEPS segmentation grades were lower for the eyes (p < 0.001). Across all OARs and all physicians, STEPS produced segmentations graded as well as manual contouring at a rate of 83%, giving a lower bound on this rate of 80% with 95% confidence. Reduction in manual interaction time was on average 61% and 93% when automatic segmentations did and did not, respectively, require manual editing. Conclusions: The STEPS algorithm showed better performance than the STAPLE algorithm in segmenting OARs for radiotherapy of the head and neck. It can automatically produce clinically acceptable segmentation of OARs, with results as relevant as manual contouring for the brainstem, spinal canal, the parotids (left/right), and optic chiasm. A substantial reduction in manual labor was achieved when using STEPS even when manual editing was necessary.

60 APPLIED LIFE SCIENCES↗