Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “verifications”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

WE-EF-303-07: Imaging of Prompt Gamma Rays Emitted During Delivery of Clinical Proton Beams with a Compton Camera: Feasibility Studies for Range Verification

Purpose: Evaluation of a prototype Compton camera (CC) for imaging prompt gamma rays (PG) emitted during clinical proton beam irradiation for in vivo beam range verification. Methods: We irradiated a water phantom with 114 MeV and 150 MeV proton pencil beams at clinical beam currents ranging from 1 nA up to 5 nA. The CC was placed 15 cm from the beam central axis and PGs from 0.2 MeV up to 6.5 MeV were measured during irradiation. From the measured data, 2-dimensional (2D) PG images were reconstructed. One-dimensional (1D) profiles from the PG images were compared to measured depth dose curves. Results: The CC was able to measure PG emission during delivery of both a single 150 MeV pencil beam and a 5 cm x 5 cm mono-energetic layer of 114 MeV pencil beams. From the 2D images, a strong correlation was seen between the depth of the distal falloff of PG emission and the Bragg peak (BP). 1D profiles extracted from the PG images show that the distal 60% falloff of the PG emission lined up well with the distal 90% of the BP. Shifts as small as 3 mm in the beam range could be detected on both the 2D PG images and 1D profiles with an uncertainty of 1.5 mm. With the current CC prototype, a minimum dose delivery of 400 cGy was required to produce usable PG images. Conclusions: It was possible to measure and image PG emission with our prototype CC during proton beam delivery and to detect shifts in the BP range in the images. Therefore prompt gamma imaging with a CC for the purpose of in vivo range verification is feasible. However, for the studied system improvements in detector efficiency and reconstruction algorithms are necessary to make it clinically viable.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Compiler verification meets cross-language linking via data abstraction

Many real programs are written in multiple different programming languages, and supporting this pattern creates challenges for formal compiler verification. We describe our Coq verification of a compiler for a high-level language, such that the compiler correctness theorem allows us to derive partial-correctness Hoare-logic theorems for programs built by linking the assembly code output by our compiler and assembly code produced by other means. Our compiler supports such tricky features as storable cross-language function pointers, without giving up the usual benefits of being able to verify different compiler phases (including, in our case, two classic optimizations) independently. Here, the key technical innovation is a mixed operational and axiomatic semantics for the source language, with a built-in notion of abstract data types, such that compiled code interfaces with other languages only through axiomatically specified methods that mutate encapsulated private data, represented in whatever formats are most natural for those languages.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

High-performance End-to-End Integrity Verification on Big Data Transfer

The scale of scientific data generated by experimental facilities and simulations in high-performance computing facilities has been proliferating with the emergence of IoT-based big data. In many cases, this data must be transmitted rapidly and reliably to remote facilities for storage, analysis, or sharing, for the Internet of Things (IoT) applications. Simultaneously, IoT data can be verified using a checksum after the data has been written to the disk at the destination to ensure its integrity. However, this end-to-end integrity verification inevitably creates overheads (extra disk I/O and more computation). Thus, the overall data transfer time increases. In this article, we evaluate strategies to maximize the overlap between data transfer and checksum computation for astronomical observation data. Specifically, we examine file-level and block-level (with various block sizes) pipelining to overlap data transfer and checksum computation. We analyze these pipelining approaches in the context of GridFTP, a widely used protocol for scientific data transfers. Theoretical analysis and experiments are conducted to evaluate our methods. The results show that block-level pipelining is effective in maximizing the overlap mentioned above, and can improve the overall data transfer time with end-to-end integrity verification by up to 70% compared to the sequential execution of transfer and checksum, and by up to 60% compared to file-level pipelining.

data integrity↗
DOE OSTI2012

Independent Verification of the Central Campus and Southeast Laboratory Complex Building Slabs at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Oak Ridge Associated Universities/Oak Ridge Institute for Science and Education (ORAU/ORISE) has completed the independent verification survey of the Central Campus and Southeast Lab Complex Building Slabs. The results of this effort are provided. The objective of this verification survey was to provide independent review and field assessment of remediation actions conducted by SEC, and to independently assess whether the final radiological condition of the slabs met the release guidelines.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Independent Verification Survey of the SPRU Lower Level Hillside Area at the Knolls Atomic Power Laboratory, Niskayuna, New York (Final Report)

During August 10, 2011 through August 19, 2011, and October 23, 2011 through November 4, 2011, ORAU/ORISE conducted verification survey activities at the Separations Process Research Unit (SPRU) site that included in-process inspections, surface scans, and soil sampling of the Lower Level Hillside Area. According to the Type-B Investigation Report, Sr-90 was the primary contributor to the majority of the activity (60 times greater than the Cs-137 activity). The evaluation of the scan data and sample results obtained during verification activities determined that the primary radionuclide of concern, Sr-90, was well below the agreed upon soil cleanup objective (SCO) of 30 pCi/g for the site. However, the concentration of Cs-137 in the four judgmental samples collected in final status survey (FSS) Units A and B was greater than the SCO. Both ORAU and aRc surveys identified higher Cs-137 concentrations in FSS Units A and B; the greatest concentrations were identified in FSS Unit A.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2013

Technical Assessment of the Passive Neutron Enrichment Meter (PNEM) for an Unattended Cylinder Verification Station (UCVS)

The International Atomic Energy Agency (IAEA) is exploring the potential roles of an Unattended Cylinder Verifications Station (UCVS) in a new generation of safeguards technology for uranium enrichment plants. The UCVS is envisioned to combine an operator accountancy scale, a nondestructive assay (NDA) system such as the Passive Neutron Enrichment Meter (PNEM), a cylinder identification system, and a surveillance system for verification of product, feed, and tails cylinders as well as continuity of knowledge at material balance area boundaries. The IAEA has identified several preliminary requirements and development questions for the UCVS. Specifically, the IAEA has identified the accuracy of the enrichment assay as the key metric for the NDA system with uncertainty targets of 3%, 6%, and 9% on product, feed, and tails cylinders, respectively. The NDA system should also provide full volume interrogation of the cylinders in order to ensure detection of partial defects within the cylinder. The development questions are concerned primarily with the sources and magnitude of the uncertainty and quantitative analysis of the interrogation depth and partial defect sensitivity. The objective of this report is to address these requirements and questions based on Monte Carlo modeling and field trial experience with the PNEM.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Verification studies of CCH and xALE [Slides]

CCH is a new cell-centered alternative to Lagrangian Staggered Grid Hydro (SGH). xALE is ALE based upon an exact intersection remap – an alternative to traditional swept face methods. CCH (& xALE) began as an LDRD/DR project and is now beginning to feed into several other efforts. Verification is a necessary step towards acceptance of these methods for production purposes. Here, we focus on verification as a companion (and guide) to the code development process. During the development stage of a method many choices of component algorithms are possible. We emphasize comparisons of these algorithmic variations and sometimes a progression of variations. In some cases, our findings also suggest improvements in FLAG hydro algorithms or their manner of use.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

MCNP6 Cerenkov Radiation Feature Verification

The MCNP6 code has being upgraded to treat Cerenkov radiation emission. Emission is performed using the Frank-Tamm Cerenkov theory with piecewiseconstant coefficients. This document discusses preliminary verification efforts for the Cerenkov feature. Tests were conducted using MCNP6 version MCNP6_Beta3_branch_r. The Frank-Tamm formulation has been coded in an auxiliary Perl script cr.pl. Comparisons of the photon production per wavelength bin and the aggregate photon production are made for 4-MeV electrons and 4000- MeV alphas in water using MCNP6 and cr.pl. The agreement is excellent. Verification calculations for the spectrum of light emerging from the surface of the water are presented for constant, Cauchy, and Sellmeier treatments of the refractive index. Efforts to conduct validation studies were limited by lack of time and limited useful measured data.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2013

Independent Verification Survey of Section 3, Survey Units 1, 4 and 5 Excavated Surfaces, Whittaker Corporation, Reynolds Industrial Park, Transfer, Pennsylvania (Interim Report)

At Pennsylvania Department of Environmental Protection's request, ORAU's IEAV program conducted verification surveys on the excavated surfaces of Section 3, SUs 1, 4, and 5 at the Whittaker site on March 13 and 14, 2013. The survey activities included visual inspections, gamma radiation surface scans, gamma activity measurements, and soil sampling activities. Verification activities also included the review and assessment of the licensee's project documentation and methodologies. Surface scans identified four areas of elevated direct gamma radiation distinguishable from background; one area within SUs 1 and 4 and two areas within SU5. One area within SU5 was remediated by removing a golf ball size piece of slag while ORAU staff was onsite. With the exception of the golf ball size piece of slag within SU5, a review of the ESL Section 3 EXS data packages for SUs 1, 4, and 5 indicated that these locations of elevated gamma radiation were also identified by the ESL gamma scans and that ESL personnel performed additional investigations and soil sampling within these areas. The investigative results indicated that the areas met the release criteria.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Independent verification survey report for exposure units Z2-24, Z2-31, Z2-32, AND Z2-36 in zone 2 of the East Tennessee technology park Oak Ridge, Tennessee

The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management selected Oak Ridge Associated Universities (ORAU), through the Oak Ridge Institute for Science and Education (ORISE) contract, to perform independent verification (IV) at Zone 2 of the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. ORAU has concluded IV surveys, per the project-specific plan (PSP) (ORAU 2013a) covering exposure units (EUs) Z2-24, -31, -32, and -36. The objective of this effort was to verify the target EUs comply with requirements in the Zone 2 Record of Decision (ROD) (DOE 2005), as implemented by using the dynamic verification strategy presented in the dynamic work plan (DWP) (BJC 2007); and confirm commitments in the DWP were adequately implemented, as verified via IV surveys and soil sampling.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Laboratory demonstration of a multi-sensor unattended cylinder verification station for uranium enrichment plant safeguards

The objective of safeguards is the timely detection of the diversion of a significant quantity of nuclear materials, and safeguarding uranium enrichment plants is especially important in preventing the spread of nuclear weapons. The IAEA’s proposed Unattended Cylinder Verification Station (UCVS) for UF 6 cylinder verification would combine the operator’s accountancy scale with a nondestructive assay system such as the Passive Neutron Enrichment Meter (PNEM) and cylinder identification and surveillance systems. In this project, we built a laboratory-scale UCVS and demonstrated its capabilities using mock UF 6 cylinders. We developed a signal processing algorithm to automate the data collection and processing from four continuous, unattended sensors. The laboratory demonstration of the system showed that the software could successfully identify cylinders, snip sensor data at the appropriate points in time, determine the relevant characteristics of the cylinder contents, check for consistency among sensors, and output the cylinder data to a file. This paper describes the equipment, algorithm and software development, laboratory demonstration, and recommendations for a full-scale UCVS.

42 ENGINEERING↗
DOE OSTI2012

Double-Difference Tomography for Sequestration MVA [monitoring, verification, and accounting]

Analysis of synthetic data was performed to determine the most cost-effective tomographic monitoring system for a geologic carbon sequestration injection site. Double-difference tomographic inversion was performed on 125 synthetic data sets: five stages of CO2 plume growth, five seismic event regions, and five geophone arrays. Each resulting velocity model was compared quantitatively to its respective synthetic velocity model to determine an accuracy value. The results were examined to determine a relationship between cost and accuracy in monitoring, verification, and accounting applications using double-difference tomography. The geophone arrays with widely-varying geophone locations, both laterally and vertically, performed best. Additionally, double difference seismic tomography was performed using travel time data from a carbon sequestration site at the Aneth oil field in southeast Utah as part of a Department of Energy initiative on monitoring, verification, and accounting (MVA) of sequestered CO2. A total of 1,211 seismic events were recorded from a borehole array consisting of 22 geophones. Artificial velocity models were created to determine the ease with which different CO2 plume locations and sizes can be detected. Most likely because of the poor geophone arrangement, a low velocity zone in the Desert Creek reservoir can only be detected when regions of test site containing the highest ray path coverage are considered. MVA accuracy and precision may be improved through the use of a receiver array that provides more comprehensive ray path coverage.

47 OTHER INSTRUMENTATION↗
DOE OSTI2014

Verification and Validation of Carbon-Fiber Laminate Low Velocity Impact Simulations.

Presented is a model verification and validation effort using low - velocity impact (LVI) of carbon fiber reinforced polymer laminate experiments. A flat cylindrical indenter impacts the laminate with enough energy to produce delamination, matrix cracks and fiber breaks. Included in the experimental efforts are ultrasonic scans of the damage for qualitative validation of the models. However, the primary quantitative metrics of validation are the force time history measured through the instrumented indenter and initial and final velocities. The simulations, whi ch are run on Sandia's Sierra finite element codes , consist of all physics and material parameters of importance as determined by a sensitivity analysis conducted on the LVI simulation. A novel orthotropic damage and failure constitutive model that is cap able of predicting progressive composite damage and failure is described in detail and material properties are measured, estimated from micromechanics or optimized through calibration. A thorough verification and calibration to the accompanying experiment s are presented. Specia l emphasis is given to the four - point bend experiment. For all simulations of interest, the mesh and material behavior is verified through extensive convergence studies. An ensemble of simulations incorporating model parameter unc ertainties is used to predict a response distribution which is then compared to experimental output. The result is a quantifiable confidence in material characterization and model physics when simulating this phenomenon in structures of interest.

English, Shawn Allen↗
DOE OSTI2012

International comparison of product certification and verification methods for appliances

Enforcement of appliance standards and consumer trust in appliance labeling are important foundations of growing a more energy efficient economy. Product certification and verification increase compliance rates which in turn increase both energy savings and consumer trust. This paper will serve two purposes: 1) to review international practices for product certification and verification as they relate to the enforcement of standards and labeling programs in the U.S., E.U., Australia, Japan, Canada, and China; and 2) to make recommendations for China to implement improved certification processes related to their mandatory standards and labeling program such as to increase compliance rates and energy savings potential.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2012

International Comparison of Product Certification and Verification Methods for Appliances

Enforcement of appliance standards and consumer trust in appliance labeling are important foundations of growing a more energy efficient economy. Product certification and verification increase compliance rates which in turn increase both energy savings and consumer trust. This paper will serve two purposes: 1) to review international practices for product certification and verification as they relate to the enforcement of standards and labeling programs in the U.S., E.U., Australia, Japan, Canada, and China; and 2) to make recommendations for China to implement improved certification processes related to their mandatory standards and labeling program such as to increase compliance rates and energy savings potential.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

SPR Hydrostatic Column Model Verification and Validation.

A Hydrostatic Column Model (HCM) was developed to help differentiate between normal "tight" well behavior and small-leak behavior under nitrogen for testing the pressure integrity of crude oil storage wells at the U.S. Strategic Petroleum Reserve. This effort was motivated by steady, yet distinct, pressure behavior of a series of Big Hill caverns that have been placed under nitrogen for extended period of time. This report describes the HCM model, its functional requirements, the model structure and the verification and validation process. Different modes of operation are also described, which illustrate how the software can be used to model extended nitrogen monitoring and Mechanical Integrity Tests by predicting wellhead pressures along with nitrogen interface movements. Model verification has shown that the program runs correctly and it is implemented as intended. The cavern BH101 long term nitrogen test was used to validate the model which showed very good agreement with measured data. This supports the claim that the model is, in fact, capturing the relevant physical phenomena and can be used to make accurate predictions of both wellhead pressure and interface movements.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Verification and Validation of a Coordinate Transformation Method in Axisymmetric Transient Magnetics.

We present a verification and validation analysis of a coordinate-transformation-based numerical solution method for the two-dimensional axisymmetric magnetic diffusion equation, implemented in the finite-element simulation code ALEGRA. The transformation, suggested by Melissen and Simkin, yields an equation set perfectly suited for linear finite elements and for problems with large jumps in material conductivity near the axis. The verification analysis examines transient magnetic diffusion in a rod or wire in a very low conductivity background by first deriving an approximate analytic solution using perturbation theory. This approach for generating a reference solution is shown to be not fully satisfactory. A specialized approach for manufacturing an exact solution is then used to demonstrate second-order convergence under spatial refinement and tem- poral refinement. For this new implementation, a significant improvement relative to previously available formulations is observed. Benefits in accuracy for computed current density and Joule heating are also demonstrated. The validation analysis examines the circuit-driven explosion of a copper wire using resistive magnetohydrodynamics modeling, in comparison to experimental tests. The new implementation matches the accuracy of the existing formulation, with both formulations capturing the experimental burst time and action to within approximately 2%.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Preliminary report for using X-rays as verification and authentication tool

We examined x-rays for the use as authentication and verification tool in treaty verification. Several x-ray pictures were taken to determine the quality and feasibility of x-rays for these tasks. This document describes the capability of the used x-ray system and outlines its parameters and possible use.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗