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At least 955 records · Page 53

High-Resolution Characterization of Comingled Contaminants in the Deep Vadose Zone, Hanford Site, Washington - 17387

The contaminated deep vadose zone in the Central Plateau of the Hanford Site in Washington state presents a unique challenge to remediation. The Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as the CERCLA project responsible for addressing these deep contaminants is designated as the 200-Deep Vadose Zone Operable Unit (DV-1 project). The vadose zone is 55-82 meters (180-270 feet) thick and is contaminated with both radiological and chemical contaminants from multiple historical waste streams. The mobile contaminants from this waste are still present in the deep vadose zone and pose a potential threat to the groundwater. Characterizing the nature and extent of the comingled mobile contaminants is an important step before assessing possible remedial alternatives. One factor controlling the migration and distribution of subsurface contaminants is the lithologic heterogeneity of the vadose zone sediments. A sampling plan for the DV-1 project includes continuous sediment core collection and analysis to identify key lithologic factors (i.e., small-scale bedding and structural features) that act as barriers, preferential pathways or conduits for mobile contaminants migrating through the vadose zone. Over six hundred meters (2,000 feet) of intact sediment core from 26 boreholes were collected in 1.5 meters (5 feet) long, 10 centimeter (4-inch) diameter segments. These intact sediment samples provide significant improvement in the level of detail and understanding of mechanisms and features controlling contaminant distribution that is not possible with traditional homogenized drill cuttings or conventional split-spoon samples. Detailed geological descriptions and photographs of the intact core are correlated to high-resolution geophysical logs which aid in the development of a comprehensive contaminant distribution profile of the borehole. These lithologic interpretations are used to define specific depth intervals for sampling based on changes in moisture, lithology, and elevated gamma radiation. The selected samples are analyzed for contaminants of concern, geochemical parameters, and hydraulic properties. Significant lithologic features observed in the intact cores include sharp contact boundaries to graded bedding, iron-oxide and carbonate cementation, silty laminations, clastic dike intrusions, and soft sediment deformation. Preliminary geologic logs integrated with the sample analysis indicate features that correlate to the variable distribution of contaminants both laterally and vertically. Integration of measured hydraulic parameters to lithologic units in individual borehole profiles provide key inputs for more precise geo-framework and vadose zone flux models supporting the DV-1 project. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Forecasts on the Dark Matter Density Profiles of Dwarf Spheroidal Galaxies with Current and Future Kinematic Observations

We forecast parameter uncertainties on the mass profile of a typical Milky Way dwarf spheroidal galaxy (dSph) using the spherical Jeans equation and Fisher matrix formalism. For a Draco-like system we show that radial velocity measurements for 1000 individual stars can constrain the mass contained within the effective radius of a dSph to within 5%. This is consistent with constraints extracted from current observational data. We compare two systems, a cusp and core, and demonstrate that a minimum sample of 100,000 (10,000) stars with both radial and proper motions measurements is required to disentangle their inner slopes at the 2σ (1σ) level. If using the log-slope measured at the half-light radius as a proxy for differentiating between a core or cusp slope, only 1000 line-of-sight and proper motions measurements are required; however, we show this choice of radius does not always unambiguously differentiate between core and cusped profiles. Once observational errors are below half the value of the intrinsic dispersion, improving the observational precision yields little change in the density profile uncertainties. The choice of priors in our profile shape analysis plays a crucial role when the number of stars in a system is less than 100 but does not affect the resulting uncertainties for larger kinematic samples. Our predicted 2D confidence regions agree well with those from a full likelihood analysis run on a mock kinematic data set taken from the Gaia Challenge, validating our Fisher predictions. Our methodology is flexible, allowing us to predict density profile uncertainties for a wide range of current and future kinematic data sets.

79 ASTRONOMY AND ASTROPHYSICS↗

The Dark Energy Survey Supernova Programme: Modelling Selection Efficiency and Observed Core-collapse Supernova Contamination

The analysis of current and future cosmological surveys of Type Ia supernovae (SNe Ia) at high redshift depends on the accuratephotometric classification of the SN events detected. Generating realistic simulations of photometric SN surveys constitutes anessential step for training and testing photometric classification algorithms, and for correcting biases introduced by selectioneffects and contamination arising from core-collapse SNe in the photometric SN Ia samples. We use published SN time-seriesspectrophotometric templates, rates, luminosity functions, and empirical relationships between SNe and their host galaxies toconstruct a framework for simulating photometric SN surveys. We present this framework in the context of the Dark EnergySurvey (DES) 5-yr photometric SN sample, comparing our simulations of DES with the observed DES transient populations.We demonstrate excellent agreement in many distributions, including Hubble residuals, between our simulations and data.We estimate the core collapse fraction expected in the DES SN sample after selection requirements are applied and beforephotometric classification. After testing different modelling choices and astrophysical assumptions underlying our simulation,we find that the predicted contamination varies from 7.2 to 11.7 per cent, with an average of 8.8 per cent and an r.m.s. of 1.1 percent. Our simulations are the first to reproduce the observed photometric SN and host galaxy properties in high-redshift surveyswithout fine-tuning the input parameters. The simulation methods presented here will be a critical component of the cosmologyanalysis of the DES photometric SN Ia sample: correcting for biases arising from contamination, and evaluating the associatedsystematic uncertainty.

M Vincenzi↗

Recent upgrades and new scientific infrastructure of MARIA research reactor, Otwock-Swierk, Poland

The MARIA reactor is open-pool type, water and beryllium moderated. It has two independent primary cooling systems: fuel and pool cooling system. Each fuel assembly is cooled down separately in pressurized channels with individual performances characterization. The fuel assemblies consist of five layers of bent plates or six concentric tubes. Currently it is one of the most powerful research reactors in Europe with operation availability at least up to 2030. Its nominal thermal power is 30 MW. It is characterized by high neutron flux density: up to 3x10{sup 14} n cm{sup -2} s{sup -1} in case of thermal neutrons, and up to 2x10{sup 13} n cm{sup -2} s{sup -1} in case of fast neutrons. The reactor is operated for ca. 4000 h per year. The reactor facility is equipped with fully equipped three hot cells with shielding up to 10{sup 15} Bq. Adjacent to the reactor facility, the radio-pharmaceutics plant (POLATOM) and Material Research Laboratory are located. They are equipped with a number of hot cells with instrumentation. The transport system of radioactive materials from reactor facility to Material Research Laboratory is available. During 2014 the MARIA reactor has been operated with three different types of fuel the same time: previous 36% enriched fuel, and two types of new LEU fuels. In the meantime, molybdenum irradiation programme has been developed. Maria is a multifunctional research tool, with a notable application in production of radioisotopes, radio-pharmaceutics manufacturing (ca. 600 TBq/y), {sup 99}Mo for medical scintigraphy (ca. 6000 TBq/y), neutron transmutation doping of silicon single crystals, wide scientific research based on neutron beams utilization. From the beginning MARIA reactor was intended for loop and fuel testing research activities. Currently it is used mostly as material testing and irradiation facility and for that reason it has wide experimental capabilities. There are eight horizontal irradiation channels from among whom six of them are equipped with instrumentation for condensed matter physics research: - H3 - spectrometer and diffractometer with double monochromator; - H4 - small angle scattering spectrometer; - H5 - polarized neutrons spectrometer; - H6, H7 - two 3-axial crystal neutron spectrometers; - H8 - neutron radiography stand. For two horizontal channels are ongoing exploitation programs: - H2 - station with epithermal neutron beam produced in uranium converter is being developed. Intelligent converter will be installed on the periphery of reactor core. The intensity of the beam will be at the level 2x10{sup 9} n cm{sup -2}s{sup -1} what makes the beam unique in the Europe. - H1 - special pneumatic horizontal mail is being developed for irradiation material samples in the vicinity of the core i.e. in the distal part of the H1 channel. The number of neutron irradiation facilities in MARIA reactor is increasing every year. Numerous of thermal neutron irradiation channels including fast hydraulic rabbit system and large size channels for fast neutron irradiation are used routinely. Recently new in-pile facility with ITER-like neutron energy spectrum for 14 MeV neutron irradiation has been constructed. Taking into account its performance and ability of almost incessant operation the facility appears as one of the most powerful 14 MeV neutron sources. The facility shall be used for material research connected with thermonuclear devices (ITER) and 4. generation nuclear reactors. The system of independent fuels channels used in MARIA reactor appear to be very flexible and very convenient to be used as irradiation channels for uranium targets for {sup 99}Mo production. Currently, MARIA reactor supplies ca. 18% world production of {sup 99}Mo. The MARIA reactor research activities are still extended. The current scientific projects are connected e.g. with silicon neutron transmutation doping, in-pile gamma heating measurements, French calculation codes implementation (TRIPOLI4, APOLLO2). The horizontal neutron beams utilization is also developed. The MARIA reactor, due to its primary application connected with loop and fuel testing, is very convenient for testing the nuclear instrumentation, control and measurement systems.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Petrology, chemistry, age and irradiation history of Luna 24 samples

The results of petrological, chemical, isotopic age determination and irradiation studies of sample 24170 from the 170 cm depth of the regolith core returned from Mare Crisium by Luna 24 are presented. The sample is found to be comprised of fragments from a single igneous rock, with mineralogical evidence indicating it to be a mare basalt. The crystallization age is determined by Sm-Nd and Ar(40)-Ar(39) ages to be 3.30 AE, establishing the presence of relatively young flows. All soil samples show low trace element compositions with minimum contamination by KREEPUTh-rich materials. Rb-Sr and Sm-Nd relations reflect the absence of significant fractionation at ages younger than 4.5 AE. One soil sample shows extremely large neutron capture effects, imposing a new lower limit to the neutron production rate in the regolith and requiring the addition of irradiated materials from depth.

Wasserburg, G. J.↗

The Dark Energy Survey supernova programme: modelling selection efficiency and observed core-collapse supernova contamination

ABSTRACT The analysis of current and future cosmological surveys of Type Ia supernovae (SNe Ia) at high redshift depends on the accurate photometric classification of the SN events detected. Generating realistic simulations of photometric SN surveys constitutes an essential step for training and testing photometric classification algorithms, and for correcting biases introduced by selection effects and contamination arising from core-collapse SNe in the photometric SN Ia samples. We use published SN time-series spectrophotometric templates, rates, luminosity functions, and empirical relationships between SNe and their host galaxies to construct a framework for simulating photometric SN surveys. We present this framework in the context of the Dark Energy Survey (DES) 5-yr photometric SN sample, comparing our simulations of DES with the observed DES transient populations. We demonstrate excellent agreement in many distributions, including Hubble residuals, between our simulations and data. We estimate the core collapse fraction expected in the DES SN sample after selection requirements are applied and before photometric classification. After testing different modelling choices and astrophysical assumptions underlying our simulation, we find that the predicted contamination varies from 7.2 to 11.7 per cent, with an average of 8.8 per cent and an r.m.s. of 1.1 per cent. Our simulations are the first to reproduce the observed photometric SN and host galaxy properties in high-redshift surveys without fine-tuning the input parameters. The simulation methods presented here will be a critical component of the cosmology analysis of the DES photometric SN Ia sample: correcting for biases arising from contamination, and evaluating the associated systematic uncertainty.

79 ASTRONOMY AND ASTROPHYSICS↗

Finite temperature effects on the X-ray absorption spectra of lithium compounds: First-principles interpretation of X-ray Raman measurements

We elucidate the role of room-temperature-induced instantaneous structural distortions in the Li K-edge X-ray absorption spectra (XAS) of crystalline LiF, Li{sub 2}SO{sub 4}, Li{sub 2}O, Li{sub 3}N, and Li{sub 2}CO{sub 3} using high resolution X-ray Raman spectroscopy (XRS) measurements and first-principles density functional theory calculations within the eXcited electron and Core Hole approach. Based on thermodynamic sampling via ab initio molecular dynamics simulations, we find calculated XAS in much better agreement with experiment than those computed using the rigid crystal structure alone. We show that local instantaneous distortion of the atomic lattice perturbs the symmetry of the Li 1s core-excited-state electronic structure, broadening spectral line-shapes and, in some cases, producing additional spectral features. The excellent agreement with high-resolution XRS measurements validates the accuracy of our first-principles approach to simulating XAS, and provides both accurate benchmarks for model compounds and a predictive theoretical capability for identification and characterization of multi-component systems, such as lithium-ion batteries, under working conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Core-flood Effluent and Shale Surface Chemistries in Predicting Interaction between Shale, Brine, and Reactive Fluid

We report field and laboratory observations to date indicate that the efficiency of hydraulic fracturing, as it relates to hydrocarbon recovery, depends significantly on geochemical alterations to rock surfaces that diminish accessibility by partial or total plugging of the pore and fracture networks. This is caused by mineral scale deposition such as coating of fracture surfaces with precipitates, particle migration, and/or crack closure due to dissolution under stress. In reactive flow-through experiments, mineral reactions in response to acidic fluid injection significantly reduced system porosity and core permeability. The present study focuses on changes to fluid chemistry and shale surfaces (inlet and fracture walls) resulting from shale-fluid interactions and integrating these findings for an improved estimate of transport-related consequences. The reacted shale surfaces were examined by spatially-resolved scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS) analysis. Importantly, inductively coupled plasma - mass spectrometry/optical emission spectroscopy (ICP-MS/OES) was utilized to probe the chemical evolution of the core-flood effluents. The three study cores selected from the Marcellus formation represent different mineralogies and structural features. In flow-through experiments, lab-generated brine and HCl-based fracture fluid (pH=2) were injected sequentially under effective stress (up to 500 psi) at reservoir temperature (80°C). SEM-EDS results confirmed by the ICP concentration trends showed significant Fe hydroxide precipitates in clay- and pyrite-rich outcrop samples due to partial oxidation of Fe-bearing phases in the case of intrusion of low salinity water-based fluids. Porosity reduction in the MSEEL (Marcellus Shale Energy and Environmental Laboratory) carbonate-rich sample is related to compaction of cores under stress due to matrix softening with substantial dissolution, and pore-filling by hydroxides, as well as barite and salts. Despite the same fluid compositions and experimental conditions used for both MSEEL samples, barite precipitation was much more intense in the MSEEL clay-rich sample due to its greater sorption capacity and additional sulfate source as well as fissile nature with multiple lengthwise cracks. ICP tests revealed time-resolved concentration trends in produced brine and reactive fluids that in turn complemented the pre-/post-reaction SEM-EDS observations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

RARE EARTH AND CRITICAL ELEMENT RELATIONSHIPS TO COAL DEPOSIT LITHOLOGIES IN SOUTHWEST WYOMING AND NORTHWEST COLORADO

Rare earth elements (REE) and critical minerals (CM) are vital components in a wide variety of applications, not only in the renewable energy sector but also in military, telecommunication, and other civilian uses. The association of REE and CM with coal deposits is widely known but not thoroughly understood. While individual coal samples or beds themselves might not host significant concentrations of REE, recent studies indicate temporal relationships among some REE with coal beds and their immediately adjacent non-coal bounding strata, including interbeds. These strata most commonly include clays, carbonaceous shales, and ash beds, but other related strata are possible in different coal-bearing settings. Variations in REE and CM concentrations and their direct or indirect association with coal beds are not always predictable. This study presents recent findings from studying different associations between coal beds and adjacent rocks to identify possible relationships between REE-CM concentrations and the coals and adjacent rocks. For this study we collected and analyzed several dozen samples from the U.S. Geological Survey’s Core Research Center (CRC). Additionally, a small number of coal mine outcrops and their adjacent non-coal rocks were included. Most samples are of Cretaceous age. Previous work has shown a potential link between coals in the Upper Cretaceous Williams Fork Formation and REE occurrences in the Yampa ash bed in northwest Colorado. While data are uncommon and sparse, this possible link may suggest REE or CM enrichment from leaching or reworking of the ash bed. Trace element geochemistry, whole rock data, and microscopic examinations are used here to explore these relationships and guide future studies.

REE, CM, ash, volcanic ash, coal↗

Iris-leaf core retainer for a surface drill

Iris-leaf core retainer insures retention of a complete sample within the drill string. Individual overlapping leaves will not rupture or tear out when they come in contact with the oncoming core.

Olivari, H.↗

5-GHz observations of cores in extended radio galaxies

Results are presented from a search for radio cores at 5 GHz with the VLA in 18 moderately luminous radio galaxies from the second Bologna catalogue. Maps of several of the ten detected cores indicate structure on arcsecond scales in addition to the unresolved central source. Higher-resolution, multifrequency observations are very desirable in future studies of such cores. A statistical study of these and previously observed samples of radio galaxies was then performed. It was found that the radio core luminosity is much stronger in galaxies that are optically bright than faint, and that strong cores tend to occur only in galaxies with luminous extended sources while weak cores can occur in all ranges of extended source luminosity.

Ulrich, M.-H.↗

Impact of exposure to brine/CO 2 on the mechanical and transport properties of the Mt. Simon Sandstone

When sandstone rocks are exposed to CO 2 -saturated brine, their transport and mechanical properties can, potentially, change due to chemical reactions as a result of such exposure. This paper investigates changes in the flow-through characteristics, porosity, and the mechanical properties of Mt. Simon Sandstone samples caused by such exposure to brine/CO 2 . A core, extracted from the Mt. Simon formation, was first characterized for its porosity and relevant transport properties, and it was then aged for over 500 hr in CO 2 -saturated brine at formation-relevant pressure, temperature, and confining stress conditions. The deformation of the sample was measured in situ during aging via strain gauges attached to the core's surface. Following the aging experiment, the sample's porosity and transport properties were again analyzed. Our experiments show that both the porosity and permeability of the Mt. Simon sandstone sample increase due to exposure to brine/CO 2 , with the impact on permeability being more significant. The deformation measurements employing strain gauges indicate a weakening of the core material. Analysis of the composition of the brine at the conclusion of the testing reveals changes, specifically, an increase in the concentration of several of the cations. These changes are indicative of mineral/clay dissolution, consistent with the porosity, permeability, and strain gauge measurements.

58 GEOSCIENCES↗

Geochemical Comparison of Four Cores from the Manson Impact Structure

Concentrations of 33 elements were determined in relatively unaltered, matrix-rich samples of impact breccia at approximately 3-m-depth intervals in the M-1 core from the Manson impact structure, Iowa. In addition, 46 matrix-rich samples from visibly altered regions of the M-7, M-8, and M-10 cores were studied, along with 42 small clasts from all four cores. Major element compositions were determined for a subset of impact breccias from the M-1 core, including matrix-rich impact-melt breccia. Major- and trace-element compositions were also determined for a suite of likely target rocks. In the M-1 core, different breccia units identified from lithologic examination of cores are compositionally distinct. There is a sharp compositional discontinuity at the boundary between the Keweenawan-shale-clast breccia and the underlying unit of impact-melt breccia (IMB) for most elements, suggesting minimal physical mixing between the two units during emplacement. Samples from the 40-m-thick IMB (M-1) are all similar to each other in composition, although there are slight increases in concentration with depth for those elements that have high concentrations in the underlying fragmental-matrix suevite breccia (SB) (e.g., Na, Ca, Fe, Sc), presumably as a result of greater clast proportions at the bottom margin of the unit of impact-melt breccia. The high degree of compositional similarity we observe in the impact-melt breccias supports the interpretation that the matrix of this unit represents impact melt. That our analyses show such compositional similarity results in part from our technique for sampling these breccias: for each sample we analyzed a few small fragments (total mass: approximately 200 mg) selected to be relatively free of large clasts and visible signs of alteration instead of subsamples of powders prepared from a large mass of breccia. The mean composition of the matrix-rich part of impact-melt breccia from the M-1 core can be modeled as a mixture of approximately 35% shale and siltstone (Proterozoic "Red Clastics"), 23% granite, 40% hornblende-biotite gneiss, and a small component (less than 2%) of mafic-dike rocks.

Korotev, Randy L.↗

Chicxulub Impact Melts: Geochemical Signatures of Target Lithology Mixing and Post-Impact Hydrothermal Fluid Processes

Impact melts within complex impact craters are generally homogeneous, unless they differentiated, contain immiscible melt components, or were hydrothermally altered while cooling. The details of these processes, however, and their chemical consequences, are poorly understood. The best opportunity to unravel them may lie with the Chicxulub impact structure, because it is the world s most pristine (albeit buried) large impact crater. The Chicxulub Scientific Drilling Project recovered approx. 100 meters of impactites in a continuous core from the Yaxcopoil-1 (YAX-1) borehole. This dramatically increased the amount of melt available for analyses, which was previously limited to two small samples N17 and N19) recovered from the Yucatan-6 (Y-6) borehole and one sample (N10) recovered from the Chicxulub-1 (C-1) borehole. In this study, we describe the chemical compositions of six melt samples over an approx. 40 m section of the core and compare them to previous melt samples from the Y-6 and C-1 boreholes.

Kring, David A.↗

Deep Direct-Use Feasibility Study Estimation of Reservoir Properties for the Tuscarora Sandstone

This dataset contains black-and-white photographic images of individual core segments from well Preston 119 and photomicrographs taken of petrographic thin sections from well Clay 513. Minipermeameter measurement results of 2,260 samples for fracture and matrix permeability on core segments for well Preston 119. These results are summarized in figures, spreadsheets, and PowerPoints. Microsoft Excel will be necessary to examine the permeability data and software capable of reading a .PDF file will be needed to view the file of annotated core CT scans. Microsoft Powerpoint will be necessary to view the photomicrograph presentation.

15 GEOTHERMAL ENERGY↗

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

We describe the lithology and present spatially resolved geochemical analyses of samples from the hydrothermally altered Iceland Deep Drilling Project (IDDP) drill core RN-17B. The 9.3 m long RN-17B core was collected from the seawater-dominated Reykjanes geothermal system, located on the Reykjanes Peninsula, Iceland. The nature of fluids and the location of the Reykjanes geothermal system make it a useful analog for seafloor hydrothermal processes, although there are important differences. Here, the recovery of drill core from the Reykjanes geothermal system, as opposed to drill cuttings, has provided the opportunity to investigate evolving geothermal conditions by utilizing in-situ geochemical techniques in the context of observed paragenetic and spatial relationships of alteration minerals.

15 GEOTHERMAL ENERGY↗

Williston Basin Carbon Ore, Rare Earth, and Critical Minerals (CORE-CM) Program

The U.S. Department of Energy’s (DOE’s) Office of Fossil Energy awarded 13 Carbon Ore, Rare-Earth and Critical Minerals (CORE-CM) programs as part of the CORE-CM Initiative, designed to develop the technology and upstream and midstream supply chains to extract rare-earth elements (REEs) and CMs from the nation’s coal supplies. The intent is to catalyze regional economic growth and job creation while strengthening the use of domestic resources. The Williston Basin CORE-CM Program aims to drive the expansion and transformation of coal and coal-based resource usage within the Williston Basin to produce REEs, CMs, and nonfuel carbon-based products (CBPs). The work constitutes Phase 1 of a long-term program. The objectives of Phase 1 are to identify the existing knowledge base and gaps and to develop a series of assessments/plans, including an initial basinal assessment; a characterization and data acquisition plan; a waste stream reuse plan; a basinal strategies assessment for infrastructure, industries, and business; a technology assessment, development, and field-testing plan; a technology innovation center plan(s); and a stakeholder outreach and education plan. Originally, the CORE-CM programs were to do little if any sample collection as part of the Phase 1 program. As part of the ongoing interactions with DOE regarding the progress of the 13 CORE-CM programs, DOE has decided to extend Phase 1 with additional funding to allow all of the Phase 1 CORE-CM programs to collect and characterize more samples that have potential to be sources of REEs and CMs. The goal of this project is to initiate the development of a new industry in the resource-rich Williston Basin that will generate economic growth and job creation through a coalition team of private industry; university; and state, local, and federal government entities. A coalition team of nearly 30 private industry; university; and state, local, and federal government partners was formed for this program. Partners include the University of North Dakota Energy & Environmental Research Center, Institute for Energy Studies, and Nistler College; North Dakota State University; Montana Tech University; Pacific Northwest National Laboratory; Critical Materials Institute; North Dakota Geological Survey; South Dakota Geological Survey; U.S. Geological Survey; North American Coal Corporation; BNI Energy; Basin Electric Power Cooperative; Minnkota Power Cooperative; and many more.

Kay, John P.↗

An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

Cosgriff, Laura M.↗