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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.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Validation of formability of laminated sheet metal for deep drawing process using GTN damage model

In this study, we studied formability of PET/PVC laminated sheet metal which named VCM (Vinyl Coated Metal). VCM offers various patterns and good-looking metal steel used for appliances such as refrigerator and washing machine. But, this sheet has problems which are crack and peeling of film when the material is formed by deep drawing process. To predict the problems, we used finite element method and GTN (Gurson-Tvergaard-Needleman) damage model to represent damage of material. We divided the VCM into 3 layers (PET film, adhesive and steel added PVC) in finite element analysis model to express the crack and peeling phenomenon. The material properties of each layer are determined by reverse engineering based on tensile test result. Furthermore, we performed the simple rectangular deep drawing and simulated it. The simulation result shows good agreement with drawing experiment result in position, punch stroke of crack occurrence. Also, we studied the fracture mechanism of PET film on VCM by comparing the width direction strain of metal and PET film.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Development of taste sensor system for differentiation of Indonesian herbal medicines

In Indonesia, herbal medicines are usually produced by small and medium enterprises which are relatively low in quality control. The purpose of this paper is to report that we have developed a taste sensor system with global selectivity, i.e., electronic tongue (e-tongue) for differentiation of Indonesian herbal medicines. The e-tongue was composed of five kinds of ion selective electrodes as working electrodes, data acquisition system, and pattern recognition system. Each ion selective electrode (ISE) was built by attaching lipid/polymer membrane. For this purpose, the five kinds of membranes were built by mixing lipid, plasticizer (nitrophenyl octyl ether/NPOE), polyvinyl chloride (PVC), and tetrahydrofuran (THF). In this study, we employed five kinds of lipid, namely oleic acid (OA), dioctyl phosphate (DOP), decyl alcohol (DA), dodecylamine (DDC), and trioctyl methyl ammonium chloride (TOMA). In this case, the membranes transform information of taste substances into electric signal. The five kinds of Indonesian herbal medicine were purchased from local supermarket in Yogyakarta, i.e., kunyit asam (made from turmeric and tamarind), beras kencur (made from rice and kencur), jahe wangi (made from ginger and fragrance), sirih wangi (made from betel leaf), and temulawak (made from Javanese ginger). Prior to detecting the taste from the Indonesian herbal medicine samples, each ion selective electrode was tested with five basic taste samples, i.e., for saltiness, sweetness, umami, bitterness, and sourness. All ISEs showed global selectivity to all samples. Furthermore, the array of ISEs showed specific response pattern to each Indonesian herbal medicine. For pattern recognition system, we employed principle component analysis (PCA). As a result, the e-tongue was able to differentiate five kinds of Indonesian herbal medicines, proven by the total variance of first and second principle components is about 93%. For the future, the e-tongue may be developed for quality control application in herbal medicine industries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Robustness analysis of an air heating plant and control law by using polynomial chaos

This paper presents a robustness analysis of an air heating plant with a multivariable closed-loop control law by using the polynomial chaos methodology (MPC). The plant consists of a PVC tube with a fan in the air input (that forces the air through the tube) and a mass flux sensor in the output. A heating resistance warms the air as it flows inside the tube, and a thermo-couple sensor measures the air temperature. The plant has thus two inputs (the fan's rotation intensity and heat generated by the resistance, both measured in percent of the maximum value) and two outputs (air temperature and air mass flux, also in percent of the maximal value). The mathematical model is obtained by System Identification techniques. The mass flux sensor, which is nonlinear, is linearized and the delays in the transfer functions are properly approximated by non-minimum phase transfer functions. The resulting model is transformed to a state-space model, which is used for control design purposes. The multivariable robust control design techniques used is the LQG/LTR, and the controllers are validated in simulation software and in the real plant. Finally, the MPC is applied by considering some of the system's parameters as random variables (one at a time, and the system's stochastic differential equations are solved by expanding the solution (a stochastic process) in an orthogonal basis of polynomial functions of the basic random variables. This method transforms the stochastic equations in a set of deterministic differential equations, which can be solved by traditional numerical methods (That is the MPC). Statistical data for the system (like expected values and variances) are then calculated. The effects of randomness in the parameters are evaluated in the open-loop and closed-loop pole's positions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Effect of radiation on properties of ENR/PVC/SiO{sub 2} membrane

In this study epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) matrix was prepared by melt blending. The matrix was swelled in THF and silica as a filler was introduced to the solution to generate pore formation. The ENR/PVC/10 % SiO{sub 2} membrane was prepared using a casting knife technique. The membrane was irradiated using 2 MeV electron beam accelerator at a dose range of 10-100 kGy. The effect of electron beam irradiation of the membrane was studied by undergo characterization of Scanning electron microscope (SEM) and Fourier transform infra red (FTIR). Morphological studies showed that pores generated in ENR/PVC/10 % SiO{sub 2} membrane increased with the dosage of radiation. While FTIR analysis showed the presence of peak of Si-O-Si asymmetric stretching at 834 cm{sup −1}. There are no significant changes in the functional group before and after radiation.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Dielectric Spectroscopy on Thermally Aged, Intact Poly-vinyl Chloride/Ethylene Propylene Rubber (PVC/EPR) Multipolar Cables

As a contribution to condition monitoring diagnostics on low voltage cables used in nuclear power plants, this work shows that broadband dielectric spectroscopy can be an effective technique to assess aging state of these cables. Broadband dielectric spectroscopy has been performed on three-conductor (tri-core) cables, insulated by EPR with PVC jacket. The main challenge has been to perform the measurement on the intact cables, by means of a custom-built connector, conceiving a non-destructive and non-intrusive technique. Results show that capacitance and dissipation factor can provide information about the aging state of the cable, without the need to destroy the sample in the measurement process.

dielectric spectroscopy, nondestructive evaluation↗
DOE OSTI2015

SU-E-T-75: A Simple Technique for Proton Beam Range Verification

Purpose: To develop a measurement-based technique to verify the range of proton beams for quality assurance (QA). Methods: We developed a simple technique to verify the proton beam range with in-house fabricated devices. Two separate devices were fabricated; a clear acrylic rectangular cuboid and a solid polyvinyl chloride (PVC) step wedge. For efficiency in our clinic, we used the rectangular cuboid for double scattering (DS) beams and the step wedge for pencil beam scanning (PBS) beams. These devices were added to our QA phantom to measure dose points along the distal fall-off region (between 80% and 20%) in addition to dose at mid-SOBP (spread out Bragg peak) using a two-dimensional parallel plate chamber array (MatriXX™, IBA Dosimetry, Schwarzenbruck, Germany). This method relies on the fact that the slope of the distal fall-off is linear and does not vary with small changes in energy. Using a multi-layer ionization chamber (Zebra™, IBA Dosimetry), percent depth dose (PDD) curves were measured for our standard daily QA beams. The range (energy) for each beam was then varied (i.e. ±2mm and ±5mm) and additional PDD curves were measured. The distal fall-off of all PDD curves was fit to a linear equation. The distal fall-off measured dose for a particular beam was used in our linear equation to determine the beam range. Results: The linear fit of the fall-off region for the PDD curves, when varying the range by a few millimeters for a specific QA beam, yielded identical slopes. The calculated range based on measured point dose(s) in the fall-off region using the slope resulted in agreement of ±1mm of the expected beam range. Conclusion: We developed a simple technique for accurately verifying the beam range for proton therapy QA programs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

SU-E-T-280: Dose Evaluation in Using CT Density Versus Relative Stopping Power for Pencil Beam Planning and Treating IROC Proton Phantom

Purpose: The purpose of this study is to evaluate any effects of converted CT density variation in treatment planning system (TPS) of spot scanning proton therapy with an IROC proton prostate phantom at our new ProteusOne Proton Therapy Center. Methods: A proton prostate phantom was requested from the Imaging and Radiation Oncology Core Houston (IROC), The University of Texas MD Anderson Cancer Center, Houston, TX, where GAF Chromic films and couples of thermo luminescent dosemeter (TLD) capsules in target and adjacent structures were embedded for imaging and dose monitoring. Various material such as PVC, PBT HI polystyrene as dosimetry inserts and acrylic were within phantom. Relative stopping power (SP) were provided. However our treatment planning system (TPS) doesn’t require SP instead relative density was converted relative to water in TPS. Phantom was irradiated and the results were compared with IROC measurements. The range of relative density was converted from SP into relative density of water as a new assigned material and tested. Results: The summary of TLD measurements of the prostate and femoral heads were well within 2% of the TPS and met the criteria established by IROC. The film at coronal plane was found to be shift in superior-inferior direction due to locking position of cylinder insert was off and was corrected. The converted CT density worked precisely to correlated relative stopping power. Conclusion: The proton prostate phantom provided by IROC is a useful methodology to evaluate our new commissioned proton pencil beam and TPS within certain confidence in proton therapy. The relative stopping power was converted into relative physical density relatively to water and the results were satisfied.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

SU-E-T-454: Impact of Air Gap On PDDs of 6 MV Photon Beam for Various Field Sizes in Inhomogeneous Phantoms

Purpose: To investigate how the shape of air gap and its size will impact the percent depth doses (PDDs) of a 6MV photon beam for various field sizes. Methods: Two in-house phantoms were manufactured containing rectangular (phantom A) and circular (phantom B) air gaps. Both phantoms A and B were composed of same top layer (solid-water; 30×30cm{sup 2},5cm thickness) and bottom layer (solid-water; 30×30cm {sup 2},8cm thickness), but middle layer was varied to observe air gap effects and scatter contribution to the measurement point. In phantom A, a rectangular shaped air gap (30×30cm{sup 2},7cm thickness) was created by placing Styrofoam blocks between top and bottom layers of the phantom. In phantom B, middle layer was replaced by “inhomogenous block”, composed of acrylic plate (30×30cm{sup 2}, 4cm thickness) followed by PVC(30×30cm{sup 2},3cm thickness). Additionally, circular air gap was created by drilling a hole (diameter=2.8cm, length=7cm) at the center of “inhomogenous block”. In both phantoms, measurement readings were obtained at 13cm depth (i.e., 1cm after air gap) and depth of maximum dose(6MV energy; 100 MUs; field sizes ranged from 3×3cm{sup 2} to 10×10cm{sup 2}). The PDDs at 13cm depth were compared in both phantoms. Results: The measurements in both phantoms A and B showed an almost linear increase in PDDs with increasing field size, especially for smaller field sizes (from 3×3 to 7×7cm{sup 2}). For each field size, the PDD in phantom A was smaller compared to the one in phantom B. The difference in PDDs between two phantoms decreased with an increase in field size as the PDD difference decreased from 9.0% to 6.4%. Conclusion: The shape and size of air gap affect the PDD measurements in secondary build-up region as 6 MV primary beam traverses through the center of air gap. The scatter contribution due to increase in field size was more noticeable for field sizes ≤7×7cm{sup 2}.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Disposing of waste package with respect to physico-chemical characteristics - 15041

The waste inventory to be taken into account for the design of the Cigeo project is defined in the industrial program for waste management established in cooperation between nuclear operators (EDF, AREVA, CEA) and Andra. This waste inventory has been constituted with a list of different families of radioactive waste packages from High Level Waste (HLW) to Intermediate Level Long-lived Waste (IL-LLW). IL-LLW include a large variety of items such as structural elements from fuel assemblies (cladding from the fuel rods called 'hulls', end pieces called 'end caps' and assembly spacer grids, etc.), sludge from effluent treatment or miscellaneous equipment (filters, pumps, etc.). Most ILLW (except solidified sludges) are basically metallic but organic and inorganic components such as plastics (cellulose, PVC...) and salts may also be included. The rules used for designing Cigeo are based on the separation of waste having different physico-chemical characteristics in different cells. However it could be possible to dispose of waste packages with different physico-chemical characteristics in the same cell if we can demonstrate that a type of waste does not generate significant physico-chemical perturbations on other co-stored families. The first step of our analysis has been the identification of categories of materials present in waste likely to interact with each other. The second step consisted in analysing qualitatively the physico-chemical interactions between these materials. In the third step, we defined criteria allowing evaluation of the consequences of these interactions on (i) gas production (mainly H{sub 2}), (ii) radionuclide release and transfer and (iii) degradation of concrete components of the disposal cell. We built then a table allowing qualitative comparison of the consequences of the interactions between the materials types defined in the first step. The conclusion of this study shows that it is necessary to pay a very careful attention before disposing of waste packages containing organic components nearby waste packages containing actinides radionuclides. The geochemical phenomena coupling must also be quantitatively evaluated so as to analyse possible interaction processes between the released organic compounds and the cementitious components of the cells, the near-field clay-stone and the radionuclides migration. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

The DISTINCTIVE University Consortium: Transforming High Activity Materials Research in the UK - 18212

The DISTINCTIVE consortium (Decommissioning, Immobilisation and Storage Solutions for Nuclear Waste Inventories) is a partnership of 11 research universities, working to decommission and clean up the legacy of civil nuclear energy generation, sponsored by the Engineering and Physical Sciences Research Council (EPSRC). An important component of the research programme is to develop the skills and facilities to address key research questions, requiring the use of highly radioactive materials. Here we highlight the outcomes of four research projects in which access to state of the art research facilities for working with radioactive materials, supported by international partnerships, has advanced research in plutonium storage and immobilisation, and the disposal of spent nuclear fuels. First, we have developed a viable formulation and process for immobilisation of the UK plutonium stockpile, including commissioning of a radiological hot isostatic press and validation studies using plutonium-239. Second, we have further underpinned the interim storage of PuO{sub 2}, through understanding of water and chlorine sorption / desorption, pertinent to the historic practice of containment within, and degradation of PVC bags. Third, we have developed a novel methodology to investigate the in situ radiolysis induced dissolution of actinide oxide thin films, using synchrotron radiation, to underpin the geological disposal of spent nuclear fuel. Fourth we monitored in situ the oxidation and self-ignition mechanism of uranium carbide, a legacy fuel from the Dounreay Prototype Fast Reactor that is waiting for oxidation treatment prior to permanent storage and/or disposal. Through this programme of research, the DISTINCTIVE consortium is rebuilding the UK capability for research with transuranic materials, which, hitherto, was eroded over decades of disinvestment. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Chlorine Validation through Critical Integral Experiments

An increased interest in the validation of chlorine nuclear data, specifically 35Cl, in recent years has led to the prioritization of conducting chlorine critical experiments for nuclear data validation and criticality safety evaluations. A previous experiment was conducted with PVC and CPVC (chlorinated polyvinyl chloride) to reduce the margin of subcriticality for PF-4 operations with aqueous plutonium chloride solutions. Challenges in determining the composition of specific polymers, namely the CPVC, made it difficult to characterize, and therefore benchmark. Additional materials that were utilizable for chlorine validation were not immediately clear, as form, strength, purity, and composition are all important. A series of possible absorber materials were identified and studied, but ultimately granular sodium chloride was chosen. In addition to the needs of LANL’s PF-4 other industry collaborators have brought attention to the need for chlorine validation. Specifically, the need for HEU electrorefining with LiCl salts at Y-12 was taken into consideration for this experiment, with the experimental configurations being finely tuned to best meet their needs. Needs for validation were also presented by Idaho National Lab (INL) and TerraPower for validation of their Molten Chloride Reactor Experiment (MCRE) and Molten Chloride Fast Reactor (MCFR) and have also been considered.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Bio‐Inspired Cascade Photocatalysis on Fe Single‐Atom Carbon Nitride Upcycles Plastic Wastes for Effective Acetic Acid Production

Plastic imposes a critical threat to the environment, ecosystems, and human health because of the low utilization efficiency of plastics. Here, we demonstrate a sustainable, highly efficient cascade photocatalysis for upcycle plastics to value-added acetic acid using Fe single-atom catalysts (Fe@C 3 N 4 SAC) at ambient conditions. Inspired by Phanerochaete chrysosporium microbial, the defective Fe@C 3 N 4 SAC acts as a bifunctional cascade photocatalyst for both Fenton-like and CO 2 reduction reactions. During the reaction, hydroxyl radicals (*OH) form and subsequently oxidize plastics into CO 2 intermediates. These CO 2 intermediates are then photo-reduced to CH 3 COOH on the same catalyst via cascade photocatalysis. The mechanism is confirmed by in situ multimodal microscopy and spectroscopies, with density functional theory calculations. A state-of-art CH 3 COOH yield of 63.8 mg h −1 gcat −1 from PVC, 12.7 mg h −1 gcat −1 from PE, 5.4 mg h −1 gcat −1 from PET, and 5.3 mg h −1 gcat −1 from PP are directly obtained under AM1.5G solar irradiation and further validated under real sunlight (≈0.6 sun), achieving 5.6 mg h −1 gcat −1 from PET, using low-cost Fe@C 3 N 4 SAC in a sealed reactor by enhancing the photon transport and utilization efficiency. The techno-economic analysis shows it is promising to practically mitigate plastic based on broader social welfare assessments.

cascade photocatalysis↗
DOE OSTI2022

Development of green-colour-emitting pyrotechnics as a core for 3D temperature imaging sensors inside coal boilers

Efficiency in the control operation of the boilers for coal and coal with biomass can be further improved if the flue gas temperature distribution can be better characterized. This is very difficult in these harsh environmental systems, where spatially resolved measurements are nearly impossible with solid-state sensors. Here, in this work, we evaluate the development of pyrotechnic compounds that would serve as the basis for a novel optical mapping of the temperature inside coal boilers. For this purpose, various green-colour-emitting pyrotechnics using BaCl 2 · 2H 2 O and Ba(NO 3 ) 2 as the green light source were prepared, as this colour offers a distinct signal from the combustion-based background in the boiler. These pyrotechnics were characterized using thermogravimetric analysis (TGA) and X-ray diffraction (XRD) and tested using a flat-flame burner. Furthermore, the composition was varied to evaluate the effect of different metal fuels such as Sn, Co, and Mg, as well as various binders such as ethylcellulose, shellac, parlon, and PVC on green light emission. The emission intensity and the apparent ignition temperature were strongly dependent on the metal type, with Mg showing higher intensities. On the other hand, the effect of the binder showed that the ignition behaviour, emission intensity, and spectral purity were influenced by the nature and exothermicity of the binder. The addition of other potential green light-producing materials, such as boric acid, increased the intensity of emission by 17% for a BaCl 2 · 2H 2 O-based composition. This study identified prospective compositions with intense and bright green-colour emissions that have high spectral purities.

42 ENGINEERING↗
DOE OSTI2024

Making Uintah Performance Portable for Department of Energy Exascale Testbeds

To help ease ports to forthcoming Department of Energy (DOE) exascale systems, testbeds have been made available to select users. These testbeds are helpful for preparing codes to run on the same hardware and similar software as in their respective exascale systems. This paper describes how the Uintah Computational Framework, an open-source asynchronous many-task (AMT) runtime system, has been modified to be performance portable across the DOE Crusher, DOE Polaris, and DOE Sunspot testbeds in preparation for portable simulations across the exascale DOE Frontier and DOE Aurora systems. The Crusher, Polaris, and Sunspot testbeds feature the AMD MI250X, NVIDIA A100, and Intel PVC GPUs, respectively. This performance portability has been made possible by extending Uintah’s intermediate portability layer [18] to additionally support the Kokkos::HIP, Kokkos::OpenMPTarget, and Kokkos::SYCL back-ends. This paper also describes notable updates to Uintah’s support for Kokkos, which were required to make this extension possible. Results are shown for a challenging radiative heat transfer calculation, central to the University of Utah’s predictive boiler simulations. These results demonstrate single-source portability across AMD-, NVIDIA-, and Intel-based GPUs using various Kokkos back-ends.

Holmen, John↗
DOE OSTI2018

Quantification of intramyocardial blood volume with {sup 99m}Tc-RBC SPECT-CT imaging: A preclinical study

Background: Currently, there is no established non-invasive imaging approach to directly evaluate myocardial microcirculatory function in order to diagnose microvascular disease independent of co-existing epicardial disease. In this work, we developed a methodological framework for quantification of intramyocardial blood volume (IMBV) as a novel index of microcirculatory function with SPECT/CT imaging of {sup 99m}Tc-labeled red blood cells (RBCs). Methods: Dual-gated myocardial SPECT/CT equilibrium imaging of {sup 99m}Tc-RBCs was performed on twelve canines under resting conditions. Five correction schemes were studied: cardiac gating with no other corrections (CG), CG with attenuation correction (CG + AC), CG + AC with scatter correction (CG + AC + SC), dual cardiorespiratory gating with AC + SC (DG + AC + SC), and DG + AC + SC with partial volume correction (DG + AC + SC + PVC). Quantification of IMBV using each approach was evaluated in comparison to those obtained from all corrections. The in vivo SPECT estimates of IMBV values were validated against those obtained from ex vivo microCT imaging of the casted hearts. Results: The estimated IMBV with all corrections was 0.15 ± 0.03 for the end-diastolic phase and 0.11 ± 0.03 for the end-systolic phase. The cycle-dependent change in IMBV (ΔIMBV) with all corrections was 23.9 ± 8.6%. Schemes that applied no correction or partial correction resulted in significant over-estimation of IMBV and significant under-underestimation of ΔIMBV. Estimates of IMBV and ΔIMBV using all corrections were consistent with values reported in the literature using invasive techniques. In vivo SPECT estimates of IMBV strongly correlated (R{sup 2} ≥ 0.70) with ex vivo measures for the various correction schemes, while the fully corrected scheme yielded the smallest bias. Conclusions: Non-invasive quantification of IMBV is feasible using {sup 99m}Tc-RBCs SPECT/CT imaging, however, requires full compensation of physical degradation factors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

Reduced-order condensed-phase kinetic models for polyethylene, polypropylene and polystyrene thermochemical recycling

Thermochemical recycling of plastic waste (PW) into chemicals and energy vectors requires coupling particle and reactor-scale simulations to accurate condensed phase pyrolysis mechanisms for each constituent. This work proposes a methodology to derive reduced-order condensed-phase kinetic models from validated semi-detailed kinetic mechanisms. Two types of kinetic models are obtained for polyethylene (PE), polypropylene (PP) and polystyrene (PS): reduced semi-detailed models and multi-step fully lumped ones. These families offer different compromises between accuracy and computational cost. The former employ 50–100 gas + liquid species and describe both the radical degradation and the detailed carbon distribution of the products. Conversely, the latter involves 5–10 species per polymer tracking only the main petroleum cuts. The kinetic mechanisms are complemented by the definition of thermochemical properties of gas, liquid, and solid-phase species, accounting for phase-transitions through pseudo-chemical reactions. Model validations are performed by comparison with experimental data and the original semi-detailed mechanisms in terms of mass loss, heat fluxes and product distribution profiles. The resulting CHEMKIN-like condensed-phase models are attached as Supplementary Material and as a GitHub repository. Extending the proposed approach to other polymers and coupling it with existing subsets in the CRECK kinetic framework (e.g., biomass, PVC, PET) offers a powerful tool to model thermochemical recycling of PW and biomass/PW mixtures.

kinetics↗
DOE OSTI2017

Considerations and code for partial volume correcting [ 18 F]-AV-1451 tau PET data

[ 18 F]-AV-1451 is a leading tracer used with positron emission tomography (PET) to quantify tau pathology. However, [ 18 F]-AV-1451 shows “off target” or non-specific binding, which we define as binding of the tracer in unexpected areas unlikely to harbor aggregated tau based on autopsy literature. Along with caudate, putamen, pallidum and thalamus nonspecific binding, we have found binding in the superior portion of the cerebellar gray matter, leading us to use inferior cerebellar gray as the reference region. We also addressed binding in the posterior portion of the choroid plexus. PET signal unlikely to be associated with tau also occurs in skull, meninges and soft tissue. We refer to [ 18 F]- AV-1451 binding in the skull and meninges as extra-cortical hotspots (ECH) and find them near lateral and medial orbitofrontal, lateral occipital, inferior and middle temporal, superior and inferior parietal, and inferior cerebellar gray matter. Lastly, the choroid plexus also shows nonspecific binding that bleeds into hippocampus. We are providing the code (http://www.runmycode.org/companion/view/2798) used to create different regions of interest (ROIs) that we then used to perform Partial Volume Correction (PVC) using the Rousset geometric transfer matrix method. This method was used in the companion article, “Comparison of multiple tau-PET measures as biomarkers in aging and Alzheimer's Disease” (DOI 10.1016/j.neuroimage.2017.05.058).

59 BASIC BIOLOGICAL SCIENCES↗