Results for “66” — Page 17

DOE OSTI2021

The Algae Foundation® and Algae Technology Educational Consortium

Abstract The Algae Foundation established in February 2013 has developed a diverse portfolio of algal‐based education and workforce development programs covering education levels from kindergarten through college, aquaculture extension, and free online courses. The Algae Foundation created the Algae Technology Educational Consortium (ATEC) with five major foci including community college certificate program in algae cultivation; community college curriculum adopted for algal biotechnology degree programs; Algal Massive Open Online Courses (Algal MOOCs); Algae Academy, a kindergarten to 12th grade STEM curriculum initiative; and aquaculture extension education through the Algae Cultivation Extension Short courses (ACES). The results include the education and training of over 102,000 students, aquaculturists, entrepreneurs, and bioeconomy‐based professionals aged 8–75 years in all 50 U.S. states and 66 countries. ATEC has completed agreements with 21 community colleges and universities located in Arizona, California, Connecticut, Hawaii, Louisiana, Maine, New Mexico, North Carolina, Oregon, Texas, and Washington. The first ATEC‐sponsored certificate degree program graduation was in May 2018. The Algae MOOC #1 has had over 15,752 students enrolled. ATEC initiated the Algae Academy in spring 2016 in Carlsbad, CA, and expanded to serving over 34,000 students in 46 states during the academic year 2019–2020. ACES has enrolled over 1,550 students from 66 countries.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2011

Evaluation of brachytherapy lung implant dose distributions from photon-emitting sources due to tissue heterogeneities

Purpose: Photon-emitting brachytherapy sources are used for permanent implantation to treat lung cancer. However, the current brachytherapy dose calculation formalism assumes a homogeneous water medium without considering the influence of radiation scatter or tissue heterogeneities. The purpose of this study was to determine the dosimetric effects of tissue heterogeneities for permanent lung brachytherapy. Methods: The MCNP5 v1.40 radiation transport code was used for Monte Carlo (MC) simulations. Point sources with energies of 0.02, 0.03, 0.05, 0.1, 0.2, and 0.4 MeV were simulated to cover the range of pertinent brachytherapy energies and to glean dosimetric trends independent of specific radionuclide emissions. Source positions from postimplant CT scans of five patient implants were used for source coordinates, with dose normalized to 200 Gy at the center of each implant. With the presence of fibrosis (around the implant), cortical bone, lung, and healthy tissues, dose distributions and {sub PTV}DVH were calculated using the MCNP *FMESH4 tally and the NIST mass-energy absorption coefficients. This process was repeated upon replacing all tissues with water. For all photon energies, 10{sup 9} histories were simulated to achieve statistical errors (k = 1) typically of 1%. Results: The mean PTV doses calculated using tissue heterogeneities for all five patients changed (compared to dose to water) by only a few percent over the examined photon energy range, as did PTV dose at the implant center. The {sub PTV}V{sub 100} values were 81.2%, 90.0% (as normalized), 94.3%, 93.9%, 92.7%, and 92.2% for 0.02, 0.03, 0.05, 0.1, 0.2, and 0.4 MeV source photons, respectively. Relative to water, the maximum bone doses were higher by factors of 3.7, 5.1, 5.2, 2.4, 1.2, and 1.0 The maximum lung doses were about 0.98, 0.94, 0.91, 0.94, 0.97, and 0.99. Relative to water, the maximum healthy tissue doses at the mediastinal position were higher by factors of 9.8, 2.2, 1.3, 1.1, 1.1, and 1.1. However, the maximum doses to these healthy tissues were only 3.1, 7.2, 11.3, 10.9, 9.0, and 8.1 Gy while maximum bone doses were 66, 177, 236, 106, 49, and 39 Gy, respectively. Similarly, maximum lung doses were 55, 66, 73, 74, 73, and 73 Gy, respectively. Conclusions: The current brachytherapy dose calculation formalism overestimates PTV dose and significantly underestimates doses to bone and healthy tissue. Further investigation using specific brachytherapy source models and patient-based CT datasets as MC input may indicate whether the observed trends can be generalized for low-energy lung brachytherapy dosimetry.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2014

Feature-space assessment of electrical impedance tomography coregistered with computed tomography in detecting multiple contrast targets

Purpose: Fusion of electrical impedance tomography (EIT) with computed tomography (CT) can be useful as a clinical tool for providing additional physiological information about tissues, but requires suitable fusion algorithms and validation procedures. This work explores the feasibility of fusing EIT and CT images using an algorithm for coregistration. The imaging performance is validated through feature space assessment on phantom contrast targets. Methods: EIT data were acquired by scanning a phantom using a circuit, configured for injecting current through 16 electrodes, placed around the phantom. A conductivity image of the phantom was obtained from the data using electrical impedance and diffuse optical tomography reconstruction software (EIDORS). A CT image of the phantom was also acquired. The EIT and CT images were fused using a region of interest (ROI) coregistration fusion algorithm. Phantom imaging experiments were carried out on objects of different contrasts, sizes, and positions. The conductive medium of the phantoms was made of a tissue-mimicking bolus material that is routinely used in clinical radiation therapy settings. To validate the imaging performance in detecting different contrasts, the ROI of the phantom was filled with distilled water and normal saline. Spatially separated cylindrical objects of different sizes were used for validating the imaging performance in multiple target detection. Analyses of the CT, EIT and the EIT/CT phantom images were carried out based on the variations of contrast, correlation, energy, and homogeneity, using a gray level co-occurrence matrix (GLCM). A reference image of the phantom was simulated using EIDORS, and the performances of the CT and EIT imaging systems were evaluated and compared against the performance of the EIT/CT system using various feature metrics, detectability, and structural similarity index measures. Results: In detecting distilled and normal saline water in bolus medium, EIT as a stand-alone imaging system showed contrast discrimination of 47%, while the CT imaging system showed a discrimination of only 1.5%. The structural similarity index measure showed a drop of 24% with EIT imaging compared to CT imaging. The average detectability measure for CT imaging was found to be 2.375 ± 0.19 before fusion. After complementing with EIT information, the detectability measure increased to 11.06 ± 2.04. Based on the feature metrics, the functional imaging quality of CT and EIT were found to be 2.29% and 86%, respectively, before fusion. Structural imaging quality was found to be 66% for CT and 16% for EIT. After fusion, functional imaging quality improved in CT imaging from 2.29% to 42% and the structural imaging quality of EIT imaging changed from 16% to 66%. The improvement in image quality was also observed in detecting objects of different sizes. Conclusions: The authors found a significant improvement in the contrast detectability performance of CT imaging when complemented with functional imaging information from EIT. Along with the feature assessment metrics, the concept of complementing CT with EIT imaging can lead to an EIT/CT imaging modality which might fully utilize the functional imaging abilities of EIT imaging, thereby enhancing the quality of care in the areas of cancer diagnosis and radiotherapy treatment planning.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2015

WE-B-207-00: CT Lung Cancer Screening Part 1

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: Review and summarize relevant NLST findings and conclusions. Understand the scope and scale of the NLST specific to participant dosimetry. Provide a comprehensive review of NLST participant dosimetry assessments. Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: Review and summarize relevant NLST findings and conclusions. Understand the scope and scale of the NLST specific to participant dosimetry. Provide a comprehensive review of NLST participant dosimetry assessments. Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: Review and summarize relevant NLST findings and conclusions. Understand the scope and scale of the NLST specific to participant dosimetry. Provide a comprehensive review of NLST participant dosimetry assessments. Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

SU-F-E-07: Web-Based Training for Radiosurgery: Methods and Metrics for Global Reach

Purpose: Webinars have become an evolving tool with greater or lesser success in reaching health care providers (HCPs). This study seeks to assess best practices and metrics for success in webinar deployment for optimal global reach. Methods: Webinars have been developed and launched to reach practicing health care providers in the field of radiation oncology and radiosurgery. One such webinar was launched in early February 2016. “Multiple Brain Metastases & Volumetric Modulated Arc Radiosurgery: Refining the Single-Isocenter Technique to Benefit Surgeons and Patients” presented by Drs. Fiveash and Thomas from UAB was submitted to and accredited by the Institute for Medical Education as qualifying for CME as well as MDCB for educational credit for dosimetrists, in order to encourage participation. MedicalPhysicsWeb was chosen as the platform to inform attendees regarding the webinar. Further IME accredited the activity for 1 AMA PRA Category 1 credit for physicians & medical physicists. The program was qualified by the ABR in meeting the criteria for self-assessment towards fulfilling MOC requirements. Free SAMs credits were underwritten by an educational grant from Varian Medical Systems. Results: The webinar in question attracted 992 pre-registrants from 66 countries. Outside the US and Canada; 11 were from the Americas; 32 were from Europe; 9 from the Middle East and Africa. Australasia and the Indian subcontinent represented the remaining 14 countries. Pre-registrants included 423 Medical Physicists, 225 Medical Dosimetrists, 24 Radiation Therapists, 66 Radiation Oncologists & other. Conclusion: The effectiveness of CME and SAM-CME programs such as this can be gauged by the high rate of respondents who state an intention to change practice habits, a primary goal of continuing medical education and self-assessment. This webinar succeeded in being the most successful webinar on Medical Physics Web as measured by pre-registration, participation and participation to pre-registration ratio. R.A. Schulz is an employee of Varian Medical Systems.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

Development of bimetallic (Zn@Au) nanoparticles as potential PET-imageable radiosensitizers

Purpose: Gold nanoparticles (GNPs) are being investigated actively for various applications in cancer diagnosis and therapy. As an effort to improve the imaging of GNPs in vivo, the authors developed bimetallic hybrid Zn@Au NPs with zinc cores and gold shells, aiming to render them in vivo visibility through positron emission tomography (PET) after the proton activation of the zinc core as well as capability to induce radiosensitization through the secondary electrons produced from the gold shell when irradiated by various radiation sources. Methods: Nearly spherical zinc NPs (∼5-nm diameter) were synthesized and then coated with a ∼4.25-nm gold layer to make Zn@Au NPs (∼13.5-nm total diameter). 28.6 mg of these Zn@Au NPs was deposited (∼100 μm thick) on a thin cellulose target and placed in an aluminum target holder and subsequently irradiated with 14.15-MeV protons from a GE PETtrace cyclotron with 5-μA current for 5 min. After irradiation, the cellulose matrix with the NPs was placed in a dose calibrator to assess the induced radioactivity. The same procedure was repeated with 8-MeV protons. Gamma ray spectroscopy using an high-purity germanium detector was conducted on a very small fraction (<1 mg) of the irradiated NPs for each proton energy. In addition to experimental measurements, Monte Carlo simulations were also performed with radioactive Zn@Au NPs and solid GNPs of the same size irradiated with 160-MeV protons and 250-kVp x-rays. Results: The authors measured 168 μCi of activity 32 min after the end of bombardment for the 14.15-MeV proton energy sample using the {sup 66}Ga setting on a dose calibrator; activity decreased to 2 μCi over a 24-h period. For the 8-MeV proton energy sample, PET imaging was additionally performed for 5 min after a 12-h delay. A 12-h gamma ray spectrum showed strong peaks at 511 keV (2.05 × 10{sup 6} counts) with several other peaks of smaller magnitude for each proton energy sample. PET imaging showed strong PET signals from mostly decaying {sup 66}Ga. The Monte Carlo results showed that radioactive Zn@Au NPs and solid GNPs provided similar characteristics in terms of their secondary electron spectra when irradiated. Conclusions: The Zn@Au NPs developed in this investigation have the potential to be used as PET-imageable radiosensitizers for radiotherapy applications as well as PET tracers for molecular imaging applications.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2013

Excitation of intense acoustic waves in hexagonal crystals

Resonant excitation of an intense elastic wave using reflection of a pump wave from a free surface of hexagonal crystal is described. A resonance arises in the case of specially chosen propagation geometry where the reflecting boundary slightly deviates from symmetric orientation and the propagation direction of an intense reflected wave is close to that of an exceptional bulk wave, which satisfies the free boundary condition in unperturbed symmetric orientation. It is shown that, in crystals with elastic moduli c{sub 44}>c{sub 66}, a resonance arises when the initial boundary is chosen parallel to the hexagonal axis 6, whereas in crystals characterized by the relation c{sub 44}<c{sub 66} a resonance occurs when the initial boundary is orthogonal to this axis. The fraction of the pump energy transferred to the excited beam depends on the specific relations between the elastic moduli and can be rather significant for specially chosen crystals. Examples of crystals are presented in which the beam intensity can be increased by a factor of 5-10 at sufficiently high frequencies, with beam divergence remaining acceptable.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2015

Linking preferred orientations to elastic anisotropy in Muderong Shale, Australia

The significance of shales as unconventional hydrocarbon reservoirs, nuclear waste repositories, and geological carbon storage has opened new research frontiers in geophysics. Among many of its unique physical properties, elastic anisotropy has long been investigated by both experimental and computational approaches. Here we calculate elastic properties of Cretaceous Muderong Shale from Australia with a self-consistent averaging method based on microstructural information. The volume fraction and crystallographic preferred orientation distributions of constituent minerals are based on synchrotron X-ray diffraction experiments. Aspect ratios of minerals and pores, determined from scanning electron microscopy (SEM), are introduced in the self-consistent averaging. Our analysis suggests that phyllosilicates (i.e., illite-mica, illite-smectite, kaolinite, and chlorite) are dominant with ~70 vol.%. The shape of clay platelets displays an average aspect ratio of 0.05. These platelets are aligned parallel to the bedding plane with a rather high degree of preferred orientation. The estimated porosity at ambient pressure is ~17 vol.% and is divided into equiaxial pores and flat pores with an average aspect ratio of 0.01. Our model shows results (e.g. at pressure of ~50 MPa with C 11 = 26.3; C 13 =12.5; C 33 = 18.2; C 44 = 2.8; C 66 = 6.8 [GPa]) that compare satisfactorily with values derived from ultrasonic velocity measurements (C 11 = 26.6; C 13 = 16.2; C 33 = 18.3; C 44 = 4.5; C 66 = 8.8 [GPa]), confirming the validity and reliability of our approximations and averaging approach.

58 GEOSCIENCES↗

DOE OSTI2026

Data for "Adsorptive Separation and Recovery of Triacetic Acid Lactone from Fermentation Broth"

Triacetic acid lactone (TAL) can be microbially produced and further chemically upgraded to several high-value chemicals. In this work, several acidic and basic ion-exchange resins and activated charcoal were evaluated for their ability to adsorb microbially produced TAL. Activated charcoal and a weak base resin, Dowex 66, showed similar TAL adsorption capacity of 0.18 ± 0.002 g/g. At 15% w/v activated charcoal, about 98% of TAL present in fermentation broth could be adsorbed. Further, ethanol washing allowed recovery of 72% of adsorbed TAL. A biorefinery producing TAL from sucrose was designed, simulated, and evaluated (through technoeconomic analysis) under uncertainty, for an estimated TAL minimum product selling price (MPSP) of $4.27/kg [$3.71−4.94/kg; 5th-95th percentiles] for the current state of technology and $2.83/kg [$2.46–3.29/kg] following potential near-term improvements to fermentation. Thus, this work provides an adsorptive process to recover microbially produced TAL that can be chemically upgraded to several industrial products.

Bioproducts↗

DOE OSTI2020

Hawaii Play Fairway Analysis: Noble Gas Raw Data for Hawaii, Maui, Oahu, Kauai, and Lanai islands

Noble gas raw data for the Hawaiian islands of Big Island, Maui, Oahu, Lanai, and Kauai. Based on results from prior phases of the Hawaii Play Fairway Analysis, this project targeted 66 wells on the islands of Hawaii, Maui, Lanai, Oahu, and Kauai for sampling of dissolved noble gases, trace metals, common ions, and the stable isotopes 2H and 18O. Ultimately, 23 of the 66 well targets were sampled. Noble gas data from this study is supplemented with data shared by the United States Geologic Survey for the summit of Kilauea, and by the geothermal energy company Ormat Technologies Inc. for their geothermal power plant Puna Geothermal Venture on the Lower East Rift of Kilauea, and for their exploration of Kona and Hualalai on Hawaii, as well as the Southwest Rift of Haleakala on Maui. The noble gas helium is used as an indicator of geothermal heat when excess 3He and/or 4He is present when compared to the atmospheric ratio of those isotopes (R/Ra). R/Ra is minimally affected by dilution and transport, allowing even those wells not perfectly situated over a geothermal system to indicate a geothermal anomaly. R/Ra anomalies are present on every island in this study. There is a strong correlation between R/Ra anomalies and proximity to rift zones and calderas. The Hawaii Play Fairway project was funded by the U.S. Department of Energy Geothermal Technologies Office (award DE-EE0006729). For more information, see Colin Ferguson's Master of Science thesis "Exploration for Blind Geothermal Resources in the State of Hawaii Utilizing Dissolved Noble Gasses in Well Waters."

15 GEOTHERMAL ENERGY↗

DOE OSTI2020

Exploration for Blind Geothermal Resources in the State of Hawaii Utilizing Dissolved Noble Gasses in Well Waters

This study is an extension of the Hawaii Play Fairway Analysis (PFA), a statewide geothermal exploration project funded by the United States Department of Energy. Based on results from prior phases of the PFA, this project targeted 66 wells on the islands of Hawaii, Maui, Lanai, Oahu, and Kauai for sampling of dissolved noble gases, trace metals, common ions, and the stable isotopes 2H and 18O. Ultimately, 23 of the 66 well targets were sampled. The noble gas helium is used as an indicator of geothermal heat when excess 3He and/or 4He is present when compared to the atmospheric ratio of those isotopes (R/Ra). R/Ra is minimally affected by dilution and transport, allowing even those wells not perfectly situated over a geothermal system to indicate a geothermal anomaly. R/Ra anomalies are present on every island in this study. There is a strong correlation between R/Ra anomalies and proximity to rift zones and calderas. Across the islands R/Ra ranged from 15-16 on Kilauea's lower east rift zone, which is a mantle plume value, to 0.37 on Lanai, which is a crustal value. The majority of anomalous well samples had R/Ra values consistent with an upper mantle source. Mixing between upper mantle and crustal helium is evident on all islands. Geographically, R/Ra decreases from the high at Kilauea to upper mantle values at Mauna Loa, and remains at upper mantle values for all wells across the other volcanoes, with the exception of two of four sampled wells on Lanai.

15 GEOTHERMAL ENERGY↗

DOE OSTI2020

Materials Data on TbYb2PrS6 by Materials Project

PrTbYb2S6 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Yb3+ sites. In the first Yb3+ site, Yb3+ is bonded to six S2- atoms to form YbS6 octahedra that share corners with two equivalent SYb3Pr2S octahedra, corners with three equivalent YbS6 octahedra, and edges with four equivalent YbS6 octahedra. The corner-sharing octahedra tilt angles range from 59–66°. There are a spread of Yb–S bond distances ranging from 2.65–3.18 Å. In the second Yb3+ site, Yb3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing YbS6 octahedra. The corner-sharing octahedra tilt angles range from 59–62°. There are a spread of Yb–S bond distances ranging from 2.55–3.09 Å. Tb3+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Tb–S bond distances ranging from 2.65–3.04 Å. Pr3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pr–S bond distances ranging from 2.83–3.07 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Tb3+ and three equivalent Pr3+ atoms to form distorted STb2Pr3 trigonal bipyramids that share corners with four equivalent SYb3Pr2S octahedra, corners with five STb3Yb tetrahedra, an edgeedge with one SYb3Pr2S octahedra, edges with three STb3Yb tetrahedra, and edges with four equivalent STb2Pr3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 24–56°. In the second S2- site, S2- is bonded to one Yb3+ and three equivalent Tb3+ atoms to form distorted STb3Yb tetrahedra that share corners with five STb3Yb tetrahedra, corners with four equivalent STb2Pr3 trigonal bipyramids, corners with three equivalent SYb4 trigonal pyramids, edges with two equivalent STb3Yb tetrahedra, and an edgeedge with one STb2Pr3 trigonal bipyramid. In the third S2- site, S2- is bonded to two equivalent Yb3+, one Tb3+, and one Pr3+ atom to form distorted STbYb2Pr tetrahedra that share corners with two equivalent SYb3Pr2S octahedra, corners with five STb3Yb tetrahedra, a cornercorner with one STb2Pr3 trigonal bipyramid, corners with two equivalent SYb4 trigonal pyramids, edges with three equivalent SYb3Pr2S octahedra, and edges with two equivalent STb2Pr3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 12°. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Yb3+, two equivalent Pr3+, and one S2- atom. The S–S bond length is 2.12 Å. In the fifth S2- site, S2- is bonded to three equivalent Yb3+, two equivalent Pr3+, and one S2- atom to form distorted SYb3Pr2S octahedra that share corners with two equivalent YbS6 octahedra, corners with two equivalent STbYb2Pr tetrahedra, corners with four equivalent STb2Pr3 trigonal bipyramids, corners with three equivalent SYb4 trigonal pyramids, edges with four equivalent SYb3Pr2S octahedra, edges with three equivalent STbYb2Pr tetrahedra, and an edgeedge with one STb2Pr3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the sixth S2- site, S2- is bonded to four Yb3+ atoms to form distorted SYb4 trigonal pyramids that share corners with three equivalent SYb3Pr2S octahedra, corners with five STb3Yb tetrahedra, corners with two equivalent SYb4 trigonal pyramids, and edges with two equivalent SYb4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 2–87°.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on LiTmSiO4 by Materials Project

LiTmSiO4 is Spinel-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four equivalent TmO6 octahedra, corners with two equivalent SiO4 tetrahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent TmO6 octahedra, and edges with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–66°. There are a spread of Li–O bond distances ranging from 2.19–2.27 Å. Tm3+ is bonded to six O2- atoms to form TmO6 octahedra that share corners with four equivalent LiO6 octahedra, corners with four equivalent TmO6 octahedra, corners with four equivalent SiO4 tetrahedra, edges with two equivalent LiO6 octahedra, and an edgeedge with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–66°. There are a spread of Tm–O bond distances ranging from 2.20–2.30 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent LiO6 octahedra, corners with four equivalent TmO6 octahedra, an edgeedge with one TmO6 octahedra, and edges with two equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two equivalent Tm3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+, one Tm3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Li1+, one Tm3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaTbGeO4 by Materials Project

NaTbGeO4 is Hausmannite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with four equivalent TbO6 octahedra, corners with two equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, edges with two equivalent TbO6 octahedra, and edges with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–66°. There are a spread of Na–O bond distances ranging from 2.41–2.56 Å. Tb3+ is bonded to six O2- atoms to form TbO6 octahedra that share corners with four equivalent NaO6 octahedra, corners with four equivalent TbO6 octahedra, corners with four equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–66°. There are a spread of Tb–O bond distances ranging from 2.24–2.38 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with four equivalent TbO6 octahedra, an edgeedge with one TbO6 octahedra, and edges with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 45–63°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Na1+, one Tb3+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Tb3+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Tb3+, and one Ge4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaYGeO4 by Materials Project

NaYGeO4 is Hausmannite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with four equivalent YO6 octahedra, corners with two equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, edges with two equivalent YO6 octahedra, and edges with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–66°. There are a spread of Na–O bond distances ranging from 2.40–2.56 Å. Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with four equivalent NaO6 octahedra, corners with four equivalent YO6 octahedra, corners with four equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–66°. There are a spread of Y–O bond distances ranging from 2.23–2.37 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with four equivalent YO6 octahedra, an edgeedge with one YO6 octahedra, and edges with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 45–63°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Y3+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Na1+, one Y3+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Y3+, and one Ge4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaErGeO4 by Materials Project

NaErGeO4 is Hausmannite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with four equivalent ErO6 octahedra, corners with two equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, edges with two equivalent ErO6 octahedra, and edges with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–66°. There are a spread of Na–O bond distances ranging from 2.38–2.55 Å. Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four equivalent NaO6 octahedra, corners with four equivalent ErO6 octahedra, corners with four equivalent GeO4 tetrahedra, edges with two equivalent NaO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–66°. There are a spread of Er–O bond distances ranging from 2.21–2.34 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with four equivalent ErO6 octahedra, an edgeedge with one ErO6 octahedra, and edges with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 44–63°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Er3+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one Er3+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Er3+, and one Ge4+ atom.

36 MATERIALS SCIENCE↗