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- Creator:
- Su, Xue, Zhang, Youxue, Liu, Yang, and Holder, Robert M.
- Description:
- It is commonly thought that volcanic glass only records volatile loss during the eruptions in the Moon. However, our recent work shows that Na, K and Cu (moderately volatile elements) in lunar 74220 orange glass beads are enriched near the bead surfaces and depleted in the bead interiors, forming an overall “U-shaped” profile. The “U-shaped” profile means that rather than being “lost” into space, Na, K and Cu were “gained” into the volcanic glass during the eruption, which is contrary to the “volatile loss” story. Three different instruments (EMP, SIMS and LA-ICP-MS) were used to verify the discovery. We propose that such U-shaped Na, K and Cu profiles were formed by initial outgassing and subsequent in-gassing of Na, K and Cu when the beads were flying from the vent onto the surface through the cooling volcanic gas plume. Hence, in-gassing and the formation of surface coatings are two processes that are genetically linked during the pyroclastic eruption and evolution of the gas cloud. To quantify the processes that formed the U-shaped profiles, we developed a diffusion and surface-equilibrium model using available literature data on Na and Cu diffusivity in basaltic melts. The model reproduced U-shaped Na and Cu concentration profiles with outgassing at high temperature and subsequent in-gassing as beads cooled. By fitting the measured Na and Cu profiles, we found that the cooling time scales of individual orange glass beads range from 48 to 179 s. This is the first time that both outgassing and in-gassing were modeled and the cooling time scales of individual 74220 volcanic orange glass beads were estimated. The discovery of the U-shaped profiles of moderately volatile elements inside volcanic beads provides significant constraints on partial pressures of relevant volcanic gas species in the eruption plume.
- Keyword:
- Moon, Volcanic orange glass beads, Moderately volatile elements, Outgassing and in-gassing, and Cooling time scales
- Citation to related publication:
- Su, X., Zhang, Y., Liu, Y. and Holder, R.M. (2023) Outgassing and in-gassing of Na, K and Cu in lunar 74220 orange glass beads. Earth and Planetary Science Letters 602. https://doi.org/10.1016/j.epsl.2022.117924
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and Micro and Nano CT Advanced Imaging Core, Orthopaedic Research Laboratories, University of Michigan
- Description:
- Reconstructed CT slices for UMMP VP 118710 Mammuthus primigenius proximal tusk segment as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Elephantidae, UMMP, University of Michigan Museum of Paleontology, and 4760d0fa-a763-23d2-1be9-89bb1aaf711c
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology, University of Michigan School of Dentostry MicroCT Core, and Lynch, Michelle
- Description:
- Reconstructed CT slices for UMMP VP 118186 Loxodonta africana tusk core as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, CT, Elephantidae, UMMP, University of Michigan Museum of Paleontology, and a4f83cc6-09f2-0032-8a09-60ea798f787c
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for tusk block number 2 of Mammuthus primigenius (University of Michigan Museum of Paleontology catalog number UMMP VP 118711) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Elephantidae, UMMP, University of Michigan Museum of Paleontology, Pleistocene, and eb7acb05-b8b5-9642-b90a-b7d49a83de4d
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology, University of Michigan School of Dentistry MicroCT Core, and Lynch, Michelle
- Description:
- Reconstructed CT slices for UMMP VP 118711 Mammuthus primigenius block number 10 (distalmost) removed from tusk as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Elephantidae, UMMP, University of Michigan Museum of Paleontology, Pleistocene, and eb7acb05-b8b5-9642-b90a-b7d49a83de4d
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology, University of Michigan School of Dentistry MicroCT Core, and Lynch, Michelle
- Description:
- Reconstructed CT slices for UMMP VP 118711 Mammuthus primigenius block number 1 (proximalmost) removed from tusk as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Elephantidae, UMMP, University of Michigan Museum of Paleontology, Pleistocene, and eb7acb05-b8b5-9642-b90a-b7d49a83de4d
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for Posterior cranium fragment (juvenile) of Dorudon atrox (University of Michigan Museum of Paleontology catalog number UMMP VP 100142) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Basilosauridae, Eocene, CTEES, UMMP, University of Michigan Museum of Paleontology, and a470edbc-75b1-f352-d947-330dd1043256
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for skull of Stylemys nebrascensis (University of Michigan Museum of Paleontology catalog number UMMP VP 9318) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Testudinidae, UMMP, University of Michigan Museum of Paleontology, Oligocene, CTEES, and c38728f5-6f38-d862-7bcf-9745e69db222
- Discipline:
- Science
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- Creator:
- Kharbush, Jenan J, Carter, Susan J, and Robinson, Rebecca S
- Description:
- Nitrogen availability is hypothesized to play a central role in cyanoHAB progression, as well as production of the N-rich toxin microcystin. Recent work implicated reduced N substrates like ammonium and dissolved organic N (DON) in promoting greater bloom biomass and longevity. To examine the relative importance of oxidized and reduced N substrates to phytoplankton during different bloom stages, we measured concentrations and natural abundance δ15N isotope values of dissolved N substrates and phytoplankton biomass throughout the entirety of the 2020 cyanoHAB in Western Lake Erie. This is the first data on DON concentrations and isotope values in Western Lake Erie. We measured nitrate concentrations and isotope values to compare with DON and also with particulate organic matter (POM) 15N isotope values. This dataset is described and analyzed in the publication, "Patterns in sources and forms of nitrogen during a freshwater cyanobacterial harmful algal bloom".
- Keyword:
- Dissolved organic nitrogen, cyanobacteria, nitrate, particulate organic matter, δ15N, stable isotopes
- Citation to related publication:
- Kharbush, Jenan J., Robinson, Rebecca S., Carter, Susan J. In revision. Patterns in sources and forms of nitrogen during a freshwater cyanobacterial harmful algal bloom. Limnology and Oceanography.
- Discipline:
- Science
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- Creator:
- Zhou, Peng and Mi, Zetian
- Description:
- Production of hydrogen fuel from sunlight and water offers one of the most promising pathways for carbon neutrality. Some solar hydrogen production approaches, e.g., photoelectrochemical water splitting, often requires corrosive electrolyte, limiting their performance stability and environmental sustainability. Alternatively, clean hydrogen can be produced directly from tap water, or seawater by wireless photocatalytic water splitting. The solar-to-hydrogen (STH) efficiency, however, is still lower than 3%. Herein, we have developed a unique strategy to overcome the efficiency bottleneck. A high STH efficiency of 9.2% was achieved by utilizing pure water, concentrated solar light, and visible-light-responsive InGaN photocatalyst. The success of this strategy was explained by the synergistic effects of promoting forward hydrogen-oxygen evolution and inhibiting the reverse hydrogen-oxygen recombination by operating at an optimal reaction temperature (~70 °C). Such an optimal temperature can be readily achieved by harvesting the previously wasted infrared light of the solar spectrum without other energy consumption. This temperature-dependent strategy also leads to the STH efficiencies of ~7% from the widely available tap water and seawater. A large-scale photocatalytic water splitting system with a natural solar light capacity of 257 W on a 4 cm × 4 cm photocatalyst wafer achieves a STH of 6.2% at ~70 oC. Our study offers a practical approach to produce hydrogen fuel efficiently from natural solar and water, overcoming some of the major barriers for green hydrogen economy.
- Keyword:
- photocatalysis, water splitting, and solar hydrogen
- Discipline:
- Science