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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Mercury trophic transfer in Bear Creek

Mercury (especially when transformed by environmental microbes into methylmercury [MeHg]) is one of the only metals known to biomagnify in aquatic food webs, leading to elevated concentrations of this toxicant in fish. However, because Hg is predominantly accumulated in fish via dietary rather than aqueous exposure, the link between aqueous Hg concentrations and concentrations in fish is not always straightforward. This is particularly confounding for remediation efforts at contaminated sites because although reducing aqueous Hg concentrations may be achievable, concentrations in fish may not respond to these reductions in aqueous concentrations if a sufficient amount of Hg remains within the food web or if conditions favor Hg methylation in the environment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Mercury Trophic Transfer in Bear Creek

Mercury (especially when transformed by environmental microbes into methylmercury [MeHg]) is one of the only metals known to biomagnify in aquatic food webs, leading to elevated concentrations of this toxicant in fish. However, because Hg is predominantly accumulated in fish via dietary rather than aqueous exposure, the link between aqueous Hg concentrations and concentrations in fish is not always straightforward. This is particularly confounding for remediation efforts at contaminated sites because although reducing aqueous Hg concentrations may be achievable, concentrations in fish may not respond to these reductions in aqueous concentrations if a sufficient amount of Hg remains within the food web or if conditions favor Hg methylation in the environment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Direct Mercury Detection in Landfill Leachate Using a Novel AuNP-Biopolymer Carbon Screen-Printed Electrode Sensor

A novel Au nanoparticle (AuNP)-biopolymer coated carbon screen-printed electrode (SPE) sensor was developed through the co-electrodeposition of Au and chitosan for mercury (Hg) ion detection. This new sensor showed successful Hg2+ detection in landfill leachate using square wave anodic stripping voltammetry (SWASV) with an optimized condition: a deposition potential of −0.6 V, deposition time of 200 s, amplitude of 25 mV, frequency of 60 Hz, and square wave step voltage of 4 mV. A noticeable peak was observed at +0.58 V associated with the stripping current of the Hg ion. The sensor exhibited a good sensitivity of ~0.09 μA/μg (~0.02 μA/nM) and a linear response over the concentration range of 10 to 100 ppb (50–500 nM). The limit of detection (LOD) was 1.69 ppb, which is significantly lower than the safety limit defined by the United States Environmental Protection Agency (USEPA). The sensor had an excellent selective response to Hg2+ in landfill leachate against other interfering cations (e.g., Zn2+, Pb2+, Cd2+, and Cu2+). Fifteen successive measurements with a stable peak current and a lower relative standard deviation (RSD = 5.1%) were recorded continuously using the AuNP-biopolymer-coated carbon SPE sensor, which showed excellent stability, sensitivity and reproducibility and consistent performance in detecting the Hg2+ ion. It also exhibited a good reliability and performance in measuring heavy metals in landfill leachate.

Hwang, Jae-Hoon (ORCID:0000000220100864)↗
NASA NTRS1962

ASTRONAUT'S REPORT ON PROJECT MERCURY

There has been so much recent information put out on the orbital flight and on Project Mercury that I thought that, rather than give details of the flight and Project, I would discuss briefly some of the general aspects of space flight.

Atlas ICBM↗
NASA NTRS1965

High-intensity flashing beacon powered by mercury cells

Pair of xenon flashlamps powered by mercury batteries in a transistorized circuit provides a flashing beacon with an effective intensity of a second-magnitude star at a distance of ten statute miles. This beacon is lightweight, long lasting and it withstands shock and vibration.

Source record↗