Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Hg”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Controlling thermoelectric transport via native defects in the diamond-like semiconductors Cu 2 HgGeTe 4 and Hg 2 GeTe 4

Diamond like semiconductors (DLS) have emerged as candidates for thermoelectric energy conversion. Towards understanding and optimizing performance, we present a comprehensive investigation of the electronic properties of two DLS phases, quaternary Cu 2 HgGeTe 4 and related ordered vacancy compound Hg 2 GeTe 4 , including thermodynamic stability, defect chemistry, and transport properties. To establish the thermodynamic link between the related but distinct phases, the stability region for both is visualized in chemical potential space. In spite of their similar structure and bonding, we show that the two materials exhibit reciprocal behaviors for dopability. Cu 2 HgGeTe 4 is degenerately p-type in all environments despite its wide stability region, due to the presence of low-energy acceptor defects V Cu and Cu Hg and is resistant to extrinsic n-type doping. Meanwhile Hg 2 GeTe 4 has a narrow stability region and intrinsic behavior due to the relatively high formation energy of native defects, but presents an opportunity for bi-polar doping. While these two compounds have similar structure, bonding, and chemical constituents, the reciprocal nature of their dopability emerges from significant differences in band edge positions. A Brouwer band diagram approach is utilized to visualize the role of native defects on carrier concentrations, dopability, and transport properties. Here this study elucidates the doping asymmetry between two solid-solution forming DLS phases Cu 2 HgGeTe 4 and Hg 2 GeTe 4 by revealing the defect chemistry of each compound, and suggests design strategies for defect engineering of DLS phases.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Fine structure in the α decay of $^{179}$Hg and $^{177}$Au

Abstract The$$\upalpha $$ α -decay fine structure of$$^{179}$$ 179 Hg and$$^{177}$$ 177 Au was studied by means of decay spectroscopy. Two experiments were performed at the Accelerator Laboratory of the University of Jyväskylä (JYFL), Finland, utilizing the recoil separator RITU and a digital data acquisition system. The heavy-ion induced fusion-evaporation reactions$$^{82}_{36}$$ 36 82 Kr + $$^{100}_{44}$$ 44 100 Ru and$$^{88}_{38}$$ 38 88 Kr + $$^{92}_{42}$$ 42 92 Mo were used to produce the$$^{179}$$ 179 Hg and$$^{177}$$ 177 Au nuclei, respectively. Studying the evaporation residues (ER, recoils)-$$\alpha _1$$ α 1 -$$\alpha _2$$ α 2 correlations and$$\upalpha $$ α -$$\gamma $$ γ coincidences, a new$$\upalpha $$ α decay with E$$_\alpha $$ α = 6156(10) keV was observed from$$^{179}$$ 179 Hg. This decay populates the (9/2$$^-$$ - ) excited state at an excitation energy of 131.3(5) keV in$$^{175}$$ 175 Pt. The internal conversion coefficient for the 131.3(5) keV transition de-exciting this state was measured for the first time. Regarding the$$^{177}$$ 177 Au nucleus, a new$$\upalpha $$ α decay with E$$_\alpha $$ α = 5998(9) keV was observed to populate the 156.1(6) keV excited state in$$^{173}$$ 173 Ir. Two de-excitation paths were observed from this excited state. Moreover, a new 215.7(13) keV transition was observed to depopulate the 424.4(13) keV excited state in$$^{173}$$ 173 Ir. Properties of the$$^{179}$$ 179 Hg and$$^{177}$$ 177 Au$$\upalpha $$ α decays were examined in a framework of reduced widths and hindrance factors. For clarity and simplicity, the spin and parity assignments (e.g.$$J^{\pi }$$ J π ) are presented without brackets throughout the text.

Physics↗
DOE OSTI2020

Materials Data on Hg(CN)2 by Materials Project

Hg(CN)2 is Potassium Silver Cyanide-derived structured and crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. Hg2+ is bonded in a 4-coordinate geometry to two equivalent C2+ and four equivalent N3- atoms. Both Hg–C bond lengths are 2.05 Å. There are two shorter (2.82 Å) and two longer (3.16 Å) Hg–N bond lengths. C2+ is bonded in a linear geometry to one Hg2+ and one N3- atom. The C–N bond length is 1.17 Å. N3- is bonded in a distorted single-bond geometry to two equivalent Hg2+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Sequentially prepared Mo-V-Based SCR catalyst for simultaneous Hg 0 oxidation and NO reduction

Molybdenum (Mo)-vanadium (V)-based selective catalytic reduction (SCR) catalyst synthesized by the sequential impregnation of Mo and W followed by V was investigated for simultaneous elemental mercury (Hg 0 ) oxidation and nitrogen oxide (NO) reduction in an existing SCR unit with respect to different TiO 2 phases, calcination temperatures, flue gas constituents, gas velocities, and reaction temperatures. Anatase phase TiO 2 and the calcination temperatures of 400 and 500 degrees C resulted in similar to 69% Hg 0 oxidation at 10 ppmv HCl and 350 degrees C. The high calcination temperature of 700 degrees C resulted in TiO 2 phase transformation from anatase to rutile and agglomeration. The modified SCR catalyst prepared with the impregnation sequence of Mo and W followed by V using anatase TiO 2 and calcination temperature 500 degrees C showed similar to 99% Hg 0 oxidation and 87% NO reduction conversions at an NH 3 /NO molar ratio of 0.9 under 350 degrees C and 5,000 hr -1 space velocity in typical sub-bituminous and lignite coal simulated flue gases. Finally, the effects of these parameters and conditions were further investigated using various characterization techniques including BET, TEM, XRD, NH 3 TPD and XAFS.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Concentrations and Health Implications of As, Hg, and Cd and Micronutrients in Rice and Emissions of CH 4 From Variably Flooded Paddies

Abstract The flooded soil conditions under which rice is typically grown are beneficial for boosting yield and decreasing herbicide inputs but may pose a food safety and environmental health risk. Flooded soils lead to reducing conditions and anaerobic metabolisms of soil microorganisms, which mobilizes arsenic from soil into soil solution, where it can be absorbed by rice roots and transported to grain. These conditions also promote the production and emission of methane (CH 4 )—a potent greenhouse gas. To evaluate how water management affects metal(loid) grain concentrations and CH 4 emissions, we conducted a 2‐year field study in which rice paddy water was managed under a range of soil redox conditions that spanned from flooded to non‐flooded. We observed that growing rice under less flooded conditions decreased CH 4 emissions and concentrations of grain total As, grain inorganic As, grain total Hg, and grain inorganic Hg relative to flooded conditions, with more reductions observed as conditions were drier; grain organic As and Hg (MeHg) species also decreased with drier conditions particularly in Year 1. However, the driest conditions tested led to a 50%–97% increase in grain Cd concentrations that exceeded the CODEX limit and grain yield reductions as high as 25% and 40% in Year 1 and 2, respectively. While concentrations of toxic metal(loid)s could be manipulated by water management, micronutrient concentrations were similar or decreased with drier conditions, potentially increasing grain Cd bioaccessibility to humans. Because practices for rice water management are gaining momentum, more research should monitor grain Cd levels along with micronutrients.

Environmental Sciences & Ecology↗
DOE OSTI2020

Multinucleon transfer in the interaction of 977 MeV and 1143 MeV Hg 204 with Pb 208

A previous study of symmetric collisions of massive nuclei has shown that current models of multinucleon transfer (MNT) reactions do not adequately describe the transfer product yields. To gain further insight into this problem, we have measured the yields of MNT products in the interaction of 977 (E/A = 4.79 MeV) and 1143 MeV (E/A = 5.60 MeV) 204 Hg with 208 Pb. We find that the yield of multinucleon transfer products are similar in these two reactions and are substantially lower than those observed in the reaction of 1257 MeV (E/A = 6.16 MeV) 204 Hg+ 198 Pt. We compare our measurements with the predictions of the GRAZING-F, dinuclear systems (DNS), and improved quantum molecular dynamics (ImQMD) models. We report that for the observed isotopes of the elements Au, Hg, Tl, Pb, and Bi, the measured values of the MNT cross sections are orders of magnitude larger than the predicted values. Furthermore, the various models predict the formation of nuclides near the N = 126 shell, which are not observed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Materials Data on Hg(PO3)2 by Materials Project

Hg(PO3)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Hg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Hg–O bond distances ranging from 2.23–2.63 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Hg2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Hg2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Hg2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Hg2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(IO3)2 by Materials Project

Hg(IO3)2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Hg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Hg–O bond distances ranging from 2.25–2.97 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Hg2+ and two I5+ atoms. There are one shorter (1.84 Å) and one longer (2.60 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Hg2+ and two equivalent I5+ atoms. There are one shorter (1.83 Å) and one longer (2.71 Å) O–I bond lengths. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Hg2+ and two I5+ atoms. There are one shorter (1.86 Å) and one longer (2.79 Å) O–I bond lengths. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Hg2+ and two equivalent I5+ atoms. There are one shorter (1.84 Å) and one longer (2.66 Å) O–I bond lengths. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Hg2+ and one I5+ atom. The O–I bond length is 1.88 Å. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Hg2+ and two I5+ atoms. There are one shorter (1.86 Å) and one longer (2.64 Å) O–I bond lengths. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded to six O2- atoms to form distorted corner-sharing IO6 octahedra. The corner-sharing octahedral tilt angles are 48°. In the second I5+ site, I5+ is bonded in a 5-coordinate geometry to five O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(Mo3Cl7)2 by Materials Project

Hg(Mo3Cl7)2 crystallizes in the cubic Pn-3 space group. The structure is three-dimensional. Mo2+ is bonded to five Cl1- atoms to form MoCl5 square pyramids that share a cornercorner with one HgCl6 octahedra and edges with four equivalent MoCl5 square pyramids. The corner-sharing octahedral tilt angles are 48°. There are three shorter (2.48 Å) and two longer (2.49 Å) Mo–Cl bond lengths. Hg2+ is bonded to six equivalent Cl1- atoms to form HgCl6 octahedra that share corners with six equivalent MoCl5 square pyramids. All Hg–Cl bond lengths are 2.74 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 12-coordinate geometry to three equivalent Mo2+ atoms. In the second Cl1- site, Cl1- is bonded in a distorted bent 120 degrees geometry to one Mo2+ and one Hg2+ atom. In the third Cl1- site, Cl1- is bonded in a 3-coordinate geometry to three equivalent Mo2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(AuF4)2 by Materials Project

Hg(AuF4)2 crystallizes in the tetragonal P4/mcc space group. The structure is three-dimensional. Au3+ is bonded in a square co-planar geometry to four equivalent F1- atoms. All Au–F bond lengths are 1.97 Å. Hg2+ is bonded in a 8-coordinate geometry to eight equivalent F1- atoms. All Hg–F bond lengths are 2.43 Å. F1- is bonded in a distorted bent 120 degrees geometry to one Au3+ and one Hg2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(AsO3)2 by Materials Project

Hg(AsO3)2 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. Hg2+ is bonded to six equivalent O2- atoms to form HgO6 octahedra that share corners with twelve equivalent AsO6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Hg–O bond lengths are 2.41 Å. As5+ is bonded to six equivalent O2- atoms to form AsO6 octahedra that share corners with six equivalent HgO6 octahedra and edges with three equivalent AsO6 octahedra. The corner-sharing octahedral tilt angles are 53°. All As–O bond lengths are 1.87 Å. O2- is bonded in a distorted trigonal planar geometry to one Hg2+ and two equivalent As5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(CO2)2 by Materials Project

Hg(CO2)2 crystallizes in the monoclinic P2_1 space group. The structure is zero-dimensional and consists of two mercuric formate molecules. Hg2+ is bonded in a distorted linear geometry to two O2- atoms. Both Hg–O bond lengths are 2.13 Å. There are two inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C3+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C3+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Hg2+ and one C3+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Hg2+ and one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(BiS2)2 by Materials Project

HgBi2S4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to six S2- atoms to form distorted HgS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with two equivalent HgS6 octahedra, and edges with six equivalent BiS7 square pyramids. The corner-sharing octahedral tilt angles are 66°. There are two shorter (2.40 Å) and four longer (3.24 Å) Hg–S bond lengths. In the second Hg2+ site, Hg2+ is bonded to six S2- atoms to form distorted HgS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with two equivalent HgS6 octahedra, and edges with six equivalent BiS6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two shorter (2.39 Å) and four longer (3.27 Å) Hg–S bond lengths. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three HgS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with three equivalent HgS6 octahedra, edges with four equivalent BiS6 octahedra, and an edgeedge with one BiS7 square pyramid. The corner-sharing octahedra tilt angles range from 8–66°. There are a spread of Bi–S bond distances ranging from 2.65–3.17 Å. In the second Bi3+ site, Bi3+ is bonded to seven S2- atoms to form distorted BiS7 square pyramids that share corners with four HgS6 octahedra, corners with four equivalent BiS6 octahedra, an edgeedge with one BiS6 octahedra, edges with three equivalent HgS6 octahedra, edges with two equivalent BiS7 square pyramids, and faces with two equivalent BiS7 square pyramids. The corner-sharing octahedra tilt angles range from 9–64°. There are a spread of Bi–S bond distances ranging from 2.62–3.48 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to one Hg2+ and four Bi3+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Hg2+ and three equivalent Bi3+ atoms. In the third S2- site, S2- is bonded to one Hg2+ and three Bi3+ atoms to form distorted SHgBi3 tetrahedra that share corners with three equivalent SHg2Bi3 square pyramids and corners with three equivalent SHgBi3 tetrahedra. In the fourth S2- site, S2- is bonded to two equivalent Hg2+ and three equivalent Bi3+ atoms to form distorted SHg2Bi3 square pyramids that share corners with two equivalent SHg2Bi3 square pyramids, corners with three equivalent SHgBi3 tetrahedra, and edges with five equivalent SHg2Bi3 square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(SbO3)2 by Materials Project

Hg(SbO3)2 is zeta iron carbide-derived structured and crystallizes in the trigonal P-31m space group. The structure is three-dimensional. Hg2+ is bonded to six equivalent O2- atoms to form HgO6 octahedra that share corners with twelve equivalent SbO6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Hg–O bond lengths are 2.44 Å. Sb5+ is bonded to six equivalent O2- atoms to form SbO6 octahedra that share corners with six equivalent HgO6 octahedra and edges with three equivalent SbO6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Sb–O bond lengths are 2.02 Å. O2- is bonded in a distorted trigonal planar geometry to one Hg2+ and two equivalent Sb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(BiO3)2 by Materials Project

Hg(BiO3)2 is Hydrophilite-derived structured and crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Hg2+ is bonded to six O2- atoms to form HgO6 octahedra that share corners with eight equivalent BiO6 octahedra and edges with two equivalent BiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–54°. There are two shorter (2.27 Å) and four longer (2.34 Å) Hg–O bond lengths. Bi5+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with four equivalent HgO6 octahedra, corners with four equivalent BiO6 octahedra, an edgeedge with one HgO6 octahedra, and an edgeedge with one BiO6 octahedra. The corner-sharing octahedra tilt angles range from 47–54°. There are a spread of Bi–O bond distances ranging from 2.16–2.21 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Hg2+ and two equivalent Bi5+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Hg2+ and two equivalent Bi5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(SbO3)2 by Materials Project

Hg(SbO3)2 is zeta iron carbide-derived structured and crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Hg2+ is bonded to six O2- atoms to form HgO6 octahedra that share corners with eight equivalent SbO6 octahedra and edges with two equivalent SbO6 octahedra. The corner-sharing octahedra tilt angles range from 54–57°. There are two shorter (2.27 Å) and four longer (2.35 Å) Hg–O bond lengths. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with four equivalent HgO6 octahedra, corners with four equivalent SbO6 octahedra, an edgeedge with one HgO6 octahedra, and an edgeedge with one SbO6 octahedra. The corner-sharing octahedra tilt angles range from 39–57°. There are four shorter (2.03 Å) and two longer (2.05 Å) Sb–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Hg2+ and two equivalent Sb5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Hg2+ and two equivalent Sb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(TeO3)2 by Materials Project

Hg(TeO3)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Hg2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Hg–O bond distances ranging from 2.25–2.55 Å. There are two inequivalent Te5+ sites. In the first Te5+ site, Te5+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing TeO5 trigonal bipyramids. There are a spread of Te–O bond distances ranging from 1.87–2.05 Å. In the second Te5+ site, Te5+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing TeO5 square pyramids. There are a spread of Te–O bond distances ranging from 1.85–2.53 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Hg2+ and two Te5+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Hg2+ and one Te5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Hg2+ and two Te5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Hg2+ and two Te5+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Hg2+ and one Te5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Te5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg by Materials Project

Hg is Protactinium structured and crystallizes in the tetragonal I4/mmm space group. The structure is zero-dimensional and consists of two mercury molecules. Hg is bonded in a distorted body-centered cubic geometry to atoms.

36 MATERIALS SCIENCE↗