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DOE OSTI2020

Materials Data on B2(CN2)3 by Materials Project

B2(CN2)3 crystallizes in the trigonal R32 space group. The structure is two-dimensional and consists of three B2(CN2)3 sheets oriented in the (0, 0, 1) direction. B3+ is bonded in a trigonal planar geometry to three equivalent N3- atoms. All B–N bond lengths are 1.44 Å. C4+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.22 Å. N3- is bonded in a bent 150 degrees geometry to one B3+ and one C4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on CN2 by Materials Project

CN2 crystallizes in the tetragonal P-42_1m space group. The structure is two-dimensional and consists of one CN2 sheet oriented in the (0, 0, 1) direction. C4+ is bonded to four equivalent N2- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.47 Å. N2- is bonded in a distorted water-like geometry to two equivalent C4+ atoms.

36 MATERIALS SCIENCE↗

NASA NTRS2017

Path Profiles of Cn2 Derived from Radiometer Temperature Measurements and Geometrical Ray Tracing

Atmospheric turbulence has significant impairments on the operation of Free-Space Optical (FSO) communication systems, in particular temporal and spatial intensity fluctuations at the receiving aperture resulting in power surges and fades, changes in angle of arrival, spatial coherence degradation, etc. The refractive index structure parameter Cn2 is a statistical measure of the strength of turbulence in the atmosphere and is highly dependent upon vertical height. Therefore to understand atmospheric turbulence effects on vertical FSO communication links such as space-to-ground links, it is necessary to specify Cn2 profiles along the atmospheric propagation path. To avoid the limitations on the applicability of classical approaches, propagation simulation through geometrical ray tracing is applied. This is achieved by considering the atmosphere along the optical propagation path as a spatial distribution of spherical bubbles with varying relative refractive index deviations representing turbulent eddies. The relative deviations of the refractive index are statistically determined from altitude-dependent and time-varying temperature fluctuations, as measured by a microwave profiling radiometer. For each representative atmosphere ray paths are analyzed using geometrical optics, which is particularly advantageous in situations of strong turbulence where there is severe wavefront distortion and discontinuity. The refractive index structure parameter is then determined as a function of height and time.

Atmospheric turbulence↗

DOE OSTI2020

Materials Data on KLaSi(CN2)4 by Materials Project

KLaSi(CN2)4 crystallizes in the orthorhombic P2_12_12 space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of K–N bond distances ranging from 2.94–3.14 Å. La3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are a spread of La–N bond distances ranging from 2.54–2.76 Å. Si4+ is bonded in a tetrahedral geometry to four N3- atoms. There is two shorter (1.72 Å) and two longer (1.73 Å) Si–N bond length. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.20 Å) and one longer (1.27 Å) C–N bond length. In the second C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.20 Å) and one longer (1.27 Å) C–N bond length. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted bent 120 degrees geometry to one K1+, one La3+, one Si4+, and one C4+ atom. In the second N3- site, N3- is bonded in a 3-coordinate geometry to one K1+, one La3+, and one C4+ atom. In the third N3- site, N3- is bonded in a 3-coordinate geometry to one K1+, one La3+, and one C4+ atom. In the fourth N3- site, N3- is bonded in a 2-coordinate geometry to one La3+, one Si4+, and one C4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on CN2 by Materials Project

CN2 is Hittorf-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of two CN sheets oriented in the (0, 0, 1) direction and one N2 sheet oriented in the (0, 0, 1) direction. In each CN sheet, C4+ is bonded in a trigonal non-coplanar geometry to three equivalent N2- atoms. All C–N bond lengths are 1.46 Å. N2- is bonded in a trigonal non-coplanar geometry to three equivalent C4+ atoms. In the N2 sheet, N2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent N2- atoms. All N–N bond lengths are 1.54 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on CN2 by Materials Project

CN2 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. C4+ is bonded to four equivalent N2- atoms to form corner-sharing CN4 tetrahedra. All C–N bond lengths are 1.48 Å. N2- is bonded in a distorted trigonal planar geometry to two equivalent C4+ and one N2- atom. The N–N bond length is 1.36 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ba2LiAl(CN2)4 by Materials Project

LiBa2Al(CN2)4 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. Li1+ is bonded in a tetrahedral geometry to four N3- atoms. There are a spread of Li–N bond distances ranging from 2.07–2.14 Å. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are a spread of Ba–N bond distances ranging from 2.92–2.99 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are a spread of Ba–N bond distances ranging from 2.83–3.13 Å. Al3+ is bonded in a tetrahedral geometry to four N3- atoms. There is two shorter (1.85 Å) and two longer (1.86 Å) Al–N bond length. There are four inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.22 Å) and one longer (1.26 Å) C–N bond length. In the second C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.21 Å) and one longer (1.26 Å) C–N bond length. In the third C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.22 Å) and one longer (1.26 Å) C–N bond length. In the fourth C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.22 Å) and one longer (1.26 Å) C–N bond length. There are eight inequivalent N3- sites. In the first N3- site, N3- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Al3+, and one C4+ atom. In the second N3- site, N3- is bonded in a distorted bent 120 degrees geometry to two Ba2+, one Al3+, and one C4+ atom. In the third N3- site, N3- is bonded in a distorted bent 120 degrees geometry to two Ba2+, one Al3+, and one C4+ atom. In the fourth N3- site, N3- is bonded in a distorted bent 120 degrees geometry to two Ba2+, one Al3+, and one C4+ atom. In the fifth N3- site, N3- is bonded in a 4-coordinate geometry to one Li1+, two Ba2+, and one C4+ atom. In the sixth N3- site, N3- is bonded in a 2-coordinate geometry to one Li1+, two equivalent Ba2+, and one C4+ atom. In the seventh N3- site, N3- is bonded in a 2-coordinate geometry to one Li1+, two Ba2+, and one C4+ atom. In the eighth N3- site, N3- is bonded in a 2-coordinate geometry to one Li1+, two Ba2+, and one C4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on CoH9(CN2)3 by Materials Project

CoCo(NH3)6(CN)6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three azane;cobalt molecules, three cobalt molecules, and eighteen hydrogen cyanide molecules.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Mn2(CN2)3 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Mn2(CN2)3 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Sr2C2N3 by Materials Project

Sr4(CN2)3C crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional and consists of four methane molecules and one Sr4(CN2)3 framework. In the Sr4(CN2)3 framework, there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six N3- atoms. All Sr–N bond lengths are 2.59 Å. In the second Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to four N3- atoms. All Sr–N bond lengths are 2.63 Å. In the third Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to four equivalent N3- atoms. All Sr–N bond lengths are 2.63 Å. There are two inequivalent C+2.50+ sites. In the first C+2.50+ site, C+2.50+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.24 Å. In the second C+2.50+ site, C+2.50+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.24 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to three Sr2+ and one C+2.50+ atom to form a mixture of distorted corner and edge-sharing NSr3C tetrahedra. In the second N3- site, N3- is bonded to three Sr2+ and one C+2.50+ atom to form a mixture of distorted corner and edge-sharing NSr3C tetrahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaC2N3 by Materials Project

NaN(CN)2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of two CN2 ribbons oriented in the (2, 0, 1) direction and two NaCN sheets oriented in the (0, 1, 0) direction. In each CN2 ribbon, C4+ is bonded in a water-like geometry to two N3- atoms. There is one shorter (1.35 Å) and one longer (1.42 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted bent 120 degrees geometry to one C4+ and one N3- atom. The N–N bond length is 1.25 Å. In the second N3- site, N3- is bonded in a distorted bent 120 degrees geometry to one C4+ and one N3- atom. The N–N bond length is 1.29 Å. In each NaCN sheet, Na1+ is bonded in a 3-coordinate geometry to three equivalent N3- atoms. There are a spread of Na–N bond distances ranging from 2.39–2.78 Å. C4+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. N3- is bonded in a 4-coordinate geometry to three equivalent Na1+ and one C4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Passive method to measure strength of turbulence

Disclosed is a method to passively measure and calculate the strength of turbulence via the index of refraction structure constant Cn2 from video imagery gathered by an imaging device, such as a video camera. Processing may occur with any type computing device utilizing a processor executing machine executable code stored on memory. This method significantly simplifies instrumentation requirements, reduces cost, and provides rapid data output. This method combines an angle of arrival methodology, which provides scale factors, with a new spatial/temporal frequency domain method. As part of the development process, video imagery from high speed cameras was collected and analyzed. The data was decimated to video rates such that statistics could be computed and used to confirm that this passive method accurately characterizes the atmospheric turbulence. Cn2 accuracy from this method compared well with scintillometer data through two full orders of magnitude and more capability is expected beyond this verification.

O'Neill, Mary Morabito↗

DOE OSTI2024

Microbial Reduction of Geogenic and Synthetic Goethite and Hematite

The microbial reduction of Fe(III) is a major component of Fe cycling in terrestrial and aquatic environments and is affected by the Fe(III) mineralogy of the system. The majority of the research examining the bioreduction of Fe(III) oxides by Fe(III)-reducing bacteria (IRB) has focused on the reduction of poorly crystalline Fe(III) phases, primarily ferrihydrite; however, crystalline Fe(III) oxides like goethite (α-FeOOH) and hematite (α-Fe 2 O 3 ) comprise the majority of Fe(III) oxides in soils. This study examined the bioreduction of goethite and hematite of geogenic and synthetic origin by Shewanella putrefaciens CN2, a well-studied model IRB, in laboratory incubations. Overall, the rate and extent of Fe(II) production were greater for goethite than for hematite, and for geogenic Fe(III) oxides relative to their synthetic analogs. Although there was substantial production of Fe(II) (i.e., >5 mM Fe(II)) in many of the systems, X-ray diffraction analysis of the solids at the end of the incubation did not indicate the formation of any Fe(II)-bearing secondary minerals (e.g., magnetite, siderite, green rust, etc.). The results of this study demonstrate the variability in the extent of bioreduction of geogenic goethite and hematite, and furthermore, that synthetic goethite and hematite may not be good analogs for the biogeochemical behavior of Fe(III) oxides in aquatic and terrestrial environments.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS1978

Ground-to-space optical power transfer

Using laser radiation as the energy input to a rocket, it is possible to consider the transfer of large payloads economically between low initial orbits and higher energy orbits. In this paper we will discuss the results of an investigation to use a ground-based High Energy Laser (HEL) coupled to an adaptive antenna to transmit multi-megawatts of power to a satellite in low-earth orbit. Our investigation included diffraction effects, atmospheric transmission efficiency, adaptive compensation for atmospheric turbulence effects, including the servo bandwidth requirements for this correction, and the adaptive compensation for thermal blooming. For these evaluations we developed vertical profile models of atmospheric absorption, strength of optical turbulence (CN2), wind, temperature, and other parameters necessary to calculate system performance. Our atmospheric investigations were performed for CO2, 12C18O2 isotope, CO and DF wavelengths. For all of these considerations, output antenna locations of both sea level and mountain top (3.5 km above sea level) were used. Several adaptive system concepts were evaluated with a multiple source phased array concept being selected. This system uses an adaption technique of phase locking independent laser oscillators. When both system losses and atmospheric effects were assessed, the results predicted an overall power transfer efficiency of slightly greater than 50%.

Mevers, G. E.↗

NASA NTRS2006

Comets, Asteroids, Meteorites, and the Origin of the Biosphere

During the past few decades, the delivery of water, organics, and prebiotic chemicals to the Biosphere of Earth during the Hadean (4.5-3.8 Ga) period of heavy bombardment by comets and asteroids has become more widely accepted. Comets are still largely regarded as frigid, pristine bodies of protosolar nebula material that are devoid of liquid water and therefore unsuitable for life. Complex organic compounds have been observed in comets and on the water-rich asteroid 1998 KY26 and near IR observations have indicated the presence of crystalline water ice and ammonia hydrate on the large Kuiper Belt object (50000) Quaoar that has resurfacing suggesting cryovolcanic outgassing. Spacecraft observations of the chemical compositions and characteristics of the nuclei of several comets (Halley, Borrelly, Wild 2, and Tempel 1) have shown that comets contain complex organic chemicals; that water is the predominant volatile; and that extremely high temperatures (approx. 350-400 K) can be reached on the surfae of the very black (albedo approx. 0.03) nuclei of comets when they approach the Sun. Impact craters and pinnacles observed on comet Wild 2 suggest a thick crust. Episodic outbursts and jets from the nuclei of several comets indicate that localized regimes of liquid water and water vapor can periodically exist beneath the comet crust. The Deep Impact mission found the temperature of the nucleus of comet Tempel 1 at 1.5 AU varied from a minimum of 280 plus or minus 8 K the 330K (57 C) on the sunlit side. In this paper it is argued that that pools and films of liquid water exist (within a wide range of temperatures) in cavities and voids just beneath the hot, black crust. The possibility of liquid water existing over a wide range of temperatures significantly enhances the possibility that comets might contain niches suitable for the growth of microbial communities and ecosystems. These regimes would be ideal for the growth of psychrophilic, mesophilic, and thermophilic photoautotrophs and chemolithotrophs such as the motile filamentous cyanobacteria (e.g., Calothrix, Oscillatoria, Phormidium, and Spirulina) that grow in geothermal springs and geysers of Earth at temperatures ranging fiom 320K to 345K and are also found growing in cold polar desert soils. The mineralized remains of morphotypes of all of these cyanobacteria have also been found in the Orgueil CI1 and the Murchison CN2 carbonaceous meteorites that may derive from cometary parent bodies. Observational results that support the hypothesis that liquid water can in active regions just beneath the surface of comets and that comets, carbonaceous meteorites, and asteroids may have played a significant role in the origin and evolution of the Biosphere and in the distribution of microbial life throughout the Solar System.

Hoover, Richard B.↗

NASA NTRS2015

A Microwave Radiometric Method to Obtain the Average Path Profile of Atmospheric Temperature and Humidity Structure Parameters and Its Application to Optical Propagation System Assessment

The values of the key atmospheric propagation parameters Ct2, Cq2, and Ctq are highly dependent upon the vertical height within the atmosphere thus making it necessary to specify profiles of these values along the atmospheric propagation path. The remote sensing method suggested and described in this work makes use of a rapidly integrating microwave profiling radiometer to capture profiles of temperature and humidity through the atmosphere. The integration times of currently available profiling radiometers are such that they are approaching the temporal intervals over which one can possibly make meaningful assessments of these key atmospheric parameters. Since these parameters are fundamental to all propagation conditions, they can be used to obtain Cn2 profiles for any frequency, including those for an optical propagation path. In this case the important performance parameters of the prevailing isoplanatic angle and Greenwood frequency can be obtained. The integration times are such that Kolmogorov turbulence theory and the Taylor frozen-flow hypothesis must be transcended. Appropriate modifications to these classical approaches are derived from first principles and an expression for the structure functions are obtained. The theory is then applied to an experimental scenario and shows very good results.

Atmospheric turbulence↗