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At least 703 records · Page 39

A high-performance organic cathode customized for sulfide-based all-solid-state batteries

All-solid-state batteries (ASSBs) have become increasingly attractive recently due to their better safety and prospective long-term stability compared with conventional liquid batteries. However, obtaining a sustainable cathode candidate to match the solid electrolyte with regards to operating potential, chemical compatibility, and mechanical property is still an open challenge. In this work, the chemical incompatibility of quinone-based active materials and sulfide-based electrolyte were unveiled for the first time through a heteroconjugate addition reaction mechanism. To develop a quinone cathode customized for sulfide-based ASSBs, poly-(anthraquinonyl sulfide)-graphene (PAQS-G) nanocomposite was reported. The stable polymer framework of PAQS can protect the quinone redox center by preventing nucleophilic attack from sulfide-based solid electrolytes. The graphene additives can ameliorate redox kinetics and improve active material utilization. The PAQS-G cathode exhibited a specific capacity of ~178 mAh g -1 and a high material utilization of ~79%. Excellent cycling stability was achieved with 94 % capacity after 200 cycles in lithium batteries and 95.5 % capacity after 300 cycles in sodium batteries at 0.1C rate, respectively. A promising potential for energy storage applications was demonstrated.

25 ENERGY STORAGE↗

Mixing and Transport in the Solar Nebula

Boss & Vanhala (2000, 2001) prepared reviews of triggered collapse and injection models, using Prudence Foster's finite differences code at very high spatial resolution (440 x 1440 cells) to demonstrate the convergence of the R-T fingers in triggered injection models. A two dimensional hydrodynamical calculation with unprecedentedly high spatial resolution (960 x 2880 zones, or almost 3 million grid points) demonstrated that it suitable shock front can both trigger the collapse of an otherwise stable presolar cloud, and inject shock front particles into the collapsing cloud through the formation of what become Rayleigh-Taylor fingers of compressed fluid layers falling into the gravitational potential well of the growing protostar. These calculations suggest that heterogeneity derived from these R-T fingers will persist down to the scale of their injection onto the surface of the solar nebula. Haghighipour developed a numerical code capable of calculating the orbital evolution of dust grains of varied sizes in a gaseous nebula, subject to Epstein and Stokes drag as well as the self-gravity of the disk. In collaboration with the PI and George W. Wetherill, Haghighipour has been involved in development of a new idea on the possibility of rapid formation of ice giant planets via the disk instability mechanism. Haghighipour studied the stability of a five-body system consisting of the Sun and four protoplanets by numerically integrating their equations of motions. Using Levison and Duncan s SWIFT integrator, Haghighipour showed that, depending on the orbital parameters of the bodies, such a system can be stable for 0.1-10 Myr. Time periods of 1 Myr or more are long enough to be consistent with the time scale proposed for the formation of giant planets by the disk instability mechanism and the photoevaporation of the gaseous envelopes of the outermost protoplanets by a nearby OB star, resulting in the formation of ice giant planets. The PI has used his three dimensional models of marginally gravitationally unstable disks to study the preservation of isotopic heterogeneity in evolving protoplanetary disks. Such heterogeneity might arise from the infall onto the disk s surface of solids processed in the X-wind region of the disk, or derived from stellar nucleosynthesis and injected by R-T fingers. The technique used consists of solving a color equation, identical to the gas continuity equation, which follows the time evolution in three space dimensions of an arbitrarily placed initial color field, i.e., a dye inserted the disk. The models show that significant concentrations of color could persist for time periods of about a thousand years or more, even in the most dynamically active region of such a disk. Such a time period might be long enough for solids to coagulate and grow to significant sizes while retaining the isotopic signature of their birth region in the nebula.

Boss, Alan P.↗

General Services Administration Reclamation Yard (SWMU 010) 2020-2021 Groundwater Monitoring Report

This report presents a summary of the groundwater monitoring activities that occurred from October 2020 through June 2021 at General Services Administration Reclamation Yard, Solid Waste Management Unit 010, located at the John F. Kennedy Space Center (KSC), Florida. For the purposes of this report, two separate plumes, known as the Polychlorinated Biphenyl (PCB)/Volatile Organic Aromatic (VOA) Plume and the Chlorinated Volatile Organic Compound (VOC) Plume were identified for this site. The contaminants of concern (COCs) for the PCB/VOA Plume consists of PCBs, 1,2,4-trichlorobenzene, and breakdown products of 1,2,4-trichlorobenzene. The COCs for the Chlorinated VOC Plume are tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride. The activities presented in this report include four field events: (1) October 2020 – Chlorinated VOC Plume groundwater sampling via Direct Push Technology (DPT) – 68 groundwater samples were collected from 14 locations at varying intervals; (2) December 2020 – Site-wide semi-annual water level measurements of 52 monitoring wells and sampling of 39 monitoring wells; (3) May 2021 – Chlorinated VOC Plume monitoring well installation – two monitoring wells were installed and screened from 10 to 20 feet below land surface (bls); and (4) May/June 2021 – Site-wide semi-annual water level measurements of 53 monitoring wells and sampling of 40 monitoring wells. Results showed substantial reduction of both plumes. Conclusions and recommendations are presented.

VOC↗

Multifactorial genetic control and magnesium levels govern the production of a Streptomyces antibiotic with unusual cell density dependence

Streptomyces bacteria are renowned both for their antibiotic production capabilities and for their cryptic metabolic potential. Their metabolic repertoire is subject to stringent genetic control, with many of the associated biosynthetic gene clusters being repressed by the conserved nucleoid-associated protein Lsr2. In an effort to stimulate new antibiotic production in wild Streptomyces isolates, we leveraged the activity of an Lsr2 knockdown construct and successfully enhanced antibiotic production in the wild Streptomyces isolate WAC07094. We determined that this new activity stemmed from increased levels of the angucycline-like family member saquayamycin. Saquayamycin has both antibiotic and anti-cancer activities, and intriguingly, beyond Lsr2-mediated repression, we found saquayamycin production was also suppressed at high density on solid or in liquid growth media; its levels were greatest in low-density cultures. This density-dependent control was exerted at the level of the cluster-situated regulatory gene sqnR and was mediated in part through the activity of the PhoRP two-component regulatory system, where deleting phoRP led to both constitutive antibiotic production and sqnR expression. This suggests that PhoP functions to repress the expression of sqnR at high cell density. We further discovered that magnesium supplementation could alleviate this density dependence, although its action was independent of PhoP. Finally, we revealed that the nitrogen-responsive regulators GlnR and AfsQ1 could relieve the repression exerted by Lsr2 and PhoP. Intriguingly, we found that this low density-dependent production of saquayamycin was not unique to WAC07094; saquayamycin production by another wild isolate also exhibited low-density activation, suggesting that this spatial control may serve an important ecological function in their native environments.

59 BASIC BIOLOGICAL SCIENCES↗

Solid Waste Release Calculations for the Composite Analysis Baseline Assessment

The purpose of the Hanford Site Composite Analysis (CA) is to provide an estimate of the cumulative radiological impacts from active and planned low-level radioactive waste disposals and other potentially interacting radioactive waste disposal sources that will remain following Hanford Site closure. The need for a waste form release model addressing multiple solid waste forms is documented in CP-60410, Hanford Site Composite Analysis Technical Approach Description: Waste Form Release.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Light-Hydrocarbon Bearing Solids on Planetesimal 5145 Pholus

Object 5145 Pholus (=1992 AD) is a planetesimal in an orbit that crosses those of Saturn, Uranus, and Neptune (period 92.7 years). It is particularly notable because of its extreme red color, corroborated by several observing teams. A spectrum of Pholus obtained in 1992 shows a strong absorption band with a characteristic shape at 2.27 micrometers, plus a weaker band at 1.7 micrometers. A better spectrum of the 2.0-2.5 micrometer region in 1993 confirms the position and shape of the 2.27-micrometer band. The color and spectral bands are identified with the aliphatic-rich and high H/C organic solid called asphaltite, which in a terrestrial setting originates from thermal processing of products of biological activity. In Pholus, this material is attributed to formation from radiation processing of ices on grains in the interstellar medium. Laboratory spectra of asphaltite and related materials have been published by Moroz et al., while Cloutis showed similar bands in comparable materials and identified them as the overtone and combination bands of C-H stretching and bending modes in CH2 and CH3 groups. Asphaltites, kerites, and anthraxolites are solid non-graphite members of a sequence ranging from oil to graphite; diffuse reflectance spectra of suites of these intermediate materials show color characteristics similar to those of the low-albedo asteroids (C,P,D), although specific identifications have not been made because of the lack of distinct absorption bands in the spectra of most low-albedo solar system bodies. In the case of Pholus, however, the primary band is strong; its wavelength and its shape, plus the match of the extremely red color, leads us to the identification of aliphatic-rich, asphaltite-like organic solid. The C, P, and D-type asteroids vary in degree of "redness", but are all less red than Pholus. Pholus and the Ctype asteroids are the end members of a sequence that represents the radiation processing of hydrocarbons, with Pholus being the least processed. Solar irradiation processes and heating reduce the H/C and aliphatic content of hydrocarbons preserved from the interstellar medium, and in the end produce opaque solids of neutral reflectance, including the kerogens (similar to anthraxolites) found in profusion in the carbonaceous meteorites.

Cruikshank, Dale P.↗

Light-Hydrocarbon Bearing Solids on Planetesimal 5145 Pholus

Object 5145 Pholus (=1992 AD) is a planetesimal in an orbit that crosses those of Saturn, Uranus, and Neptune (period 92.7 years). It is particularly notable because of its extreme red color, corroborated by several observing teams. A spectrum of Pholus obtained in 1992 shows a strong absorption band with a characteristic shape at 2.27 micron, plus a weaker band at 1.7 microns. A better spectrum of the 2.0-2.5 micron region in 1993 confirms the position and shape of the 2.27 micron band. The color and spectral bands are identified with the aliphatic-rich and high H/C organic solid called asphaltite, which in a terrestrial setting originates from thermal processing of products of biological activity. In Pholus, this material is attributed to formation from radiation processing of ices on grains in the interstellar medium. Laboratory spectra of asphaltite and related materials have been published by Moroz et al., while Cloutis showed similar bands in comparable materials and identified them as the overtone and combination bands of C-H stretching and bending modes in CH2 and CH3 groups. Asphaltites, kerites, and anthraxolites are solid non-graphite members of a sequence ranging from oil to graphite; diffuse reflectance spectra of suites of these intermediate materials show color characteristics similar to those of the low-albedo asteroids (C,P,D), although specific identifications have not been made because of the lack of distinct absorption bands in the spectra of most low-albedo solar system bodies. In the case of Pholus, however, the primary band is strong; its wavelength and its shape, plus the match of the extremely red color, leads us to the identification of aliphatic-rich, asphaltite-like organic solid. The C, P, and D-type asteroids vary in degree of 'redness', but are all less red than Pholus. Pholus and the C-type asteroids are the end members of a sequence that represents the radiation processing of hydrocarbons, with Pholus being the least processed. Solar irradiation processes and heating reduce the H/C and aliphatic content of hydrocarbons preserved from the interstellar medium, and in the end produce opaque solids of neutral reflectance, including the kerogens (similar to anthraxolites) found in profusion in the carbonaceous meteorites.

Cruikshank, Dale P.↗

One dislocation at a time

The direct observation of enhanced dislocation mobility in iron by in situ electron microscopy offers key insights and adds to the ongoing debate on the mechanisms of hydrogen embrittlement. The tiniest atom in nature, hydrogen, is pervasive and sneaky. When hydrogen atoms, either from gas or liquid sources, come into contact with a metal, they rush into the solid and squeeze through the narrow spaces between the host atoms. Being chemically active, atomic hydrogen can potentially bind to either host or impurity atoms, forming hydrides and thus changing a material’s properties. Metals, which are well known and widely used in industry for their strength and ductility, can become dangerously brittle when exposed to hydrogen. Furthermore, this phenomenon is known as hydrogen embrittlement and can lead to catastrophic failure of a load-bearing part. For example, the hydrogen produced when water molecules break apart in coolants in a nuclear reactor can cause sudden failure of the pressure vessel. In another example, although blending hydrogen in natural-gas pipelines provides a promising pathway to transition into the hydrogen economy, it could lower the fatigue resistance of the pipeline steel, making it more susceptible to crack growth due to cyclic loading induced by pressure fluctuations in the pipeline. Remarkably, perhaps as a result of a multitude of recognized failure mechanisms in which hydrogen can potentially participate, it still remains unknown exactly why hydrogen makes a metal brittle. Now, writing in Nature Materials, Longchao Huang and colleagues present unambiguous experimental observations of hydrogen-enhanced dislocation mobility in iron, offering key insights into the hydrogen embrittlement mechanisms.

36 MATERIALS SCIENCE↗

Measurement of the π - -Ar total hadronic cross section at the LArIAT experiment

We present the first measurement of the negative pion total hadronic cross section on argon in a restricted phase space, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5° are included. The pions have kinetic energies in the range 100–700 MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab test beam facility. LArIAT employs a 0.24 ton active mass liquid argon time projection chamber (LArTPC) to measure the pion hadronic interactions. For this measurement, LArIAT has developed the “thin slice method,” a new technique to measure cross sections with LArTPCs. While moderately higher, our measurement of the π - -Ar total hadronic cross section is generally in agreement with the geant4 prediction.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Omics-Based Comparison of Fungal Virulence Genes, Biosynthetic Gene Clusters, and Small Molecules in Penicillium expansum and Penicillium chrysogenum

Penicillium expansum is a ubiquitous pathogenic fungus that causes blue mold decay of apple fruit postharvest, and another member of the genus, Penicillium chrysogenum, is a well-studied saprophyte valued for antibiotic and small molecule production. While these two fungi have been investigated individually, a recent discovery revealed that P. chrysogenum can block P. expansum-mediated decay of apple fruit. To shed light on this observation, we conducted a comparative genomic, transcriptomic, and metabolomic study of two P. chrysogenum (404 and 413) and two P. expansum (Pe21 and R19) isolates. Global transcriptional and metabolomic outputs were disparate between the species, nearly identical for P. chrysogenum isolates, and different between P. expansum isolates. Further, the two P. chrysogenum genomes revealed secondary metabolite gene clusters that varied widely from P. expansum. This included the absence of an intact patulin gene cluster in P. chrysogenum, which corroborates the metabolomic data regarding its inability to produce patulin. Additionally, a core subset of P. expansum virulence gene homologues were identified in P. chrysogenum and were similarly transcriptionally regulated in vitro. Molecules with varying biological activities, and phytohormone-like compounds were detected for the first time in P. expansum while antibiotics like penicillin G and other biologically active molecules were discovered in P. chrysogenum culture supernatants. Our findings provide a solid omics-based foundation of small molecule production in these two fungal species with implications in postharvest context and expand the current knowledge of the Penicillium-derived chemical repertoire for broader fundamental and practical applications.

Bartholomew, Holly P. (ORCID:0000000292726399)↗

Production of an ion-exchange membrane-catalytic electrode bonded material for electrolytic cells

A good bond is achieved by placing a metal salt in solution on one side of a membrane and a reducing agent on the other side so that the reducing agent penetrates the membrane and reduces the metal. Thus, a solution containing Pt, Rh, etc., is placed on one side of the membrane and a reducing agent such as NaBH, is placed on the other side. The bonded metal layer obtained is superior in catalytic activity and is suitable as an electrode in a cell such as for solid polymer electrolyte water electrolysis.

Takenaka, H.↗

AlxGa1-xAs Single-Quantum-Well Surface-Emitting Lasers

Surface-emitting solid-state laser contains edge-emitting Al0.08Ga0.92As single-quantum-well (SQW) active layer sandwiched between graded-index-of-refraction separate-confinement-heterostructure (GRINSCH) layers of AlxGa1-xAs, includes etched 90 degree mirrors and 45 degree facets to direct edge-emitted beam perpendicular to top surface. Laser resembles those described in "Pseudomorphic-InxGa1-xAs Surface-Emitting Lasers" (NPO-18243). Suitable for incorporation into optoelectronic integrated circuits for photonic computing; e.g., optoelectronic neural networks.

Kim, Jae H.↗

NASA total quality management 1989 accomplishments report

NASA and contractor employees achieved many notable improvements in 1989. The highlights of those improvements, described in this seventh annual Accomplishments Report, demonstrate that the people who support NASA's activities are getting more involved in quality and continuous improvement efforts. Their gains solidly support NASA's and this Nation's goal to remain a leader in space exploration and in world-wide market competition, and, when communicated to others through avenues such as this report, foster improvement efforts across government and industry. The principles in practice which led to these process refinements are important cultural elements to any organization's productivity and quality efforts. The categories in this report reflect NASA principles set forth in the 1980's and are more commonly known today as Total Quality Management (TQM): top management leadership and support; strategic planning; focus on the customer; employee training and recognition; employee empowerment and teamwork; measurement and analysis; and quality assurance.

Tai, Betty P.↗

Three-dimensional solidification and melting using magnetic field control

A new two-fluid mathematical model for fully three dimensional steady solidification under the influence of an arbitrary acceleration vector and with or without an arbitrary externally applied steady magnetic field have been formulated and integrated numerically. The model includes Joule heating and allows for separate temperature dependent physical properties within the melt and the solid. Latent heat of phase change during melting/solidification was incorporated using an enthalpy method. Mushy region was automatically captured by varying viscosity orders of magnitude between liquidus and solidus temperature. Computational results were obtained for silicon melt solidification in a parallelepiped container cooled from above and from a side. The results confirm that the magnetic field has a profound influence on the solidifying melt flow field thus changing convective heat transfer through the boundaries and the amount and shape of the solid accrued. This suggests that development of a quick-response algorithm for active control of three dimensional solidification is feasible since it would require low strength magnetic fields.

Dulikravich, George S.↗

STS-77 Flight Day 1

On this first day of the STS-77 mission, the flight crew, Cmdr. John H. Casper, Pilot Curtis L. Brown, Jr., and Mission Specialists Andrew S.W. Thomas, Ph.D., Daniel W. Bursch, Mario Runco, Jr., and Marc Garneau, Ph.D., can be seen preforming pre-launch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the 'white room' for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. Following an on-time launch, the crew of Endeavor are shown setting up a variety of experiments that will operate for much of the mission.

Source record↗

STS-78 Flight Day 1

On this first day of the STS-78 mission, the flight crew, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Ph.D. and Robert B. Thirsk, M.D., can be seen preforming pre-launch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the white room for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. Henricks shares a unique view of Columbia's climb to orbit with flight controllers from a small camera that was mounted on the flight deck. The video follows Columbia's flight from just before main engine start through main engine cutoff, showing the force of main engine and solid booster ignition as experienced by the astronauts.

Source record↗

STS-79 Flight Day 1

On this first day of the STS-79 mission, the flight crew, Cmdr. William F. Readdy, Pilot Terrence W. Wilcutt, and Mission Specialists, Thomas D. Akers, John E. Blaha, Jay Apt, and Carl E. Walz, can be seen preforming pre-launch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the white room' for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters.

Source record↗

STS-78 Mission Highlights Resource Tape

The flight crew of the STS-78 mission, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Pd.D. and Robert B. Thirsk, M.D., present a video mission over-view of their space flight. Images include: pre-launch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the white room' for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. Following an on-time launch, the crew of Endeavor are shown setting up a variety of experiments that will operate for much of the mission.

Source record↗