Biochemical, structural, and computational analyses of two new clinically identified missense mutations of ALDH7A1
Not provided.
Biochemistry & Molecular Biology↗
SEARCH · Engineering Papers
Results for “IDAES”
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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Integrating online deliberation into ecosystem service valuation
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Environmental Sciences & Ecology↗
Copper-nickel electroplating of 3D-printed acrylonitrile butadiene styrene for interference and radiation shielding applications
Here, in this study, electromagnetic and radiation shielding structures were fabricated by 3D printing acrylonitrile butadiene styrene (ABS) structures via fused filament fabrication and electroplating with copper (Cu) and nickel (Ni) metals. Prior to electroplating, the printed ABS materials were made conductive by surface electrodeposition of polypyrrole (PPy). ABS adsorbs the pyrrole monomer, which subsequently polymerizes via oxidation forming conductive PPy layer on the printed structures. The successful anchoring of PPy layer can be attributed to its hydrogen bonding and electrostatic interactions with ABS. Thermal analysis, optical, and electron microscopy equipped with energy dispersive X-ray were employed to characterize the printed shielding structures, while the interference and radiation shielding effectiveness were evaluated using a spectrum analyzer and dosimeter, respectively. The interference shielding was found to be effective at 60 ± 5 dB over relatively small frequency range. Shielding was also apparent against gamma and X-ray ionizing rays, but more significantly effective against beta rays. Furthermore, the Cu/Ni coating was able to reduce any heat-induced dimensional changes for the 3D printed ABS substrate without compromising the mechanical integrity.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Synthesis and structure of Americium(III) diglycolate oxalate Trihydrate, Am(ODA)(C 2 O 4 )(H 2 O) 3
Improving f-element separations is important for actinide(III) (An 3+ ) and lanthanide(III) (Ln 3+ ) based technologies. Unfortunately, An 3+ and Ln 3+ ions are difficult to separate from one another because they have similar chemical characteristics. One successful separation method utilizes anion exchange chromatography. This approach exploits differences in An 3+ and Ln 3+ Lewis acidities and their varying abilities to attract anionic complexing agents, like oxalates (C 2 O 4 2– ) and diglycolates (ODA 2– ). The resulting negatively charged complexes are then separated using an anion exchange resin. To better understand how this anion exchange separation works, we reacted Am 3+ (aq) (aq designates Am 3+ dissolved in water) with the anion exchange complexing agents (H 2 C 2 O 4 and H 2 ODA). Here, the resulting Am(ODA)(C 2 O 4 )(H 2 O) 3 product was characterized using single crystal X-ray diffraction and UV-Vis-NIR spectroscopy. The Am(ODA)(C 2 O 4 )(H 2 O) 3 structure was similar to that established previously for Ln 3+ analogues, namely Ln(ODA)(C 2 O 4 )(H 2 O) x . These compounds were all isomorphous, had bridging C 2 O 4 2– and ODA 2– ligands, and crystallized as 2-dimensional extended solids. In addition, the Am 3 +–O bond distances could be predicted based on relative differences in Am 3+ and Ln 3+ 9-coordinate metal ionic radii. Overall, isolation of Am(ODA)(C 2 O 4 )(H 2 O) 3 showcased similarities in complexation and crystallization chemistry for Am 3+ and Ln 3+ .
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NF-κB activation in retinal microglia is involved in the inflammatory and neovascularization signaling in laser-induced choroidal neovascularization in mice
Highlights: • IMD0354 treatment reduced the microglia infiltration, fluorescein leakage and size of the laser CNV spots. • IKK2 inhibition suppressed phospho-IκBα, VEGF-A, and COX-2 in the Laser CNV mouse eyes. • IMD-0354 treated eyes demonstrated reduced microglial migration to the laser injury site. • In vitro, IKK2 inhibition reduced NF-κB activation, COX-2, Actin-F presence, and the microglia cells' migration capacity. To evaluate Nuclear Factor NF-κB (NF-κB) signaling on microglia activation, migration, and angiogenesis in laser-induced choroidal neovascularization (CNV).
60 APPLIED LIFE SCIENCES↗
ARC disruption physics and strategy
Commonwealth Fusion Systems (CFS) plans to operate a tokamak power plant called ARC in the early 2030s. Tokamak plasmas have stability limits that, if crossed, lead to a rapid termination of the plasma, referred to as a disruption. Disruptions pose a melt risk to the first wall resulting from thermal and non-thermal particle heat fluxes, and an electromagnetic loading risk on all metal components within the equilibrium coils. A comprehensive set of models is used herein to provide an assessment of both mitigated and unmitigated ARC disruption loads. A preliminary massive gas injection system is baselined and a runaway electron mitigation coil option is proposed to close possible gaps in the baseline. It is predicted that all ARC disruption loads are within a factor of 2 of the disruption loads in SPARC, a tokamak presently under construction by CFS, and therefore SPARC provides an opportunity to calibrate models, test solutions and inform the design of ARC. The goal for ARC is disruption-free operation, however, the pragmatic design target is to withstand one mitigated disruption per day, and to restart the plasma following mitigation in tens of seconds without interrupting the power output. Unmitigated disruptions must be rare, and experience with unmitigated disruption impacts in SPARC will better define what rare means. The implications of this strategy for plasma disruptivity and disruption prediction are discussed, and operating the ARC scenario on SPARC is expected to refine the ARC final design and operational plan.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Probing the Distribution and Mobility of Aminopolymers after Multiple Sorption-Regeneration Cycles: Neutron Scattering Studies
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Synthesis and Characterization of Cerium-Oxo Clusters Capped by Acetylacetonate
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Influence of Linker Identity on the Photochemistry of Uranyl-Organic Frameworks
While uranyl-based metal–organic frameworks (MOFs) boast impressive photocatalytic abilities, significant questions remain regarding their excitation pathways and methods to fine-tune their performance due to the lack of information regarding heterogeneous uranyl catalysis. Herein, we investigated how linker identity and photoexcitation impact uranyl photocatalysis when the uranyl coordination environment remains constant. Toward this end, we prepared three uranyl-based MOFs (NU-1301, NU-1307, and ZnTCPP-U2) and then examined the structural and photochemical properties of each through X-ray diffraction, X-ray absorption, and photoluminescence. We then correlated our observations to the photocatalytic performance for fluorination of cyclooctane. The excitation profile from NU-1301 and NU-1307 exhibited spin-forbidden linker transitions and uranyl vibronic progressions, with uranyl excitation and emission being most dominant in NU-1301. Consequently, NU-1301 was a more active photocatalyst than NU-1307. In contrast, the excitation profile from ZnTCPP-U2 contained transitions associated with the porphyrin linker exclusively. Photocatalytic activity from ZnTCPP-U2 significantly underperformed in comparison to that of the other two MOFs. Furthermore, these data suggest that linkers’ photophysical properties can be used to predict the photocatalytic behavior of uranyl-containing MOFs.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Quantifying Outer- and Inner-Coordination Sphere Effects Using Uranium Redox Chemistry in Molten Salt Solutions
Defining the relative influence of intramolecular and intermolecular forces is a fundamental problem in chemistry that is difficult to quantify. To address this challenge, we developed a method to evaluate the relative impact of direct chemical bonding in the inner-coordination sphere vs effects from cations in the outer-coordination sphere by comparative analysis of uranium redox reactivity in various molten salts. We observed that outer-coordination sphere cations (M 1+ ) and inner-coordination sphere anions (X 1– ) both affected uranium redox reactivity, with more polarizing M 1+ and larger X 1– favoring uranium in low oxidation states. Changing M 1+ (Li, Na, K) shifted the U IV + e 1– ⇌ U III (U IV/III ) and U III + 3e 1– → U 0 metal potentials by +330 and +240 mV, respectively. Changing X 1– (Cl, Br, I) caused larger shifts of +440 mV for the U IV/III redox potential and +1060 mV for the U 0 metal deposition potential. Using Coulomb’s Law, we correlated these potentials with electrostatic interactions between UIII and the molten salt. This model provided a facile way of predicting redox chemistry within molten salts.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
The Impact of U.S. Re-engagement in Climate on the Paris Targets
The Paris Agreement is meant to bind together international efforts to reduce temperature increase to well-below 2ºC. While so far, ambitions in many signatories of the Paris Agreement have been insufficient to achieve this goal, optimism prevailed in the second half of 2020, with several major emitters enhancing their mitigation targets and a change of leadership in the United States (U.S.). Expectations are high for an active re-engagement in climate action by the Biden Administration, which immediately re-entered the Paris Agreement and announced a net-zero goal for 2050. Apart from the impact that U.S. federal re-engagement could have on national greenhouse gas emissions levels, there are several channels through which U.S. re-engagement in climate action could positively impact ambitions in other countries. This Policy Forum explores the impact of renewed U.S. engagement on national emissions, global emissions and end-of-century temperatures by comparing five combinations of climate ambitions in the U.S. and the rest of the world through an integrated assessment model.
54 ENVIRONMENTAL SCIENCES↗
Lewis acid-assisted reduction of nitrite to nitric and nitrous oxides via the elusive nitrite radical dianion
Reduction of nitrite anions (NO 2 - ) to nitric oxide (NO), nitrous oxide (N 2 O) and ultimately dinitrogen (N 2 ) takes place in a variety of environments, including in the soil as part of the biogeochemical nitrogen cycle and in acidified nuclear waste. Nitrite reduction typically takes place within the coordination sphere of a redox-active transition metal. In this report we show that Lewis acid coordination can substantially modify the reduction potential of this polyoxoanion to allow for its reduction under non-aqueous conditions (-0.74 V versus NHE). Detailed characterization confirms the formation of the borane-capped radical nitrite dianion (NO 2 2- ), which features a N(II) oxidation state. Protonation of the nitrite dianion results in the facile loss of nitric oxide (NO), whereas its reaction with NO results in disproportionation to nitrous oxide (N 2 O) and nitrite (NO 2 - ). This system connects three redox levels in the global nitrogen cycle and provides fundamental insights into the conversion of NO 2 - to NO.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
A multimodel analysis of post-Glasgow climate targets and feasibility challenges
The COP26 Glasgow process resulted in many countries strengthening their 2030 emissions reduction targets and announcing net-zero pledges for 2050–2070 but it is not clear how this would impact future warming. Here, we use four diverse integrated assessment models (IAMs) to assess CO 2 emission trajectories in the near- and long-term on the basis of national policies and pledges, combined with a non-CO 2 infilling model and a simple climate model to assess the temperature implications. We also consider the feasibility of national long-term pledges towards net-zero. While near-term pledges alone lead to warming above 2 °C, the addition of long-term pledges leads to emissions trajectories compatible with a future well below 2 °C, across all four IAMs. However, while IAM heterogeneity translates to diverse decarbonization pathways towards long-term targets, all modelled pathways indicate several feasibility concerns, relating to the cost of mitigation and the rates and scales of deployed technologies and measures.
climate-change mitigation↗
Observation of a reduced-turbulence regime with boron powder injection in a stellarator
Abstract In state-of-the-art stellarators, turbulence is a major cause of the degradation of plasma confinement. To maximize confinement, which eventually determines the amount of nuclear fusion reactions, turbulent transport needs to be reduced. Here we report the observation of a confinement regime in a stellarator plasma that is characterized by increased confinement and reduced turbulent fluctuations. The transition to this regime is driven by the injection of submillimetric boron powder grains into the plasma. With the line-averaged electron density being kept constant, we observe a substantial increase of stored energy and electron and ion temperatures. At the same time, the amplitude of the plasma turbulent fluctuations is halved. While lower frequency fluctuations are damped, higher frequency modes in the range between 100 and 200 kHz are excited. We have observed this regime for different heating schemes, namely with both electron and ion cyclotron resonant radio frequencies and neutral beams, for both directions of the magnetic field and both hydrogen and deuterium plasmas.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Enhancing high-fidelity nonlinear solver with reduced order model
Abstract We propose the use of reduced order modeling (ROM) to reduce the computational cost and improve the convergence rate of nonlinear solvers of full order models (FOM) for solving partial differential equations. In this study, a novel ROM-assisted approach is developed to improve the computational efficiency of FOM nonlinear solvers by using ROM’s prediction as an initial guess. We hypothesize that the nonlinear solver will take fewer steps to the converged solutions with an initial guess that is closer to the real solutions. To evaluate our approach, four physical problems with varying degrees of nonlinearity in flow and mechanics have been tested: Richards’ equation of water flow in heterogeneous porous media, a contact problem in a hyperelastic material, two-phase flow in layered porous media, and fracture propagation in a homogeneous material. Overall, our approach maintains the FOM’s accuracy while speeding up nonlinear solver by 18–73% (through suitable ROM-assisted FOMs). More importantly, the proximity of ROM’s prediction to the solution space leads to the improved convergence of FOMs that would have otherwise diverged with default initial guesses. We demonstrate that the ROM’s accuracy can impact the computational efficiency with more accurate ROM solutions, resulting in a better cost reduction. We also illustrate that this approach could be used in many FOM discretizations (e.g., finite volume, finite element, or a combination of those). Since our ROMs are data-driven and non-intrusive, the proposed procedure can easily lend itself to any nonlinear physics-based problem.
97 MATHEMATICS AND COMPUTING↗