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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Multiple-Flat-Panel System Displays Multidimensional Data

The NASA Ames hyperwall is a display system designed to facilitate the visualization of sets of multivariate and multidimensional data like those generated in complex engineering and scientific computations. The hyperwall includes a 77 matrix of computer-driven flat-panel video display units, each presenting an image of 1,280 1,024 pixels. The term hyperwall reflects the fact that this system is a more capable successor to prior computer-driven multiple-flat-panel display systems known by names that include the generic term powerwall and the trade names PowerWall and Powerwall. Each of the 49 flat-panel displays is driven by a rack-mounted, dual-central-processing- unit, workstation-class personal computer equipped with a hig-hperformance graphical-display circuit card and with a hard-disk drive having a storage capacity of 100 GB. Each such computer is a slave node in a master/ slave computing/data-communication system (see Figure 1). The computer that acts as the master node is similar to the slave-node computers, except that it runs the master portion of the system software and is equipped with a keyboard and mouse for control by a human operator. The system utilizes commercially available master/slave software along with custom software that enables the human controller to interact simultaneously with any number of selected slave nodes. In a powerwall, a single rendering task is spread across multiple processors and then the multiple outputs are tiled into one seamless super-display. It must be noted that the hyperwall concept subsumes the powerwall concept in that a single scene could be rendered as a mosaic image on the hyperwall. However, the hyperwall offers a wider set of capabilities to serve a different purpose: The hyperwall concept is one of (1) simultaneously displaying multiple different but related images, and (2) providing means for composing and controlling such sets of images. In place of elaborate software or hardware crossbar switches, the hyperwall concept substitutes reliance on the human visual system for integration, synthesis, and discrimination of patterns in complex and high-dimensional data spaces represented by the multiple displayed images. The variety of multidimensional data sets that can be displayed on the hyperwall is practically unlimited. For example, Figure 2 shows a hyperwall display of surface pressures and streamlines from a computational simulation of airflow about an aerospacecraft at various Mach numbers and angles of attack. In this display, Mach numbers increase from left to right and angles of attack increase from bottom to top. That is, all images in the same column represent simulations at the same Mach number, while all images in the same row represent simulations at the same angle of attack. The same viewing transformations and the same mapping from surface pressure to colors were used in generating all the images.

Gundo, Daniel↗
NASA NTRS2003

Modeling and Control of Aerothermoelastic Effects

Aerothermoelasticity comprises those aspects of the dynamics of an aircraft that are caused by flexibility and heating during flight. The concept of aerothermoelasticity is particularly important for hypersonic vehicles that operate at extremely high dynamic pressures. The design requirements for such vehicles often introduce long and thin fuselages subject to elastic bending in low-frequency vibrational modes. Furthermore, surface heating can significantly change the stiffness characteristics of these modes. These aerothermoelastic effects must be considered in the synthesis and analysis of control systems. The present method makes it possible to incorporate the results of computational analysis into the small linear models that are typically used in designing controls.

Lind, Rick↗
NASA NTRS1973

High temperature resistant composites from bismaleimide resin.

It is shown that bismaleimide/woven fiberglass composites molded at moderate pressures (100 psi) yield void-free laminates of good integrity. The strength of the laminates at room temperature compares favorably with epoxy/glass laminates; at 260 C, the laminates are far superior in oxidative aging to epoxy and silicon laminates. The synthesis, processing, and fabrication of a bismaleide polymer are discussed.

Gilwee, W. J.↗
DOE OSTI2025

Direct Synthesis of Polyester from Biomass Derived 1,6-hexanediol using a Copper-Ceria Catalyst

Biomass derived polyesters are gaining attention due to their increased mechanical and thermal properties, and also because of their biodegradability. These polyesters are typically synthesized from polycondensation reactions between diols with dicarboxylic acids using catalysts. Other methods such as alcoholysis and acidolysis of low molecular weight esters and alcoholysis of acyl chlorides are also well known. Direct conversion of diol to ester without using dicarboxylic acid is not well known, and to our knowledge has not been reported over a solid catalyst. In this study, we report a direct synthesis of polyester from 1,6-hexanediol using a copper-ceria catalyst without using a dicarboxylic acid monomer. The copper-ceria catalysts were synthesized by incipient wetness impregnation method and characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller (BET), and infrared spectroscopy (IR). Our initial studies show that 1,6-hexanediol can be converted to corresponding polyester at higher temperatures under atmospheric pressures of CO2 or N2. The reaction products were analyzed using nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), and IR spectroscopy.

Biomass derived diols↗
DOE OSTI2023

Polynitrogen High Energy Density Materials Synthesized by Nonequilibrium Plasma

Metal pentazolate compounds that contain 5-nitrogen singly charged anion rings are an interesting class of materials from a thermodynamics perspective. These compounds are believed to be equilibrium phases only at extremely high pressures, and thus, they constitute exotic states of matter at ambient pressure and temperature. Moreover, the energy released by these pentazolate compounds upon relaxation to the equilibrium state at ambient conditions is in the range 1 to 10 MJ per kg, rivaling that of combustion reactions. The synthesis of pentazolates is not an easy task, and there are only two known methods, each of which has significant challenges. Here, the development of new scalable synthesis routes could enable the production of these exotic materials in sufficient quantity to explore their properties more widely beyond the context of explosives and propellants. In this Perspective, it is argued that nonequilibrium plasma is a promising reaction medium for the synthesis of metal pentazolate compounds, for example from the corresponding metal azide and N 2 gas activated by the discharge at low background temperature.

Chemical reactions↗
NASA NTRS2005

Tholins as Coloring Agents on Outer Solar System Bodies

The red colors of many solid bodies in outer Solar System may be caused by tholins, which are refractory organic complexes, incorporated in their surface materials. Tholins synthesized in the laboratory are shown to match the colors of these bodies when their optical properties are used in rigorous scattering models. We review recent successes in modeling the spectra of icy outer Solar System bodies with tholins as the coloring agents. New work on the systematic laboratory synthesis and analysis of tholins made by cold plasma discharge in mixtures of gaseous CH4/N2 shows that the composition of the tholin depends strongly on the pressure in the reaction chamber, and only weakly on the mixing fraction of CH4 relative to N2. In tholins made at high pressure (e.g., 23 hPa) the abundance of aliphatic hydrocarbons is greater and the abundance of aromatic hydrocarbons is less than in tholins made at low pressure (e.g., 0.13 hPa). Tholins made at low deposition pressures show a greater abundance of N-H bonds.

Cruikshank, Dale P.↗
DOE OSTI2025

Synthesis Roadmap for Actinide Chloride Salts

Molten salt reactors (MSRs) are among the main advanced nuclear reactor types at the forefront of development by industry, with the support of the US government, for the next fleet of nuclear reactors to support the demand for energy in the coming decades. MSRs are highly unique because they are cooled and typically also fueled by molten salt. This quality brings about safety benefits such as low-pressure operation and self-stabilization of the neutron flux, operational benefits such as high-temperature operation and the ability for online refueling, and fuel and waste management benefits thanks to the flexibility of post-processing of molten salts and reprocessing options that involve removal of fission products and actinide separation. In fact, domestic deployment of molten salt (or molten salt–cooled) reactors is an approaching reality: a handful of molten salt reactor developers are planning to operate demonstration-scale reactors, as a step toward commercial-scale power reactors, within the decade. For example, Natura Resources received a construction permit in September 2024 for the deployment of MSR-1, which is a graphite-moderated thermal spectrum reactor, at Abilene Christian University. Also, TerraPower, in a collaborative effort with Southern Company and Idaho National Laboratory (INL), received approval from DOE in 2023 to proceed with the construction of the Molten Chloride Reactor Experiment (MCRE), a homogeneous chloride fast reactor at INL, and has begun assembly of system components. There are several other examples of developers at different stages of development of their own unique MSR designs (Jenet et al., 2025). As developers are in the process of obtaining approvals for their designs, deploying demonstration-scale reactors, and planning for their commercial-scale power reactors, there is a critical supply chain need for the synthesis of fuel for these reactors that must be addressed. The challenge generally is three-fold: (1) the quantity of fueled salt needed for these reactors is extraordinarily high (>100s of kilograms), but demonstrations of scaled-up techniques for fueled salt synthesis are significantly more limited than demonstrations of lab-scale syntheses; (2) each developer has a unique reactor design, which means different actinide halide elements in different carrier salts must be synthesized; and (3) there is a need for particularly high-purity salt so as to ensure the long-term operability of these reactors with minimal degradation to salt-wetted components, which necessitates synthesis techniques with high levels of quality control, repeatability, and well-characterized precursor and reactant materials. It is crucial that this supply chain challenge be addressed by demonstrating synthesis techniques that are scalable, de-risked, and well-documented so that these technologies may be adopted and utilized by industry to support the fueling needs of MSRs that are to come online within the next 10 years. With this supply chain challenge clearly defined for the developing MSR industry, it is important to consider that addressing such a challenge is oftentimes complex and context-dependent. There is not necessarily a single synthesis technique that can be scaled up and adopted to address the needs of all MSR developers; the synthesis approach that may be viable for producing a desired fuel salt will be entirely dependent on the exact salt composition needed, the quantity needed, purity needed, the refueling and waste plans, and the availability of a carrier salt for the fuel. Therefore, it is important to consider more broadly what synthesis techniques are available and have been demonstrated to understand the benefits, challenges, and general nuances that should be considered when evaluating a particular route for efficient production of high-purity fuel salts at scale.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Tracking the phase changes in micelle-based NiGa nanocatalysts for methanol synthesis under activation and working conditions

The hydrogenation of CO 2 into high energy density fuels such as methanol, where the required H 2 is obtained from renewable sources, is of utmost importance for a sustainable society. In recent years, NiGa alloys have attracted attention as promising catalyst material systems for the hydrogenation of CO 2 into methanol at ambient pressures. They thus represent an energy-saving alternative to the Cu-based catalysts employed in today's catalytic industry that require high pressures for the CO 2 hydrogenation. However, the underlying reaction mechanisms for the NiGa system are still under debate. One of the challenges here is to unravel the evolution and coexistence of the different species in the heterogeneous NiGa catalyst system under activation and reaction conditions. To shed light on their evolution under activation in H 2 and their catalytic roles under CO 2 hydrogenation working conditions on well-defined Ni 3 Ga 1 and Ni 5 Ga 3 nanoparticle (NP) catalysts, we employed a multi-probe approach in this study. It included advanced machine learning-based analysis of operando X-ray absorption spectroscopy data combined with operando powder X-ray diffraction and near ambient pressure X-ray photoelectron spectroscopy measurements, as well as reactivity studies using bed-packed mass flow reactors. In addition, we employed atomic force microscopy and scanning transmission electron microscopy for structural characterization. Under H 2 activation at 1 bar total pressure, we concluded the formation of metallic Ni, starting for Ni 3 Ga 1 at 300 °C, and for Ni 5 Ga 3 at 400 °C. At higher temperatures, the formation of NiGa alloys follows. The α'-Ni 3 Ga 1 alloy phase is predominantly formed for the Ni 3 Ga 1 NPs, while the coexistence of α'-Ni 3 Ga 1 , δ-Ni 5 Ga 3 and Ga 2 O 3 phases is observed for the Ni 5 Ga 3 NPs after the H 2 activation. The formation of the Ga 2 O 3 phase also results in the presence of excess metallic Ni. Under CO 2 hydrogenation reaction conditions, Ga partially oxidizes again to form a Ga 2 O 3 -rich particle shell for both NP compositions, yet, to a larger extent for the Ni 3 Ga 1 NPs, which, in turn, feature a higher amount of excess Ni. We reveal that metallic Ni is responsible for the high selectivity of the Ni 3 Ga 1 NPs towards the production of methane in our catalytic tests. In contrast, the Ni 5 Ga 3 NPs display a strong selectivity toward methanol production (>92%), more than one order of magnitude higher than that for the Ni 3 Ga 1 NPs, which we ascribe to the presence of the δ-Ni 5 Ga 3 phase.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
NASA NTRS1999

Synthesis of Fullerenes in Low Pressure Benzene/Oxygen Diffusion Flames

The interest in fullerenes is strongly increasing since their discovery by Kroto et al. in 1985 as products of the evaporation of carbon into inert gas at low pressure. Due to their all carbon closed-shell structure, fullerenes have many exceptional physical and chemical properties and a large potential for applications such as superconductors, sensors, catalysts, optical and electronic devices, polymers, high energy fuels, and biological and medical materials. This list is still growing, because the research on fullerenes is still at an early stage. Fullerenes can be formed not only in a system containing only carbon and an inert gas, but also in premixed hydrocarbon flames under reduced pressure and fuel rich conditions. The highest yields of fullerenes in flames are obtained under conditions of substantial soot formation. There is a need for more information on the yields of fullerenes under different conditions in order to understand the mechanisms of their formation and to enable the design of practical combustion systems for large-scale fullerene production. Little work has been reported on the formation of fullerenes in diffusion flames. In order to explore the yields of fullerenes and the effect of low pressure in diffusion flames, therefore we constructed and used a low pressure diffusion flame burner in this study.

Hebgen, Peter↗
DOE OSTI2021

Understanding Methanol Synthesis on Inverse ZnO/CuO x /Cu Catalysts: Stability of CH 3 O Species and Dynamic Nature of the Surface

Inverse ZnO/Cu catalysts are key systems in the conversion of CO 2 , a common atmospheric pollutant, into methanol, a high-value chemical and fuel. The chemistry of methanol and methoxy groups over inverse ZnO/Cu 2 O/Cu(111) catalysts was investigated employing Ambient Pressure X-ray Photoelectron Spectroscopy (AP-XPS), Scanning Tunneling Microscopy (STM) and calculations based on Density Functional Theory (DFT). The results of AP-XPS show that the adsorption of methanol on the binary oxide substrate at 300 K leads to formation of *CH 3 O and *HCOO species with a minor amount of *CH x . Furthermore, most of the methoxy groups disappeared from the surface after heating to 450 K, the onset temperature for the formation of methanol during the hydrogenation of CO 2 . The results of AP-XPS, STM and DFT point to preferential adsorption of methoxy on the ZnO regions of the binary oxide. On the supported ZnO or on a ZnO-Cu 2 O interface, the breaking of the O-H bond in methanol is an exothermic process with a negligible (1-2 kcal/mol) or non-existent energy barrier depending on the size and shape of the ZnO islands. STM

36 MATERIALS SCIENCE↗
DOE OSTI2022

Hydrogen Storage in Partially Exfoliated Magnesium Diboride Multilayers

Metal boride nanostructures have shown significant promise for hydrogen storage applications. However, the synthesis of nanoscale metal boride particles is challenging because of their high surface energy, strong inter- and intraplanar bonding, and difficult-to-control surface termination. Here, it is demonstrated that mechanochemical exfoliation of magnesium diboride in zirconia produces 3-4 nm ultrathin MgB 2 nanosheets (multilayers) in high yield. High-pressure hydrogenation of these multilayers at 70 MPa and 330 °C followed by dehydrogenation at 390 °C reveals a hydrogen capacity of 5.1 wt%, which is ≈50 times larger than the capacity of bulk MgB 2 under the same conditions. This enhancement is attributed to the creation of defective sites by ball-milling and incomplete Mg surface coverage in MgB 2 multilayers, which disrupts the stable boron-boron ring structure. The density functional theory calculations indicate that the balance of Mg on the MgB 2 nanosheet surface changes as the material hydrogenates, as it is energetically favorable to trade a small number of Mg vacancies in Mg(BH 4 ) 2 for greater Mg coverage on the MgB 2 surface. To conclude, the exfoliation and creation of ultrathin layers is a promising new direction for 2D metal boride/borohydride research with the potential to achieve high-capacity reversible hydrogen storage at more moderate pressures and temperatures.

08 HYDROGEN↗
NASA NTRS1982

Polymer research at NASA Langley Research Center

Polymer synthesis programs involve the development of Novel thermoplastics, pseudothermoplastics, and thermosets. These systems are prepared to elucidate structure-property relationships involving thermal capabilities, toughness, processability and environmental stability. Easily processable polyimides, solvent-resistant polysulfones and polyphenylquinoxalines, and tougher high and intermediate temperature polymers were developed. Characterization efforts included high pressure liquid chromatography methodology, the development of toughness tests for fiber reinforced composites, a study of electrical properties of metal ion filled polyimides, and a study of the mutagenicity of aromatic diamines. Also the mechanism of cure/degradation of experimental polymers was studied by rheology, mechanical behavior, separation techniques and spectroscopy. The degradative crosslinking of alkyl-containing polyimides, the separation and identification of crosslinked phenylquinoxalines, the rheological behavior of hot-melt polyimides, and the elucidation of the cure of norbornene endcapped imides were also studied.

Terry L. St. Clair↗
DOE OSTI2026

Selective Conversion of CO 2 to Methanol on a In 2 O 3– x –TiO 2 (110) Interface: Importance of Oxide–Oxide Interactions

Methanol is a strategic energy vector for the storage and delivery of energy and is a widely used precursor for the synthesis of many high-value chemicals. The hydrogenation of carbon dioxide (CO 2 ) into methanol is a key process in industrial operations. Here, in this study, we show that an oxide-oxide interface generated by a low loading (0.15 ML) of In 2 O 3-x on a TiO 2 (110) substrate has a high activity and selectivity as a catalyst for the CO 2 + 3H 2 → CH 3 OH + H 2 O process. The properties of the In 2 O 3-x -TiO 2 interface under reaction conditions were investigated using a combination of synchrotron-based ambient pressure X-ray photoelectron spectroscopy (AP-XPS), temperature programmed desorption (TPD), and catalytic testing. The In 2 O 3-x overlayer spread out on top of the titania and was rich in defects and O vacancies that activated CO 2 and H 2 as reactants, without destroying CH 3 O and CH 3 OH as reaction products. The In 2 O 3-x /TiO 2 (110) catalyst is at least one order of magnitude more active than bulk indium oxide while maintaining a very high selectivity (~80%) towards methanol production. Under the rich hydrogen environment of methanol synthesis, the oxide-oxide interactions allowed only a partial reduction of the In cations, preventing the formation of metal alloys as seen in the case of catalysts with metal-indium oxide interfaces. Thus, the dispersion of low loadings of In 2 O 3-x on a stable oxide substrate is a valid and low-cost approach for generating efficient catalysts for CO 2 valorization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Carbon aerogels with integrated engineered macroporous architectures for improved mass transport

Carbon aerogels (CAs) combine unique properties including ultra-high surface area, high electrical conductivity, corrosion resistance, and robust mechanical properties making them ideal materials for electrochemical applications. Traditional CA synthesis results in isotropic, random nanoporous networks that work well for applications relying on diffusional mass transport. However, many applications would benefit from integration of engineered macroporous network structures that enable directed pressure-gradient-driven mass transport. In this study, we report on using 3D-printed sacrificial polymeric templates to generate templated CAs (t-CAs) with integrated engineered nonrandom macroporous network structures. Specifically, we used projection micro-stereo-lithography (PμSL) and two-photon polymerization direct laser writing (2PP-DLW) to fabricate millimeter-to-centimeter-sized 3D sacrificial polymeric templates with features ranging from tens of microns (PμSL) to 100s of nanometers (2PP-DLW). T-CAs were fabricated by infiltrating the templates with resorcinol-formaldehyde (RF) precursor solution, followed by carbonization at 1050 °C to simultaneously convert the RF gel to a CA and decompose the 3D-printed template, leaving an embedded templated macroporous network structure behind. X-ray computer tomography confirms integration of the macroporous architecture defined by the template. The templated macroporous architecture improves mass transport in t-CAs compared to traditional bulk CA as demonstrated by more uniform activation and their response in electrochemical cyclic voltammetry and galvanostatic charge-discharge tests.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Developing a Low Cost, High Volume and Scalable Manufacturing Technology for Undoped and Heavily P-Type Doped CdTe Feedstock Materials (Final Report)

The goal of this project was to establish a cost-effective and scalable production approach of feedstock (CdTe and Cd-Se-Te) for the solar industry, with the material properties necessary to improve performance and reduce costs. The primary focus was to develop a CdTe synthesis and growth process that pushed the p-type doping of CdTe to previously unattainable levels, while creating a path to scalable production. In our approach, the first step was bulk CdTe growth doped with Group V dopants (P, As, and Sb) using the Modified Vertical Bridgman (MVB) and high Pressure Bridgman (HPB) techniques, and the second step was examination of films deposited by Close-Spaced Sublimation (CSS) and Vapor Transport Deposition (VTD) using this specialized feedstock.

14 SOLAR ENERGY↗
NASA NTRS1999

Enabling Exploration of Deep Space: High Density Storage of Antimatter

Portable electromagnetic antiproton traps are now in a state of realization. This allows facilities like NASA Marshall Space Flight Center to conduct antimatter research remote to production sites. MSFC is currently developing a trap to store 10(exp 12) antiprotons for a twenty-day half-life period to be used in future experiments including antimatter plasma guns, antimatter-initiated microfusion, and the synthesis of antihydrogen for space propulsion applications. In 1998, issues including design, safety and transportation were considered for the MSFC High Performance Antimatter Trap (HiPAT). Radial diffusion and annihilation losses of antiprotons prompted the use of a 4 Tesla superconducting magnet and a 20 KV electrostatic potential at 10(exp -12) Torr pressure. Cryogenic fluids used to maintain a trap temperature of 4K were sized accordingly to provide twenty days of stand-alone storage time (half-life). Procurement of the superconducting magnet with associated cryostat has been completed. The inner, ultra-high vacuum system with electrode structures has been fabricated, tested and delivered to MSFC along with the magnet and cryostat. Assembly of these systems is currently in progress. Testing under high vacuum conditions, using electrons and hydrogen ions will follow in the months ahead.

Smith, Gerald A.↗
DOE OSTI2020

Structural and Optical Properties of Phase-Pure UO 2 , α-U 3 O 8 , and α-UO 3 Epitaxial Thin Films Grown by Pulsed Laser Deposition

Fundamental understanding of the electronic, chemical, and structural properties of uranium oxides requires the synthesis of high-crystalline-quality epitaxial films of different polymorphs of one material or different phases with various oxygen valence states. Here we report the growth of single-phase epitaxial UO 2 , α-U 3 O 8 , and α-UO 3 thin films using pulsed laser deposition. Both oxygen partial pressure and substrate temperature play critical roles in determining the crystal structure of the uranium oxide films. X-ray diffraction and Raman spectroscopy demonstrate that the films are single phase with excellent crystallinity and epitaxially grown on a variety of substrates. Chemical valance states and optical properties of epitaxial uranium oxide films are studied by X-ray photoelectron spectroscopy and UV–vis spectroscopy, which further confirm the high-quality stoichiometric phase-pure uranium oxide thin films. Epitaxial UO2 films show a direct band gap of 2.61 eV, while epitaxial α-UO 2 , α-U 3 O 8 and α-UO 3 films exhibit indirect band gaps of 1.89 and 2.26 eV, respectively. The ability to grow high-quality epitaxy actinide oxide thin films and to access their different phases and polymorphous will have significant benefits to the future applications in nuclear science and technology.

36 MATERIALS SCIENCE↗
NASA NTRS2004

Modeling Nonlinear Acoustic Standing Waves in Resonators: Theory and Experiments

The overall goal of the cooperative research with NASA Glenn is to fundamentally understand, computationally model, and experimentally validate non-linear acoustic waves in enclosures with the ultimate goal of developing a non-contact acoustic seal. The longer term goal is to transition the Glenn acoustic seal innovation to a prototype sealing device. Lucas and coworkers are credited with pioneering work in Resonant Macrosonic Synthesis (RMS). Several Patents and publications have successfully illustrated the concept of Resonant Macrosonic Synthesis. To utilize this concept in practical application one needs to have an understanding of the details of the phenomenon and a predictive tool that can examine the waveforms produced within resonators of complex shapes. With appropriately shaped resonators one can produce un-shocked waveforms of high amplitude that would result in very high pressures in certain regions. Our goal is to control the waveforms and exploit the high pressures to produce an acoustic seal. Note that shock formation critically limits peak-to-peak pressure amplitudes and also causes excessive energy dissipation. Proper shaping of the resonator is thus critical to the use of this innovation.

Raman, Ganesh↗