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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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At least 37 records · Page 2

α- and β-CoNi binary hydroxides nanostructures: Synthesis, characterization, and application as heterogeneous catalysts

The aim of this study is to show that α- and β-CoNi binary hydroxides nanostructures can be used as heterogeneous catalysts in the oxidation of benzyl alcohol, N-formylation of aniline, and the Claisen–Schmidt condensation. The catalysts were synthesized by hydrothermal method and characterized by XRD, FE-SEM/EDX, FT-IR, TGA, UV–vis and N{sub 2} adsorption-desorption techniques. The α-phase is similar to layered double hydroxide (LDH), while β-phase is isostructural with brucite. In all of the three reactions, the conversion enhanced by increasing the amount of catalysts from 10 to 30 mg, and the catalytic activity of α-phase was better than β-phase. In benzyl alcohol oxidation, the best conversion for α- and β-phases was 90% and 80%, respectively, under solvent-free conditions. In N-formylation, the best yield for both catalysts was obtained 95% in solvent-free conditions. However, the time required for α-phase to reach this amount was a quarter of that for β-phase. For the Claisen–Schmidt condensation, the best yield was obtained at 90 °C, which was 70% and 50% for α- and β-CoNi binary hydroxides, respectively. Both catalysts were stable and subsequent to each step of recovery and reuse, no significant loss in activity was observed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Peptoid-based hierarchically-structured biomimetic nanomaterials: Synthesis, characterization and applications

Peptoids (or poly-N-substituted glycines) is a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis, high chemical stability, enzyme hydrolysis resistance, and biocompatibility. By tuning the side chain chemistry of peptoids, it allows for a precise control over sequences and achieving a large side-chain diversity. Due to these unique features, in the last several years, many amphiphilic peptoids were designed as highly tunable building blocks for the preparation of biomimetic nanomaterials with well-defined hierarchical structures and desired functionalities. In this paper, we provide an overview of the recent achievements in this area by dividing them into the following three aspects. First, mica- and silica-templated peptoid self-assembly was summarized. Here, the presence of inorganic substrates provides the guarantee of investigating their self-assembly mechanisms and interactions between peptoids and substrates using nanoscale characterization techniques, particularly in situ atomic force spectroscopy (AFM) and AFM-based dynamic force spectroscopy (AFM-DFS). Second, solution-phase self-assembly of peptoids into nanotubes and nanosheets was presented, as well as their self-repair properties. Third, the applications of peptoid based nanomaterials were outlined, including the construction of catalytic nanomaterials as a template and cytosolic delivery as cargoes.

36 MATERIALS SCIENCE↗

Characterization and application of a laser-driven intense pulsed neutron source using Trident

A team of Los Alamos researchers supported a final campaign to use the Trident laser to produce neutrons, contributed their multidisciplinary expertise to experimentally assess if laser-driven neutron sources can be useful for MaRIE. MaRIE is the Laboratory’s proposed experimental facility for the study of matter-radiation interactions in extremes. Neutrons provide a radiographic probe that is complementary to x-rays and protons, and can address imaging challenges not amenable to those beams. The team's efforts characterize the Laboratory’s responsiveness, flexibility, and ability to apply diverse expertise where needed to perform successful complex experiments.

43 PARTICLE ACCELERATORS↗

Linker-Free Magnetite-Decorated Gold Nanoparticles (Fe3O4-Au): Synthesis, Characterization, and Application for Electrochemical Detection of Arsenic (III)

Linker-free magnetite nanoparticles (Fe3O4NPs)-decorated gold nanoparticles (AuNPs) were grown using a new protocol that can be used as a new platform for synthesis of other intact metal–metal oxide nanocomposites without the need for linkers. This minimizes the distance between the metal and metal oxide nanoparticles and ensures the optimum combined effects between the two material interfaces. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed the successful synthesis of the Fe3O4-Au nanocomposite, without any change in the magnetite phase. Characterization, using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy, revealed the composite to consist of AuNPs of 70 ± 10 nm diameter decorated with tiny 10 ± 3 nm diameter Fe3O4NPs in Au:Fe mass ratio of 5:1. The prepared Fe3O4-Au nanocomposite was embedded in ionic liquid (IL) and applied for the modification of glassy carbon electrode (GCE) for the electrochemical detection of As(III) in water. By combining the excellent catalytic properties of the AuNPs with the high adsorption capacity of the tiny Fe3O4NPs towards As(III), as well as the good conductivity of IL, the Fe3O4-Au-IL nanocomposite showed excellent performance in the square wave anodic stripping voltammetry detection of As(III). Under the optimized conditions, a linear range of 1 to 100 μg/L was achieved with a detection limit of 0.22 μg/L (S/N = 3), and no interference from 100-fold higher concentrations of a wide variety of cations and anions found in water. A very low residual standard deviation of 1.16% confirmed the high precision/reproducibility of As(III) analysis and the reliability of the Fe3O4-Au-IL sensing interface. Finally, this proposed sensing interface was successfully applied to analyzing synthetic river and wastewater samples with a 95–101% recovery, demonstrating excellent accuracy, even in complex synthetic river and wastewater samples containing high concentrations of humic acid without any sample pretreatments.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Application Deconfliction Characterization and Alternatives Analysis

This report provides an overview of the domain space and solution techniques that could be used to create a robust, flexible app deconfliction service. Three approaches are reviewed with summaries of the characteristics, elements, and results from preliminary demonstrations of solution techniques based on each approach: 1) rules and heuristics, 2) cooperation, and 3) optimization. The strengths and weaknesses of each solution technique were explored through a set of numerical demonstrations on modified IEEE 123 node and 9500 node test feeders. An alternatives analysis of individual deconfliction elements was performed with each solution technique element evaluated against criteria reflecting the dynamic app environment, need to balance app objectives, and scalability issues versus the number of applications, setpoints, and distributed control areas. It is anticipated that a combined solution for a GridAPPS-D Deconfliction Service can be formulated using a combination of elements from each solution technique. The combined solution would combine 1) device control budgets to reduce the size of the solution space by constraining system setpoints to those will not result in accelerated degradation of physical assets, 2) system operations rules to constrain the solution space by eliminating setpoints that result in violations of system limits or operational best practices, 3) contextual status signals shared with or among apps such that they could update their desired setpoints based on the evolving context, 4) a mediator that incentivizes apps to come to a cooperative solution, and 5) Setpoint-informed optimization as a fallback mechanism if a cooperative solution cannot be agreed upon by applications.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Characterization and application of a high-resolution microfluidic device in atmospheric ice nucleation research and integrated science teaching

Ambient ice-nucleating particles (INPs) represent an important subset of aerosol particles that facilitate heterogeneous formation of ice crystals in the atmosphere, which can impact Earth system and energy. In this work, we developed an affordable high-resolution platform to replicate atmospheric immersion freezing through the unique capabilities of microfluidics to measure INP concentration of known ice nucleation active materials, as well as high-latitude soil samples. The new instrument produced comparable and extended freezing efficiency data for a multitude of samples over the temperature range of -5 to -35 °C as compared to an existing freezing assay within known uncertainties. Moreover, the new assay was integrated into science teaching at a primarily undergraduate and Hispanic-serving institute, contributing to fostering a deeper understanding of ice nucleation processes among college students, instilling their enthusiasm for science, and addressing the critical need for a well-informed citizenry. Student research assistants were involved in both research and pedagogical development processes. Three students from our team visited the Pacific Northwest National Laboratory to help characterize physicochemical properties of our test samples and to test modeling of atmospheric ice nucleation using a box model as well as a global climate model (E3SM) for the regional-scale conditions over the North Slope of Alaska (NSA) and Southern Great Plains (SGP). We also assessed student learning experience via hands-on training, research processes, and development of educational materials. On pre- and post-participation surveys and in exit interviews, students reported personal growth as advancements in breadth of experience, research-related skill sets, and regarding their educational and career goals. They also affirmed that the methods enacted incorporated the NASA Minority University Research and Education Program (MUREP) STEM Engagement Best Practices.

58 GEOSCIENCES↗

Chitosan–Gelatin @ Tin (IV) Tungstatophosphate Nanocomposite Ion Exchanger: Synthesis, Characterization and Applications in Environmental Remediation

The present study reported the synthesis of novel organic–inorganic hybrid nanocomposite by incorporating tin (IV) based ion exchanger into the hybrid polymer network of chitosan and gelatin prepared under vacuum for the efficient removal of heavy metal ions and toxic dyes from an aqueous fluid. The physicochemical studies such as ion exchange capacity (IEC), chemical stability, thermal stability, pH titration and distribution behaviour studies were also carried out to determine the cation exchange behaviour of the material. The surface morphology and structural properties were studied by the techniques such as FTIR, FESEM, EDS, TEM and XRD. Distribution studies confirmed the synthesized CG/STPNC had the highest selectivity for Pb{sup 2+} ions (85.3 mL/g). Maximum adsorption of methylene blue (82%) was achieved within 240 min at 500 mg of adsorbent dose, 10 mg/L of the initial concentration of dye, pH of 7 and 30 °C of temperature. Adsorption kinetic data fitted well with pseudo-second order rate model with R{sup 2} = 0.995. The correlation value 0.95 and favourable R{sub L} = 0.21 of adsorption data suggested better fit for Langmuir adsorption. Thus the synthesized nanocomposite ion exchanger was found to be a promising cation exchanger as well as an adsorbent for heavy metal ion and dye removal from textile industrial effluents. Graphical abstract: .

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Amino-Acid-Modified-Cashew Gum Flocculant: Synthesis, Characterization, and Application

Amphoteric poly(O-methacryloyl-L-serine)-grafted cashew gum (CG-g-P(SerMA)) flocculant was obtained with highly efficient in separation and sequential recovery of kaolin particles from aqueous suspension. The highest flocculation efficiency was achieved with a flocculant synthesized using an O-methacryloyl-L-serine:cashew gum molar ratio of 3:1. The CG-g-P(SerMA) at a dosage of 3.0 mg L{sup −1} resulted in a flocculation efficiency of more than 90% within 20 min for kaolin suspension. The efficiency, in standard experiments, the flocculant CG-g-P(SerMA) was superior to cashew gum and polyacrylamide-based commercial flocculants. The flocculation mechanism involves electrostatic interactions between the negatively charged surface of the kaolin and the protonated amino groups of the flocculant under acidic conditions. These results provide new opportunities and challenges for understanding and improving the removal of impurities present in water and wastewater.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

A review on bacteria-derived antioxidant metabolites: their production, purification, characterization, potential applications, and limitations

Abstract Antioxidants are organic molecules that scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS), thereby maintaining cellular redox balance in living organisms. The human body synthesizes endogenous antioxidants, whereas humans obtain exogenous antioxidants from other organisms such as plants, animals, fungi, and bacteria. This review primarily focuses on the antioxidant potential of natural metabolites and extracts from five major bacterial phyla, including the well-studiedActinobacteriaandCyanobacteria, as well as less-studiedBacteroides,Firmicutes, andProteobacteria.The literature survey revealed that the metabolites and the extracts with antioxidant activity can be obtained from bacterial cells and their culture supernatants. The metabolites with antioxidant activity include pigments, phycobiliproteins, polysaccharides, mycosporins-like amino acids, peptides, phenolic compounds, and alkaloids. Both metabolites and extracts demonstrate in vitro antioxidant capacity through radical-scavenging, metal-reducing, and metal-chelating activity assays. In in vivo models, they can scavenge ROS and RNS directly and/or indirectly eliminate them by enhancing the activities of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase. Due to their antioxidant activities, they may find applications in the cosmetic industry as anti-aging agents for the skin and in medicine as drugs or supplements for combating oxidative stress-related disorders, such as neurodegenerative diseases and diabetes. The literature survey also elucidated that some metabolites and extracts with antioxidant activity also exhibited strong antimicrobial properties. Therefore, we consider that they may have future applications in the treatment of infectious diseases, the preparation of pathogen-free healthy foods, and the extension of food shelf life.

Pharmacology & Pharmacy↗

Fabrication, characterization and applications of iron selenide

This review article presents fabrication of FeSe by solid state reactions, solution chemistry routes, chemical vapor deposition, spray pyrolysis and chemical vapor transport. Different properties and applications such as crystal structure and phase transition, band structure, spectroscopy, superconductivity, photocatalytic activity, electrochemical sensing, and fuel cell activity of FeSe have been discussed. - Graphical abstract: Iron selenide can be synthesized by solid state reactions, chemical vapor deposition, solution chemistry routes, chemical vapor transport and spray pyrolysis. - Highlights: • Different fabrication methods of iron selenide (FeSe) have been reviewed. • Crystal structure, band structure and spectroscopy of FeSe have been discussed. • Superconducting, catalytic and fuel cell application of FeSe have been presented.

36 MATERIALS SCIENCE↗

Facile and low cost oxidative conversion of MoS{sub 2} in α-MoO{sub 3}: Synthesis, characterization and application

This study describes a facile low cost route to synthesize the α-MoO{sub 3} through a conversion of the precursor MoS{sub 2} in oxidant media. The structure and morphology of the α-MoO{sub 3} were studied by high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results show that α-MoO{sub 3} was obtained with reduced size, high purity, strongly-preferred orientation and structural defects, which ensures versatility and multifunctionality to this sample. For the purpose of applications, α-MoO{sub 3} was successfully employed in inverted organic solar cells devices as a possible alternative to the PEDOT:PSS in the hole transportation layer. - Graphical abstract: Synthesis process based on low cost oxidative conversion of MoS{sub 2} in α-MoO{sub 3} Display Omitted - Highlights: • A facile route to obtain α-MoO{sub 3} by refluxing the MoS{sub 2} precursor in oxidant media. • High purity and strongly-preferred orientation. • Belt-shaped material. • Enhanced conversion efficiency (PCE) when compared with conventional PEDOT:PSS.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Photocatalytic activity of electrospun MgO nanofibres: Synthesis, characterization and applications

Highlights: • MgO nanofibres with high photocatalytic activity were successfully fabricated. • Electrospinning method via PVA/magnesium precursor based system was used. • Dye degradation of MgO nanofibres was compared with spherical MgO nanoparticles. • MgO nanofibres exhibited excellent photocatalytic activity against Reactive Yellow. • MgO nanofibres show a great potential in efficient treatment of dye effluents. - Abstract: One dimensional MgO nanofibres with high photocatalytic activity were fabricated using the electrospinning method via a polyvinyl alcohol (PVA)/magnesium precursor based system and the dye degradation efficacy of MgO nanofibres was compared with MgO nanospheres. Optimum electrospinning parameters including suitable magnesium precursors were investigated and the formation of MgO nanofibres were confirmed with scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) mapping. Furthermore, the crystalline lattice structure and surface roughness of fabricated nanofibres were evaluated using transmission electron microscopic-electron diffraction mode (TEM-SAED) and atomic force microscopy (AFM), respectively. Fabricated MgO nanofibres exhibited excellent photocatalytic degradation activity against widely used model reactive dye, Reactive Yellow (RY). In contrast to MgO nanospheres, electrospun MgO nanofibres completely degraded the reactive dye under UV irradiation. These photocatalytic MgO nanofibres show a great potential to be used in efficient treatment of industrial dye effluents.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Progress, Challenges, and Opportunities in the Synthesis, Characterization, and Application of Metal-Boride-Derived Two-Dimensional Nanostructures

Two-dimensional (2D) metal-boride-derived nanostructures have been a focus of intense research for the past decade, with an emphasis on new synthetic approaches, as well as on the exploration of possible applications in next-generation advanced materials and devices. Their unusual mechanical, electronic, optical, and chemical properties, arising from low dimensionality, present a new paradigm to the science of metal borides that has traditionally focused on their bulk properties. This Perspective discusses the current state of research on metal-boride-derived 2D nanostructures, highlights challenges that must be overcome, and identifies future opportunities to fully utilize their potential.

metals↗

Identification, Characterization, and Application of a Highly Sensitive Lactam Biosensor from Pseudomonas putida

Caprolactam is an important polymer precursor to nylon traditionally derived from petroleum and produced on a scale of 5 million tons per year. Current biological pathways for the production of caprolactam are inefficient with titers not exceeding 2 mg/L, necessitating novel pathways for its production. As development of novel metabolic routes often require thousands of designs and result in low product titers, a highly sensitive biosensor for the final product has the potential to rapidly speed up development times. Here we report a highly sensitive biosensor for valerolactam and caprolactam from Pseudomonas putida KT2440 which is > 1000 × more sensitive to an exogenous ligand than previously reported sensors. Manipulating the expression of the sensor oplR (PP_3516) substantially altered the sensing parameters, with various vectors showing K d values ranging from 700 nM (79.1 μg/L) to 1.2 mM (135.6 mg/L). Our most sensitive construct was able to detect in vivo production of caprolactam above background at~6 μg/L. The high sensitivity and range of OplR is a powerful tool toward the development of novel routes to the biological synthesis of caprolactam.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Bioinformatics-aided identification, characterization and applications of mushroom linalool synthases

Enzymes empower chemical industries and are the keystone for metabolic engineering. For example, linalool synthases are indispensable for the biosynthesis of linalool, an important fragrance used in 60–80% cosmetic and personal care products. However, plant linalool synthases have low activities while expressed in microbes. Aided by bioinformatics analysis, four linalool/nerolidol synthases (LNSs) from various Agaricomycetes were accurately predicted and validated experimentally. Furthermore, we discovered a linalool synthase (Ap.LS) with exceptionally high levels of selectivity and activity from Agrocybe pediades, ideal for linalool bioproduction. It effectively converted glucose into enantiopure (R)-linalool in Escherichia coli, 44-fold and 287-fold more efficient than its bacterial and plant counterparts, respectively. Phylogenetic analysis indicated the divergent evolution paths for plant, bacterial and fungal linalool synthases. More critically, structural comparison provided catalytic insights into Ap.LS superior specificity and activity, and mutational experiments validated the key residues responsible for the specificity.

59 BASIC BIOLOGICAL SCIENCES↗