Post-traumatic osteoarthritis progression is diminished by early mechanical unloading and anti-inflammatory treatment in mice
Not Available
Hsia, A. W. (ORCID:0000000241279680)↗
SEARCH · Engineering Papers
Results for “post”
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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Effect of Nitrogen Post-Doping on a Commercial Platinum-Ruthenium/Carbon Anode Catalyst
Abstract not provided
09 BIOMASS FUELS↗
Anchoring of Cu(II) onto surface of porous metal-organic framework through post-synthesis modification for the synthesis of benzimidazoles and benzothiazoles
Efficient synthesis of various benzimidazoles and benzothiazoles under mild conditions catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. In this manner, first, the aminated UiO-66 was modified with thiophene-2-carbaldehyde and then the prepared Schiff base was reacted with CuCl{sub 2}. The prepared catalyst was characterized by FT-IR, UV–vis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N{sub 2} adsorption, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). The UiO-66–NH{sub 2}–TC–Cu was applied as a highly efficient catalyst for synthesis of benzimidazole and benzothiazole derivatives by the reaction of aldehydes with 1,2-diaminobenzene or 2-aminothiophenol. The Cu(II)-containing MOF was reused several times without any appreciable loss of its efficiency. - Graphical abstract: Efficient synthesis of benzimidazoles and benzothiazoles catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. - Highlights: • A copper Schiff base was immobilized on UiO-66 via postsynthetic modification. • The modified MOFs were fully characterized by a variety of methods. • The catalyst was used for the preparation of benzimidazoles and benzothiazoles. • In comparison of other catalysts, our catalyst was more efficient and forceful.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Fe incorporation into hydroxyapatite channels by Fe loading and post-annealing
Apatite-type solid solutions with the formula Ca{sub 10}(PO{sub 4}){sub 6}Fe{sub x}O{sub y}H{sub z} containing Fe atoms in the channel sites of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} were successfully synthesized by impregnation with aqueous solution of Fe, followed by heat treatment at 1150 °C in air and cooling to room temperature. The unit cell volume of Ca{sub 10}(PO{sub 4}){sub 6}Fe{sub x}O{sub y}H{sub z} increased with increasing Fe content. The results of structural refinement using powder X-ray diffraction data and Raman spectroscopy suggested that the incorporated Fe ions occupied four-fold sites, away from the center of the channel in the apatite lattice. This method may be useful for synthesizing novel apatite-type functional materials containing transition metals.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Evaluating biomarkers to model cancer risk post cosmic ray exposure
Not Available
Sridharan, Deepa M.↗
Helium bubble evolution in a Zr–Sn–Nb–Fe–Cr alloy during post-annealing: An in-situ investigation
The formation of helium bubbles is considered to be detrimental to the mechanical performance of the nuclear materials. The growth behaviors of helium bubbles in a helium ion implanted Zr–Sn–Nb–Fe–Cr alloy with respect to the helium fluence and subsequently annealing procedure were investigated by in-situ transmission electron microscopy. In the as-implanted sample, the measured size distributions of the helium bubbles are consistent with the simulated helium concentrations. Moreover, the mean size of the helium bubbles increases with the increase of the irradiation temperatures and the helium fluence. The in-situ heating study performed in a transmission electron microscope indicates that the mean size of the helium bubbles increase slowly below 923 K and dramatically above 923 K. The coarsening mechanism of the helium bubbles in the alloy is suggested based on the study. - Highlights: • Helium bubble growth in zirconium with annealing was in-situ investigated in TEM. • The mean helium bubble size increase with helium fluence and annealing temperature. • Helium bubble size distribution is same as that of helium concentration by SRIM. • Mean bubble size increases slowly and quickly with temperature below and above 923 K. • The growth mechanism of the helium bubbles in Zr alloy has been discussed.
36 MATERIALS SCIENCE↗
Characterization of microstructure in hydrogen ion irradiated vanadium at room temperature and the microstructural evolution during post-irradiation annealing
The microstructure of pure vanadium after hydrogen ion irradiation at room temperature to a fluence of 1 × 10{sup 17} ions/cm{sup 2} (and 5 × 10{sup 16} ions/cm{sup 2}) was investigated by transmission electron microscopy (TEM). Small dislocation loops (black spots) and cavities are formed after the irradiation. The nature and Burgers vector of dislocation loops formed in vanadium was characterized using g·b technique and inside–outside method. Interstitial dislocation loops with Burgers vector of 1/2 < 111 > predominantly formed with less than 10% of 1/2 < 110 > type. No < 100 > type or vacancy type dislocation loop formed. The microstructural evolution during the annealing process was also studied. Density and size of dislocation loops changed sharply when the annealing temperature was lifted up to 450 °C. When the annealing temperature was higher than 500 °C, bubble coalescence occurred with some large hydrogen bubbles formed. - Highlights: • Interstitial dislocation loops with Burgers vector of 1/2<111> were predominant. • Less than 10% of 1/2<110> dislocation loops were present in pure vanadium. • No <100> or vacancy type loops were present in pure vanadium. • Density and size of dislocation loops changed sharply at temperature above 450 °C. • Bubble coalescence occurred when annealing temperature was higher than 500 °C.
36 MATERIALS SCIENCE↗
Effect of post annealing on microstructure and mechanical properties in Ni-free N-containing ODS steel
The precipitation behaviour of Y2O3 and MnO nanoparticles after isothermal treatment, in a Ni-free N-containing oxide dispersion strengthened (ODS) steel was studied by wide-angle X-ray scattering (WAXS), ultra-small-angle and small-angle X-ray scattering (USAXS/SAXS), small angle neutron scattering (SANS) and scanning transmission electron microscopy (STEM). Mechanical properties were investigated via tensile and micro-hardness testing. Additional precipitation occurred during annealing, in addition to the precipitates formed during sintering. The highest volume distribution of Y2O3, with average size of 6 nm, was determined by alloy contrast variation (ACV) analysis of SAXS and SANS for the sample annealed at 800 °C; this sample shows the highest hardness and ultimate tensile strength. Above that temperature, coarsening of both matrix and precipitates and depletion of nitrogen from matrix degraded the mechanical properties. The very fine nanoparticles and thermally induced dissolution of nitrogen influenced mechanical properties.
alloy contrast variation (ACV)↗
Calcium titanate (CaTiO{sub 3}) dielectrics prepared by plasma spray and post-deposition thermal treatment
Highlights: • Calcium titanate was sprayed by two different plasma spray systems. • Significant improvement of dielectric properties after annealing was observed. • Calcium titanate self-supporting parts can be fabricated by plasma spraying. - Abstract: This paper studies calcium titanate (CaTiO{sub 3}) dielectrics prepared by plasma spray technology. A water stabilized plasma gun (WSP) as well as a widely used gas stabilized plasma gun (GSP) were employed in this study to deposit three sample sets at different spray conditions. Prepared specimens were annealed in air at atmospheric pressure for 2 h at various temperatures from 530 to 1170 °C. X-ray diffraction (XRD), Raman spectroscopy and porosity measurements were used for sample characterization. Dielectric spectroscopy was applied to obtain relative permittivity, conductivity and loss factor frequency dependence. Band gap energy was estimated from reflectance measurements. The work is focused on the explanation of changes in microstructure and properties of a plasma sprayed deposit after thermal annealing. Obtained results show significant improvement of dielectric properties after thermal annealing.
36 MATERIALS SCIENCE↗
Addition-type alkoxysilyl-substituted polynorbornenes for post-combustion carbon dioxide separations
The separation of CO 2 from N 2 using polymeric membranes has proven a particularly challenging task. One promising class of polymers for this application is alkoxysilyl-substituted vinyl-added polynorbornenes (VAPNBs), which are high T g materials that often exhibit notable CO 2 /N 2 separation performance. This performance is believed to arise from their anomalous behavior in which they display high levels of solubility selectivity, a trait more commonly encountered in rubbery polymers than high T g glassy materials. While this trait has been documented in literature, no systematic investigations have been reported that probe the relationship between alkoxysilyl-substituted VAPNB structure and their resultant gas separation behavior. Here, we describe the synthesis and evaluation of three sets of alkoxysilyl-substituted VAPNBs that are designed to probe distinct facets of their structure-transport relationship. This includes investigations into the effect that alkoxysilyl branching, chain length, and carbon linker length have on CO 2 /N 2 permeability, solubility, and diffusivity.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
13 C NMR study of amino acid salts in facilitated transport membranes for post-combustion carbon capture
Some of amino acid salts (AASs) have been demonstrated to be effective mobile carriers in facilitated transport membranes (FTMs) to achieve superior CO 2 permeance and CO 2 /N 2 selectivity for CO 2 capture from flue gas. Understandings of how the structures of different AASs affect the chemistry of the amine–CO 2 reaction are essential for the future development of more efficient AAS mobile carriers. In this study, the reaction chemistry of selected AASs with CO 2 was investigated by 13 C nuclear magnetic resonance (NMR) spectroscopy. The CO 2 loading and the distribution of major reaction products, including carbamate and bicarbonate products of each studied AAS were quantitatively analyzed. The positive correlation between the CO 2 loading of AAS (mol CO 2 /g AAS) and the CO 2 permeance of FTMs suggested that AAS with a higher CO 2 loading may improve the performance of FTMs. Our results also showed that increasing the steric hindrance of AAS could be a practical way to promote the bicarbonate reaction pathway and thus potentially increase the CO 2 loading (mol CO 2 /mol AAS). Moreover, 2-(1-piperazinyl)ethylamine (PZEA) was found to be a more effective multi-amine than piperazine (PZ) for synthesizing AASs due to the presence of more effective nitrogen sites per molecule. The superior CO 2 permeance of the PZEA-Sar membrane is also attributed to its more uniform membrane formation. As a result, the knowledge gained from this study will inform the rational design of more effective AAS carriers for CO 2 capture.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Effect of post-deformation annealing on the microstructure and micro-mechanical behavior of Zn–Mg hybrids processed by High-Pressure Torsion
Not Available
Hernández-Escobar, David↗
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