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Smith, Mark

Publications and source records attributed to Smith, Mark.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Development of Fe-based oxygen carrier using spent FCC catalyst as support for high temperature chemical looping combustion

Chemical looping combustion is based on the transfer of oxygen from air to fuel by means of an oxygen carrier using a metal oxide. This study investigated the development of an oxygen carrier by adding iron to a spent commercial fluid catalytic cracking catalyst (Fe/FCC) and comparing to Fe/Al 2 O 3 , and Fe/SiO 2 oxygen carriers that may be suitable for the high-temperature (1100 °C) process. The FCC material was chosen as a low-cost oxygen carrier. The FCC support strongly modified the reduction behavior of the Fe-based carrier as compared to the Fe/Al 2 O 3 and Fe/SiO 2 carriers. Multicycle studies with CH 4 revealed the FCC support impacted the CO 2 selectivity (13.5%) at 1100 °C to produce more gaseous CO as compared to the 900 °C (89.7%) due to the formation of FeAl 2 O 4 and Fe 2 SiO 4 phases when the Fe 2 O 3 was reduced at 1100 °C. The FeAl 2 O 4 and Fe 2 SiO 4 phases also considerably slowed the CO 2 formation rate on the Fe/FCC oxygen carrier at 1100 °C as compared to the 900 °C reaction tests. The higher-temperature (1100 °C) decreased the oxygen transfer capacity of the Fe/FCC carrier, did not significantly increase the capacity of either the Fe/SiO 2 and Fe/Al 2 O 3 carriers. These results suggest that high-temperatures (1100 °C) may lead to carrier transformations through sintering and agglomeration that significantly reduce the kinetics and performance of the oxygen carrier. This work suggests at higher temperatures, shorter reduction times may be necessary to prevent the formation of these phases and the subsequent deactivation of the carrier for total oxidation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

SAR optimization studies on modified salicylamides as a potential treatment for acute myeloid leukemia through inhibition of the CREB pathway

Disruption of cyclic adenosine monophosphate response element binding protein (CREB) provides a potential new strategy to address acute leukemia, a disease associated with poor prognosis, and for which conventional treatment options often carry a significant risk of morbidity and mortality. In this paper, we describe the structure-activity relationships (SAR) for a series of XX-650-23 derived from naphthol AS-E phosphate that disrupts binding and activation of CREB by the CREB-binding protein (CBP). Through the development of this series, we identified several salicylamides that are potent inhibitors of acute leukemia cell viability through inhibition of CREB-CBP interaction. Among them, a biphenyl salicylamide, compound 71, was identified as a potent inhibitor of CREB-CBP interaction with improved physicochemical properties relative to previously described derivatives of naphthol AS-E phosphate.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2019

Emission-Line Metallicities from the Faint Infrared Grism Survey and VLT/MUSE

We derive direct-measurement gas-phase metallicities of 7.4 < 12 + log(O/H) < 8.4 for 14 low-mass emission- line galaxies at 0.3 < z < 0.8 identified in the Faint Infrared Grism Survey. We use deep slitless G102 grism spectroscopy of the Hubble Ultra Deep Field, dispersing light from all objects in the field at wavelengths between 0.85 and 1.15 μm. We run an automatic search routine on these spectra to robustly identify 71 emission-line sources, using archival data from Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) to measure additional lines and confirm redshifts. We identify 14 objects with 0.3 < z < 0.8 with measurable [O III] λ4363 Å emission lines in matching VLT/MUSE spectra. For these galaxies, we derive direct electron-temperature gas-phase metallicities with a range of 7.4 < 12 + log(O/H) < 8.4. With matching stellar masses in the range of 10(exp 7.9) Solar Mass < M(sub *) < 10(exp 10.4) Solar Mass, we construct a mass–metallicity (MZ) relation and find that the relation is offset to lower metallicities compared to metallicities derived from alternative methods (e.g., R(sub 23), O3N2, N2O2) and continuum selected samples. Using star formation rates derived from the Hα emission line, we calculate our galaxies’ position on the Fundamental Metallicity Relation, where we also find an offset toward lower metallicities. This demonstrates that this emission-line-selected sample probes objects of low stellar masses but even lower metallicities than many comparable surveys. We detect a trend suggesting galaxies with higher Specific Star Formation (SSFR) are more likely to have lower metallicity. This could be due to cold accretion of metal-poor gas that drives star formation, or could be because outflows of metal-rich stellar winds and SNe ejecta are more common in galaxies with higher SSFR.

Pharo, John↗
DOE OSTI2019

Thermal Loads and Cooling Design for ITER in-Port Low Field Side Reflectometer Diagnostic System

The current design for the ITER Low Field Side Reflectometer (LFSR) diagnostic system contains six circular waveguides that function as both launch and receive antennas. The front end of LFSR system, interfacing with the plasma facing DFW and its supporting diagnostic shielding Modules (DSM), is integrated into Equatorial Port Plug 11(EPP#11). In-vessel LFSR configuration is mainly divided into two sections, i.e. Front Antenna Unit (FAU) and in-vessel Transmission Line (TL) components. During plasma normal operation, the 14 MeV neutrons from D-T fusion reactions penetrate into the port plug and LFSR components. Neutronics code ATTILA is used for assessing the volumetric heating of in-vessel components. The maximum normal heat load due to radiation and the charge exchange from plasma is 0.35 MW/m 2 , which has to be applied on those surfaces affected by a viewing factor consistent with the aperture surface position and orientation. The front antenna unit (FAU) needs the active cooling to handle the radiant and nuclear heating from the plasma. Due to the specific viewing aperture layout at the front-end of in-vessel LFSR, the cooling channel design is challenging. The thermal-hydraulic iterations are performed to achieve the desirable temperature distribution of the water cooled front antenna units. The progressive ratcheting effects of the FAU subjected to cyclic thermal loading are examined by the preliminary non-linear elastic-plastic analysis.

42 ENGINEERING↗
DOE OSTI2019

Microwave-Assisted Conversion of Low Rank Coal under Methane Environment

Addition of methane during microwave coal pyrolysis could greatly affect the product distribution to valuable products including the formation of char. Here in this work, low rank coal was exposed to microwave energy in the presence of different methane concentrations (0, 25, 50, and 90%) at 980 °C for 2 h. Increasing methane concentration was found to increase both the char and tar yields mainly due to carbon deposition during methane decomposition and hydrogenation of trapped carbon into tars. Analysis of the gas composition suggested that some of the methane was activated in the presence of the coal minerals, which could act as a catalyst, forming light hydrocarbons C 2 –C 7 which account for up to 5% of the gaseous products at a methane concentration of 90%; they accounted for less than 0.5% in the absence of methane. Methyl groups may also have been substituted into aromatic compounds as observed in the tar analysis where the number of methyl substitutions in the detected parent phenol and naphthalene increased with methane concentration. Tar yield could also increase indirectly with methane addition through hydrogenation reactions with unsaturated coal compounds. The formation of char under different methane concentrations was examined by many characterization tools including Raman, dielectric properties, XRD, BET, SEM, and EDS. The results suggest that the addition of methane did not help in forming ordered carbon chars, not only due to amorphous carbon deposition on the char surface but also due to hydrogenation or alkylation reactions with char. The presence of methane enhanced the formation of C 2 s and benzene; a possible correlation between the formation rate of benzene and hydrogen during pyrolysis is proposed.

01 COAL, LIGNITE, AND PEAT↗