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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 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Thermally initiated disproportionation of manganese(II) bis(1-hydroxyethylidene)diphosphonate. Formation and properties of the lepidoid structure of manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium whiskers. Agronomical efficiency of the manganese(II) complex with (1-hydroxyethylidene)diphosphonic acid

The reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate (Mn(H{sub 3}L){sub 2}•4H{sub 2}O) with 2-aminoethanol (H{sub 2}NCH{sub 2}CH{sub 2}OH) in an aqueous medium on heating to 70—80 оС causes the initial formation of soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tris(1-hydroxyethaneaminium) (Mn(H{sub 3}L)2• •3H{sub 2}NCH{sub 2}CH{sub 2}OH•4H{sub 2}O), which then disproportionates to slightly soluble manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium (MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH) and coordination polymer of 1-hydroxyethylidenediphosphonic acid with 2-aminoethanol containing no metal cations. In the course of the reaction, MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH precipitates as whiskers that are grouped into a leaf (lepidoid) structure. The latter was examined by IR spectroscopy, X-ray phase analysis, scanning electron microscopy, atomic force microscopy, optical microscopy, and thermal desorption of nitrogen. The starting and resulting manganese compounds refer to poorly soluble crystalline complexes. The presence of a 2-aminoethanol molecule in the final product leads to an increase in the solubility from 0.40 to 0.54 g in 100 mL of the solution. Poorly soluble MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH is easily converted to a soluble form by the treatment with 2-aminoethanol or 2-amino-2-(hydroxy- methyl)propane-1,3-diol (H{sub 2}NC(CH{sub 2}OH)3). The agronomical efficiency of a solution of the Mn(H{sub 3}L){sub 2}•3H{sub 2}NCH{sub 2}CH{sub 2}OH•4H{sub 2}O complex was studied on the cultures of white lupine Degas, spring wheat Ester, spring rape, and pea Stabil.

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

Mono-C,O-chelated bromo- and triflatosilanes with an amino acid moiety: salts or covalently bonded complexes?

Derivatives of the amino acids sarcosine and proline – triflates TsN(Me)CH{sub 2}C(O)N(Me)-CH{sub 2}SiMe{sub 2}OTf and Ns–Pro–N(Me)CH2SiMe2OTf (Ns is 4-NO{sub 2}C{sub 6}H{sub 4}SO{sub 2}) – were synthesized by the reaction of trimethylsilyl triflate with halosilanes prepared previously. Bromide NsNHCH(Me)C(O)N(Me)CH2SiMe2Br was synthesized by the cleavage of the Si–O–Si moiety of the appropriate disiloxane with excess acetyl bromide. The X-ray diffraction study of these compounds and of the previously characterized bromide TsN(Ac)CH{sub 2}C(O)N(Me) CH{sub 2}SiMe{sub 2}Br showed that the Si–O coordination bond lengths in the triflates are 1.7692(14)– 1.8623(14) Å. The interatomic distances between the bromine and silicon atoms are 2.7095(8) and 2.9704(7) Å, which indicates that these bonds are weak. To elucidate the nature of Si…X bonding (X = OTf, Br), the topological analysis of electron density was performed and {sup 29}Si NMR chemical shifts were calculated. The interatomic Si…X interaction in triflate TsN(Me)CH{sub 2}C(O)- N(Me)CH{sub 2}SiMe{sub 2}OTf and bromide TsN(Ac)CH{sub 2}C(O)N(Me)CH{sub 2}SiMe{sub 2}Br is weak. In triflate Ns–Pro–N(Me)CH{sub 2}SiMe{sub 2}OTf and bromide NsNHCH(Me)C(O)N(Me) CH{sub 2} SiMe{sub 2}Br, the Si…X interaction is significantly stronger and corresponds to a weak coordination bond. Hence, the tosylates can be considered as salts, whereas the para-nitrobenzenesulfonyl derivatives are monochelated five-coordinate silicon complexes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Structural-Phase States of Fe–Cu and Fe–Ag Bimetallic Particles Produced by Electric Explosion of Two Wires

X-ray phase analysis, transmission electron microscopy, and X-ray microanalysis were used to examine the structural-phase states of Fe–Cu and Fe–Ag bimetallic nanoparticles. The nanoparticles were obtained by the electric explosion of two twisted metal wires in argon atmosphere. It was demonstrated that the nanoparticles have the structure of Janus particles. Presence of the Janus particle structure in the samples indicates formation of binary melt under conditions of combined electric explosion of two wires. Phases based on supersaturated solid solutions were not found in the examined samples. The data obtained allow arguing that it is possible to achieve uniform mixing of the two-wire explosion products under the described experiment conditions.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2012

Interdiffusion and Intrinsic Diffusion in the Mg-Al System

Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96%) and Al (99.999%). Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were utilized to identify the formation of the intermetallic phases, -Al12Mg17 and -Al3Mg2 and absence of the -phase in the diffusion couples. Thicknesses of the -Al12Mg17 and -Al3Mg2 phases were measured and the parabolic growth constants were calculated to determine the activation energies for the growth, 165 and 86 KJ/mole, respectively. Concentration profiles were determined with electron microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, -Al12Mg17 and - Al3Mg2 and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the -Al3Mg2 phase, followed by -Al12Mg17, Al-solid solution and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann s analysis (e.g., marker plane) were determined for the ~38 at.% Mg in the -Al3Mg2 phase. Activation energies and the pre-exponential factors for the inter- and intrinsic diffusion coefficients were calculated for the temperature range examined. The -Al3Mg2 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the -Al3Mg2 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared to the available self- and impurity diffusion data from literature. Thermodynamic factor, tracer diffusion coefficients and atomic mobilities at the marker plane composition were approximated using available literature values of Mg activity in the -Al3Mg2 phase.

Boltzmann-Matano↗
DOE OSTI2019

Mechanism of Ball Milling Effect on Carbothermic Reduction of Industrial Magnesia by Coke

Mechanical milling always improves the chemical reaction rate in the metallurgy process. The experiment proved that ball milling treatment on raw materials, including industrial magnesia, metallurgical coke, and fluoride calcium, could increase greatly the reaction rate of magnesia. The reaction samples and residues were analyzed by particle size measurement, X-ray diffraction (XRD) analysis, Raman spectroscopy analysis, scanning electron microscope (SEM), and transmission electron microscope (TEM). The results suggested that the positive effect of ball milling on the reaction rate came from three aspects. Ball milling could decrease magnesia particle size and peel coke into graphite sheets to enlarge their contact surface. Meanwhile, ball milling could slightly destroy the crystal grain surface of magnesia and decrease the crystallization of graphite. The nanometer-scale magnesia particles and graphite sheets would stably and strongly attract together after a longer time ball milling. The possible evolution of the particles during ball milling was given, which explained the mechanism of the ball milling effect on the carbothermic reduction of industrial magnesia by coke.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Behavior of Ga, In, Sn, and Te in Copper Matte Smelting

The distributions of Ga, In, Sn, and Te between copper-iron mattes and silica-saturated iron silicate slags over a wide range of matte grades 55 to 75 pct Cu were determined at 1300 °C using a gas-phase equilibration-quenching technique and direct phase composition analysis by Electron Probe X-ray Microanalysis and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry. Alumina from aluminum, a typical minor element of electric and electronic copper scrap, and lime were adopted as slag modifiers for increasing the trace element recoveries. Gallium and tin were distributed predominantly in the slag, indium preferred sulfide matte at low matte grades and slag at high, whereas tellurium strongly favored the sulfide matte in particular in high matte grades. The slag modifiers alumina and lime had a minor impact on the distribution coefficients of gallium and tin, but for indium and tellurium the distribution coefficients were more strongly affected by the basic oxides. The strong tendencies of tin and tellurium to vaporize at the experimental temperature were confirmed.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Formation and Decomposition Process of the Filled Skutterudite Sm{sub y}(Fe{sub x}Ni{sub 1−x}){sub 4}Sb{sub 12} (0.40 ≤ x ≤ 1) as Revealed by Differential Thermal Analysis

Filled skutterudites are among the most promising thermoelectric materials, and the obtainment of monophasic samples is crucial for the study of their transport properties. In this work, a differential thermal analysis study was performed on samples belonging to the Sm{sub y}(Fe{sub x}Ni{sub 1-x}){sub 4}Sb{sub 12} system with the aim to determine the most proper annealing temperature to possibly obtain skutterudite monophasic samples, and to study the effect of Sm addition on the thermodynamics of the Fe-Ni-Sb system. Samples were prepared through the traditional procedure consisting in melting–quenching–annealing the starting elements. DTA analyses were carried out on annealed samples, and results were interpreted using the Fe{sub 25}Sb{sub 75}-Ni{sub 25}Sb{sub 75} pseudobinary phase diagram taken from the literature as a starting point. They reveal that 870 K is the best annealing temperature, being the formation of a liquid phase just above this point; moreover, the Sm introduction results in widening the one-phase skutterudite stability region toward both higher temperatures and higher Fe concentrations compared with the Sm-free system.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Effects of Vanadium on Modification of Iron-Rich Intermetallics and Mechanical Properties in A356 Cast Alloys with 1.5 wt.% Fe

Formation of Fe-rich intermetallics and mechanical properties of vanadium-modified A356 cast alloys with 1.5 wt.% Fe were investigated using image analysis, scanning electron microscopy, differential scanning calorimetry, and a tensile test. The results showed that V content has no apparent influence on α-Al grain size in A356 alloys with high Fe content. Also, 0.8 wt.% V is beneficial for improving mechanical properties in A356 cast alloys with high Fe content. Specifically, these results can be attributed to the formation of Chinese script or block α-Fe phases, refined needle-like β-Fe (Al{sub 5}FeSi), and decreased porosities. An excessive amount of V deteriorates mechanical properties of alloys because it leads to VSi{sub 2} formation, large sized iron-rich intermetallics, and increased porosities.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Effect of Ca and Sm Combined Addition on the Microstructure and Elevated-Temperature Mechanical Properties of Mg-6Al Alloys

In the present study, the microstructure and elevated-temperature mechanical properties of Mg-6Al, Mg-6Al-4Ca, Mg-6Al-4Sm and Mg-6Al-2Ca-2Sm alloys were investigated. The experimental results showed that the microstructure and elevated-temperature mechanical property of Mg-6Al alloy changed obviously with the different elements addition. By analyzing the results of optical microscope, x-ray diffraction analysis, scanning electron microscope, and transmission electron microscope, it could be determined that there was only Mg{sub 17}Al{sub 12} phase in Mg-6Al alloy, there were Al{sub 2}Ca and (Mg, Al){sub 2}Ca phases in Mg-6Al-4Ca alloy, there were Al{sub 2}Sm and Mg{sub 17}Al{sub 12} phases in Mg-6Al-4Sm alloy, and there were (Mg, Al){sub 2}Ca, Al{sub 2}Ca and Al{sub 2}Sm phases in Mg-6Al-2Ca-2Sm alloy. In addition, the addition of alloying elements including Ca and Sm, especially the composite addition, could significantly improve the tensile properties of Mg-6Al alloy. Compared to Mg-6Al alloy, the tensile strengths of Mg-6Al-2Ca-2Sm alloy at 448, 473 and 498 K were enhanced by 50.32, 87.92, and 94.99%, respectively. Furthermore, when the stretching temperatures were 448 and 473 K, the fracture pattern of Mg-6Al-2Ca-2Sm alloy was the mixture of intergranular fracture and trans-crystalline fracture. However, when the stretching temperature was 498 K, the fracture pattern of Mg-6Al-2Ca-2Sm alloy was the intergranular fracture.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Creep Behavior of Friction Stir Processed Haynes 282

Haynes 282 is a nickel-based superalloy designed for use in hot sections of turbines for aircraft and power generation. In these applications, elevated temperature creep performance is critical. To that end, creep behavior of friction stir processed material was carried out to investigate the high-temperature performance of this alloy. Friction stir processing of Haynes 282 was successfully completed, and the processed region was found to be defect-free. Various mechanical property characterization approaches were carried out in post-heat treated condition. Transverse tensile samples repeatedly failed in the base metal indicating 100% joint efficiency. Creep property evaluation was completed at 760 °C and at various stress levels. The creep-rupture lifetime of the processed material was similar to the base metal. Detailed electron microscopy analysis of the failed sample was carried out to understand the microstructural evolution in various locations of the sample during creep.

creep↗
DOE OSTI2018

Effect of Aluminizing on the High-Temperature Oxidation Behavior of an Alumina-Forming Austenitic Stainless Steel

Due to their excellent oxidation resistance and creep resistance at elevated temperatures, alumina forming austenitic (AFA) stainless steels have emerged as potential alloys for high temperature applications. In this study, a Reactive Air Aluminizing (RAA) method was used to aluminize the surface of AFA25 stainless steel. The high temperature oxidation behavior of both as-received and aluminized AFA25 was investigated at 850 °C in dry air. The mass gain per unit area was higher for the aluminized AFA25 than for the as-received material. X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), performed on the oxide scales following the high temperature oxidation tests, confirmed the formation of alumina scale on both as-received and aluminized AFA. However, the aluminized alloy exhibited a thicker alumina scale on the surface, as well as more extensive penetration of the scale into the subsurface region of the alloy.

Rashidi, S.↗
DOE OSTI2015

Shape transformation of bimetallic Au–Pd core–shell nanocubes to multilayered Au–Pd–Au core–shell hexagonal platelets

Transformation of metallic or bimetallic (BM) nanoparticles (NPs) from one shape to another desired shape is of importance to nanoscience and nanotechnology, where new morphologies of NPs lead to enhancement of their exploitable properties. In this report, we present the shape transformation of Au octahedral NPs to Au–Pd core–shell nanocubes, followed by their transformation to nanostars and finally to multilayered Au–Pd–Au core–shell hexagonal platelets in the presence of T30 DNA. The weaker binding affinity of T30 DNA directs the growth to favor the formation of lower energy {111} facets, changing the morphology from nanocubes to nanostar. The nanostars, exhibiting unusual intermediate morphologies, are comprised two sets of shell layers and have Au core, Pd intermediate shell, and Au outer shell. Similarly, the hexagonal platelets, which also have Au core and inner Pd shell, are encased in an external gold shell. As a result, the formation of multilayered Au–Pd–Au core–shell hexagonal platelets from Au–Pd core–shell nanocubes via the multilayered nanostars is monitored using scanning/transmission electron microscopy analysis.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2018

High temperature microstructural stability and recrystallization mechanisms in 14YWT alloys

In-situ neutron diffraction experiments were performed on room temperature compressed 14YWT nanostructured ferritic alloys at 1100°C and 1150°C to understand their thermally activated static recrystallization mechanisms. The existence of high density of Y-Ti-O rich nano-oxides (<5 nm) shift the recrystallization temperature up due to Zener pinning of the grain boundaries, making these materials attractive for high temperature applications. This study serves to quantify the texture evolution in-situ and understand the effect of particles on the recrystallization mechanisms in 14YWT alloys. We have shown, both experimentally and theoretically, that there is considerable recovery in the 20% compressed sample after 6.5 h annealing at 1100°C while recrystallization occurs within an hour of annealing at 1100°C and 1150°C in the 60% compressed samples. Moreover, the 60% compressed samples show {112}<110> and {112}<111> texture components during annealing, in contrast to the conventional recrystallization textures in body centered cubic alloys. Furthermore, nano-oxide size, shape, density and distribution are considerably different in unrecrystallized and abnormally grown grains. Transmission electron microscopy analysis shows that oxide particles having a size between 5 and 30 nm play a critical role for recrystallization mechanisms in 14YWT nanostructured ferritic alloys.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Arsenic attenuation in tailings at a former Cu-W-As mine, SW Finland

Nearly half a century after mine closure, release of As from the Ylöjärvi Cu–W–As mine tailings in groundwater and surface water run-off was observed. Investigations by scanning electron microscopy (SEM), electron microprobe analysis (EMPA), synchrotron-based micro-X-ray diffraction (μ-XRD), micro-X-ray absorption near edge structure (μ-XANES) and micro-extended X-ray absorption fine structure (μ-EXAFS) spectroscopy, and a sequential extraction procedure were performed to assess As attenuation mechanisms in the vadose zone of this tailings deposit. Results of SEM, EMPA, and sequential extractions indicated that the precipitation of As bearing Fe(III) (oxy)hydroxides (up to 18.4 wt.% As 2 O 5 ) and Fe(III) arsenates were important secondary controls on As mobility. The μ-XRD, μ-XANES and μ-EXAFS analyses suggested that these phases correspond to poorly crystalline and disordered As-bearing precipitates, including arsenical ferrihydrite, scorodite, kankite, and hydrous ferric arsenate (HFA). The pH within 200 cm of the tailings surface averaged 5.7, conditions which favor the precipitation of ferrihydrite. Poorly crystalline Fe(III) arsenates are potentially unstable over time, and their transformation to ferrihydrite, which contributes to As uptake, has potential to increase the As adsorption capacity of the tailings. Arsenic mobility in tailings pore water at the Ylöjärvi mine will depend on continued arsenopyrite oxidation, dissolution or transformation of secondary Fe(III) arsenates, and the As adsorption capacity of Fe(III) (oxy)hydroxides within this tailings deposit

Parviainen, Annika↗
DOE OSTI2016

Source and distribution of naturally occurring arsenic in groundwater from Alberta’s Southern Oil Sands Regions

Arsenic (As) concentrations as high as 179 μg/L have been observed in shallow groundwater in the Alberta’s Southern Oil Sand Regions. The geology of this area of Alberta includes a thick cover (up to 200 m) of unconsolidated glacial deposits, with a number of regional interglacial sand and gravel aquifers, underlain by marine shale. Arsenic concentrations observed in 216 unconsolidated sediment samples ranged from 1 and 17 ppm. A survey of over 800 water wells sampled for As in the area found that 50% of the wells contained As concentrations exceeding drinking water guidelines of 10 μg/L. Higher As concentrations in groundwater were associated with reducing conditions. Measurements of As speciation from 175 groundwater samples indicate that As(III) was the dominant species in 74% of the wells. Speciation model calculations showed that the majority of groundwater samples were undersaturated with respect to ferrihydrite, suggesting that reductive dissolution of Fe-oxyhydroxides may be the source of some As in groundwater. Detailed mineralogical characterization of sediment samples collected from two formations revealed the presence of fresh framboidal pyrite in the deeper unoxidized sediments. Electron microprobe analysis employing wavelength dispersive spectrometry indicated that the framboidal pyrite had variable As content with an average As concentration of 530 ppm, reaching up to 1840 ppm. In contrast, the oxidized sediments did not contain framboidal pyrite, but exhibited spheroidal Fe-oxyhydroxide grains with elevated As concentrations. The habit and composition suggest that these Fe-oxyhydroxide grains in the oxidized sediment were an alteration product of former framboidal pyrite grains. X-ray absorption near edge spectroscopy (XANES) indicated that the oxidized sediments are dominated by As(V) species having spectral features similar to those of goethite or ferrihydrite with adsorbed As, suggesting that Fe-oxyhydroxides are the dominant As carriers. XANES spectra collected on unoxidized sediment samples, in contrast, indicated the presence of a reduced As species (As(-I)) characteristic of arsenopyrite and arsenian pyrite. The results of the mineralogical analyses indicate that the oxidation of framboidal pyrite during weathering may be the source of As released to shallow aquifers in this region.

58 GEOSCIENCES↗
DOE OSTI2025

Carbon nanotube coated metal mesh: Bridging nanoscale and macroscale

A novel hybrid structure has been developed by growing carbon nanotubes (CNTs) on a metal mesh that functions as a literally unlimitedly extendable backbone. This hybrid material structure provides a new approach of extending CNTs’ advantageous properties such as ultrahigh thermal and electrical conductivities, high sensitivity to gases, and distinctive wettability for different liquids with chemical inertness to macroscale—otherwise available only in nano- and microscales. In this feasibility work, CNTs were grown on a Type 316 stainless steel (SS) mesh by self-catalytical chemical vapor deposition (CVD) without the need of an externally added catalyst or catalyst support. For the radially aligned and entangled CNT forest on the SS mesh, the average CNT diameter is around 50 nm, while the length varies from 20 to 25 µm. High-resolution transmission electron microscopy analysis revealed the multiwall structure of the CNTs with >30 rolled-up graphitic sheets. Raman spectra of the CNTs showed a dominant G band, indicating a well-ordered graphitic nanostructure. Being highly hydrophobic with a water contact angle of ∼145° and oleophilic, the CNT-coated SS mesh could be used in fluid separation and organic contaminant removal from water. Moreover, CNTs are recognized for their exceptional thermal conductivity and the CNT-coated mesh offers a supportive structure with directly connected CNTs for efficient heat transfer. Proof of concept has been achieved for the CNT-coated mesh’s potentials as a liquid filter and an thermal interface material (TIM). Specifically, the CNT-coated mesh demonstrated the capability of capturing water from a water-organic mixture with a 100 % efficiency while allowing organic liquids to pass through the filter. Furthermore, when used as a TIM, the CNT-coated mesh reduced the interfacial thermal impedance by >30 %.

Carbon nanotubes (CNTS)↗
DOE OSTI2012

Influence of heart failure on nucleolar organization and protein expression in human hearts

Highlights: Black-Right-Pointing-Pointer Heart failure alters nucleolar morphology and organization. Black-Right-Pointing-Pointer Nucleolin expression is significant increased in ischemic and dilated cardiomyopathy. Black-Right-Pointing-Pointer Ventricular function of heart failure patients was related with nucleolin levels. -- Abstract: We investigate for the first time the influence of heart failure (HF) on nucleolar organization and proteins in patients with ischemic (ICM) or dilated cardiomyopathy (DCM). A total of 71 human hearts from ICM (n = 38) and DCM (n = 27) patients, undergoing heart transplantation and control donors (n = 6), were analysed by western-blotting, RT-PCR and cell biology methods. When we compared protein levels according to HF etiology, nucleolin was increased in both ICM (117%, p < 0.05) and DCM (141%, p < 0.01). Moreover, mRNA expression were also upregulated in ICM (1.46-fold, p < 0.05) and DCM (1.70-fold, p < 0.05. Immunofluorescence studies showed that the highest intensity of nucleolin was into nucleolus (p < 0.0001), and it was increased in pathological hearts (p < 0.0001). Ultrastructure analysis by electron microscopy showed an increase in the nucleus and nucleolus size in ICM (17%, p < 0.05 and 131%, p < 0.001) and DCM (56%, p < 0.01 and 69%, p < 0.01). Nucleolar organization was influenced by HF irrespective of etiology, increasing fibrillar centers (p < 0.001), perinucleolar chromatin (p < 0.01) and dense fibrillar components (p < 0.01). Finally, left ventricular function parameters were related with nucleolin levels in ischemic hearts (p < 0.0001). The present study demonstrates that HF influences on morphology and organization of nucleolar components, revealing changes in the expression and in the levels of nucleolin protein.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Effect of nanostructured carbon support on copper electrocatalytic activity toward CO 2 electroreduction to hydrocarbon fuels

The effect of support on electrocatalytic activity of Cu nanoparticles (NPs) towards CO 2 electroreduction to hydrocarbon fuels (CH 4 and C 2 H 4 ) is investigated for three types of nanostructured carbons: single wall carbon nanotubes (SWNT), graphene (GP) and onion-like carbon (OLC). Cu/SWNT, Cu/GP and Cu/OLC composite catalysts are synthesized and characterized by X-Ray diffraction analysis, transmission electron microscopy and electrochemical surface area measurements. Electrocatalytic activities of the synthesized materials, as measured in an electrochemical cell connected to a gas chromatograph, are compared to that of Cu NPs supported on Vulcan carbon. All four catalysts demonstrate higher activity towards C 2 H 4 generation vs CH 4 , with production of the latter mostly suppressed on Cu NPs supported on nanostructured substrates. Onset potentials for C 2 H 4 vs CH 4 generation are shifted positively by 200 mV for Cu/SWNT, Cu/GP, and Cu/OLC catalysts. The Cu/OLC catalyst is found to be superior to the other two nanostructured catalysts in terms of stability, activity and selectivity towards C 2 H 4 generation. Its faradaic efficiency reached 60% at -1.8 V vs Ag/AgCl. The enhanced activity and stability of Cu/OLC catalyst can be attributed to the unique catalyst design, wherein a shell of OLC surrounds the Cu NPs such that the outer layer acts as a filter that protects the Cu surface from adsorption of undesirable species, enhances its electrocatalytic performance, and improves its viability in CO 2 electroreduction reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗