34 research outputs found
Multiscale investigation of adsorption properties of novel 3D printed UTSA-16 structures
Structuring MOF materials is a fundamental step towards their commercialization. Herein we report intensive characterization of 3D-printed UTSA-16 monoliths, facilitated by the development of a new non-aqueous ink formulation, employing hydroxypropyl cellulose and boehmite to adjust the rheology of the ink. What makes this formulation and printing process different from the printed adsorbents and catalysts published previously, is that the resulting structures in this work were not sintered. The presence of the binder matrix not only produced the physical properties for printability but also ensured a homogeneous dispersion of UTSA-16 in the structures, as well as gas adsorption characteristics. The monoliths were tested for the adsorption of different gases (N2, CH4, CO2 and H2O) in order to apply them into separation processes that contribute to defossilizing energy and fuels production. Water is strongly adsorbed in this material (~14 mol/kg at 293 K) and is competing with CO2 for adsorption sites. Breakthrough curves showed that the retention time of CO2 decreases significantly when the feed stream is saturated with water. In this study, synchrotron XRD-CT data were collected in situ, in a non-destructive way, and phase distribution maps were reconstructed to, for the first time, gain insight into the spatial and temporal evolution of the UTSA-16 containing phases in the operating 3D printed monolith during the exposure to CO2.publishedVersio
Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus
A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 Ă 10-20), ER-negative BC (P=1.1 Ă 10-13), BRCA1-associated BC (P=7.7 Ă 10-16) and triple negative BC (P-diff=2 Ă 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 Ă 10-3) and ABHD8 (P<2 Ă 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3â˛-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk
A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers
Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10â8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers
Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at âs=0.9 and 2.36 TeV
Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at root s = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(ch)/d eta vertical bar(vertical bar eta vertical bar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date
Real-Time Scattering-Contrast Imaging of a Supported Cobalt-Based Catalyst Body during Activation and Fischer-Tropsch Synthesis Revealing Spatial Dependence of Particle Size and Phase on Catalytic Properties
A combination of time-resolved synchrotron Îź-X-ray diffraction computed tomography (Îź-XRD-CT) and Îź-pair distribution function computed tomography (Îź-PDF-CT) has been applied for the study of an individual Co/Îł-Al2O3 catalyst pellet during reduction and the early stages of the FischerâTropsch synthesis (FTS) reaction, revealing insight into the solid-state changes occurring from within such crystalline materials. Both sets of data were of sufficient quality so as to be able to follow the spatial dependency of Co speciation evolution from Co3O4 to CoO to face-centered cubic (fcc) Co metal nanoparticles. These data revealed the samples to be highly heterogeneous and contain two types of Co species: small (â¤6.5 nm) nanoparticles that interact strongly with the Îł-Al2O3 support which are difficult to reduce (remaining as CoO) and nanoparticles that agglomerate and have little interaction or else are weakly interacting with the support but readily reduce in H2. The Co phase evolution under FTS conditions shows a strong dependence on the Co nanoparticle location; the complementarity between the observations made using Îź-XRD-CT vs Îź-PDF-CT allowed us to conclude that at the sample periphery a significant amount of agglomerated, weakly interacting with the support, small fcc Co metal nanoparticles (â¤7.5 nm) oxidize to CoO/Co3O4 during FTS, most likely due to the presence of water vapor produced during the reaction. Catalytic tests demonstrated that this oxidation coincided with a decrease in CH4 selectivity and increased water-gas shift (WGS) activity. This oxidation of fcc Co nanoparticles (i.e., the removal of the contribution to the XRD signal) also explains the observation of sintering previously reported for such catalysts in the early stages of the FTS reaction
A multi-scale study of 3D printed Co-Al2O3 catalyst monoliths versus spheres
This study demonstrates the characteristics of two model packing configurations: 3D printed (3DP) catalyst monoliths on the one hand, and their conventional counterparts, packed beds of spheres, on the other. Cobalt deposited on alumina is selected as a convenient model system for this work, due to its wide spread use in many catalytic reactions. 3DP constructs were produced from alumina powder impregnated with cobalt nitrate while the alumina spheres were directly impregnated with the same cobalt nitrate precursor. The form of the catalyst, the impregnation process, as well as the thermal history, were found to have a significant effect on the resulting cobalt phases. Probing the catalyst bodies in situ by XRD-CT indicated that the level of dispersion of identified Co phases (Co3O4 reduced to CoO) across the support is maintained under reduction conditions. The packed bed of spheres exhibits a non-uniform distribution of cobalt phases, including a core-shell morphology with an average crystallite size of 10â14Â nm across the sphere, while the 3DP monolith exhibits a uniform distribution of cobalt phases with an average crystallite size of 5â12Â nm upon reduction from Co3O4 to CoO. Computational Fluid Dynamics (CFD) modelling was carried out to develop digital twins and assess the effect of the geometry of both configurations on the pressure drop and velocity profiles. Finally, the activity of both Cobalt-based catalyst geometries was assessed in terms of their conversion, selectivity and turn over frequencies under model multiphase (selective oxidation) reaction conditions, which showed that the desired 3D printed monolithic geometries can offer distinct advantages to the reactor design
Multiscale investigation of adsorption properties of novel 3D printed UTSA-16 structures
Structuring MOF materials is a fundamental step towards their commercialization. Herein we report intensive characterization of 3D-printed UTSA-16 monoliths, facilitated by the development of a new non-aqueous ink formulation, employing hydroxypropyl cellulose and boehmite to adjust the rheology of the ink. What makes this formulation and printing process different from the printed adsorbents and catalysts published previously, is that the resulting structures in this work were not sintered. The presence of the binder matrix not only produced the physical properties for printability but also ensured a homogeneous dispersion of UTSA-16 in the structures, as well as gas adsorption characteristics. The monoliths were tested for the adsorption of different gases (N2, CH4, CO2 and H2O) in order to apply them into separation processes that contribute to defossilizing energy and fuels production. Water is strongly adsorbed in this material (~14 mol/kg at 293 K) and is competing with CO2 for adsorption sites. Breakthrough curves showed that the retention time of CO2 decreases significantly when the feed stream is saturated with water. In this study, synchrotron XRD-CT data were collected in situ, in a non-destructive way, and phase distribution maps were reconstructed to, for the first time, gain insight into the spatial and temporal evolution of the UTSA-16 containing phases in the operating 3D printed monolith during the exposure to CO2
Emerging chemical heterogeneities in a commercial 18650 Li-ion battery during early cycling
Synchrotron X-ray diffraction computed tomography (XRD-CT) was employed to study a commercial 18650 cylindrical LiNi0.8Co0.15Al0.5O2 (NCA) battery under operating conditions and during seven cycles. Multiple chemical heterogeneities related to the lithium distribution were observed in both the cathode and the anode from the analysis of the spatially-resolved diffraction signals. It is shown that during the battery charging, the anode exhibits different degrees of activity regarding the lithiation process. Explicitly, the following three regions were identified: uniform/homogenous lithiation, delayed lithiation and inactive-to-lithiation regions. The inactive-to-lithiation anode region was a result of the specific cell geometry (i.e. due to lack of cathode tape opposite these anode areas) and throughout the cycling experiments remained present in the form of LiC30-30+. The delayed lithiation region was seen to have a direct impact on the properties of NCA in its close proximity during the battery discharging, preventing its full lithiation. Further to this, the aluminum tab negatively affected the NCA in direct contact with it, leading to different lattice parameter a and c evolution compared to the rest of the cathode
Operando and Postreaction Diffraction Imaging of the La-Sr/CaO Catalyst in the Oxidative Coupling of Methane Reaction
A LaâSr/CaO catalyst was studied operando
during the oxidative coupling of methane (OCM) reaction
using the X-ray diffraction computed tomography technique.
Full-pattern Rietveld analysis was performed in order to track
the evolving solid-state chemistry during the temperature ramp,
OCM reaction, as well as after cooling to room temperature.
We observed a uniform distribution of the catalyst main
components: La2O3, CaOâSrO mixed oxide, and the hightemperature rhombohedral polymorph of SrCO3. These were
stable initially in the reaction; however, doubling the gas hourly
space velocity resulted in the decomposition of SrCO3 to SrO,
which subsequently led to the formation of a second CaOâSrO
mixed oxide. These two mixed CaOâSrO oxides differed in
terms of the extent of Sr incorporation into their unit cell. By applying Vegardâs law during the Rietveld refinement, it was
possible to create maps showing the spatial variation of Sr occupancy in the mixed CaOâSrO oxides. The formation of the Srdoped CaO species is expected to have an important role in this system through the enhancement of the lattice oxygen diffusion
as well as increased catalyst basicity