Marilyn Morgan Olmstead (1943–2020) Roy, Mrittika; Balch, Alan L.; Carey, Janis M. ...
Journal of applied crystallography,
December 2020, 2020-12-01, 20201201, Letnik:
53, Številka:
6
Journal Article
ABSTRACT An initial three-station version of the Event Horizon Telescope, a millimeter-wavelength very-long baseline interferometer, has observed Sagittarius A* (Sgr A*) repeatedly from 2007 to 2013, ...resulting in the measurement of a variety of interferometric quantities. Of particular importance is that there is now a large set of closure phases measured over a number of independent observing epochs. We analyze these observations within the context of a realization of semi-analytic radiatively inefficient disk models, implicated by the low luminosity of Sgr A*. We find a broad consistency among the various observing epochs and between different interferometric data types, with the latter providing significant support for this class of model of Sgr A*. The new data significantly tighten existing constraints on the spin magnitude and its orientation within this model context, finding a spin magnitude of a = 0.10 − 0.10 − 0.10 + 0.30 + 0.56 , an inclination with respect to the line of sight of θ = 60 ° − 8 ° − 13 ° + 5 ° + 10 ° , and a position angle of = 156 ° − 17 ° − 27 ° + 10 ° + 14 ° east of north. These are in good agreement with previous analyses. Notably, the previous 180° degeneracy in the position angle has now been conclusively broken by the inclusion of the closure-phase measurements. A reflection degeneracy in the inclination remains, permitting two localizations of the spin vector orientation, one of which is in agreement with the orbital angular momentum of the infrared gas cloud G2 and the clockwise disk of young stars. This may support a relationship between Sgr A*'s accretion flow and these larger-scale features.
•Separation and analysis of maceral groups of 5 Victorian brown coal were studied.•The yields of float fraction correlated to the aliphaticities of the coals.•Liptinite-rich float fraction had higher ...proportions of aliphatics & triterpenoids.•Vitrinite-rich sink fraction had a higher proportion of aromatics.•Pyrolysis temperature significantly affected the product distribution.
Four selectively mined lithotypes and a run-of-mine coal (ROM) have been obtained from the Yallourn coal seam in the La Trobe Valley, Victoria, Australia and a partial maceral separation of each of them has been carried out using the sink-float method with centrifugal force on a laboratory scale. The yields of liptinite-rich float fractions were between 22.5 and 2.8 wt% in the order of Pale > Light > Med-light ≈ ROM > Dark. Elemental analysis and FTIR showed that the liptinite-rich float fractions had higher H/C ratios and aliphaticities than the corresponding vitrinite-rich sink fractions and this was confirmed by solid state 13C NMR. Pyrolysis-GC-MS using a pyrolysis temperature of 650 °C showed little difference in the distribution of aliphatic peaks but dramatic changes in the relative abundance of triterpenoids between lithotypes and in some cases between float and sink fractions of a lithotype. Variations in yields with pyrolysis temperature suggested that the triterpenoids are loosely bound to the main coal structure.
High-pressure processing (HPP) is a nonthermal process capable of inactivating and eliminating pathogenic and food spoilage microorganisms. This novel technology has enormous potential in the food ...industry, controlling food spoilage, improving food safety and extending product shelf life while retaining the characteristics of fresh, preservative-free, minimally processed foods. As with other food processing methods, such as thermal processing, HPP has somewhat limited applications as it cannot be universally applied to all food types, such as some dairy and animal products and shelf-stable low-acid foods. Herein, we discuss the effects of high-pressure processing on microbial food safety and, to a lesser degree, food quality.
Peanut allergy (PA) is a complex disease with both environmental and genetic risk factors. Previously, PA loci were identified in filaggrin (FLG) and HLA in candidate gene studies, and loci in HLA ...were identified in a genome-wide association study and meta-analysis.
We sought to investigate genetic susceptibility to PA.
Eight hundred fifty cases and 926 hyper-control subjects and more than 7.8 million genotyped and imputed single nucleotide polymorphisms (SNPs) were analyzed in a genome-wide association study to identify susceptibility variants for PA in the Canadian population. A meta-analysis of 2 phenotypes (PA and food allergy) was conducted by using 7 studies from the Canadian, American (n = 2), Australian, German, and Dutch (n = 2) populations.
An SNP near integrin α6 (ITGA6) reached genome-wide significance with PA (P = 1.80 × 10−8), whereas SNPs associated with Src kinase–associated phosphoprotein 1 (SKAP1), matrix metallopeptidase 12 (MMP12)/MMP13, catenin α3 (CTNNA3), rho GTPase–activating protein 24 (ARHGAP24), angiopoietin 4 (ANGPT4), chromosome 11 open reading frame (C11orf30/EMSY), and exocyst complex component 4 (EXOC4) reached a threshold suggestive of association (P ≤ 1.49 × 10−6). In the meta-analysis of PA, loci in or near ITGA6, ANGPT4, MMP12/MMP13, C11orf30, and EXOC4 were significant (P ≤ 1.49 × 10−6). When a phenotype of any food allergy was used for meta-analysis, the C11orf30 locus reached genome-wide significance (P = 7.50 × 10−11), whereas SNPs associated with ITGA6, ANGPT4, MMP12/MMP13, and EXOC4 and additional C11orf30 SNPs were suggestive (P ≤ 1.49 × 10−6). Functional annotation indicated that SKAP1 regulates expression of CBX1, which colocalizes with the EMSY protein coded by C11orf30.
This study identifies multiple novel loci as risk factors for PA and food allergy and establishes C11orf30 as a risk locus for both PA and food allergy. Multiple genes (C11orf30/EMSY, SKAP1, and CTNNA3) identified by this study are involved in epigenetic regulation of gene expression.
•Hot briquetting and air curing caused significant increase in compressive strength.•Hot briquetting reduced the reactivity.•High carbonization temperature reduced reactivity and surface area.•The ...proportion of graphitic structure remained small.•Compressive strength and reactivity remained higher than those of a typical BF coke.
Attempts have been made to obtain a substitute for blast furnace (BF) coke from a Victorian brown coal mixed with a tar derived from brown coal under conditions sufficiently mild to be economical. Changes to the procedure used in a previous attempt include hot briquetting of the coal–tar mixture at 150°C rather than ambient, the addition of air curing at 200°C and carbonization at higher temperature, 1200°C, rather than 900–950°C. All these changes led to a decrease in reactivity and increase in compressive strength. In addition, the higher carbonization temperature led to a decrease in surface area. Thus the combined changes led to an increase in strength and decrease in reactivity and surface area. This is the first time a carbonized product has been prepared from brown coal in good yield and of lower reactivity than brown coal char when compared with BF coke. However, the reactivity and surface area remain too high for the product to be used as a substitute for BF coke.
Direct synthesis of diamine radical cations in crystalline form proceeding through oxidation of triphenylamine followed by the formation of a new C−N bond is reported. Although the oxidative coupling ...of triphenylamine is well studied, diamine products are rarely captured in their radical cation state. The neutral diamine most frequently obtained from this reaction pathway is N,N,N’,N’‐tetraphenylbenzidine. Herein, the capture of radical cations of diamines in crystalline form in one step starting with neutral triphenylamine was demonstrated, and the formation of two products (the radical cations of N,N,N′,N′‐tetraphenyl‐1,4‐benzenediamine or N,N,N′,N′‐tetraphenylbenzidine) depending on the oxidizing agent used was observed. The radical species are characterized by single‐crystal X‐Ray diffraction, electron paramagnetic resonance spectroscopy, and optical spectroscopy.
The direct synthesis of diamine radical cations in crystalline form produced through oxidation of triphenylamine followed by the formation of either a C−N or a C‐C bond is reported. Although the oxidative coupling of triphenylamine is well studied, diamine products are rarely captured in their radical cation state. The neutral diamine most frequently obtained from this reaction pathway is N,N,N’,N’‐tetraphenylbenzidine. Herein, the capture of radical cations of diamines in crystalline form in one step starting with neutral triphenylamine was demonstrated, and the formation of two products (the radical cations of N,N,N′,N′‐tetraphenyl‐1,4‐benzenediamine or N,N,N′,N′‐tetraphenylbenzidine) depending on the oxidizing agent used was observed.
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•Novel extraction of oil from a Jordanian oil shale using supercritical propane with a co-solvent.•High oil yields achieved at very low temperature.•Above the critical temperature of ...propane (100 °C), higher yields obtained at high pressure.•The oil had more oxygen and less sulfur than high-temperature oil.•Oil was easily hydrogenated to reduce sulfur and oxygen contents dramatically.
The only method currently used for producing oil from oil shale is high temperature retorting, which is wasteful of energy and gives oil with a high content of heavy oil. The novel method of extraction used in this study, involving supercritical propane with tetrahydrofuran as a co-solvent, solves the problem of the high cost of producing oil by conventional high temperature retorting. El-Lajjun oil shale from Jordan was used to evaluate the reaction yield and the characteristics of the product. At supercritical propane temperature and pressure (100 °C and 4.3 MPa), the yield was high and comparable to that for the conventional retorting method (>350 °C). As the temperature increased to 200 °C, the oil yield increased with pressure. The oil obtained was high in aliphatic hydrocarbons but with significant amounts of ethers, some carbonyls and sulfur-oxygen compounds. Hydrodeoxygenation and hydrodesulfurization of the produced oils using NiMo-Al-SBA-15 catalysts significantly enhanced the quality of the oil by decreasing the oxygen and sulfur contents and increasing the aliphatic and diesel fractions.
This work leads to an enduring breakthrough technology that substantially reduces costs, waste, energy and the environmental impact of using oil shale as a raw material for liquid fuel production using Green Technology. Recovery of THF is high (>95%) and re-use of THF and propane would be essential for commercial application.
This investigation presents a systematic examination of the late transition metal octaethylporphyrins MII(OEP) with M = Co, Ni, Cu, and Zn as cocrystallization agents for C60. In each case, the ...fullerene was dissolved in benzene and then layered over an equimolar dichloromethane solution of the porphyrin. A striking new columnar structural type for these systems is found for CoII(OEP) and ZnII(OEP) with stoichiometric ratios 6:5 for porphyrin/fullerene. In these cocrystals, one fullerene is surrounded by two porphyrins, one is adjacent to only one porphyrin, while one makes no contact with a porphyrin; yet, all three fullerenes are ordered at 90 K. A more typical, also new, 1:1 structure with CuII(OEP) and C60 shows back-to-back porphyrins with all eight ethyl groups embracing the fullerene. In these three structures only dichloromethane is found as the solvate. The NiII(OEP) structure is related to the known structure of NiII(OEP)·C60·2C6H6 but has incorporated ca. 5% dichloromethane. In these NiII(OEP)/C60 cocrystals, four of the ethyl groups embrace the fullerene, while the other four are displaced to the opposite side of the porphyrin plane where they do not make contact with a fullerene. The porphyrin core conformations of the different metal derivatives also differ, and their possible impact on cocrystal formation is discussed.
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