CHARMM-GUI Supports Hydrogen Mass Repartitioning and Different Protonation States of Phosphates in Lipopolysaccharides

We took advantage of the ESO UVES/VLT archive of quasar spectra to build a homogeneous sample of ‘sub-DLAs’, absorption line systems with HI column densities between 1019 and 2×1020 cm−2. According to Péroux et al. (2002), these systems should contain a major fraction of the neutral hydrogen mass at z > 3.5 and may thus play an important role at high redshift. Twelve sub-DLAs have been identified. We performed a detailed chemical analysis, and addressed the issues of photoionization corrections. We obtained the first sub-DLA chemical abundance data base ideal for the study of a number of interesting properties of these systems. The implication of sub-DLAs in the cosmic metallicity evolution was our main concern. We also undertook a detailed comparison of the sub-DLA chemical properties with the well studied DLAs to see whether the sub-DLAs are associated with a different class of objects.

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Hydrogen mass transport resistance changes in a high temperature polymer membrane fuel cell as a function of current density and acid doping

Electrochimica Acta ◽

10.1016/j.electacta.2019.06.021 ◽

2019 ◽

Vol 317 ◽

pp. 521-527 ◽

Cited By ~ 6

Author(s):

Sobi Thomas ◽

Samuel Simon Araya ◽

Steffen Henrik Frensch ◽

Thomas Steenberg ◽

Søren Knudsen Kær

Keyword(s):

High Temperature ◽

Fuel Cell ◽

Mass Transport ◽

Current Density ◽

Polymer Membrane ◽

Hydrogen Mass

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A Bayesian approach to matching thermonuclear X-ray burst observations with models

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2638 ◽

2019 ◽

Vol 490 (2) ◽

pp. 2228-2240 ◽

Cited By ~ 7

Author(s):

A J Goodwin ◽

D K Galloway ◽

A Heger ◽

A Cumming ◽

Z Johnston

Keyword(s):

Neutron Star ◽

Rotation Axis ◽

Line Of Sight ◽

Type I ◽

X Ray ◽

Star Mass ◽

Disc Model ◽

Neutron Star Mass ◽

Hydrogen Mass ◽

Neutron Star Radius

ABSTRACT We present a new method of matching observations of Type-I (thermonuclear) X-ray bursts with models, comparing the predictions of a semi-analytic ignition model with X-ray observations of the accretion-powered millisecond pulsar SAX J1808.4–3658 in outburst. We used a Bayesian analysis approach to marginalize over the parameters of interest and determine parameters such as fuel composition, distance/anisotropy factors, neutron star mass, and neutron star radius. Our study includes a treatment of the system inclination effects, inferring that the rotation axis of the system is inclined $\left(69^{+4}_{-2}\right)^\circ$ from the observers line of sight, assuming a flat disc model. This method can be applied to any accreting source that exhibits Type-I X-ray bursts. We find a hydrogen mass fraction of $0.57^{+0.13}_{-0.14}$ and CNO metallicity of $0.013^{+0.006}_{-0.004}$ for the accreted fuel is required by the model to match the observed burst energies, for a distance to the source of $3.3^{+0.3}_{-0.2}\, \mathrm{kpc}$. We infer a neutron star mass of $1.5^{+0.6}_{-0.3}\, \mathrm{M}_{\odot }$ and radius of $11.8^{+1.3}_{-0.9}\, \mathrm{km}$ for a surface gravity of $1.9^{+0.7}_{-0.4}\times 10^{14}\, \mathrm{cm}\, \mathrm{s}^{-2}$ for SAX J1808.4–3658.

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High Throughput Screening and Characterization Methods of Jordanian Oil Shale as a Case Study

Energies ◽

10.3390/en12163148 ◽

2019 ◽

Vol 12 (16) ◽

pp. 3148 ◽

Cited By ~ 3

Author(s):

Ziad Abu El-Rub ◽

Joanna Kujawa ◽

Esra’a Albarahmieh ◽

Nafisah Al-Rifai ◽

Fathieh Qaimari ◽

...

Keyword(s):

High Throughput Screening ◽

Oil Shale ◽

Analytical Techniques ◽

Economic Feasibility ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Characterization Methods ◽

X Ray ◽

Hydrogen Mass

Oil shale is an important possible solution to the problem of energy in Jordan. To explore the technical and the economic feasibility of oil shale deposits, numerous samples are analyzed using the standard Fischer Assay (FA) method. However, it would be useful to develop faster, cheaper, and reliable methods for determining the oil content of oil shale. Therefore, the aim of this work was to propose and investigate rapid analytical techniques for the screening of oil shale deposits and to correlate them with the FA method. The Omari deposit located east of Jordan was selected as a case study for analysis using thermogravimetric analysis (TGA) coupled with Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), elemental analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. Results obtained from the TGA method were linearly correlated with FA with high regression factor (R2 = 0.99); a quadratic correlation (R2 = 0.98) was maintained between the FA and the elemental hydrogen mass content, and a quadratic correlation (R2 = 0.97) was found between the FA and the aliphatic hydrocarbons (FTIR peak at 2927 cm−1) produced in the pyrolysis zone. Although other techniques were less correlated, further investigation might lead to better results. Subsequently, these correlated techniques can be a practical alternative to the conventional FA method when, in particular, specific correlation is made for each deposit.

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