Derivation of Instrument Requirements for Polarimetry using Mg, Fe, and Mn lines between 250 and 290 nm

Judge et al. (2021) recently argued that a region of the solar spectrum in the near-UV between about 250 and 290 nm is optimal for studying magnetism in the solar chromosphere due to an abundance of Mg II, Fe II, and Fe I lines that sample various heights in the solar atmosphere. In this paper we derive requirements for spectropolarimetric instruments to observe these lines. We derive a relationship between the desired sensitivity to magnetic field and the signal-to-noise of the measurement from the weak-field approximation of the Zeeman effect. We find that many lines will exhibit observable polarization signals for both longitudinal and transverse magnetic field with reasonable amplitudes

The R-Process Alliance: Chemical Abundances for a Trio of R-Process-Enhanced Stars -- One Strong, One Moderate, One Mild

We present detailed chemical abundances of three new bright (V ~ 11), extremely metal-poor ([Fe/H] ~ -3.0), r-process-enhanced halo red giants based on high-resolution, high-S/N Magellan/MIKE spectra. We measured abundances for 20-25 neutron-capture elements in each of our stars. J1432-4125 is among the most r-process rich r-II stars, with [Eu/Fe]= +1.44+-0.11. J2005-3057 is an r-I star with [Eu/Fe] = +0.94+-0.07. J0858-0809 has [Eu/Fe] = +0.23+-0.05 and exhibits a carbon abundance corrected for evolutionary status of [C/Fe]_corr = +0.76, thus adding to the small number of known carbon-enhanced r-process stars. All three stars show remarkable agreement with the scaled solar r-process pattern for elements above Ba, consistent with enrichment of the birth gas cloud by a neutron star merger. The abundances for Sr, Y, and Zr, however, deviate from the scaled solar pattern. This indicates that more than one distinct r-process site might be responsible for the observed neutron-capture element abundance pattern. Thorium was detected in J1432-4125 and J2005-3057. Age estimates for J1432-4125 and J2005-3057 were adopted from one of two sets of initial production ratios each by assuming the stars are old. This yielded individual ages of 12+-6 Gyr and 10+-6 Gyr, respectively.Comment: 30 pages, includes a long table, 5 figure

Uranium Abundances and Ages of RR-process Enhanced Stars with Novel U II Lines

The ages of the oldest stars shed light on the birth, chemical enrichment, and chemical evolution of the Universe. Nucleocosmochronometry provides an avenue to determining the ages of these stars independent from stellar evolution models. The uranium abundance, which can be determined for metal-poor $r$-process enhanced (RPE) stars, has been known to constitute one of the most robust chronometers known. So far, U abundance determination has used a $single$ U II line at $\lambda3859$ \r{A}. Consequently, U abundance has been reliably determined for only five RPE stars. Here, we present the first homogeneous U abundance analysis of four RPE stars using two novel U II lines at $\lambda4050$ \r{A} and $\lambda4090$ \r{A}, in addition to the canonical $\lambda3859$ \r{A} line. We find that the U II lines at $\lambda4050$ \r{A} and $\lambda4090$ \r{A} are reliable and render U abundances in agreement with the $\lambda3859$ U abundance, for all the stars. We, thus, determine revised U abundances for RPE stars, 2MASS J09544277+5246414, RAVE J203843.2-002333, HE 1523-0901, and CS 31082-001, using multiple U II lines. We also provide nucleocosmochronometric ages of these stars based on the newly derived U, Th, and Eu abundances. The results of this study open up a new avenue to reliably and homogeneously determine U abundance for a significantly larger number of RPE stars. This will, in turn, enable robust constraints on the nucleocosmochronometric ages of RPE stars, which can be applied to understand the chemical enrichment and evolution in the early Universe, especially of $r$-process elements.Comment: Resubmitted to Ap

Valorisation of plastic waste from the beverage industry through its transformation into adsorbent and solid fuel materials

In the present study, char and activated carbon (AC) materials were prepared from water bottles, recuperated from the waste collection point in Mourouj, Ben Arous, Tunisia, by using a rotative horizontal tubular furnace, on a lab/pilot scale and through chemical and physical activation. Different samples were characterized by $\text{N}_2$ adsorption isotherms, SEM-EDX, XRD, EA as well as by the determination of the $\text{pH}_{\mathrm{zpc}}$. The efficiency of the ACs to remove (2-methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetic acid (2,4-D)) herbicides from aqueous solutions was also investigated. The results demonstrated that a maximum adsorption capacity of $192~\text{mg}{\cdot }\text{g}^{-1}$, for MCPA, and $290~\text{mg}{\cdot }\text{g}^{-1}$ for 2,4-D had been attained. The adsorption kinetics was fitted to pseudo first, second order and Elovich model, while the adsorption isotherms were fitted applying the Langmuir and Freundlich isotherm models. The potential use as solid fuel materials was evaluated using elemental analysis and numerical high calorific value (HCV). The experimental results were compared to the conventional solid fuels classified in the Van Krevelen graph. The essays performed showed that the HCV was in the range of 10.2–11.9 MJ/kg

Valorisation of plastic waste from the beverage industry through its transformation into adsorbent and solid fuel materials

In the present study, char and activated carbon (AC) materials were prepared from water bottles, recuperated from the waste collection point in Mourouj, Ben Arous, Tunisia, by using a rotative horizontal tubular furnace, on a lab/pilot scale and through chemical and physical activation. Different samples were characterized by $\text{N}_2$ adsorption isotherms, SEM-EDX, XRD, EA as well as by the determination of the $\text{pH}_{\mathrm{zpc}}$. The efficiency of the ACs to remove (2-methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetic acid (2,4-D)) herbicides from aqueous solutions was also investigated. The results demonstrated that a maximum adsorption capacity of $192~\text{mg}{\cdot }\text{g}^{-1}$, for MCPA, and $290~\text{mg}{\cdot }\text{g}^{-1}$ for 2,4-D had been attained. The adsorption kinetics was fitted to pseudo first, second order and Elovich model, while the adsorption isotherms were fitted applying the Langmuir and Freundlich isotherm models. The potential use as solid fuel materials was evaluated using elemental analysis and numerical high calorific value (HCV). The experimental results were compared to the conventional solid fuels classified in the Van Krevelen graph. The essays performed showed that the HCV was in the range of 10.2–11.9 MJ/kg

The R-process Alliance: First Magellan/MIKE Release from the Southern Search for R-Process-enhanced Stars

Extensive progress has been recently made into our understanding of heavy element production via the $r$-process in the Universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational wave signal detected by LIGO, GW170817. The chemical abundance patterns of metal-poor $r$-process-enhanced stars provides key evidence into the dominant site(s) of the $r$-process, and whether NSBMs are sufficiently frequent or prolific $r$-process sources to be responsible for the majority of $r$-process material in the Universe. We present atmospheric stellar parameters (using a Non-Local Thermodynamic Equilibrium analysis) and abundances from a detailed analysis of 141 metal-poor stars, carried out as part of the $R$-Process Alliance (RPA) effort. We obtained high-resolution "snapshot" spectroscopy of the stars using the MIKE spectrograph on the 6.5m Magellan Clay telescope at Las Campanas Observatory in Chile. We find 10 new highly enhanced $r$-II (with [Eu/Fe] $> +1.0$), 62 new moderately enhanced $r$-I ($+0.3 <$ [Eu/Fe] $\le +1.0$) and 17 new limited-$r$ ([Eu/Fe] $< +0.3$) stars. Among those, we find 17 new carbon-enhanced metal-poor (CEMP) stars, of which five are CEMP-no. We also identify one new $s$-process-enhanced ([Ba/Eu ]$> +0.5$), and five new $r/s$ ($0.0 <$ [Ba/Eu] $< +0.5$) stars. In the process, we discover a new ultra metal-poor (UMP) star at [Fe/H]=$-$4.02. One of the $r$-II stars shows a deficit in $\alpha$ and Fe-peak elements, typical of dwarf galaxy stars. Our search for $r$-process-enhanced stars by RPA efforts, has already roughly doubled the known $r$-process sample.Comment: 17 pages, 9 figures, 6 tables, Accepted for publication in Ap

Dasatinib induces notable hematologic and cytogenetic responses in chronic-phase chronic myeloid leukemia after failure of imatinib therapy

AbstractAlthough imatinib induces marked responses in patients with chronic myeloid leukemia (CML), resistance is increasingly problematic, and treatment options for imatinib-resistant or -intolerant CML are limited. Dasatinib, a novel, highly potent, oral, multitargeted kinase inhibitor of BCR-ABL and SRC family kinases, induced cytogenetic responses in a phase 1 study in imatinib-resistant or -intolerant CML and was well tolerated. Initial results are presented from a phase 2 study of 186 patients with imatinib-resistant or -intolerant chronic-phase CML (CML-CP) designed to further establish the efficacy and safety of dasatinib (70 mg twice daily). At 8-months' follow-up, dasatinib induced notable responses, with 90% and 52% of patients achieving complete hematologic and major cytogenetic responses (MCyR), respectively. Responses were long lasting: only 2% of patients achieving MCyR progressed or died. Importantly, comparable responses were achieved by patients carrying BCR-ABL mutations conferring imatinib resistance. Dasatinib also induced molecular responses, reducing BCR-ABL/ABL transcript ratios from 66% at baseline to 2.6% at 9 months. Nonhematologic adverse events were generally mild to moderate, and most cytopenias were effectively managed with dose modifications. Cross-intolerance with imatinib was not evident. To conclude, dasatinib induces notable responses in imatinib-resistant or -intolerant CML-CP, is well tolerated, and represents a promising therapeutic option for these patients. This trial was registered at www.clinicaltrials.gov as CA180013

Rapid Assessment Tool for Haemophilus influenzae type b Disease in Developing Countries1

Haemophilus influenzae type b disease prevalence in children provides estimates of national disease prevalence

The R-Process Alliance: The Peculiar Chemical Abundance Pattern of RAVE J183013.5-455510

We report on the spectroscopic analysis of RAVE J183013.5-455510, an extremely metal-poor star, highly enhanced in CNO, and with discernible contributions from the rapid neutron-capture process. There is no evidence of binarity for this object. At [Fe/H]=-3.57, this is one of the lowest metallicity stars currently observed, with 18 measured abundances of neutron-capture elements. The presence of Ba, La, and Ce abundances above the Solar System r-process predictions suggest that there must have been a non-standard source of r-process elements operating at such low metallicities. One plausible explanation is that this enhancement originates from material ejected at unusually fast velocities in a neutron star merger event. We also explore the possibility that the neutron-capture elements were produced during the evolution and explosion of a rotating massive star. In addition, based on comparisons with yields from zero-metallicity faint supernova, we speculate that RAVE J1830-4555 was formed from a gas cloud pre-enriched by both progenitor types. From analysis based on Gaia DR2 measurements, we show that this star has orbital properties similar to the Galactic metal-weak thick-disk stellar population.Comment: Accepted for publication in Ap