3XMM J185246.6+003317: another low magnetic field magnetar

We study the outburst of the newly discovered X-ray transient 3XMMJ185246.6+003317, re-analyzing all available XMM-Newton observations of the source to perform a phase-coherent timing analysis, and derive updated values of the period and period derivative. We find the source rotating at P = 11.55871346(6) s (90% confidence level; at epoch MJD 54728.7) but no evidence for a period derivative in the seven months of outburst decay spanned by the observations. This translates to a 3σ upper limit for the period derivative of ˙ P <1.4×10−13 s s−1, which, assuming the classical magneto-dipolar braking model, gives a limit on the dipolar magnetic field of Bdip < 4.1×1013 G. The X-ray outburst and spectral characteristics of 3XMM J185246.6+003317 confirm its identification as a magnetar, but the magnetic field upper limit we derive defines it as the third “low-B” magnetar discovered in the past 3 yr, after SGR 0418+5729 and Swift J1822.3−1606. We have also obtained an upper limit to the quiescent luminosity (<4×1033 erg s−1), in line with the expectations for an old magnetar. The discovery of this new low field magnetar reaffirms the prediction of about one outburst per year from the hidden population of aged magnetars.

Orbital and Physical Properties of the σ Ori Aa, Ab, B Triple System

We provide a complete characterization of the astrophysical properties of the σ Ori Aa, Ab, B hierarchical triple system and an improved set of orbital parameters for the highly eccentric σ Ori Aa, Ab spectroscopic binary. We compiled a spectroscopic data set comprising 90 high-resolution spectra covering a total time span of 1963 days. We applied the Lehman-Filhés method for a detailed orbital analysis of the radial velocity curves and performed a combined quantitative spectroscopic analysis of the σ Ori Aa, Ab, B system by means of the stellar atmosphere code FASTWIND. We used our own plus other available information on photometry and distance to the system for measuring the radii, luminosities, and spectroscopic masses of the three components. We also inferred evolutionary masses and stellar ages using the Bayesian code BONNSAI. The orbital analysis of the new radial velocity curves led to a very accurate orbital solution of the σ Ori Aa, Ab pair. We provided indirect arguments indicating that σ Ori B is a fast-rotating early B dwarf. The FASTWIND+BONNSAI analysis showed that the Aa, Ab pair contains the hottest and most massive components of the triple system while σ Ori B is a bit cooler and less massive. The derived stellar ages of the inner pair are intriguingly younger than the one widely accepted for the σ Orionis cluster, at 3 ± 1 Ma. The outcome of this study will be of key importance for a precise determination of the distance to the σ Orionis cluster, the interpretation of the strong X-ray emission detected for σ Ori Aa, Ab, B, and the investigation of the formation and evolution of multiple massive stellar systems and substellar objects.

On the formation and evolution of the first Be star in a black hole binary MWC 656

We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead to significant accretion and spin up of the B star. We predict ∼10–100 of B-BH binaries to currently reside in the Galactic disc, among which around 1/3 contain a Be star, but there is only a small chance to observe a system with parameters resembling MWC 656. If MWC 656 is representative of intrinsic Galactic Be-BH binary population, it may indicate that standard evolutionary theory needs to be revised. This would pose another evolutionary problem in understanding black hole (BH) binaries, with BH X-ray novae formation issue being the prime example. Future evolution of MWC 656 with an ∼5 M⊙ BH and with an ∼13 M⊙ main-sequence companion on an ∼60 d orbit may lead to the formation of a coalescing BH–NS (neutron star) system. The estimated Advanced LIGO/Virgo detection rate of such systems is up to ∼0.2 yr−1. This empirical estimate is a lower limit as it is obtained with only one particular evolutionary scenario, the MWC 656 binary. This is only a third such estimate available (after Cyg X-1 and Cyg X-3), and it lends additional support to the existence of so far undetected BH–NS binaries.

Evidence of Local pH Changes during Ethanol Oxidation at Pt Electrodes in Alkaline Media

Local changes of the interfacial pH can significantly affect the rate and mechanism during the course of an electrodic reaction. For instance, different pH values will have a significant effect on the equilibrium properties of both solution and surface species, altering the reactions kinetics. Ethanol oxidation at platinum electrodes in alkaline media involves the fast consumption of OH− species that will change the local pH at the electrode surface, decreasing the reaction rate. In this study, the local pH change during ethanol oxidation in alkaline media is accomplished by using rotating ring-disc electrode (RRDE) experiments. The current at the ring when polarized at the onset of hydrogen evolution serves as a measure of the local pH in the vicinity of the electrode. The results show that the current at the ring at 0.1 V (vs. RHE) becomes more negative during ethanol oxidation, owing to a change in the equilibrium potential of the hydrogen evolution reaction caused by a change in the local pH.

Role of the interfacial water structure on electrocatalysis: Oxygen reduction on Pt(1 1 1) in methanesulfonic acid

Most of electrocatalytic reactions occur in an aqueous environment. Understanding the influence of water structure on reaction dynamics is fundamental in electrocatalysis. In this work, the role of liquid water structure on the oxygen reduction at Pt(1 1 1) electrode is analyzed in methanesulfonic (MTSA) and perchloric acids. This is because these different anions can exert a different influence on liquid water structure. Results reveal a lower ORR electrode activity in MTSA than in HClO4 solutions and they are discussed in light of anion's influence on water structural ordering. From them, the existence of an outer-sphere, rate determining, step in the ORR mechanism is suggested.

Proposal of a New Parameter for the Weathering Characterization of Carbonate Flysch-Like Rock Masses: The Potential Degradation Index (PDI)

The susceptibility of clay bearing rocks to weathering (erosion and/or differential degradation) is known to influence the stability of heterogeneous slopes. However, not all of these rocks show the same behaviour, as there are considerable differences in the speed and type of weathering observed. As such, it is very important to establish relationships between behaviour quantified in a laboratory environment with that observed in the field. The slake durability test is the laboratory test most commonly used to evaluate the relationship between slaking behaviour and rock durability. However, it has a number of disadvantages; it does not account for changes in shape and size in fragments retained in the 2 mm sieve, nor does its most commonly used index (Id2) accurately reflect weathering behaviour observed in the field. The main aim of this paper is to propose a simple methodology for characterizing the weathering behaviour of carbonate lithologies that outcrop in heterogeneous rock masses (such as Flysch slopes), for use by practitioners. To this end, the Potential Degradation Index (PDI) is proposed. This is calculated using the fragment size distribution curves taken from material retained in the drum after each cycle of the slake durability test. The number of slaking cycles has also been increased to five. Through laboratory testing of 117 samples of carbonate rocks, extracted from strata in selected slopes, 6 different rock types were established based on their slaking behaviour, and corresponding to the different weathering behaviours observed in the field.

Structural Analysis with ANSYS on Stone Constructions in the Historical Spanish Heritage

According to the importance of rehabilitation and recovery of Architectural Heritage in the live of people, this paper is aimed to strengthen the traditional methods of stone vaults calculation taking advantage of the technological characteristics of the powerful program ANSYS Workbench. As an example of this, it could find out the possible pathologies that could arise during the construction history of the building. To limit this research, the upper vault of the main chapel of the Santiago parish church in Orihuela -Alicante- is selected as a reference which is a Jeronimo Quijano´s important building work in the XVI century in the Renaissance. Moreover, it is an innovative stone masonry vault that consists of 8 double intercrossed arches with each other and braced by severies. During the seventeenth century there was a lantern in the central cap and it is unknown why it was removed. Its construction could justify the original constructive solution with intercrossed arches that freed the center to create a more enlightened and comfortable presbytery. By similarity with other Quijano’s works, it is considered a small lantern drilling the central spherical cap. It is proposed to carry out a comparative study of it with different architectural solutions from the same period and based on several common parameters such as: a vault of square plant with spherical surround, intercrossed arches, a possible lantern, the dimension of the permitted space, similar states of loads and compact limestone masonry. The three solutions are mainly differentiated by their size and the type of lantern and its comparison lets us know which one is the most resistant and stable. The other two building works maintain some connection with the Quijano's professional scope. It has selected the particular case of the Communion chapel of the Basilica in Elche (a large prismatic lantern with a large cylindrical drum that starts from the own arches and an upper hemispherical dome), for its conservation, its proximity to Orihuela and its implementation during the century XVIII. Finally, a significant Dome Spanish Renaissance complete the selection: a cross vault of the Benavides Chapel of the Saint Francisco Convent in Baeza - Jaén-, designed by Andres of Vandelvira in the sixteenth century (a large hemispherical dome that starts from the own arcs). To simplify the calculation and standardize the work that have to be contrasted, all of them were considered with some similar characteristics: 30 cm constant thickness, the intercrossed arches were specifically analyzed and had identical loads, Young's modulus and Poisson's ratio. Regarding the calculation solutions, in general terms, the compressive stresses predominate, influencing on it the joint collaboration of the filling material on the vault, the vault itself, the thick side walls, the buttresses and the top cover weight . In addition, the three solutions are suitable, being the Orihuela one the safest and the Baeza one the riskiest for its large dimensions. Thus, the idea of intercrossed arches with suitable thickness would allow carry out the heaviest lantern and this would confirm it as a Renaissance architectural typology built in stone.

Djabote [videorecording]: Senegalese drumming & song from master drummer Doudou N'Diaye Rose

A film of Eric Serra's audio recording session of Doudou N'Diaye Rose and his drumming ensemble outdoors on the island of Gorée, off the coast of Dakar, Senegal. The film concentrates on two performances -- one shot in daytime, and one at night. Two performances are filmed, punctuated by images of the island.

A proof of Jesus Christ's being the ancient promised Messiah: a sermon preached in the Chapel of Harvard College at Cambridge in New England, June 23, 1756

The hand-sewn notebook contains a 24-page manuscript draft of the second Dudleian lecture, delivered by John Barnard on June 23, 1756. The copy includes a small number of edits and struck-out words adopted in the printed version published by J. Draper of Boston in 1756. The sermon begins with the Biblical text Mark 14:61, 62. The covers are no longer with the item.

Popery a complex falsehood: or an attempt to clear and evidence, that it is so, in a lecture had at Harvard College in Cambridge, New England, on May 10th, 1769

The hand-sewn notebook contains a 30-page manuscript draft of the Dudleian lecture delivered by Samuel Mather on May 10, 1769 at Harvard College. The sermon begins with the Biblical text 2 Thess. 11:11, 12. The copy includes a small number of edits and struck-out words. The item has unattached pages and is in fragile condition. The lecture was never published.

Diocesan Episcopacy: as Founded on the supposed Episcopacy of Timothy & Titus, subverted in a sermon preached at Harvard College May 9, 1770 at the Lecture founded by Paul Dudley

Two handwritten drafts of the Dudleian lecture delivered by Amos Adams on May 9, 1770 at Harvard College written in the same hand. The sermon begins with the Biblical text Titus 1:5. The first copy (HUC 5340.70) is bound between black paper covers and includes edits and citations written on interleaved pages. The second copy (HUC 5340.70.2) appears to be a subsequent draft of the address with additional edits.

Sermon at the annual Dudleian lecture at Harvard College in Cambridge, May 14th, 1760

The hand-sewn notebook contains a 41-page manuscript draft of the Dudleian lecture delivered by Samuel Wigglesworth on May 14, 1760 at Harvard College. The sermon begins with the Biblical text I Cor. 1:21. The copy includes a small number of edits and struck-out words. The covers are no longer with the item.

Mr. Abbot's sermon at the Dudleian lecture at Harvard College in Cambridge August 29, 1764 pm: being the third in course on the important subject of Reveal'd-religion

The hand-sewn notebook contains a 27-page manuscript draft of the Dudleian lecture delivered by Hull Abbot on August 29, 1764 at Harvard College on the topic of revealed religion. The sermon begins with the Biblical text Zech. 4:6 and Rom. 10:18. The copy includes a small number of edits and struck-out words. The lecture was not printed.

Sermon at the annual Dudleian lecture, May 13th, 1772

The hand-sewn notebook contains a 108-page manuscript draft of the Dudleian lecture delivered by Benjamin Stevens on May 13, 1772 at Harvard College. The sermon begins with the Biblical text Heb. 1:1, 2. The copy includes a small number of edits and struck-out words. The cover page is no longer attached.

A discourse on natural religion: delivered in the Chapel of the University at Cambridge, September 5, 1787

The hand-sewn notebook contains a 35-page manuscript draft of the Dudleian lecture delivered by Simeon Howard on September 5, 1787 at Harvard College. The sermon begins with the Biblical text Acts 17:28. The copy includes a small number of edits and struck-out words. The covers are no longer with the item. The lecture was not printed.