Liquid metals as electrodes in polymer light emitting diodes

We demonstrate that liquid metals can be used as cathodes in light emitting diodes (pLEDs). The main difference between the use of liquid cathodes and evaporated cathodes is the sharpness of the metal–polymer interface. Liquid metal cathodes result in significantly sharper metal–organic interfaces than vapor deposited cathodes, due to the high surface energy of the metals. The sharper interface in pLEDs with liquid metal cathodes is observed by neutral impact collision ion scattering spectroscopy and low energy ion scattering spectroscopy measurements. The influence of interface sharpness on device performance was studied by comparing current–voltage-light characteristics of devices with OC1C10 paraphenylenevinylene (PPV) as electroluminescent polymer and indium tin oxide (ITO) as hole injection electrode, and different cathodes. Comparison of devices using a liquid Ga cathode and an evaporated Al cathode showed that light emission for the liquid Ga cathode is two orders of magnitude larger than for the evaporated Al cathode, and that the external light efficiency is increased by an order of magnitude. Since the work function of Ga and Al is nearly the same, the poor performance for evaporated Al LEDs is attributed to the formation of an interfacial layer where Al has diffused into, and reacted with, the PPV. This interfacial layer has poor electrical conduction compared to pure PPV, and contains quenching sites which reduce light emission. Low work function liquid metal cathodes were studied by using liquid Ca and Ba amalgams. The improved performance of liquid amalgam pLEDs is attributed to the different structure of the metal–polymer interface. The enormous increase in light and current through the amalgam devices compared to those using pure Hg demonstrate that less than 1 ML of a metal with a low work function at the polymer-cathode interface can have a dramatic effect on the performance of the devices. Devices with a liquid Ca amalgam cathode showed an increase of the current (by 50%) and brightness (80%) compared to devices with an evaporated Ca cathode, which is ascribed to reduced diffusion of Ca into the emissive PPV laye

Editorial workflow of a community-led, all-volunteer scientific journal: lessons from the launch of Seismica

Seismica is a community-led, volunteer-run, diamond open-access journal for seismology and earthquake science, and Seismica's mission and core values align with the principles of Open Science. This article describes the editorial workflow that Seismica uses to go from a submitted manuscript to a published article. In keeping with Open Science principles, the main goals of sharing this workflow description are to increase transparency around academic publishing, and to enable others to use elements of Seismica's workflow for journals of a similar size and ethos. We highlight aspects of Seismica's workflow that differ from practices at journals with paid staff members, and also discuss some of the challenges encountered, solutions developed, and lessons learned while this workflow was developed and deployed over Seismica's first year of operations

Editorial workflow of a community-led, all-volunteer scientific journal: lessons from the launch of Seismica

Seismica is a community-led, volunteer-run, diamond open-access journal for seismology and earthquake science, and Seismica's mission and core values align with the principles of Open Science. This article describes the editorial workflow that Seismica uses to go from a submitted manuscript to a published article. In keeping with Open Science principles, the main goals of sharing this workflow description are to increase transparency around academic publishing, and to enable others to use elements of Seismica's workflow for journals of a similar size and ethos. We highlight aspects of Seismica's workflow that differ from practices at journals with paid staff members, and also discuss some of the challenges encountered, solutions developed, and lessons learned while this workflow was developed and deployed over Seismica's first year of operations

The starburst-active galactic nucleus connection in the merger galaxy Mrk 938: An infrared and X-ray view

Mrk 938 is a luminous infrared (IR) galaxy in the local Universe believed to be the remnant of a galaxy merger. It shows a Seyfert 2 nucleus and intense star formation according to optical spectroscopic observations. We have studied this galaxy using new Herschel far-IR imaging data in addition to archival X-ray, UV, optical, near-IR and mid-IR data. Mid- and far-IR data are crucial to characterize the starburst contribution, allowing us to shed new light on its nature and to study the coexistence of active galactic nuclei (AGN) and starburst activity in the local Universe. The decomposition of the mid-IR Spitzer spectrum shows that the AGN bolometric contribution to the mid-IR and total IR luminosity is small [Lbol(AGN)/LIR ? 0.02], which agrees with previous estimations. We have characterized the physical nature of its strong IR emission and constrained it to a relatively compact emitting region of ?2 kpc. It is in this obscured region where most of the current star formation activity is taking place as expected for luminous IR galaxies. We have used Herschel imaging data for the first time to constrain the cold dust emission with unprecedented accuracy. We have fitted the integrated far-IR spectral energy distribution and derived the properties of the dust, obtaining a dust mass of 3 × 107 M . The far-IR is dominated by emission at 35 K, consistent with dust heated by the ongoing star formation activityThanks to F. Schweizer for kindly providing the optical image of Mrk 938, to J. Gallimore for providing the MIPS SED data, and to H. Krimm and W. Baumgartner for the analysis of the BAT ob- servations. PE, AA-H and MP-S acknowledge support from the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under grant AYA2009-05705-E. AA-H and MP-S acknowledge support under grant AYA2010-21161-C02-01. MP-S acknowledges support from the CSIC under grant JAE-Predoc-2007. AMP-G acknowledges support by the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under the grant AYA2008-06311-CO2-01. CRA acknowledges fi- nancial support from STFC (ST/G001758/1) and from the Span- ish Ministry of Science and Innovation (MICINN) through project Consolider-Ingenio 2010 Programme grant CSD2006-00070: First Science with the GTC. MP acknowledges Junta de Andaluc ́ıa and Spanish Ministry of Science and Innovation through projects PO8- TIC-03531 and AYA2010-15169. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF- IFSI/OAA/OAP/OAT, LENS, SISSA (Italy) and IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including University of Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, University of Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, University of Sus- sex (UK) and Caltech, JPL, NHSC, University of Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK) and NASA (USA). This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Labo- ratory, California Institute of Technology, under NASA contract 1407

Phylogenetic relationships of Burmeistera (Campanulaceae: Lobelioideae): Combining whole plastome with targeted loci data in a recent radiation

© 2016 Elsevier Inc. The field of molecular systematics has benefited greatly with the advent of high-throughput sequencing (HTS), making large genomic datasets commonplace. However, a large number of targeted Sanger sequences produced by many studies over the last two decades are publicly available and should not be overlooked. In this study, we elucidate the phylogenetic relationships of the plant genus Burmeistera (Campanulaceae: Lobelioideae), while investigating how to best combine targeted Sanger loci with HTS data. We sequence, annotate, and analyze complete to nearly complete plastomes for a subset of the genus. We then combine these data with a much larger taxonomic dataset for which only Sanger sequences are available, making this the most comprehensively sampled study in the genus to date. We show that using a phylogeny inferred from the species with plastome data as a topological constraint for the larger dataset increases the resolution of our data and produces a more robust evolutionary hypothesis for the group. We then use the resulting phylogeny to study the evolution of morphological traits thought to be important in Burmeistera, and assess their usefulness in the current taxonomic classification of the genus. The main morphological character used to delimit subgeneric sections, the presence or absence of hairs on the apex of the two ventral anthers, shows a complex evolutionary history with many changes in the tree, suggesting that this character should not be used for taxonomic classification. Although it is too soon to propose a new subgeneric classification for Burmeistera, our results highlight some morphological traits shared by whole clades that could potentially be used in future taxonomic work