Adsorbed and near surface structure of ionic liquids at a solid interface

The structure of solid–ionic liquid (IL) interfaces has been characterised with unprecedented clarity by employing a range of atomic force microscopy (AFM) imaging techniques and tip pressures appropriate for the system under study. Soft contact and amplitude-modulation (AM) AFM imaging have been used to elucidate the lateral structure of ILs adsorbed onto mica, and in the near surface ion layers. Data is presented for ethylammonium nitrate (EAN) and 1-ethyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide (EMIm TFSI). Whereas EAN is a protic IL that forms a nanostructured sponge phase in the bulk, EMIm TFSI is aprotic and has weak (or absent) bulk association structure. Comparison of results obtained for the two liquids elucidates how the strength of bulk liquid morphology effects lateral organisation at the surface, and any effect of IL class, i.e. protic versus aprotic. Imaging reveals EAN self assembles at the solid surface in a worm-like morphology, whereas EMIm cations adsorb in a more isolated fashion, but still in rows templated by the mica surface. To the authors’ knowledge, the wormlike structures present at the EAN–mica interface are the smallest self-assembled aggregates ever imaged on a solid surface

CW laser operation around 2-μm in (Tm,Yb):KLu(WO4) 2

Laser generation in continuous wave (CW) regime at 1.94-μm from (Tm,Yb) codoped system has been investigated in two different hosts: KLu(WO 4)2 and KY(WO4)2. The high quality crystals were grown by the Top-Seeded Solution Growth Slow Cooling (TSSG-SC) method with doping levels of 2.5 at. %Tm and 5 at. %Yb. The active media were pumped with a diode laser at 980 nm. We demonstrated the superior performance of KLu(WO4)2 compared to that of KY(WO4) 2 and improved the results already obtained in the literature. The maximum laser output power reached was 157 mW for (Tm,Yb):KLu(WO 4)2 and 123 mW for (Tm,Yb):KY(WO4)2. © 2010 Published by Elsevier Ltd

CW laser operation around 2-μm in (Tm,Yb):KLu(WO4) 2

Laser generation in continuous wave (CW) regime at 1.94-μm from (Tm,Yb) codoped system has been investigated in two different hosts: KLu(WO 4)2 and KY(WO4)2. The high quality crystals were grown by the Top-Seeded Solution Growth Slow Cooling (TSSG-SC) method with doping levels of 2.5 at. %Tm and 5 at. %Yb. The active media were pumped with a diode laser at 980 nm. We demonstrated the superior performance of KLu(WO4)2 compared to that of KY(WO4) 2 and improved the results already obtained in the literature. The maximum laser output power reached was 157 mW for (Tm,Yb):KLu(WO 4)2 and 123 mW for (Tm,Yb):KY(WO4)2. © 2010 Published by Elsevier Ltd

Influence of the Pecking Motion Frequency on the Cyclic Fatigue Resistance of Endodontic Rotary Files

Purpose: To analyze the influence of the pecking motion frequency on the cyclic fatigue resistance of endodontic rotary files. Material and Methods: Sixty PlexV 25.06 endodontic rotary files were selected and distributed into three groups: 30 movements/min (n = 20), 60 movements/min (n = 20), and 120 movements/min (n = 20). A dynamic cyclic fatigue device was designed using Computer Aided Design/ Computer Aided Engineering (CAD/CAE) technology and manufactured by 3D impressions to simulate the pecking motion performed by an operator. Failures of the endodontic rotary files were detected by a Light-Emitting Diode (LED)/Light-Dependent Resistor (LDR) system controlled by an Arduino-Driver complex and management software. Endodontic rotary files were tested on an artificial root canal manufactured by wire electrical discharge machining (EDM), with similar dimensions to those of the instrument under examination. Endodontic rotary files were used following the manufacturer's recommendations. The results were analyzed by ANOVA and Weibull statistics. Results: All pairwise comparisons revealed statistically significant differences in all three variables, except for the difference in the number of cycles between the groups with 60 and 120 movements/min (p = 0.298). The scale distribution parameter of Weibull statistics showed statistically significant differences in all three variables, except for the differences in the number of cycles between groups with 30 and 60 movements/min (p = 0.0722). No statistically significant differences in the three variables were observed for the shape distribution parameter. Conclusion: A low frequency of pecking motion is recommended to reduce the risk of failure of endodontic rotary files associated with cyclic fatigue

The electronics of the energy plane of the NEXT-White detector

[EN] This paper describes the electronics of NEXT-White (NEW) detector PMT plane, a high pressure xenon TPC with electroluminescent amplification (HPXe-EL) currently operating at the Laboratorio Subterraneo de Canfranc (LSC) in Huesca, Spain. In NEXT-White the energy of the event is measured by a plane of photomultipliers (PMTs) located behind a transparent cathode. The PMTs are Hamamatsu R11410-10 chosen due to their low radioactivity. The electronics have been designed and implemented to fulfill strict requirements: an overall energy resolution below 1% and a radiopurity budget of 20 mBq unit(-1) in the chain of Bi-214. All the components and materials have been carefully screened to assure a low radioactivity level and at the same time meet the required front-end electronics specifications. In order to reduce low frequency noise effects and enhance detector safety a grounded cathode connection has been used for the PMTs. This implies an AC-coupled readout and baseline variations in the PMT signals. A detailed description of the electronics and a novel approach based on a digital baseline restoration to obtain a linear response and handle AC coupling effects is presented. The final PMT channel design has been characterized with linearity better than 0.4% and noise below 0.4mV.We acknowledge support from the following agencies and institutions: the European Research Council (ERC), Spain under the Advanced Grant 339787-NEXT; the Ministerio de Economia y Competitividad of Spain under grants FIS2014-53371-C04, the Severo Ochoa Program, Spain SEV-2014-0398 and the Maria de Maetzu Program, Spain MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT and FEDER, Spain through the program COMPETE, projects PTDC/FIS-NUC/2525/2014 and UID/FIS/04559/2013; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and de-sc0017721 (University of Texas at Arlington); and the University of Texas at Arlington. We acknowledge partial support from the European Union Horizon 2020 research and innovation programme, Spain under the Marie Sklodowska-Curie grant agreements No. 690575 and 674896. We also warmly acknowledge the Laboratorio Nazionale di Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.Álvarez-Puerta, V.; Herrero Bosch, V.; Esteve Bosch, R.; Laing, A.; Rodriguez-Samaniego, J.; Querol-Segura, M.; Monrabal, F.... (2019). The electronics of the energy plane of the NEXT-White detector. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 917:68-76. https://doi.org/10.1016/j.nima.2018.11.126S687691

Consideraciones prácticas para la implementación de la transformada d-q monofásica para la detección de SAGs.

La detección del voltaje pico de línea mediante la transformada d-q convencional ha permitido la implementación de controladores que contrarresten los efectos de perturbaciones como SAGs y SWELLs. En teoría, con la transformada d-q convencional se puede obtener el voltaje pico en cualquier instante del ciclo de una señal senoidal, sin embargo, esta característica puede cumplirse o no dependiendo de la técnica que se utilice para su implementación en un dispositivo programable tal como un Microcontrolador, DSP (por sus siglas en ingles Digital Signal Processor), o un FPGA (por sus siglas en ingles Field Programmable Gate Array). En este artículo se hace una comparación de dos técnicas que se pueden utilizar para la implementación de la transformada d-q convencional en un microcontrolador de la familia dsPIC de Microchip

Disc polarization from both emission and scattering of magnetically aligned grains: the case of NGC 1333 IRAS 4A1

Stars and planetary system

Habitable Zones and UV Habitable Zones around Host Stars

Ultraviolet radiation is a double-edged sword to life. If it is too strong, the terrestrial biological systems will be damaged. And if it is too weak, the synthesis of many biochemical compounds can not go along. We try to obtain the continuous ultraviolet habitable zones, and compare the ultraviolet habitable zones with the habitable zones of host stars. Using the boundary ultraviolet radiation of ultraviolet habitable zone, we calculate the ultraviolet habitable zones of host stars with masses from 0.08 to 4.00 \mo. For the host stars with effective temperatures lower than 4,600 K, the ultraviolet habitable zones are closer than the habitable zones. For the host stars with effective temperatures higher than 7,137 K, the ultraviolet habitable zones are farther than the habitable zones. For hot subdwarf as a host star, the distance of the ultraviolet habitable zone is about ten times more than that of the habitable zone, which is not suitable for life existence.Comment: 5 pages, 3 figure

The VLA Nascent Disk And Multiplicity Survey of Perseus Protostars (VANDAM). III. Extended Radio Emission from Protostars in Perseus

Interstellar matter and star formatio