AC impedance study of degradation of porous nickel battery electrodes

AC impedance spectra of porous nickel battery electrodes were recorded periodically during charge/discharge cycling in concentrated KOH solution at various temperatures. A transmission line model (TLM) was adopted to represent the impedance of the porous electrodes, and various model parameters were adjusted in a curve fitting routine to reproduce the experimental impedances. Degradation processes were deduced from changes in model parameters with electrode cycling time. In developing the TLM, impedance spectra of planar (nonporous) electrodes were used to represent the pore wall and backing plate interfacial impedances. These data were measured over a range of potentials and temperatures, and an equivalent circuit model was adopted to represent the planar electrode data. Cyclic voltammetry was used to study the characteristics of the oxygen evolution reaction on planar nickel electrodes during charging, since oxygen evolution can affect battery electrode charging efficiency and ultimately electrode cycle life if the overpotential for oxygen evolution is sufficiently low

Plasma Diagnostics by Antenna Impedance Measurements

The impedance of an electrically short antenna immersed in a plasma provides an excellent in situ diagnostic tool for electron density and other plasma parameters. By electrically short we mean that the wavelength of the free-space electromagnetic wave that would be excited at the driving frequency is much longer than the physical size of the antenna. Probes using this impedance technique have had a long history with sounding rockets and satellites, stretching back to the early 1960s. This active technique could provide information on composition and temperature of plasmas for comet or planetary missions. Advantages of the impedance probe technique are discussed and two classes of instruments built and flown by SDL-USU for determining electron density (the capacitance and plasma frequency probes) are described

Listening to young people’s views of the coast:Living Coast Youth Voice

We have summarised the knowledge that was co-created with young people here. However, we would like to encourage those adults who planned to read just this summary to also hear directly form the young people by reading Chapter 3. Introduction Living Coast was a national partnership pilot project developed by Natural England1 (an organisation that looks after nature and landscapes in England). Natural England wants to help people from all walks-of-life enjoy the benefits of a new long distance path around England: the England Coast Path. By 2020, the path will stretch for approximately 2,700 miles around our beautiful English coastline and open up new stretches of the coastline. Natural England wants to understand how and why young people already use and enjoy the coast, and why others do not (or cannot). They want to know what can be done to help as many young people as possible benefit from the spectacular views, sea air, exercise and nature that the path and surrounding areas offer. In this research, we worked with young people aged 11 – 18 to create new knowledge about what makes it easy or hard for them to make the most of the coast, and what they suggest would help. This is important because there is little other evidence about this, nationally. This research took place in Barrow-in-Furness in Cumbria – a place with a high quality natural environment and areas that fall in the bottom 10% and 3% nationally on measures of deprivation. Cumbria was one of three Living Coast pilot areas in 2018/19. The other two are on the Durham Heritage Coast and the Solent. All three will inform how Natural England and its partners develop work at the coast.2 Research focus The study asked the following research questions: Q What do you think of the coast? Q How do you use the coast? Q How do you benefit from the coast? Q What makes it easy to go to, and enjoy, the coast? Q What makes it hard to go to, and enjoy, the coast? Q What would help you to go more often? Q What suggestions would you make to Natural England about how they can help? Methods used Our methods mixed and blended methods, techniques and principles from participation practice and social science. To do this we: 2 1. In total, we met 59 young people from a mix of ages, genders, ethnicities, and distances from the coast, prioritising those who live in areas that fall in the lowest 3% or 10% in the Indices of Multiple Deprivation. 2. Set up a Participatory Advisory Group (PAG) of eight young people, aged 14, to be our research advisors, comment on our methods and help us interpret and analyse our findings. 3. Met with 47 young people in six groups, from a range of community and educational settings, for 90-minutes each. During these sessions, we worked with young people to create maps, discuss their good and bad experiences, ease of getting to the coast, and the influence of money, jobs, belonging and culture to their views of the coast. 4. Summarised what young people said in this first round in pictures. 5. Ran two ‘Creative Horizons’ events a fortnight later, in two sessions when 22 young people (of those who had taken part in the mapping sessions) were joined by 4 new young people. In these sessions young people took charge of which topics to explore and how to create new knowledge through art, story, rap, music, poems, drama, or discussion. 6. Faithfully reported what young people said in this report and in a film. Findings We found that young people have a mix of attitudes towards the coast, with some finding it a place of enjoyment, peace, and adventure and others finding it boring, uncomfortable and a place of natural and human dangers. Young people go to a mix of places. Some are familiar beaches, which are closer to home and easier to get to, and others are destinations young people enjoy with friends and family but require transport to get to. Walking and dog walking were most often mentioned as activities to do at the coast, with some saying they swam in the sea but many others not mentioning swimming at all or saying they couldn’t swim. For a few, cycling was a key part of enjoying the coast and a couple of young people mentioned anglin g and water sports. Young people in all groups described psychological, physical and social wellbeing benefits of being by the sea. They said that it helped them cope with stress, be fitter and enjoy time with family and friends. The things that made it easier to go included: their own attitudes and confidence, being able to get there, having someone available to go with, feeling safe and belonging and also the time of year and the weather. The barriers to going to the seaside were numerous and interconnected and particularly hard for young people living with multiple pressures and disadvantages. Negative personal attitudes and fears included boredom and anxiety, such as about risks or body shaming. A range of issues around social barriers included not feeling safe from attack, feeling they didn’t belong, that adults and peers were judging them badly as well as outright racism, sexism and homophobia. Young people also said they lacked information about where to go, how to get there, what to do once there, natural risks such as tides, quick sands and rock falls. Getting there and affording to go were practical barriers, as was having someone available to go with them. Litter and dirty beaches deter young people. At this exposed location, bad weather with fierce winds and driving rain can make it too unpleasant to go. Young peoples’ messages to the Natural England and its partners about enjoying the coast: Help make it safe (from attack and by changing adult attitudes toward us) 3 Help us get there Give us information Provide affordable events and activities Run nature trips Provide shelter

Formation of Pillars at the Boundaries between H II Regions and Molecular Clouds

We investigate numerically the hydrodynamic instability of an ionization front (IF) accelerating into a molecular cloud, with imposed initial perturbations of different amplitudes. When the initial amplitude is small, the imposed perturbation is completely stabilized and does not grow. When the initial perturbation amplitude is large enough, roughly the ratio of the initial amplitude to wavelength is greater than 0.02, portions of the IF temporarily separate from the molecular cloud surface, locally decreasing the ablation pressure. This causes the appearance of a large, warm HI region and triggers nonlinear dynamics of the IF. The local difference of the ablation pressure and acceleration enhances the appearance and growth of a multimode perturbation. The stabilization usually seen at the IF in the linear regimes does not work due to the mismatch of the modes of the perturbations at the cloud surface and in density in HII region above the cloud surface. Molecular pillars are observed in the late stages of the large amplitude perturbation case. The velocity gradient in the pillars is in reasonably good agreement with that observed in the Eagle Nebula. The initial perturbation is imposed in three different ways: in density, in incident photon number flux, and in the surface shape. All cases show both stabilization for a small initial perturbation and large growth of the second harmonic by increasing amplitude of the initial perturbation above a critical value.Comment: 21 pages, 8 figures, accepted for publication in ApJ. high resolution figures available upon reques

The late Pliocene palaeoenvironments and palaeoclimates of the western Iberian Atlantic margin from the Rio Maior flora

Using a revised chronology, a new palynological study on the late Pliocene (Piacenzian and earliest Gelasian) Rio Maior site of the Tagus Basin in western Portugal has been undertaken from the F98 core. Combining light microscopy and scanning electron microscopy, a total of 127 different pollen and spore taxa have been identified from the Piacenzian Lake and indicate the presence of a subtropical to warm-temperate mixed forest during the majority of the Piacenzian (3.6–2.8 Ma). It is only in the latest Piacenzian (after 2.8 Ma) that progressive ex- tinctions of climate sensitive taxa and a drop in diversity indicate a cooling and drying climate trend that has also been recorded from high-latitude localities. By the earliest Gelasian (2.58 Ma), a low diversity Ericaceae and Pinus dominated vegetation remained. The Piacenzian flora of Rio Maior also shows fluctuations in the presence of climate sensitive taxa and pollen-spore diversity that may be related to Piacenzian glaciations.This research work was part of the PhD project supported by the Portuguese Foundation for Science and Technology (Ref. SFRH/BD/18754/2004). The work of Diamantino I. Pereira was partially co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Fundação para a Ciência e Tecnologia

Trends and Issues in Educational Psychology

The review of issues in educational psychology looks at areas of innovation as well as areas of stagnation. The authors challenge researchers to find meaningful information which has utility in the development and improvement of teaching

Gravitational redshift of galaxies in clusters as predicted by general relativity

The theoretical framework of cosmology is mainly defined by gravity, of which general relativity is the current model. Recent tests of general relativity within the \Lambda Cold Dark Matter (CDM) model have found a concordance between predictions and the observations of the growth rate and clustering of the cosmic web. General relativity has not hitherto been tested on cosmological scales independent of the assumptions of the \Lambda CDM model. Here we report observation of the gravitational redshift of light coming from galaxies in clusters at the 99 per cent confidence level, based upon archival data. The measurement agrees with the predictions of general relativity and its modification created to explain cosmic acceleration without the need for dark energy (f(R) theory), but is inconsistent with alternative models designed to avoid the presence of dark matter.Comment: Published in Nature issued on 29 September 2011. This version includes the Letter published there as well as the Supplementary Information. 23 pages, 7 figure

Signatures of Young Star Formation Activity Within Two Parsecs of Sgr A*

We present radio and infrared observations indicating on-going star formation activity inside the $\sim2-5$ pc circumnuclear ring at the Galactic center. Collectively these measurements suggest a continued disk-based mode of on-going star formation has taken place near Sgr A* over the last few million years. First, VLA observations with spatial resolution 2.17$"\times0.81"$ reveal 13 water masers, several of which have multiple velocity components. The presence of interstellar water masers suggests gas densities that are sufficient for self-gravity to overcome the tidal shear of the 4$\times10^6$ \msol\, black hole. Second, SED modeling of stellar sources indicate massive YSO candidates interior to the molecular ring, supporting in-situ star formation near Sgr A* and appear to show a distribution similar to that of the counter-rotating disks of $\sim$100 OB stars orbiting Sgr A*. Some YSO candidates (e.g., IRS~5) have bow shock structures suggesting that they have have gaseous disks that are phototoevaporated and photoionized by the strong radiation field. Third, we detect clumps of SiO (2-1) and (5-4) line emission in the ring based on CARMA and SMA observations. The FWHM and luminosity of the SiO emission is consistent with shocked protostellar outflows. Fourth, two linear ionized features with an extent of $\sim0.8$ pc show blue and redshifted velocities between $+50$ and $-40$ \kms, suggesting protostellar jet driven outflows with mass loss rates of $\sim5\times10^{-5}$ solar mass yr$^{-1}$. Finally, we present the imprint of radio dark clouds at 44 GHz, representing a reservoir of molecular gas that feeds star formation activity close to Sgr A*.Comment: 38 pages, 10 figures, ApJ (in press

Tracing the Bipolar Outflow from Orion Source I

Using CARMA, we imaged the 87 GHz SiO v=0 J=2-1 line toward Orion-KL with 0.45 arcsec angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE--SW axis, in agreement with the model of Greenhill et al. (2004). The extended high velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High velocity gas extends farthest along a NW--SE axis, suggesting that the outflow direction changes on time scales of a few hundred years.Comment: 4 pages, 4 figures; accepted for publication in Ap J Letter

South Carolina Bond for money between D. Goudelock and Anderson Pound[?], Union District, February 8, 1860. Signed by States Rights Gist and John R. R. Giles

$5000 South Carolina bond for money between D. Goudelock and Anderson Pound[?], Union District, February 8, 1860. Signed by States Rights Gist, John R. R. Giles, T.W.G. Giles and one other.https://digitalcommons.wofford.edu/littlejohnmss/1243/thumbnail.jp