EOS MLS observations of dehydration in the 2004-2005 polar winters

We prove various estimates for the first eigenvalue of the magnetic Dirichlet Laplacian on a bounded domain in two dimensions. When the magnetic field is constant, we give lower and upper bounds in terms of geometric quantities of the domain. We furthermore prove a lower bound for the first magnetic Neumann eigenvalue in the case of constant field.Comment: 19 page

The integration of single case designs in coaching contexts: A commentary for applied sport psychologists

From personal experiences of working with coaches toward the modification of behaviors and psychological constructs that include motivation, enjoyment, and self-confidence, this commentary highlights how the integration of single case designs can enhance the services of sport psychology practitioners. Interventions within golf, soccer, and tennis are outlined, targeting factors pertinent to the coaches, their players or team members, and the development of relationships with parents. Single case designs are posited as enabling the implementation of personal, evidence-based interventions that yield perceptible differences in cognitive, affective, and behavioral responses within athletic populations; factors that enhance and underpin the practitioner-coach relationship

Metal removal from soil leachates using DTPA-functionalised maghemite nanoparticles, a potential soil washing technology

There is significant current interest in the application of magnetic (magnetite or maghemite) nanoparticles functionalised with chelating agents for the environmental remediation of metal contaminated waters and solutions. Whilst there is a body of knowledge about the potential remediation efficacy of such engineered nanoparticles from studies involving synthetic solutions of single metals, there is relatively little data involving mixed-metal solutions and virtually no studies about nanoparticle performance in chemically complex environmental solutions representing those to which a scaled-up nanoremediation process might eventually be applied. Therefore, we investigated the ability of diethylenetriaminepentaacetic acid (DTPA)-functionalised, silica-coated maghemite nanoparticles to extract potentially toxic (Cd, Co, Cu) and "non-toxic" (Ca, Mg) metals from solution (initial [metal] = 10 mg L ; pH range: 2-8) and to extract a wider range of elements (As, Ca, Cd, Co, Cr, Cu, Mg, Na, Pb, Zn) from leachate obtained from 10 different contaminated soils with variable initial pH, (semi-)metal and dissolved organic carbon (DOC) concentrations. The functionalised nanoparticles could extract the potentially toxic metals with high efficiency (in general >70%) from single metal solutions and with efficiencies that were either unaffected or reduced from the soil leachates. K values remained high (>500 L kg ), even for the soil leachate extractions. Our findings show that DOC and relatively high concentrations of non-toxic elements do not necessarily reduce the efficiency of metal contaminant removal by DTPA-functionalised magnetic nanoparticles and thus demonstrate the remediation potential of such particles when added to chemically complex soil-derived contaminated solutions. [Abstract copyright: Copyright © 2018 Elsevier Ltd. All rights reserved.

Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field

Accepted for publication in Astronomy & Astrophysics. Reproduced with permission from Astronomy & Astrophysics, © 2017 ESO.The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied extragalactic field. We create mock catalogues of low-power radio galaxies based on Monte Carlo simulations to derive first-order predictions of the fraction of remnants in radio flux limited samples for comparison with our Lockman-Hole sample. We have combined LOFAR observations at 150 MHz with public surveys at higher frequencies to perform a complete selection and have used, for the first time, a combination of spectral criteria (e.g. the classical ultra-steep spectral index and high spectral curvature) as well as morphological criteria (e.g. low radio core prominence and relaxed shapes). Mock catalogues of radio galaxies are created based on existing spectral and dynamical evolution models combined with observed source properties. We have identified 23 candidate remnant radio galaxies which cover a variety of morphologies and spectral characteristics. We suggest that these different properties are related to different stages of the remnant evolution. We find that ultra-steep spectrum remnants represent only a fraction of our remnant sample suggesting a very rapid luminosity evolution of the radio plasma. Results from mock catalogues demonstrate the importance of dynamical evolution in the remnant phase of low-power radio galaxies to obtain fractions of remnant sources consistent with our observations. Moreover, these results confirm that ultra-steep spectrum remnants represent only a subset of the entire population ($\sim$50%) when frequencies higher than 1400 MHz are not included in the selection process, and that they are biased towards old ages.Peer reviewe

Measurement of complex fragments and clues to the entropy production from 42-137-MeV/nucleon Ar + Au

Intermediate-rapidity fragments with A=1-14 emitted from 42-137-MeV/nucleon Ar + Au have been measured. Evidence is presented that these fragments arise from a common moving source. Entropy values are extracted from the mass distributions by use of quantum statistical and Hauser-Feshbach theories. The extracted entropy values of S/A≈2-2.4 are much smaller than the values expected from measured deuteron-to-proton ratios, but are still considerably higher than theoretically predicted values

LOFAR discovery of a 700-kpc remnant radio galaxy at low redshift

Remnant radio galaxies represent the final dying phase of radio galaxy evolution, in which the jets are no longer active. Due to their rarity in flux limited samples and the difficulty of identification, this dying phase remains poorly understood and the luminosity evolution largely unconstrained. Here we present the discovery and detailed analysis of a large (700 kpc) remnant radio galaxy with a low surface brightness that has been identified in LOFAR images at 150 MHz. By combining LOFAR data with new follow-up Westerbork observations and archival data at higher frequencies, we investigated the source morphology and spectral properties from 116 to 4850 MHz. By modelling the radio spectrum we probed characteristic timescales of the radio activity. The source has a relatively smooth, diffuse, amorphous appearance together with a very weak central compact core which is associated with the host galaxy located at z=0.051. From our ageing and morphological analysis it is clear that the nuclear engine is currently switched off or, at most, active at a very low power state. The host galaxy is currently interacting with another galaxy located at a projected separation of 15 kpc and a radial velocity offset of 300 km/s. This interaction may have played a role in the triggering and/or shut down of the radio jets. The spectral shape of this remnant radio galaxy differs from the majority of the previously identified remnant sources, which show steep or curved spectra at low to intermediate frequencies. In light of this finding and in preparation for new-generation deep low-frequency surveys, we discuss the selection criteria to be used to select representative samples of these sources.Comment: 10 pages, 6 figures, 5 tables, A&A accepte

Light particle spectra from 35 MeV/nucleon 12C-induced reactions on 197Au

Energy spectra for p, d, t, 3He, 4He, and 6He from the reaction 12C+197Au at 35 MeV/nucleon are presented. A common intermediate rapidity source is identified using a moving source fit to the spectra that yields cross sections which are compared to analogous data at other bombarding energies and to several different models. The excitation function of the composite to proton ratios is compared with quantum statistical, hydrodynamic, and thermal models

Remnant radio-loud AGN in the Herschel-ATLAS field

Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting ‘remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of Low-Frequency Array (LOFAR) and the Very Large Array, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (−1.5 ⩽ α1400150 ⩽ −0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population