Robust Superamphiphilic Membrane with a Closed-Loop Life Cycle

Oil-spill remediation is an international environmental challenge, and superamphiphilic membranes, as a promising solution, have recently drawn lots of attention. However, the robustness of the conventional membrane design is less satisfying under severe conditions during practical applications. Additionally, it is unavoidable for the membranes to face a series of foulants in their practical working environment, for example, algae and sand. These foulants will block the membrane, which leads to a new economic and environmental problem in terms of waste management at the end of their life. To address the aforementioned challenges, a new generation of superamphiphilic vitrimer epoxy resin membranes (SAVER) to separate oil and water efficiently is reported. Similar to classical epoxy resins, SAVER shows strong mechanical robustness and sustains exposure to aqua regia and sodium hydroxide solutions. Furthermore, the blocked membrane can be easily recovered when contaminated with mixed foulants by using dynamic transesterification reactions in the polymer network. The ease with which biobased SAVER can be manufactured, used, recycled, and re-used without losing value points to new directions in designing a closed-loop superamphiphilic membrane life cycle

BioAcoustica : a free and open repository and analysis platform for bioacoustics

We describe an online open repository and analysis platform, BioAcoustica (http://bio. acousti.ca), for recordings of wildlife sounds. Recordings can be annotated using a crowdsourced approach, allowing voice introductions and sections with extraneous noise to be removed from analyses. This system is based on the Scratchpads virtual research environment, the BioVeL portal and the Taverna workflow management tool, which allows for analysis of recordings using a grid computing service. At present the analyses include spectrograms, oscillograms and dominant frequency analysis. Further analyses can be integrated to meet the needs of specific researchers or projects. Researchers can upload and annotate their recordings to supplement traditional publication

First assessment of Mercury (Hg) concentrations in skin and Carapace of Flatback Turtles (Natator depressus) (Garman) from Western Australia

Mercury pollution in the surface ocean has more than doubled over the past century. Within oceanic food webs, sea turtles have life history characteristics that make them especially vulnerable to mercury (Hg) accumulation. In this study we investigated Hg concentrations in the skin and carapace of nesting flatback turtles (Natator depressus) from two rookeries in Western Australia. A total of 50 skin samples and 52 carapace samples were collected from nesting turtles at Thevenard Island, and 23 skin and 28 carapace samples from nesting turtles at Eighty Mile Beach. We tested the influence of turtle size on Hg concentrations, hypothesising that larger and likely older adult turtles would exhibit higher concentrations due to more prolonged exposure to Hg. We compared the rookeries, hypothesising that the turtles from the southern rookery (Thevenard Island) were more likely to forage and reside in the Pilbara region closer to industrial mining activity and loading ports (potential exposure to higher environmental Hg concentrations) with turtles from the northern rookery (Eighty Mile Beach) more likely to reside and feed in the remote Kimberley. Turtles from the Eighty Mile Beach rookery had significantly higher skin Hg concentrations (x̄ = 19.4 ± 4.8 ng/g) than turtles from Thevenard Island (x̄ = 15.2 ± 5.8 ng/g). There was no significant difference in carapace Hg concentrations in turtles between Eighty Mile Beach (x̄ = 48.4 ± 21.8 ng/g) and Thevenard Island (x̄ = 41.3 ± 16.5 ng/g). Turtle size did not explain Hg concentrations in skin samples from Eighty Mile Beach and Thevenard Island, but turtle size explained 43.1% of Hg concentrations in the carapace of turtles from Eighty Mile Beach and 44.2% from Thevenard Island. Mercury concentrations in the flatback turtles sampled in this study are relatively low compared to other sea turtles worldwide, likely a result of the generally low concentrations of Hg in the Australian environment. Although we predicted that mining activities would influence flatback turtle Hg bioaccumulations, our data did not support this effect. This may be a result of foraging ground overlap between the two rookeries, or the predominant wind direction carrying atmospheric Hg inland rather than seaward. This is the first Hg study in skin and carapace of flatback turtles and represents a baseline to compare Hg contamination in Australia’s surrounding oceans

Hymenopterous parasites associated with Phyllonorycter blancardella [Lepidoptera: Gracillariidae] in Nova Scotia and Quebec

Une étude a été effectuée dans des vergers commerciaux et non-traités du Québec et de la Nouvelle-Écosse pour déterminer l’abondance et la diversité des parasites de la mineuse marbrée, Phyllonorycter blancardella [Lepidoptera : Gracillariidae]. Au Québec, 29 espèces de parasites ont été retrouvées et elles appartenaient à 7 familles, soit Aphelinidae, Braconidae, Chalcidae, Eulophidae, Ichneumonidae, Pteromalidae et Scelionidae. Les espèces les plus fréquentes étaient : Pholetesor ornigis (67 %), Sympiesis marylandensis (11 %), S. serviceicornis (7 %), Pnigalio maculipes (1,5 %), Tetrasticus spp. (1,2 %). Toutes les autres espèces représentaient moins de 1 % des espèces trouvées. Pholetesor pedias, une espèce braconide relâchée à Frelighsburg, Québec en 1983 n’a pas été détectée en 1984 et 1985. En Nouvelle-Écosse, 19 espèces ont été trouvées et elles appartenaient à 5 familles, soit Braconidae, Chalcidae, Eulophidae, Ichneumonidae et Pteromalidae. Les espèces les plus fréquentes étaient : Pholetesor ornigis (52 %), Pnigalio maculipes (14 %), Sympiesis serviceicornis (12 %), S. marylandensis (9,5 %), Sympiesis spp. (5 %), Horismenus fraternus (1,8 %), Paraleurocerus sp. (1,3 %), Stictopisthus flaviceps (1,1 %); toutes les autres espèces représentaient moins de 1 % des espèces trouvées. Sept et cinq espèces d’hyperparasites ont été retrouvées en Nouvelle-Écosse et au Québec, respectivement. Sticopisthus bilineatus, S. flaviceps, Euderis sp., Pnigalio epilobii, P. pallipes and Paraleurocerus bicoloripes constituent des nouvelles mentions comme parasites de la mineuse marbrée pour l’Amérique du Nord.Mined leaves were collected in commercial and unsprayed (no insecticides) apple orchards of Quebec and Nova Scotia to determine the relative abundance and diversity of parasites of the spotted tentiform leafminer, Phyllonorycter blancardella [Lepidoptera: Gracillariidae]. In Quebec, 29 species of leafminer parasites were recovered, belonging to 7 families: Aphelinidae, Braconidae, Chalcidae, Eulophidae, Ichneumonidae, Pteromalidae and Scelionidae. The most prevalent species were Pholetesor ornigis (67%), Sympiesis marylandensis (11%), S. serviceicornis (7%), Pnigalio maculipes (1.5%), Tetrasticus spp. (1.2%), while all other species accounted for < 1.0%. Pholetesor pedias, a braconid released in 1983 at Frelighsburg, Quebec, was not found in the 1984 and 1985 surveys. In Nova Scotia, 19 parasite species were recovered, belonging to 5 families : Braconidae, Encyrtidae, Eulophidae, Ichneumonidae and Pteromalidae. The most prevalent species were: Pholetesor ornigis (52%), Pnigalio maculipes (14%), Sympiesis serviceicornis (12%), S. marylandensis (9.5%), Sympiesis spp. (5%), Horismenus fraternus (1.8%), Paraleurocerus sp. (1.3%), Stictopisthus flaviceps (1.1%), while all other species accounted for < 1%. Seven and five species of hyperparasites were recovered in Nova Scotia and Quebec, respectively. New records for North America for the spotted tentiform leafminer as a host are : Sticopisthus bilineatus, S. flaviceps, Euderis sp., Pnigalio epilobii, P. pallipes and Paraleurocerus bicoloripes

Biobased Photopolymer Resin for 3D Printing Containing Dynamic Imine Bonds for Fast Reprocessability

Acrylic photopolymer resins are widely used in stereolithographic 3D printing. However, the growing demand for such thermosetting resins is weighing on global issues such as waste management and fossil fuel consumption. Therefore, there is an increasing demand for reactive components that are biobased and enable recyclability of the resulting thermoset products. In this work, the synthesis of a photo-cross-linkable molecule containing dynamic imine bonds based on biobased vanillin and dimer fatty diamine is described. Using the biobased building blocks, formulations containing reactive diluent and a photoinitiator were prepared. The mixtures could be rapidly cross-linked under UV light, yielding vitrimers. Using digital light processing, 3D-printed parts were prepared, which were rigid, thermally stable, and reprocessed within 5 min at elevated temperature and pressure. The addition of a building block containing a higher concentration of imine bonds accelerated the stress relaxation and improved the mechanical rigidity of the vitrimers. This work will contribute to the development of biobased and recyclable 3D-printed resins to facilitate the transition to a circular economy.</p

Excited-state calculations with quantum Monte Carlo

Quantum Monte Carlo methods are first-principle approaches that approximately solve the Schr\"odinger equation stochastically. As compared to traditional quantum chemistry methods, they offer important advantages such as the ability to handle a large variety of many-body wave functions, the favorable scaling with the number of particles, and the intrinsic parallelism of the algorithms which are particularly suitable to modern massively parallel computers. In this chapter, we focus on the two quantum Monte Carlo approaches most widely used for electronic structure problems, namely, the variational and diffusion Monte Carlo methods. We give particular attention to the recent progress in the techniques for the optimization of the wave function, a challenging and important step to achieve accurate results in both the ground and the excited state. We conclude with an overview of the current status of excited-state calculations for molecular systems, demonstrating the potential of quantum Monte Carlo methods in this field of applications

Carboniferous petroleum systems around the Mid North Sea High, UK

The existence of an extensive, prospective Visean–Namurian Carboniferous petroleum system in and around the hitherto under-explored Mid North Sea High is documented. Evidence is drawn from integrated analysis of over 50,000 line kilometres of seismic data and well data, together with regional source rock screening, reservoir analysis and basin modelling. Visean-Namurian marine and non-marine mudstones and coal source rocks are interbedded within fluvial and marine reservoir sandstones within a stacked succession up to 5 km thick. Source rocks are dominantly gas-prone with oil-prone intervals, and have reached oil to gas maturity levels dependent on location. Burial/thermal history modelling indicates a kitchen area on the southern margin of the Mid North Sea High with northwest and northeastwards migration of gas and oil during Mesozoic and Cenozoic times. A variety of structural and stratigraphic traps are possible, including intraformational Carboniferous traps, with a regional seal at Permian (Zechstein) level. Synthesis of many previously unpublished datasets demonstrates the Visean–Namurian play south of the Mid North Sea High as part of an extensive petroleum system from the East Irish Sea, across onshore to offshore UK and into The Netherlands sector of the North Sea. The purpose of this synthesis is to highlight future exploration opportunities beneath and northwards of the productive Westphalian Southern North Sea gas basin, and to begin to de-risk the petroleum systems that are exemplified by the lower Carboniferous Breagh Field in a frontier area of the mature North Sea province

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio