12 research outputs found

    Organic photovoltaic devices with enhanced efficiency processed from non-halogenated binary solvent blends

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    The development of processing routes to fabricate organic photovoltaic devices (OPVs) using non-halogenated solvents is a necessary step towards their eventual commercialisation. To address this issue, we have used Hansen solubility parameter analysis to identify a non-halogenated solvent blend based on a mixture of carbon disulphide and acetone. This solvent blend was then used to deposit a donor–acceptor polymer–fullerene thin-film that was then used as the active layer of bulk-heterojunction OPV. For the benchmark polymer:fullerene system PCDTBT:PC70BM, a power conversion efficiency of 6.75% was achieved; a 20% relative improvement over reference cells processed using the chlorinated-solvent chlorobenzene. Improvements in device efficiency are attributed to an increase in electron and hole conductivity resulting from enhanced fullerene crystallisation; a property that leads to enhanced device efficiency through improved charge extraction

    Carboniferous and Permian Rugosochonetidae (Brachiopoda) from West Spitsbergen

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    The rugosochonetid brachiopod species Lissochonetes geinitzianus from the Kazimovian of the Nordenskioldbreen Formation, and Dyoros (Dyoros) mucronata sp. nov., Dyoros (Dyoros) spitzbergianus and Lissochonetes superba from the Artinskian to latest Permian Kapp Starostin Formation in West Spitsbergen are described and figured. Dyoros is generally restricted to the Boreal Realm, whereas Lissochonetes is mostly distributed in the Boreal Realm, but occasionally present in the Palaeoequatorial and Gondwanan Realms<br /

    Preliminary lithofacies assessment and 40Ar/39Ar ages of Cenozoic volcanic sequences in eastern Marie Byrd Land

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    Because of its remoteness, Marie Byrd Land is among the most inaccessible and least visited parts of Antarctica. However, it contains a very poorly studied, large Cenozoic alkaline volcanic province and an outstanding record of volcanism coeval with glaciation (LeMasurier & Thomson 1990). This short note describes the results of the second of two planned periods of fieldwork, which form part of the West Antarctic Volcano Exploration (WAVE) project. The background to WAVE and preliminary results of the 1989–1990 fieldwork are described in Smellie et al. (1990) and McIntosh et al. (1990). The studies described here took place between 2 November 1990 and 11 January 1991

    Recent volcanic accretion at 9 degrees N-10 degrees N East Pacific Rise as resolved by combined geochemical and geological observations

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    The ridge crest at 9°N-10°N East Pacific Rise (EPR) is dominated by overlapping lava flows that have overflowed the axial summit trough and flowed off-axis, forming a shingle-patterned terrain up to ∌2-4 km on either side of the axial summit trough. In this study, we employ 230Th- 226Ra dating methods, in conjunction with geochemistry and seafloor geological observations, in an effort to discern the stratigraphic relationships between adjacent flows. We measured major and trace elements and 87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, and 238U-230Th- 226Ra for lava glass samples collected from several flow units up to ∌2 km away from the axial summit trough on the ridge crest at 9°50â€ČN EPR. Statistical analysis of the 238U- 230Th-226Ra data indicates that all but one measured sample from these flows cannot be resolved from the zero-age population; thus, we cannot confidently assign model ages to samples for discerning stratigraphic relationships among flows. However, because groups of samples can be distinguished based on similarities in geochemical compositions, particularly incompatible element abundances with high precision-normalized variability such as U and Th, and because the range of compositions is much greater than that represented by samples from the 1991-1992 and 2005-2006 eruptions, we suggest that the dive samples represent 6-10 eruptive units despite indistinguishable model ages. Geochemical variability between individual flows with similar ages requires relatively rapid changes in parental melt composition over the past ∌2 ka, and this likely reflects variations in the relative mixing proportions of depleted and enriched melts derived from a heterogeneous mantle source. ©2013. American Geophysical Union. All Rights Reserved

    Prevalence of oral human papillomavirus infection among Australian Indigenous adults

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    Importance: Human papillomavirus (HPV) infection is associated with oropharyngeal squamous cell carcinoma. International estimates suggest overall oral HPV prevalence is 7.5%, with prevalence of oral HPV types 16 and 18 being 1.6%; prior Australian estimates suggest oral HPV prevalence is 2.3%, with HPV-16 and HPV-18 being 1.3%. Objectives: To estimate the prevalence of oral HPV infection among Indigenous Australians and to report the prevalence of factors associated with high-risk HPV types (ie, HPV-16 and HPV-18) and HPV types linked with Heck disease (ie, HPV-13 and HPV-32). Design, Setting, and Participants: This cross-sectional study analyzed HPV screening results from saliva samples collected from 1011 Indigenous Australians between February 2018 and January 2019. Data were analyzed from May 2018 to May 2019. Recruitment occurred through Aboriginal Community Controlled Health Organisations in South Australia. Eligibility included identifying as Indigenous, residing in South Australia, and being aged 18 years or older. Main Outcomes and Measures: Saliva samples were collected, with microbial DNA for genotyping extracted. Sociodemographic parameters, health-related behaviors, and sexual history data were collected. Analyses were stratified by sex as well as by HPV types 13 and 32 (Heck disease) and 16 and 18 (high risk of oropharyngeal squamous cell carcinoma). Multivariable analyses were conducted to obtain adjusted odds ratios (ORs). Results: Data were obtained for 910 participants (median [interquartile range] age, 37 [27-51] years); 595 participants (65%) were female and 572 (63%) resided in nonmetropolitan locations. In all, 321 saliva samples (35.3%; 95% CI, 32.2%-38.4%) were positive for oral HPV (106 [33.7%] men; 215 [36.1%] women). The highest prevalence was found for HPV types 13 and 32 (207 [22.7%] total; 60 [19.0%] men; 147 [24.7%] women) followed by HPV types 16 and 18 (30 [3.3%] total; 9 [2.9%] men; 21 [3.5%] women). After multivariable analysis, risk factors associated with HPV types 13 and 32 included nonmetropolitan residential status (OR, 2.06; 95% CI, 1.10-3.88) and not having had a tonsillectomy (OR, 2.74; 95% CI, 1.05-7.16). Among women, having obtained a high school education or less was associated with lower odds of HPV-16 and HPV-18 infection (OR, 0.16; 95% CI, 0.03-0.97). Conclusions and Relevance: Prevalence of oral HPV infection in a large sample of Indigenous Australians was high, with one-third testing positive. The most prevalent HPV types were those associated with Heck disease. The prevalence of HPV types associated with oropharyngeal squamous cell carcinoma exceeded both Australian and international population-level estimates.Lisa M. Jamieson ... Xiangqun Ju ... Richard M. Logan ... Sneha Sethi ... David Roder ... Joanne Hedges ... et al

    Permian marine invertebrate provinces of the Gondwanan Realm

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    Antarctic surface temperature and elevation during the Last Glacial Maximum

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    Water-stable isotopes in polar ice cores are a widely used temperature proxy in paleoclimate reconstruction, yet calibration remains challenging in East Antarctica. Here, we reconstruct the magnitude and spatial pattern of Last Glacial Maximum surface cooling in Antarctica using borehole thermometry and firn properties in seven ice cores. West Antarctic sites cooled ~10°C relative to the preindustrial period. East Antarctic sites show a range from ~4° to ~7°C cooling, which is consistent with the results of global climate models when the effects of topographic changes indicated with ice core air-content data are included, but less than those indicated with the use of water-stable isotopes calibrated against modern spatial gradients. An altered Antarctic temperature inversion during the glacial reconciles our estimates with water-isotope observations. © 2021 American Association for the Advancement of Science. All rights reserved

    Globalization of tephrochronology: new views from Australasia

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