1,386 research outputs found

    Sustainable packaging in the healthcare industry

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    The recycling of plastics tends to lag behind other packaging materials. The research investigates opportunities to improve the capture of valuable packaging polymers and to preserve their specification during recycle operations, thus increasing second user opportunity. The legislative and policy drivers on the sustainable use of plastics are described and discussed with particular reference to achieving sustainability, reuse and recycle of healthcare packaging materials. Four strategic methods of achieving improvements in sustainability, reuse and recycle are developed to represent aspects of sorting of materials, collection of recyclables, replacement of unsustainable packaging materials and measurement of the environmental impacts of packaging and changes in packaging, using examples of packaging from GlaxoSmithKline consumer healthcare and medical products. The use of radio frequency identification methodology as a means of separating high quality plastics and individual reusable devices from mixed waste streams has been developed and trialled under simulated materials recycling and separation conditions. The use of Reverse Vending Machines (RVM's) designed to capture high quality polyethylene terephthalate polymers is described along with results of successful trials on this method of capture in the out of home consumption sector. Recovered material is suitable for reuse in food grade applications after reprocessing. A novel biodegradable packaging material has been successfully developed from sources of green waste as an alternative to existing polymer packaging materials for transport of vaccines, and provides results that are extendable to the replacement of other types of packaging over a wide range of consumer goods. The material also offers intangible benefits to a business in terms of claims that can be made within a corporate social responsibility (CSR) report. Life cycle analysis methodologies have been used to illustrate the environmental benefits that can be achieved by reuse of polypropylene as an example of a widely used packaging polymer with potential for reuse in other industrial sectors. The implications of the results obtained in this work should be of value in the future eco-design of polymer products designed to make end-of-life recovery and recycle more efficient and environmentally beneficial

    An R Framework for the Partitioning of Linkage Disequilibrium between and Within Populations

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    Patterns of linkage disequilibrium (LD) across the genome result from a myriad of contributing factors including selection and genetic drift. Natural selection can increase LD near individually selected loci, or it can influence LD between epistatically selected groups of loci. Statistics have previously been derived which compare levels of linkage disequilibrium in subpopulations relative to the total population. These statistics may be leveraged to identify loci that may be under selection or epistatic selection. This is a powerful approach, but to date no framework exists to support its use on a genome-wide scale. We present ohtadstats, an R package designed to facilitate the implementation of Ohta’s D statistics in a variety of use cases. Statistics calculated by this package can be used to determine whether a locus is under selection or not, and can provide insight into the nature of the selection that is taking place (hard sweep or epistatic selection). This package is available on the Comprehensive R Archive Network (CRAN).   Funding statement: This research was supported by funding from the USDA Agricultural Research Service. PFP is funded by the University of Missouri Life Sciences Fellowship and a training grant from the National Institute of Health (T32GM008396)

    Ultraviolet Emission Line Ratios of Cataclysmic Variables

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    We present a statistical analysis of the ultraviolet emission lines of cataclysmic variables (CVs) based on ≈430\approx 430 ultraviolet spectra of 20 sources extracted from the International Ultraviolet Explorer Uniform Low Dispersion Archive. These spectra are used to measure the emission line fluxes of N V, Si IV, C IV, and He II and to construct diagnostic flux ratio diagrams. We investigate the flux ratio parameter space populated by individual CVs and by various CV subclasses (e.g., AM Her stars, DQ Her stars, dwarf novae, nova-like variables). For most systems, these ratios are clustered within a range of ∼1\sim 1 decade for log Si IV/C IV ≈−0.5\approx -0.5 and log He II/C IV ≈−1.0\approx -1.0 and ∼1.5\sim 1.5 decades for log N V/C IV ≈−0.25\approx -0.25. These ratios are compared to photoionization and collisional ionization models to constrain the excitation mechanism and the physical conditions of the line-emitting gas. We find that the collisional models do the poorest job of reproducing the data. The photoionization models reproduce the Si IV/C IV line ratios for some shapes of the ionizing spectrum, but the predicted N V/C IV line ratios are simultaneously too low by typically ∼0.5\sim 0.5 decades. Worse, for no parameters are any of the models able to reproduce the observed He II/C IV line ratios; this ratio is far too small in the collisional and scattering models and too large by typically ∼0.5\sim 0.5 decades in the photoionization models.Comment: LaTeX format, uses aaspp4.sty, 28 pages, 11 Postscript figures, accepted for publication in The Astrophysical Journal 10/16/9

    Mechanical properties and characterization of epoxy composites containing highly entangled as-received and acid treated carbon nanotubes

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    Huntsman–Merrimack MIRALON® carbon nanotubes (CNTs) are a novel, highly entan-gled, commercially available, and scalable format of nanotubes. As-received and acid-treated CNTs were added to aerospace grade epoxy (CYCOM® 977-3), and the composites were characterized. The epoxy resin is expected to infiltrate the network of the CNTs and could improve mechanical properties. Epoxy composites were tested for flexural and viscoelastic properties and the as-re-ceived and acid treated CNTs were characterized using Field-Emission Scanning and Transmission Electron Microscopy, X-Ray Photoelectron Spectroscopy, and Thermogravimetric Analysis. Composites containing 0.4 wt% as-received CNTs showed an increase in flexural strength, from 136.9 MPa for neat epoxy to 147.5 MPa. In addition, the flexural modulus increased from 3.88 GPa for the neat epoxy to 4.24 GPa and 4.49 GPa for the 2.0 wt% and 3.0 wt% as-received CNT/epoxy compo-sites, respectively. FE-SEM micrographs indicated good dispersion of the CNTs in the as-received CNT/epoxy composites and the 10 M nitric acid 6 h treatment at 120 °C CNT/epoxy composites. CNTs treated with 10 M nitric acid for 6 h at 120 °C added oxygen containing functional groups (C– O, C=O, and O=C–O) and removed iron catalyst present on the as-received CNTs, but the flexural properties were not improved compared to the as-received CNT/epoxy composites

    People of the British Isles: preliminary analysis of genotypes and surnames in a UK control population

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    There is a great deal of interest in fine scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to play a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. Here we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK control population that can be used as a resource by the research community as well as providing fine scale genetic information on the British population. So far, some 4,000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3,865 samples that have been geocoded indicates that 75% have a mean distance between grandparental places of birth of 37.3km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1,057 samples demonstrates the value of these samples for investigating fine scale population structure within the UK, and shows how this can be enhanced by the use of surnames

    Perspectives on laser-plasma physics in the relativistic transparency regime

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    With the advent of multi-petawatt lasers, the relativistic transparency regime of laser-plasma interactions becomes readily accessible for near-solid density targets. Initially opaque targets that undergo relativistic self-induced transparency (RSIT) have already shown to result in promising particle acceleration and radiation generation mechanisms, as well as relativistic optical and photonics phenomena that modify the spatial, temporal, spectral and polarization properties of the laser pulse itself. At the maximum laser intensities currently available, this opaque-to-RSIT transition regime can be achieved through ultrafast ionization, heating and expansion of initially ultrathin foil targets. Here, we review findings from our programme of work exploring this regime experimentally and numerically, including changes to the laser energy absorption, mechanisms for laser-driven particle acceleration and the generation of a relativistic plasma aperture. New physics induced by this aperture, such as the production of intense light with higher order spatial modes and higher harmonics, and spatially-structured and temporally-varying polarization states, is summarized. Prospects for exploring the physics of the RSIT regime with higher intensity and high repetition rate lasers, including expected new phenomena such as high-field effects and the application of new techniques such as machine learning, are also discussed; outlining directions for the future development of this promising laser-plasma interaction regime
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