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Now showing items 1 - 15 of 15

  • Production of ceramics from coal furnace bottom ash

    Glymond, Daniel   Roberts, Aaron   Russell, Mark   Cheeseman, Christopher  

    Furnace bottom ash (FBA) is generated in significant quantities from coal fired power stations and is a problem when commercially viable reuse applications do not exist locally. Representative samples of FBA from the Kilroot power station in Northern Ireland have been milled, pressed and sintered at a range of temperatures to form new ceramic materials. The effect of adding recycled glass to the mix has been investigated. The optimum FBA ceramics were produced by sintering at 960 degrees C and these had a density of 2.388 g/cm(3), zero water adsorption indicating minimal open porosity, and a Vickers hardness comparable to commercially available glass-ceramics. The addition of 20% by weight of glass reduced shrinkage during sintering, while the samples maintained high density and hardness. This glass addition allows greater dimensional control during sintering to form FBA ceramic tiles. The research demonstrates that FBA can be processed into ceramics for use in higher value products compared to conventional use as lightweight aggregate. Further research is required to optimize processing and fully characterize material properties. This novel approach to managing FBA has potential to transform a problematic waste in Northern Ireland into a valuable resource.
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  • Mirtazapine for symptom control in refractory gastroparesis

    Malamood, Mark   Roberts, Aaron   Kataria, Rahul   Parkman, Henry P.   Schey, Ron  

    Introduction: Gastroparesis symptoms can be severe and debilitating. Many patients do not respond to currently available treatments. Mirtazapine has been shown in case reports to reduce symptoms in gastroparesis. Aim: To assess the efficacy and safety of mirtazapine in gastroparetic patients. Methods: Adults with gastroparesis and poorly controlled symptoms were eligible. Participants were prescribed mirtazapine 15 mg PO qhs. Questionnaires containing the gastrointestinal cardinal symptom index (GCSI) and the clinical patient grading assessment scale (CPGAS) were completed by patients' pretreatment, at 2 weeks, and at 4 weeks. Primary end point was nausea and vomiting response to mirtazapine using the GCSI. Secondary end point was nausea and vomiting severity assessment using the CPGAS. P-values were calculated using the paired two-tailed Student's t-test. Intention to treat analysis was used. Results: A total of 30 patients aged 19-86 years were enrolled. Of those, 24 patients (80%) completed 4 weeks of therapy. There were statistically significant improvements in nausea, vomiting, retching, and perceived loss of appetite at 2 and 4 weeks (all P-values < 0.05) compared with pretreatment. There was a statistically significant improvement in the CPGAS score at week 2 (P=3D0.003) and week 4 (P < 0.001). Of the total patients, 14 (46.7%) experienced adverse effects from mirtazapine and due to this, 6 patients stopped therapy. Conclusion: Mirtazapine significantly improved both nausea and vomiting in gastroparetics after 2 and 4 weeks of treatment. Side effects led to treatment self-cessation in a fifth of patients. From these data, we conclude that mirtazapine improves nausea and vomiting, among other symptoms, in patients with gastroparesis and might be useful in select patients.
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  • Stephen J. Klaine In Memoriam

    Rice, Charles   Burton, G. Allen, Jr.   Wenning, Richard J.   Ward, Herb   Fernandes, Teresa F.   Lead, Jamie   Roberts, Aaron   van Genderen, Eric  

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  • Effect of Telavancin (Vibativ) on Routine Coagulation Test Results

    Gosselin, Robert   Dager, William   Roberts, Aaron   Freeman, Leslie   Gandy, Lisa   Gregg, Jeffrey   Dwyre, Denis  

    Telavancin (Vibativ, Astellas Pharma US, Deerfield, IL) is a lipoglycopeptide antibiotic that has activity against gram-positive microorganisms, but also has the ability to bind to artificial phospholipids found in coagulation reagents. Normal pooled plasma was spiked with telavancin to obtain concentrations of 0, 12.5, 25, 50, 75, 100, 125, and 150 mu g/mL of drug. Samples were tested using 3 different prothrombin time/international normalized ratio (INR) and activated partial thromboplastin time (aPTT) reagent systems, as well as for fibrinogen level, thrombin time, D-dimer level, dilute Russell viper venom time (DRVVT), protein C activity, and protein S activity. There was no effect of telavancin seen with non phospholipid-dependent assays: fibrinogen level, thrombin time, and D-dimer testing. All INR and aPTT systems demonstrated concentration-dependent increases in clotting times, with Innovin (Siemens Healthcare Diagnostics, Deerfield, IL) INRs the most dramatic. False-positive DRVVT ratios started at 12.5 mu g/mL of telavancin, with no effect on protein C or protein S levels until the telavancin level reached more than 100 mu g/mL.
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  • Acoustic kappa-density fluctuation waves in suprathermal kappa function fluids

    Collier, Michael R.   Roberts, Aaron   Vinas, Adolfo  

    We describe a new wave mode similar to the acoustic wave in which both density and velocity fluctuate. Unlike the acoustic wave in which the underlying distribution is Maxwellian, this new wave mode occurs when the underlying distribution is a suprathermal kappa-function and involves fluctuations in the power law index, kappa. This wave mode always propagates faster than the acoustic wave with an equivalent effective temperature and becomes the acoustic wave in the Maxwellian limit as kappa -> infinity. Published by Elsevier Ltd. on behalf of COSPAR.
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  • Effects of dietary methylmercury on the dopaminergic system of adult fathead minnows and their offspring

    Bridges, Kristin   Venables, Barney   Roberts, Aaron  

    Mercury (Hg) is a ubiquitous environmental contaminant and potent neurotoxin, which may be transformed by bacteria in aquatic ecosystems to methylmercury (MeHg), an organic form which bioaccumulates and biomagnifies. Consequently, long-lived organisms at the top of the food web are at risk of dietary MeHg exposure, which can be actively transferred from mother to offspring. Exposure during neurodevelopment can lead to serious, irreversible neurological dysfunction, associated with a variety of cognitive and motor abnormalities. At low dietary concentrations, MeHg exposure has been associated with deficits in attention and hyperactivity in multiple species. Pathways associated with cognitive function and motor activity are primarily associated with the dopaminergic system. The present study used a model fish species, Pimephales promelas, to examine the effects of MeHg exposure on dopamine concentrations and monoamine oxidase activity in embryos and adult brains. Adult fatheads were exposed for 30d to either a control or a treated diet (0.72ppm Hg). Embryonic and larval exposures were a result of maternal transfer of dietary MeHg. The authors confirmed hyperactive behaviors in embryos and detected significant changes in embryonic dopamine concentrations. Similar effects on dopamine concentrations were seen in the telencephalon of adult brains. Exposure to MeHg also corresponded with a significant decrease in monoamine oxidase activity in both embryos and brain tissue. Collectively, these results suggest that current exposure scenarios in North America are sufficient to induce alterations to this highly conserved neurochemical pathway in offspring, which may have adverse effects on fish behavior and cognition. (C) 2016 SETAC
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  • The Command Team Experimental Test-bed Stage 1: Design and Build of a Submarine Command Room Simulator

    Roberts, Aaron   Stanton, Neville   Fay, Daniel  

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  • Ultraviolet Radiation Enhances the Toxicity of Deepwater Horizon Oil to Mahi-mahi (Coryphaena hippurus) Embryos

    Alloy, Matthew   Baxter, David   Stieglitz, John   Mager, Edward   Hoenig, Ronald   Benetti, Daniel   Grosell, Martin   Oris, James   Roberts, Aaron  

    The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions barrels of crude oil into the Gulf of Mexico. Photoinduced toxicity following coexposure to ultraviolet (UV) radiation is one mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Mahi-mahi (Coryphaena hippurus), an important fishery resource, have positively buoyant, transparent eggs. These characteristics may result in mahi mahi embryos being at particular risk from photoinduced toxicity. The goal of this study was to determine whether exposure to ultraviolet radiation as natural sunlight enhances the toxicity of crude oil to embryonic mahi mahi. Mahi-mahi embryos were exposed to several dilutions of water accommodated fractions (WAF) from slick oil collected during the 2010 spill and gradations of natural sunlight in a fully factorial design. Here, we report that coexposure to natural sunlight and WAF significantly reduced percent hatch in mahi mahi embryos. Effect concentrations of PAH in WAF were within the range of surface PAH concentrations reported in the Gulf of Mexico during the Deepwater Horizon spill. These data suggest that laboratory toxicity tests that do not include UV may underestimate the toxicity of oil spills to early lifestage fish species.
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  • Special issue on enabling open and interoperable access to Planetary Science?and Heliophysics databases and tools

    Cecconi, Baptiste   Roberts, Aaron   Yamamoto, Yukio  

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  • Race and Immigration in the New Ireland eds. by Julieann Veronica Ulin, Heather Edwards, and Sean O’Brien

    Roberts, Aaron  

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    An electronic mail (email) communications system may include a mobile wireless communications device, a wireless communications network connected to the Internet, and an Internet Service Provider (ISP) server connected to the Internet for receiving emails for a given user. The system may further include an email proxy server connected to the Internet for pushing emails from the ISP server to the mobile wireless communications device via the wireless communications network. A user computer may be connected to the Internet and may include a client email application for periodically polling the ISP server to detect new emails. The client email application may also send new email notifications to the email proxy server upon detection of new emails to cause the email proxy server to push the new emails to the mobile wireless communications device.
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  • Reply [to “Comment on ‘Do interplanetary Alfvén waves cause auroral activity?’ by D. Aaron Roberts and Melvyn L. Goldstein”]

    Roberts, D. Aaron   Goldstein, Melvyn L.  

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    Alloy, Matthew   Garner, Thomas Ross   Bridges, Kristin   Mansfield, Charles   Carney, Michael   Forth, Heather   Krasnec, Michelle   Lay, Claire   Takeshita, Ryan   Morris, Jeffrey   Bonnot, Shane   Oris, James   Roberts, Aaron  

    The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions of barrels of crude oil into the Gulf of Mexico. Photo-induced toxicity following co-exposure to ultraviolet (UV) radiation is 1 mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Red drum and speckled seatrout are both important fishery resources in the Gulf of Mexico. They spawn near-shore and produce positively buoyant embryos that hatch into larvae in approximately 24 h. The goal of the present study was to determine whether exposure to UV as natural sunlight enhances the toxicity of crude oil to early lifestage red drum and speckled seatrout. Larval fish were exposed to several dilutions of high-energy water-accommodated fractions (HEWAFs) from 2 different oils collected in the field under chain of custody during the 2010 spill and 3 gradations of natural sunlight in a factorial design. Co-exposure to natural sunlight and oil significantly reduced larval survival compared with exposure to oil alone. Although both species were sensitive at PAH concentrations reported during the Deepwater Horizon spill, speckled seatrout demonstrated a greater sensitivity to photo-induced toxicity than red drum. These data demonstrate that even advanced weathering of slicks does not ameliorate the potential for photo-induced toxicity of oil to these species. (C) 2016 SETAC
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  • Is the Isle of Bardsey in Carnarvonshire or Pembrokeshire?

    Roberts, Aaron  

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  • Oliver Cromwell

    Roberts, Aaron  

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