448 research outputs found

    The application of synthesized transition metal compounds as paint additives for the preparation of a self-decontaminating coating

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    Thesis (M.S.) University of Alaska Fairbanks, 2011The synthesis of transition metal compounds has been performed to create reactive additives that can be incorporated into commercial grade paints for the purpose of developing a continuous self-decontaminating coating. The coatings were designed to allow for the decontamination of persistent chemical warfare agents: sulfur mustard and organophosphate nerve agents. Since the persistence of these chemicals on surfaces due to their low volatility and long hydrolysis half lives could possibly lead to involuntary exposures, a continuous self-decontaminating coating would provide an alternative approach to eliminate residual chemical warfare agents without further treatment to the painted surface. The synthesized additives include metal oxide nanoparticles,polyoxometallates,andmetalfunctionalizedcyclodextrins. Coatings were formulated with 1% w/w synthesized additives, and tested for their ability to decontaminate chemical warfare agent simulants of sulfur mustard and organophosphate nerve agents. The Dawson structure polyoxometallate α2- K8P2W17O61(Ni2+ ∙OH2)∙17H2O coatings exhibited percent reductions of three of the four simulants above 30% with a high of 53% reduction of Malathion in 24 hours. The nickel functionalized gamma cyclodextrin coatings exhibited percent reductions for all simulants above 28% with a high of 61% reduction of Malathion in 24 hours. Overall, coatings enhanced with additives were tested and produced painted surfaces capable of decontaminating chemical warfare agent simulants

    Development of a Long-term, Multimetric Structural Health Monitoring System for a Historic Steel Truss Swing Bridge

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    The bridge stock across the United States is ageing, with many bridges approaching the end of their design life. The situation is so dire that the American Society of Civil Engineers gave the nation’s bridges a grade of “C+” in the 2013 edition of their Report Card on America’s Infrastructure. In fact, at the end of 2011, nearly a quarter of all bridges in the United States were classified as either structurally deficient or functionally obsolete. Thus, the nation’s bridges are in desperate need of rehabilitation and maintenance. However, limited funds are available for the repair of bridges. Management of the nation’s bridge infrastructure requires an efficient and effective use of available funds to direct the maintenance and repair efforts. Structural health monitoring has the potential to supplement the current routine of scheduled bridge inspections by providing an objective and detailed source of information about the status of the bridge. This research develops a framework for the long-term monitoring of bridges that leverages multimetric data to provide value to the bridge manager. The framework is applied to the Rock Island Arsenal Government Bridge. This bridge is a historic, steel truss, swing bridge that spans the Mississippi River between Rock Island, IL and Davenport, IA. The bridge is owned and operated by the US Army Corps of Engineers (USACE) and is a vital link for vehicular, train, and barge traffic. The USACE had a system of fiber optic strain gages installed on the bridge. As part of this research, this system was supplemented with a wireless sensor network that measured accelerations on the bridge. The multimetric data from the sensor systems was collected using a program developed in the course of this research. The data was then analyzed and metrics were developed that could be used to determine the health of the structure and the sensor networks themselves. Statistical process control methods were established to detect anomalous behavior in the short and long term time scales. Methods to locate and quantify the damage that has occurred in the structure once an anomaly has been detected were demonstrated. One of the methods developed as part of this research was a first order flexibility method. The SHM system this research develops has the desirable characteristics of being continuous temporally, multimetric, scalable, robust, autonomous, and informative. By necessity, some aspects of the developed SHM framework are unique and customized exclusively for the Rock Island Government Bridge. However, the principles developed in the framework are applicable to the development of an SHM system for any other bridge. Application of the SHM framework this research develops to other bridges has the potential to increase objectivity in the evaluation of bridges and focus maintenance efforts and funds on the bridges that are most critical to the public safety.Financial support for this research was provided in part by the Army Corps of Engineers Construction Engineering Research Laboratory (CERL) through a subcontract with Mandaree Enterprise Corporation.Ope

    Solubility evaluation of murine hybridoma antibodies

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    The successful development of antibody therapeutics depends on the molecules having properties that are suitable for manufacturing, as well as use by patients. Because high solubility is a desirable property for antibodies, screening for solubility has become an essential step during the early candidate selection process. In considering the screening process, we formed a hypothesis that hybridoma antibodies are filtered by nature to possess high solubility and tested this hypothesis using a large number of murine hybridoma-derived antibodies. Using the cross-interaction chromatography (CIC) method, we screened the solubility of 92 murine hybridoma-derived monoclonal antibodies and found that all of these molecules exhibited CIC profiles that are indicative of high solubility (>100mg/mL). Further investigations revealed that variable region N-linked glycosylation or isoelectric parameters are unlikely to contribute to the high solubility of these antibodies. These results support the general hypothesis that hybridoma monoclonal antibodies are highly soluble

    The Elusive Rentier Rich: Piketty's Data Battles and the Power of Absent Evidence

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    The popularity of Thomas Piketty?s research on wealth inequality has drawn attention to a curious question: why was widening wealth inequality largely neglected by mainstream economists in recent decades? To explore and explain that neglect, I draw on the writing of the early neoclassical economist John Bates Clark, who introduced the notion of the marginal productivity of income distribution at the end of the nineteenth century. I then turn to Piketty?s Capital in order to analyze the salience of marginal productivity theories of income today. I suggest that most of the criticism and praise for Piketty?s research is focused on data that are accessible and measurable, obscuring attention to questions over whether current methods for measuring economic capital are defensible or not. My overarching aim is to explore how ?absent? data in economics as a whole help to reinforce blind spots within mainstream economic theory

    A randomised trial of the effect of omega-3 polyunsaturated fatty acid supplements on the human intestinal microbiota

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    Objective; Omega-3 polyunsaturated fatty acids (PUFAs) have anticolorectal cancer (CRC) activity. The intestinal microbiota has been implicated in colorectal carcinogenesis. Dietary omega-3 PUFAs alter the mouse intestinal microbiome compatible with antineoplastic activity. Therefore, we investigated the effect of omega-3 PUFA supplements on the faecal microbiome in middle-aged, healthy volunteers (n=22). Design A randomised, open-label, cross-over trial of 8 weeks’ treatment with 4 g mixed eicosapentaenoic acid/docosahexaenoic acid in two formulations (soft-gel capsules and Smartfish drinks), separated by a 12-week ‘washout’ period. Faecal samples were collected at five time-points for microbiome analysis by 16S ribosomal RNA PCR and Illumina MiSeq sequencing. Red blood cell (RBC) fatty acid analysis was performed by liquid chromatography tandem mass spectrometry. Results; Both omega-3 PUFA formulations induced similar changes in RBC fatty acid content, except that drinks were associated with a larger, and more prolonged, decrease in omega-6 PUFA arachidonic acid than the capsule intervention (p=0.02). There were no significant changes in α or ÎČ diversity, or phyla composition, associated with omega-3 PUFA supplementation. However, a reversible increased abundance of several genera, including Bifidobacterium, Roseburia and Lactobacillus was observed with one or both omega-3 PUFA interventions. Microbiome changes did not correlate with RBC omega-3 PUFA incorporation or development of omega-3 PUFA-induced diarrhoea. There were no treatment order effects. Conclusion; Omega-3 PUFA supplementation induces a reversible increase in several short-chain fatty acid-producing bacteria, independently of the method of administration. There is no simple relationship between the intestinal microbiome and systemic omega-3 PUFA exposure. Trial registration number; ISRCTN18662143

    Study protocol for the management of impacted maxillary central incisors: a multicentre randomised clinical trial: the iMAC Trial

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    BACKGROUND Failure of eruption of the maxillary permanent incisor teeth usually presents in the mixed dentition between the ages of 7 and 9 years. Missing and unerupted maxillary incisors can be regarded as unattractive and have a potentially negative impact on facial and dental aesthetics. The presence of a supernumerary tooth (or odontoma) is commonly responsible for failed eruption or impaction of the permanent maxillary incisors. The primary objective of this trial is to investigate the success of eruption associated with maxillary incisor teeth that have failed to erupt because of a supernumerary tooth in the anterior maxilla. METHODS This protocol describes an interventional multicentre two-arm randomised clinical trial. Participants meeting the eligibility criteria will be randomised (unrestricted equal participant allocation [1:1]) to either space creation with an orthodontic appliance, removal of the supernumerary tooth and application of direct orthodontic traction or space creation with an orthodontic appliance, removal of the supernumerary tooth and monitoring. The primary outcome of this trial is to determine the prevalence of successfully erupted maxillary central permanent incisors at 6 months following removal of the supernumerary tooth. Secondary outcome measures include (1) the effect of initial tooth position (assessed radiographically) on time taken for the tooth to erupt, (2) time taken to align the unerupted tooth to the correct occlusal position, (3) gingival aesthetics and (4) changes in the self-reported Oral Health Related-Quality of Life (OHRQoL) (pre-and post-treatment). DISCUSSION There is a lack of high-quality robust prospective studies comparing the effectiveness of interventions to manage this condition. Furthermore, the UK national clinical guidelines have highlighted a lack of definitive treatment protocols for the management of children who present with an unerupted maxillary incisor due to the presence of a supernumerary tooth. The results of this trial will inform future treatment guidelines for the management of this condition in young children. TRIAL REGISTRATION ISRCTN Registry ISRCTN12709966 . Registered on 16 June 2022

    Beyond sarcasm: the metalanguage and structures of mock politeness

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    This paper aims to cast light on the somewhat neglected area of mock politeness. The principle objectives are to describe the ways that mock politeness is talked about and performed. In order to investigate such usage, I analyse data from informal, naturally occurring conversations in a UK-based online forum. The paper introduces a range of metalinguistic expressions which are used to refer to mock polite behaviours in lay interactions and describes the different structures of mock polite behaviours. The analysis shows that both metalanguage and structure are more diverse than anticipated by previous research and, as a result, the paper argues against equating mock politeness with sarcasm and calls for further research into mock politeness as an important strategy of impoliteness
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