5,323 research outputs found

    A Review and Comparison of Low-Level Radioactive Waste Disposal Facilities

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    In 2002, the Department of Energy (DOE) released the draft Hanford Solid Waste Environmental Impact Statement (DOE 2002). That draft called for the disposal of over 12 million cubic feet of low-level radioactive waste (LLRW) at Hanford in unlined near-surface disposal trenches. The draft EIS was withdrawn by USDOE following public comment, as urged by numerous official agency, advisory board and public commentators. In April, 2003, USDOE issued the Revised Draft Hanford Solid Waste EIS, which forecast that USDOE would dispose of up to 12.3 million cubic feet of LLRW in near-surface burial trenches.1 Sixty three percent (63%) of this LLRW would be imported to Hanford for burial. At an undefined future date, the Revised Draft EIS proposed that LLRW would be buried together in new trenches with up to 5 million cubic feet of Mixed Low-Level Waste, which is Low-Level Radioactive Waste mixed with hazardous chemical wastes.2 To develop a technical position on the proposal for use of Hanford newr- surface burial for Low-Level Wastes, Heart of America NW wanted to know if the Low-Level Radioactive Waste Burial Grounds meet the basic engineering requirements for such facilities and how they compare with other similar facilities and alternative potential disposal sites available to USDOE for these wastes. As such, this report represents the first independent, publicly available Cross-Site Comparison of USDOE Low-Level Radioactive Waste Burial Ground Alternatives. Performing a complete engineering review of multiple facilities was clearly beyond the potential budget capacity so a proposal was proffered to limit the investigation to the geotechnical aspects of representative LLRW disposal facilities. This type of focused review was accomplished by visiting the sites and reviewing documentation on the sites. Performance standards and review criteria were identified and the disposal facilities were evaluated to determine how well they meet the performance standards. This is the basis for a comparison of the facilities. This report presents the results of this study. This research was completed money allocated during Round 3 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/heartofam/1000/thumbnail.jp

    On the role of API in determining porosity, pore structure and bulk modulus of the skeletal material in pharmaceutical tablets formed with MCC as sole excipient

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    The physical properties and mechanical integrity of pharmaceutical tablets are of major importance when loading with active pharmaceutical ingredient(s) (API) in order to ensure ease of processing, control of dosage and stability during transportation and handling prior to patient consumption. The interaction between API and excipient, acting as functional extender and binder, however, is little understood in this context. The API indomethacin is combined in this study with microcrystalline cellulose (MCC) at increasing loading levels. Tablets from the defined API/MCC ratios are made under conditions of controlled porosity and tablet thickness, resulting from different compression conditions, and thus compaction levels. Mercury intrusion porosimetry is used to establish the accessible pore volume, pore size distribution and, adopting the observed region of elastic intrusion-extrusion at high pressure, an elastic bulk modulus of the skeletal material is recorded. Porosity values are compared to previously published values derived from terahertz (THz) refractive index data obtained from exactly the same tablet sample sets. It is shown that the elastic bulk modulus is dependent on API wt% loading under constant tablet preparation conditions delivering equal dimensions and porosity. The findings are considered of novel value in respect to establishing consistency of tablet production and optimisation of physical properties

    Modelling and Monitoring of Phosphorus Transport and Speciation in Soil

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    Merged with duplicate record 10026.1/1270 on 08.03.2017 by CS (TIS)Flow through soil into groundwater has been classically conceptualised as taking place through a set of aligned capillary tubes. In solute transport models these approximations are also present. Pore-Cor (a network model) has been used to model the void structure of soil by using water retention and mercury porosimetry curves. The model successfully predicts trends in saturated hydraulic conductivity. The effect of the assumptions used in the Pore-Cor geometry have been investigated by comparing of two dimensional slices of the simulated networks with two dimensional image analysis data. The geometric limitations of the model cause packing inefficiencies which prevent the model from representing the size distribution of voids found in real samples. The observation of environmental events is dependent upon the implementation of rapid and reliable analytical techniques. This work presents an adaptation of an FI method for the determination of dissolved reactive phosphorus (DRP) and a new method for the determination of total dissolved phosphorus (TDP). Both are ideally suited to the detection of phosphorus species in soil leachate and runoff waters over the concentration range 3 to 1000 ng 1-1. The effect of compaction on solute transport is described and the experimental data have been modelled using a modified form of the convection dispersion equation (CDE). The parameters of the CDE have been given structural interpretation by the network model. The model was used to interpret a change in dispersivity and the behaviour of reactive phosphorus species on compaction.The Institute of Grassland and Environmental Research, North Wyke, Devo

    Emerging technologies for the non-invasive characterization of physical-mechanical properties of tablets

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    The density, porosity, breaking force, viscoelastic properties, and the presence or absence of any structural defects or irregularities are important physical-mechanical quality attributes of popular solid dosage forms like tablets. The irregularities associated with these attributes may influence the drug product functionality. Thus, an accurate and efficient characterization of these properties is critical for successful development and manufacturing of a robust tablets. These properties are mainly analyzed and monitored with traditional pharmacopeial and non-pharmacopeial methods. Such methods are associated with several challenges such as lack of spatial resolution, efficiency, or sample-sparing attributes. Recent advances in technology, design, instrumentation, and software have led to the emergence of newer techniques for non-invasive characterization of physical-mechanical properties of tablets. These techniques include near infrared spectroscopy, Raman spectroscopy, X-ray microtomography, nuclear magnetic resonance (NMR) imaging, terahertz pulsed imaging, laser-induced breakdown spectroscopy, and various acoustic- and thermal-based techniques. Such state-of-the-art techniques are currently applied at various stages of development and manufacturing of tablets at industrial scale. Each technique has specific advantages or challenges with respect to operational efficiency and cost, compared to traditional analytical methods. Currently, most of these techniques are used as secondary analytical tools to support the traditional methods in characterizing or monitoring tablet quality attributes. Therefore, further development in the instrumentation and software, and studies on the applications are necessary for their adoption in routine analysis and monitoring of tablet physical-mechanical properties

    Verifying and Monitoring IoTs Network Behavior using MUD Profiles

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    IoT devices are increasingly being implicated in cyber-attacks, raising community concern about the risks they pose to critical infrastructure, corporations, and citizens. In order to reduce this risk, the IETF is pushing IoT vendors to develop formal specifications of the intended purpose of their IoT devices, in the form of a Manufacturer Usage Description (MUD), so that their network behavior in any operating environment can be locked down and verified rigorously. This paper aims to assist IoT manufacturers in developing and verifying MUD profiles, while also helping adopters of these devices to ensure they are compatible with their organizational policies and track devices network behavior based on their MUD profile. Our first contribution is to develop a tool that takes the traffic trace of an arbitrary IoT device as input and automatically generates the MUD profile for it. We contribute our tool as open source, apply it to 28 consumer IoT devices, and highlight insights and challenges encountered in the process. Our second contribution is to apply a formal semantic framework that not only validates a given MUD profile for consistency, but also checks its compatibility with a given organizational policy. We apply our framework to representative organizations and selected devices, to demonstrate how MUD can reduce the effort needed for IoT acceptance testing. Finally, we show how operators can dynamically identify IoT devices using known MUD profiles and monitor their behavioral changes on their network.Comment: 17 pages, 17 figures. arXiv admin note: text overlap with arXiv:1804.0435
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