4,787 research outputs found

    Electrochemical Preparation and Characterization of Chemically Modified Electrodes

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    This chapter will focus on the use of electropolymerization schemes and reactions to modify electrode surfaces with organo- and organometallic compounds such as metal(II)-4, 9, 16, 23-tetraminophthalocyanines and metal complexes of 5-amino-1, 10-phenanthroline. The chemical modification described herein focuses on the formation of polymer films on electrode surfaces. In addition, the characterization of such films using cyclic voltammetry, chronoamperometry, chronocoulometry, and electrochemical impedance spectroscopy will be a key emphasis within this chapter. A brief review of the literature concerning these techniques along with relevant compounds that have been used in studies related to these voltammetric techniques is presented

    Class I and Class III Cultural Resource Inventory Survey for the Kinder Morgan’s Station No. 142 and Oasis Meter Station on NGPL’s Lockridge-Delhi Line near Pyote, Ward County, Texas

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    TRC Environmental (TRC) conducted a Class I archival and records search and Class III intensive 100 percent pedestrian survey of a 1.1-acre parcel of private land at Kinder Morgan’s Station No. 142 and 1.8-acre parcel of private land at Kinder Morgan’s Oasis Meter Station on NGPL’s Lockridge-Delhi Line in central Ward County, Texas. Kenneth L. Brown, Ph.D., RPA, served as Principal Investigator and Field Supervisor. Kinder Morgan is designing upgrades and performing maintenance for their existing facilities. The project involves the modification of the Oasis Meter Station and the installation of pig launcher and receivers in order to make the pipeline segment smart piggable. TRC conducted the Class I and Class III cultural resource investigations according to the Texas Historical Commission (THC) standards. The cultural resource survey was completed on December 8, 2017. The Class I archival research indicated no previously recorded sites were in the project areas or their vicinities. The Class III survey did not find any new sites at either facility. TRC recommends Kinder Morgan be allowed to develop their proposed natural gas facilities

    Verification of TG-61 dose for synchrotron-produced monochromatic x-ray beams using fluence-normalized MCNP5 calculations

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    Ion chamber dosimetry is being used to calibrate dose for cell irradiations designed to investigate photoactivated Auger electron therapy at the Louisiana State University CAMD synchrotron facility. This study performed a dosimetry intercomparison for synchrotron-produced monochromatic x-ray beams at 25 and 35 keV. Ion chamber depth-dose measurements in a PMMA phantom were compared with the product of MCNP5 Monte Carlo calculations of dose per fluence and measured incident fluence. Monochromatic beams of 25 and 35 keV were generated on the tomography beamline at CAMD. A cylindrical, air-equivalent ion chamber was used to measure the ionization created in a 10x10x10-cm3 PMMA phantom for depths from 0.6 to 7.7 cm. The American Association of Physicists in Medicine TG-61 protocol was applied to convert measured ionization into dose. Photon fluence was determined using a NaI detector to make scattering measurements of the beam from a thin polyethylene target at angles 30 degrees to 60 degrees. Differential Compton and Rayleigh scattering cross sections obtained from xraylib, an ANSI C library for x-ray-matter interactions, were applied to derive the incident fluence. MCNP5 simulations of the irradiation geometry provided the dose deposition per photon fluence as a function of depth in the phantom. At 25 keV the fluence-normalized MCNP5 dose overestimated the ion-chamber measured dose by an average of 7.2+/-3.0% to 2.1+/-3.0% for PMMA depths from 0.6 to 7.7 cm, respectively. At 35 keV the fluence-normalized MCNP5 dose underestimated the ion-chamber measured dose by an average of 1.0+/-3.4% to 2.5+/-3.4%, respectively. These results showed that TG-61 ion chamber dosimetry, used to calibrate dose output for cell irradiations, agreed with fluence-normalized MCNP5 calculations to within approximately 7% and 3% at 25 and 35 keV, respectively.Comment: 22 pages, 5 figure

    Changing the view:towards the theory of visualisation comprehension

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    The core problem of the evaluation of information visualisation is that the end product of visualisation - the comprehension of the information from the data - is difficult to measure objectively. This paper outlines a description of visualisation comprehension based on two existing theories of perception: principles of perceptual organisation and the reverse hierarchy theory. The resulting account of the processes involved in visualisation comprehension enables evaluation that is not only objective, but also non-comparative, providing an absolute efficiency classification. Finally, as a sample application of this approach, an experiment studying the benefits of interactivity in 3D scatterplots is presented

    A reflective characterisation of occasional user

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    This work revisits established user classifications and aims to characterise a historically unspecified user category, the Occasional User (OU). Three user categories, novice, intermediate and expert, have dominated the work of user interface (UI) designers, researchers and educators for decades. These categories were created to conceptualise user's needs, strategies and goals around the 80s. Since then, UI paradigm shifts, such as direct manipulation and touch, along with other advances in technology, gave new access to people with little computer knowledge. This fact produced a diversification of the existing user categories not observed in the literature review of traditional classification of users. The findings of this work include a new characterisation of the occasional user, distinguished by user's uncertainty of repetitive use of an interface and little knowledge about its functioning. In addition, the specification of the OU, together with principles and recommendations will help UI community to informatively design for users without requiring a prospective use and previous knowledge of the UI. The OU is an essential type of user to apply user-centred design approach to understand the interaction with technology as universal, accessible and transparent for the user, independently of accumulated experience and technological era that users live in

    Strategies for Preparing and Delivering an Effective Online Presentation

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    Stellar Polarimetry: Where Are We and Where Are We Going?

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    On the final day of the Stellar Polarimetry conference, participants split up into three "breakout sessions" to discuss the future of the field in the areas of instrumentation, upcoming opportunities, and community priorities. This contribution compiles the major recommendations arising from each breakout session. We hope that the polarimetric community will find these ideas useful as we consider how to maintain the vitality of polarimetry in the coming years.Comment: 7 pages, published in proceedings of "Stellar Polarimetry: From Birth to Death" (Madison, WI, June 2011
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