71 research outputs found

    Infrared reflectance measurements of Missouri waters for water quality applications

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    Students supported: 2 studentsThe relative specular reflectance of laboratory solutions of 3.0 M Sulfuric Acid and 0.5 M Sodium Nitrate was measured in the 2.0 - 20-[mu]m wavelength region of the infrared. The relative specular reflectance of natural samples of (1) acid mine drainage taken from a ditch leading from the Peabody Mark Twain Mine to Hinkson Creek; (2) surface water runoff from an agricultural test plot which had received a 314 lb/acre application of nitrate fertilizer; and (3) an oil sample from the Mexico, Missouri oil release into the Salt River was measured in the same spectral region. The data was collected using a Perkin Elmer E-14 spectrophotometer and a reflectometer consisting of a Cassegrain unit which collimated the radiant flux to about 18 mrad divergence, a sample holder and a Cassegrain condenser for focusing the radiant flux, reflected by the sample, onto the entrance slit of the monochromator. The angle of incidence was 70 degrees. The index of refraction, extinction coefficient and phase difference spectrum throughout the 2-20-[mu]m wavelength region was determined for the mine drainage, fuel oil, sulfuric acid, sodium nitrate and nitrate runoff samples using the relative reflectance measurements, the optical constants of distilled water and an algorithm for Kramers-Kronig analysis. The absolute reflectance spectrum of the alluvium and loess was determined using the relative reflectance measurements, the optical constants of distilled water and the Cauchy equation for reflectance. It is very desirable to make water quality measurements remotely. However before such measurements can be taken the characteristic manner in which aqueous solutions reflect electromagnetic radiation (in the optical properties) must be known. Thus the results obtained from this research are a part of a much larger goal to determine water quality remotely.Project # A-063-MO Agreement # 14-31-0001-382

    Dogslife: A web-based longitudinal study of Labrador Retriever health in the UK

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    <p>Abstract</p> <p>Background</p> <p>Dogslife is the first large-scale internet-based longitudinal study of canine health. The study has been designed to examine how environmental and genetic factors influence the health and development of a birth cohort of UK-based pedigree Labrador Retrievers.</p> <p>Results</p> <p>In the first 12 months of the study 1,407 Kennel Club (KC) registered eligible dogs were recruited, at a mean age of 119 days of age (SD 69 days, range 3 days – 504 days). Recruitment rates varied depending upon the study team’s ability to contact owners. Where owners authorised the provision of contact details 8.4% of dogs were recruited compared to 1.3% where no direct contact was possible. The proportion of dogs recruited was higher for owners who transferred the registration of their puppy from the breeder to themselves with the KC, and for owners who were sent an e-mail or postcard requesting participation in the project. Compliance with monthly updates was highly variable. For the 280 dogs that were aged 400 days or more on the 30<sup>th</sup> June 2011, we estimated between 39% and 45% of owners were still actively involved in the project. Initial evaluation suggests that the cohort is representative of the general population of the KC registered Labrador Retrievers eligible to enrol with the project. Clinical signs of illnesses were reported in 44.3% of Labrador Retrievers registered with Dogslife (median age of first illness 138 days), although only 44.1% of these resulted in a veterinary presentation (median age 316 days).</p> <p>Conclusions</p> <p>The web-based platform has enabled the recruitment of a representative population of KC registered Labrador Retrievers, providing the first large-scale longitudinal population-based study of dog health. The use of multiple different methods (e-mail, post and telephone) of contact with dog owners was essential to maximise recruitment and retention of the cohort.</p

    Optical Properties of Calcite and Gypsum in Crystalline and Powdered Form in the Infrared and Far-Infrared

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    The Complex Indices of Refraction for Crystalline Gypsum and Calcite Were Determined from Reflectance Measurements for Both Single Crystals and Pressed Powder Pellets. These Optical Constants Were Determined from a Classical Dispersive Analysis (DA) of the Reflectance Data to Facilitate Comparisons between the Crystal and Powdered Data. This Study Was Done to Show the Usefulness and the Limitations of using Pressed Pellets for Determining the Complex Refractive Index of Materials Unavailable in Single Crystals. © 1993

    Optical Properties of Fourteen Metals in the Infrared and Far Infrared: Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W

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    Infrared Optical Constants Collected from the Literature Are Tabulated for Mo and V. New Data Are Presented for Cu, Fe, and Ni. Drude Model Parameters Wtand Wpare Given for the Fourteen Metals Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W. the Drude Model Parameters for Cu Are Revised from Our Earlier Tabulation Due to the Availability of Additional Data. Refinements in Our Fitting Technique Have Resulted in Only Slight Changes in the Drude Model Parameters for Al, Au, Ag, and W. the Drude Model Parameters for Pb Correct a Numerical Error in Our Earlier Tabulation. for All Fourteen Metals, the Optical Resistivity Has Been Calculated from the Drude Model Parameters Wtand Wpand Compared to Handbook Values for the Dc Resistivity. © 1985 Optical Society of America
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