122 research outputs found
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Guide to Using Satellite Images in Support of Exceptional Event Demonstrations
The Exceptional Events Rule, contained in Title 40 of the Code of Federal Regulations Part 50.14 (40CFR50.14), was revised by EPA in October of 2016. Although many elements go into the technical support document for an exceptional event, this guidance will cover the resources available from satellite images and data to support the weight of evidence. The following guidance played a critical role for the State of Connecticut in its successful demonstration to exclude ozone data from May 25-26, 2016 at several of its monitors because of the transport of pollutants from the wildfires at Fort McMurray, Alberta, Canada
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A Brief Tutorial on Using the Ozone Monitoring Instrument (OMI) Nitrogen Dioxide (NO2) Data Product for SIPS Preparation
Although State Implementation Plans (SIPs) typically rely on observations from ground-level monitoring networks and regulatory modeling, satellite data is increasingly available to state agencies. Below is an example of how one state agency used satellite data to supplement a state implementation plan to improve air quality. An advantage of satellite data is that it provides information for a broader area than sampled by ground-based networks. This document provides examples and guidance for using satellite products of nitrogen dioxide (NO2), a precursor to ground-level ozone and nitrate aerosol, in state implementation plans. It also provides some guidance on using SO2, a precursor to sulfate aerosol
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Using satellite observed formaldehyde (HCHO) and nitrogen dioxide (NO2) as an indicator of ozone sensitivity in a SIP
Although State Implementation Plans (SIPs) typically rely on observations from ground-based networks and regulatory models, satellite data is increasingly available to state agencies and can also inform and supplement state implementation plans to improve air quality. An advantage of satellite data is that it provides information for a broader area than sampled by ground-based networks. This document provides examples and guidance for using satellite products of formaldehyde (HCHO) and nitrogen dioxide (NO2) to inform ground-level ozone sensitivity to emissions of nitrogen oxides (NOx) versus volatile organic compounds (VOC) in state implementation plans. Analysis of changes in ozone sensitivity over periods where emission controls have been implemented can provide insights into the efficacy of those past strategies and the likely efficacy of proposed future emission control programs
Optimization of Freeze Drying Conditions for Purified Pectinase from Mango (Mangifera indica cv. Chokanan) Peel
Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (−2.66, 62.66 mg/mL), Arabic gum (−1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05) effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved
The effect of solvent on the catalytic properties of microperoxidase-11
peer-reviewedThe effect of a range of solvents on the catalytic oxidation of methyl phenyl sulfide to methyl phenyl sulfoxide by MP-11 and by a cyclodextrin derivative of MP-11 was examined. The addition of low concentrations of alcohols enhanced the initial rate of sulfoxidation, most likely due to dispersion of MP-11 aggregates. Higher alcohol concentrations resulted in a decrease in activity arising from solvation of the hydrophobic sulfide, disrupting binding to the catalyst. In alcohols, the yield of product was decreased due to increased rates of MP-11 deactivation via the formation of aldehydes (for primary alcohols) or by peroxide-based deactivation. The catalytic activity of the cyclodextrin modified MP-11 was similar to that of MP-11 itself, demonstrating that it is the N-terminal side of MP-11 which is the determinant of catalytic activity.ACCEPTEDpeer-reviewe
Oxidized and Aggregated Recombinant Human Interferon Beta is Immunogenic in Human Interferon Beta Transgenic Mice
PurposeTo study the effect of oxidation on the structure of recombinant human interferon beta-1a (rhIFNβ-1a) and its immunogenicity in wild-type and immune-tolerant transgenic mice.MethodsUntreated rhIFNβ-1a was degraded by metal-catalyzed oxidation, H2O2-mediated oxidation, and guanidine-mediated unfolding/refolding. Four rhIFNβ-1a preparations with different levels of oxidation and aggregation were injected intraperitoneally in mice 15× during 3 weeks. Both binding and neutralizing antibodies were measured.ResultsAll rhIFNβ-1a preparations contained substantial amounts of aggregates. Metal-catalyzed oxidized rhIFNβ-1a contained high levels of covalent aggregates as compared with untreated rhIFNβ-1a. H2O2-treated rhIFNβ-1a showed an increase in oligomer and unrecovered protein content by HP-SEC; RP-HPLC revealed protein oxidation. Guanidine-treated rhIFNβ-1a mostly consisted of dimers and oligomers and some non-covalent aggregates smaller in size than those in untreated rhIFNβ-1a. All degraded samples showed alterations in tertiary protein structure. Wild-type mice showed equally high antibody responses against all preparations. Transgenic mice were discriminative, showing elevated antibody responses against both metal-catalyzed oxidized and H2O2-treated rhIFNβ-1a as compared to untreated and guanidine-treated rhIFNβ-1a.ConclusionsOxidation-mediated aggregation increased the immunogenicity of rhIFNβ-1a in transgenic mice, whereas aggregated preparations devoid of measurable oxidation levels were hardly immunogenic
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