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Physical Sciences and Mathematics Commons

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Social and Behavioral Sciences

North Carolina Agricultural and Technical State University

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Full-Text Articles in Physical Sciences and Mathematics

Sources And Atmospheric Oxidation Of Sulfur Dioxide And Formaldehyde Based On Wintertime Aircraft Observations Over The Eastern United States, Jaime R. Green Jan 2019

Sources And Atmospheric Oxidation Of Sulfur Dioxide And Formaldehyde Based On Wintertime Aircraft Observations Over The Eastern United States, Jaime R. Green

Dissertations

Plume intercepts from flights on the NSF-C-130 during the Wintertime Investigation of Transport, Emission and Reactivity (WINTER) campaign were used to estimate (1) the oxidation rates of Sulfur Dioxide (SO2) under wintertime conditions and the factors that determine SO2 removal; and (2) to examine the oxidation, lifetime and source apportionment of formaldehyde (HCHO). Observations suggest that OH governs the rate SO2 oxidation in the eastern United States during winter. The range of mean oxidation rates during the day from power plants were 0.22–0.71%/hr, producing SO2 lifetimes of 13–43 days, if SO2 consumption is assumed to occur during 10.5 hr of …


Use Of Sweet Potato To Develop A Medium For Cultivation Of Lactic Acid Bacteria, Saeed A. Hayek Jan 2013

Use Of Sweet Potato To Develop A Medium For Cultivation Of Lactic Acid Bacteria, Saeed A. Hayek

Dissertations

This study investigated the use of sweet potatoes (Ipomoea batatas) as a basic component to develop a medium for cultivation of lactic acid bacteria (LAB). Extract from baked sweet potatoes was used to form a sweet potato medium (SPM). SPM was supplemented with 4 g/L of each nitrogen source (beef extract, yeast extract, and proteose peptone #3). Lactobacilli MRS was used as a control medium. Ten LAB strains were used to determine the suitability of SPM serving the growth of LAB. Our results showed no significant (p < 0.05) differences in the optical density, maximum specific growth rates, and bacterial populations between MRS and SPM. SPM also maintained higher pH values throughout the incubation period compared to that in MRS. The cost of SPM was 47% less than the cost of MRS. Further step was taken to determine the suitability of SPM serving LAB enzymatic activity. LAB strains growing in SPM showed relatively higher β-glucosidases, acid phosphatase, and phytase activities and lower a-glucosidase compared to that in MRS. Strains of L. reuteri showed the …