Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

The Clean Air Act And Its Impact On Ground Level Ozone Pollution Levels In Los Angeles, California, Rebecca G. Ford Oct 2017

The Clean Air Act And Its Impact On Ground Level Ozone Pollution Levels In Los Angeles, California, Rebecca G. Ford

Honors Theses

Ozone (O3) occurs naturally as a protective, ultraviolet radiation-shielding “Ozone Layer” in the Stratosphere and as a photochemically produced pollutant in the Troposphere. The Clean Air Act (CAA) of 1970 regulates the emission and concentration of O3 and five other atmospheric pollutants. Since the signing of the CAA, the ongoing question has been whether or not the National Ambient Air Quality Standards (NAAQS) and regulatory policies have had an effect on decreasing O3 concentration. The Los Angeles metropolitan area is a prime example of how O3 can be a public health hazard, and taint a …


A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel Jan 2017

A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel

Honors Theses

Nitrogen (15N) isotope tracer studies are an invaluable tool for understanding the rate of N transformations in the environment. A mechanistic understanding of N cycling is critical to management of excess N availability in freshwater and marine ecosystems. Conventional methods for measuring 15N:14N of dissolved inorganic nitrogen species are time consuming and require large sample volumes. Here, we present a technique for measuring 15N:14N in ammonium (NH4+) using electrospray ionization mass spectrometry (ESI-MS). NH4+ present in small volumes of sample (3 ml) is complexed with phenol via …