People turn to mass spectrometry to answer some of life’s most important questions. From carbon dating of archeological finds to newborn blood screening tests, mass spectrometry allows us to measure molecules which helps advance our knowledge of life and the world we live in. One area of mass spectrometry that...
Detection of illicit drug residues from wastewater provides a new route toward community level assessment of drug abuse that is critical to public health. However, traditional chemistry analytical tools such as liquid chromatography in tandem with mass spectrometry cannot meet the large-scale testing requirement in terms of cost, throughput, and...
When data are not missing at random, approaches to reduce nonresponse bias include subsampling nonresponding units and modeling. The objective of this thesis is to develop unbiased and precise model-assisted estimators of the population total that are applicable to data from a complex survey design with nonignorable nonresponse. When information...