INVESTIGATING THE POSTWAR DECLINE OF RACE IN SCIENCE

Race as a biological category has a long and troubling history as a central ordering concept in the life and human sciences. The mid-twentieth century has been marked as the point where biological concepts of race began to disappear from science. However, biological definitions of race continue to penetrate scientific understandings and uses of racial concepts. Using the theoretical frameworks of critical race theory and science and technology studies and an in-depth case study of the discipline of immunology, this dissertation explores the appearance of a mid-century decline of concepts of biological race in science. I argue that biological concepts of race did not disappear in the middle of the twentieth century but were reconfigured into genetic language. In this dissertation I offer a periodization of biological concepts of race. Focusing on continuities and the effects of contingent events, I compare how biological concepts of race articulate with racisms in each period. The discipline of immunology serves as a case study that demonstrates how biological concepts of race did not decline in the postwar era, but were translated into the language of genetics and populations. I argue that the appearance of a decline was due to events both internal and external to the science of immunology. By framing the mid-twentieth century disappearance of race in science as the triumph of an antiracist racial project of science, it allows us to more clearly see the more recent resurgence of race in science as a recycling of older themes and tactics from the racist science projects of the past.

UTILIZING ELECTRONIC NOSE AND GC-MS TO EXAMINE CRITICAL FACTORS INFLUENCING THE FORMATION OF ODOROUS VOC’S IN BIOSOLIDS.

Despite the efforts to better manage biosolids field application programs, biosolids managers still lack of efficient and reliable tools to apply large quantities of material while avoiding odor complaints. Objectives of this research were to determine the capabilities of an electronic nose in supporting process monitoring of biosolids production and, to compare odor characteristics of biosolids produced through thermal-hydrolysis anaerobic digestion (TH-AD) to those of alkaline stabilization in the plant, under storage and in the field. A method to quantify key odorants was developed and full scale sampling and laboratory simulations were performed. The portable electronic nose (PEN3) was tested for its capabilities of distinguishing alkali dosages in the biosolids production process. Frequency of recognition of unknown samples was tested achieving highest accuracy of 81.1%. This work exposed the need for a different and more sensitive electronic nose to assure its applicability at full scale for this process. GC-MS results were consistent with those reported in literature and helped to elucidate the behavior of the pattern recognition of the PEN3. Odor characterization of TH-AD and alkaline stabilized biosolids was achieved using olfactometry measurements and GC-MS. Dilution-to-threshold of TH-AD biosolids increased under storage conditions but no correlation was found with the target compounds. The presence of furan and three methylated homologues in TH-AD biosolids was reported for the first time proposing that these compounds are produced during thermal hydrolysis process however, additional research is needed to fully describe the formation of these compounds and the increase in odors. Alkaline stabilized biosolids reported similar odor concentration but did not increase and the ‘fishy’ odor from trimethylamine emissions resulted in more offensive and unpleasant odors when compared to TH-AD. Alkaline stabilized biosolids showed a spike in sulfur and trimethylamine after 3 days of field application when the alkali addition was not sufficient to meet regulatory standards. Concentrations of target compounds from field application of TH-AD biosolids gradually decreased to below the odor threshold after 3 days. This work increased the scientific understanding on odor characteristics and behavior of two types of biosolids and on the application of electronic noses to the environmental engineering field.