Parameter Identification and On-Line Estimation of a Reduced Kinetic Model

In this work, we present the estimation techniques used to update the model parameters in a reduced kinetic model describing the oxidation-reduction re- actions in a hydrothermal oxidation reactor. The model is used in a nonlinear model-based controller that minimizes the total aqueous nitrogen in the reac- tor effluent. Model reduction is accomplished by com- bining similar reacting compounds into one of four component groups and considering the global reac- tion pathways for each of these groups. The reduced kinetic model developed for thk reaction system pro- vides a means to characterize the complex chemical reaction system without considering each chemicaJ species present and the reaction kinetics of every pos- sible reaction pathway. For the reaction system under study, model reduction is essential in order to reduce the computational requirement so that on-line imple- mentation of the nonlinear model-based controller is possible and also to reduce the amount of a priori information required for the model

St. Louis FUSRAP-A Strategy for Success

In October 1997, Congress transferred the Formerly Utilized Sites Remedial Action Program (FUSRAP) from the Department of Energy (DOE) to the United States Army Corps of Engineers (USACE). FUSRAP addresses contamination generated by activities of the Manhattan Engineering District and the Atomic Energy Commission during the 1940's and 50's in support of the nation's nuclear weapons development program. The USACE Operation Order for FUSRAP gave responsibility for remediation of five sites in Missouri and Illinois to the USACESt. Louis District. The principal site is the St. Louis Airport Site (SLAPS), which involves the removal, transportation, disposal, and restoration of approximately 28 acres and 245,000 bank cubic yards (bcy) of contaminated soils. This paper will focus on the progress and achievements in removal action efficiencies of the SLAPS team. This team consists primarily of the USACE and Stone & Webster, Incorporated

GENE STRUCTURE OF THE HELICOBACTER-PYLORI CYTOTOXIN AND EVIDENCE OF ITS KEY ROLE IN GASTRIC DISEASE

The gram negative, microaerophilic bacterium Helicobacter pylori colonizes the human gastric mucosa and establishes a chronic infection that is tightly associated with atrophic gastritis, peptic ulcer, and gastric carcinoma. Cloning of the H. pylori cytotoxin gene shows that the protein is synthesized as a 140-kD precursor that is processed to a 94-kD fully active toxin. Oral administration to mice of the purified 94-kD protein caused ulceration and gastric lesions that bear some similarities to the pathology observed in humans. The cloning of the cytotoxin gene and the development of a mouse model of human gastric disease will provide the basis for the understanding of H. pylori pathogenesis and the development of therapeutics and vaccines