Field validation of cable monitoring and rating system (CMARS) laboratory model. First semi-annual report, 1 November 1978-30 April 1979

The goal of this project is to quantitatively validate the Cable Monitoring and Rating System (CMARS) software and associated hardware as applied to commercially operating underground transmission systems which are representative of the bulk of this type of system used in the USA. In the course of the project, it is expected that improvements and refinements of the CMARS will occur resulting in improved accuracy, flexibility and predictive capability for CMARS. The circuits to be utilized are equipped with extensive monitoring facilities, which will allow the determination of CMARS accuracy. In addition, recommendations will be made regarding accuracy vs. cost tradeoffs as a function of the amount and complexity of data which might be available on or retrofitted to existing systems, or considered for future systems. Information displays will be optimized by discussions with system operators, transmission planners and underground transmission engineering groups. Finally, hardware installation problems for sensor equipment as well as data acquisition equipment will be readily identified. At the completion of the proposed work, specifications for CMARS software and hardware, and all associated sensor, data acquisition and communications equipment will be available to the industry. The first semi-annual report on the project is presented

Contribution of Energetically Reactive Surface Features to the Dissolution of CeO2 and ThO2 Analogues for Spent Nuclear Fuel Microstructures

In the safety case for the geological disposal of nuclear waste, the release of radioactivity from the repository is controlled by the dissolution of the spent fuel in groundwater. There remain several uncertainties associated with understanding spent fuel dissolution, including the contribution of energetically reactive surface sites to the dissolution rate. In this study, we investigate how surface features influence the dissolution rate of synthetic CeO2 and ThO2, spent nuclear fuel analogues that approximate as closely as possible the microstructure characteristics of fuel-grade UO2 but are not sensitive to changes in oxidation state of the cation. The morphology of grain boundaries (natural features) and surface facets (specimen preparation-induced features) was investigated during dissolution. The effects of surface polishing on dissolution rate were also investigated. We show that preferential dissolution occurs at grain boundaries, resulting in grain boundary decohesion and enhanced dissolution rates. A strong crystallographic control was exerted, with high misorientation angle grain boundaries retreating more rapidly than those with low misorientation angles, which may be due to the accommodation of defects in the grain boundary structure. The data from these simplified analogue systems support the hypothesis that grain boundaries play a role in the so-called “instant release fraction” of spent fuel, and should be carefully considered, in conjunction with other chemical effects, in safety performance assessements for the geological disposal of spent fuel. Surface facets formed during the sample annealing process also exhibited a strong crystallographic control and were found to dissolve rapidly on initial contact with dissolution medium. Defects and strain induced during sample polishing caused an overestimation of the dissolution rate, by up to 3 orders of magnitude

Adenovirus-mediated correction of the genetic defect in hepatocytes from patients with familial hypercholesterolemia

Familial hypercholesterolemia (FH) is an inherited deficiency of LDL receptors that has been an important model for liver-directed gene therapy. We are developing approaches for treating FH that are based on direct delivery of recombinant LDL receptor genes to liver in vivo. As a first step towards this goal, replication-defective recombinant adenoviruses were constructed which contained either the lacZ gene or the human LDL receptor cDNA expressed from a β-actin promoter. Primary cultures of hepatocytes were established from two patients with homozygous FH and one nonFH patient, and subsequently exposed to recombinant adenoviruses at MOIs ranging from 0.1 to 5. Essentially all of the cells expressed high levels of the transgene without demonstrable expression of an early or late adenoviral gene product; the level of recombinant-derived LDL receptor protein in transduced FH hepatocytes exceeded the endogenous levels by at least 20-fold. These studies support the utility of recombinant adenoviruses for efficient transduction of recombinant LDL receptor genes into human FH hepatocytes without expression of viral proteins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45545/1/11188_2005_Article_BF01233250.pd

A Bayesian model to predict oil spill consequences of management plans in the Gulf of Mexico

A Bayesian risk analysis model, comprising of a release assessment module and an exposure assessment module for the oil transportation system in the Gulf of Mexico is described in this paper. The model is used to compute probability distributions for oil spill quantities for 160 grid cells in the Gulf of Mexico, and the volumes of that oil to reach 58 coastline segments over a user-specified planning period. In addition to historical oil spill data, the model can accept subjective information on management alternatives involving changes in the oil transportation system. For example, volumes, tugboat escorts, mechanical equipment and hull design can be altered, and user confidence can be entered concerning how changes will effect spill number and size. The release assessment module uses a predictive Bayesian negative binomial distribution for spill number, and a predictive Bayesian distribution based on the Pareto I distribution for spill size. Conditional transport probabilities developed by the Minerals Management Service and the results of the release assessment module were used in the exposure assessment module. Oil spill data maintained by the U.S. Coast Guard for the years 1991-1995 were analyzed along with two basic oil transportation management scenarios