34 research outputs found
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Synthesis and Assessment Product
This document, part of the Synthesis and Assessment Products described in the U.S. Climate Change Science Program (CCSP) Strategic Plan. Climate affects the design, construction, safety, operations, and maintenance of transportation infrastructure and systems. The prospect of a changing climate raises critical questions regarding how alterations in temperature, precipitation, storm events, and other aspects of the climate could affect the nation's roads, airports, rail, transit systems, pipelines, ports, and waterways. Phase I of this regional assessment of climate change and its potential impacts on transportation systems addresses these questions for the region of the U.S. central Gulf Coast between Galveston, Texas and Mobile, Alabama. This region contains multimodal transportation infrastructure that is critical to regional and national transportation services. Historical trends and future climate scenarios were used to establish a context for examining the potential effects of climate change on all major transportation modes within the region. Climate changes anticipated during the next 50 to 100 years for the central Gulf Coast include warming temperatures, changes in precipitation patterns, and increased storm intensity. The warming of the oceans and decline of polar ice sheets is expected to accelerate the rate of sea level rise globally. The effects of sea level rise in most central Gulf Coast counties will be exacerbated by the sinking of the land surface, which is accounted for in this assessment. The significance of these climate factors for transportation systems was assessed
Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from Pseudomonas aeruginosa
The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action
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Evaluation of options for CO{sub 2} capture/utilization/disposal
The project objective is to develop engineering evaluations of technologies for the capture, use, and disposal of carbon dioxide (CO{sub 2}). This project emphasizes CO{sub 2}-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems. Commercially available CO{sub 2}-capture technology is providing a performance and economic baseline against which to compare innovative technologies. The intent is to provide the CO{sub 2} budget, or an {open_quotes}equivalent CO{sub 2}{close_quotes} budget associated with each of the individual energy-cycle steps in addition to process design capital and operating costs. The value used for the {open_quotes}equivalent CO{sub 2}{close_quotes} budget is 1 kg CO{sub 2}/kWhe. The base case is a 458-MW (Gross) IGCC system using an O{sub 2}-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized bed gasifier, Illinois No. 6 bituminous coal feed and low-pressure glycol sulfur removal followed by a Claus/SCOT treatment to produce a salable product. Mining, feed preparation and conversion result in a net electric power production for the entire energy cycle of 411-MW with a 0.801 kg/kWhe CO{sub 2} release rate. For comparison, the gasifier output was taken through water-gas shift and then to either low-pressure glycol or chilled methanol for H{sub 2}S recovery; low-pressure glycol or membranes for CO{sub 2} recovery; and finally either a combustion turbine or fuel cell as the topping cycle. CO{sub 2} recovery was set at 80% for all cases so that the membrane system could be compared with the glycol on a consistent basis. The combustion turbine was then fed a high hydrogen content fuel. From the IGCC plant, a 500-km pipeline took the CO{sub 2} to geological sequestering. For the optimal case, the net electric power projection was reduced by 73-MW with a 0.277-kg/kWhe CO{sub 2}, release rate (when make-up power was considered)
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Summary of PERF air program review - August 22-23, 2007, Annapolis, Maryland.
For many years, the U.S. Department of Energy (DOE) has supported and sponsored various types of environmental research related to the oil and gas industry through its Office of Fossil Energy and its National Energy Technology Laboratory (NETL). In November 2005, Argonne National Laboratory (Argonne) organized and coordinated a review of DOE's water research program in conjunction with the fall 2005 meeting of the Petroleum Environmental Research Forum (PERF). PERF is a nonprofit organization created in 1986 to provide a stimulus and forum for collecting, exchanging, and analyzing research information related to the development of technology for the petroleum industry and also to provide a mechanism for establishing joint research projects in that field. Additional information on PERF can be accessed at http://www.perf.org. The water program review was so successful that both DOE and PERF agreed that a second program review would be useful -- this time on air research and issues. Argonne coordinated the air program review, which was held in Annapolis, Maryland, on August 22 and 23, 2007. This report summarizes the presentations and related discussions that were part of the air program review. The full agenda for the program review is included as Appendix A
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Toxicologic studies of SRC materials
Investigations on the toxicity of SRC materials are reported. Toxicological studies include: microbial mutageneis (Ames test); in vitro mammalian cell toxicity and transformation assays; epidermal carcinogenesis (skin painting); acute and subchronic oral toxicity; developmental toxicity; dominant lethal assays; inhalation toxicity; and dosimetry and metabolism. The materials tested include: SRC-I process solvent, wash solvent, and light oil; SRC-II heavy distillate, middle distillate, and light distillate; shale oil; crude petroleum; and pure carcinogens. (DC