Publications

Results 83626–83650 of 96,771

Search results

Jump to search filters

Thoughts on critical infrastructure collaboration

Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work

Scholand, Andrew J.; Linebarger, John M.; Ehlen, Mark E.

In this paper, we describe what we believe to be the characteristics of the collaborations required in the domain of critical infrastructure modeling, based on our experiences to date. We adopt a knowledge management philosophy, which imposes two classes of requirements, contextual who, when, and why), and semantic what interactions are conducted around). We observe that infrastructure models can often engender more insight when used as the basis for a meaningful discussion between the disparate stakeholder groups (private industry, trade organizations, industry lobbying groups, etc.) than when exercised computationally.

More Details
TYPE Conference YEAR 2005
DOIOSTIScopus

Advanced proton-exchange materials for energy efficient fuel cells

Cornelius, Christopher J.; Fujimoto, Cy F.; Hickner, Michael A.; Staiger, Chad S.

The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

More Details
TYPE SAND Report YEAR 2005
OSTIDOI

Structure and dynamics of microbe-exuded polymers and their interactions with calcite surfaces

Cygan, Randall T.

Cation binding by polysaccharides is observed in many environments and is important for predictive environmental modeling, and numerous industrial and food technology applications. The complexities of these organo-cation interactions are well suited to predictive molecular modeling studies for investigating the roles of conformation and configuration of polysaccharides on cation binding. In this study, alginic acid was chosen as a model polymer and representative disaccharide and polysaccharide subunits were modeled. The ability of disaccharide subunits to bind calcium and to associate with the surface of calcite was investigated. The findings were extended to modeling polymer interactions with calcium ions.

More Details
TYPE SAND Report YEAR 2005
OSTIDOI

Reverse engineering biological networks :applications in immune responses to bio-toxins

Faulon, Jean-Loup M.; Zhang, Zhaoduo Z.; Martino, Anthony M.; Timlin, Jerilyn A.; Haaland, David M.; Davidson, George S.; May, Elebeoba E.; Slepoy, Alexander S.

Our aim is to determine the network of events, or the regulatory network, that defines an immune response to a bio-toxin. As a model system, we are studying T cell regulatory network triggered through tyrosine kinase receptor activation using a combination of pathway stimulation and time-series microarray experiments. Our approach is composed of five steps (1) microarray experiments and data error analysis, (2) data clustering, (3) data smoothing and discretization, (4) network reverse engineering, and (5) network dynamics analysis and fingerprint identification. The technological outcome of this study is a suite of experimental protocols and computational tools that reverse engineer regulatory networks provided gene expression data. The practical biological outcome of this work is an immune response fingerprint in terms of gene expression levels. Inferring regulatory networks from microarray data is a new field of investigation that is no more than five years old. To the best of our knowledge, this work is the first attempt that integrates experiments, error analyses, data clustering, inference, and network analysis to solve a practical problem. Our systematic approach of counting, enumeration, and sampling networks matching experimental data is new to the field of network reverse engineering. The resulting mathematical analyses and computational tools lead to new results on their own and should be useful to others who analyze and infer networks.

More Details
TYPE SAND Report YEAR 2005
OSTIDOI
Results 83626–83650 of 96,771
Results 83626–83650 of 96,771