Evidence of Intracrystalline Mesostructured Porosity in Zeolites by Advanced Gas Sorption, Electron Tomography and Rotation Electron Diffraction

The small size of micropores (typically <1 nm) in zeolites causes slow diffusion of reactant and product molecules in and out of the pores and negatively impacts the product selectivity of zeolite based catalysts, for example, fluid catalytic cracking (FCC) catalysts. Size-tailored mesoporosity was introduced into commercial zeolite Y crystals by a simple surfactant-templating post-synthetic mesostructuring process. The resulting mesoporous zeolite Y showed significantly improved product selectivity in both laboratory testing and refinery trials. Advanced characterization techniques such as electron tomography, three-dimensional rotation electron diffraction, and high resolution gas adsorption coupled with hysteresis scanning and density functional theory, unambiguously revealed the intracystalline nature and connectivity of the introduced mesopores. They can be considered as molecular highways that help reactant and product molecules diffuse quickly to and away from the catalytically active sites within the zeolite crystals and, thus, shift the selectivity to favor the production of more of the valuable liquid fuels at reduced yields of coke and unconverted feed.

Massachusetts: a map for Brent Lane of Dell Computer Corporation

produced by the Metropolitan Area Planning Council GIS Lab.

Road map of Massachusetts, 1922 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Road map of Massachusetts, prepared by General Drafting Co., Inc. ; published and presented by the First National Bank of Boston, May 1922. Scale [ca. 1:285,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as roads by condition (first class trunk line highways, trunk line highways, good or fairly good roads, poor roads, very poor roads), distances in miles between places, drainage, county boundaries and more. Relief is shown by hachures. Includes insets: Important routes of lower New England -- Cape Cod -- [Boston and Cambridge]. This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Evaluation of the corridor safety improvement program.

Oregon Department of Transportation, Salem

Identification, quantification and structuring of two-lane rural highway safety problems and solutions. Volume I - technical report. Final report.

Federal Highway Administration, Washington, D.C.

Protection of personnel in maintenance and construction zones. Interim report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

Driving performance after an extended period of travel in an automated highway system.

Federal Highway Administration, Office of Safety and Traffic Operations, Washington, D.C.

Virtual weigh station.

Indiana Department of Transportation, Indianapolis

The benefits from improved investment rules: a case study of the interstate highway system. Final report.

Transportation Department, Office of University Research, Washington, D.C.

Accident trend monitoring and exploratory analysis. Final report.

National Highway Traffic Safety Administration, National Center for Statistics and Analysis, Washington, D.C.

The interstate highway trade-in program. Volume 1 - assessment. Final report.

Transportation Department, Office of University Research, Washington, D.C.

The interstate highway trade-in programs. Volume 2 - synopsis of trade-ins. Final report.

Transportation Department, Office of University Research, Washington, D.C.

Some measures of accessibility of large trucks to the Texas highway system. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

Bridge deck designs for railing impacts. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

The economics of reducing the county road system: three case studies in Iowa. Final report.

Transportation Department, Office of University Research, Washington, D.C.