Nonlinear seismic analysis of a reactor structure impact between core components

The seismic analysis of the FFTF-PIOTA (Fast Flux Test Facility-Postirradiation Open Test Assembly), subjected to a horizontal DBE (Design Base Earthquake) is presented. The PIOTA is the first in a set of open test assemblies to be designed for the FFTF. Employing the direct method of transient analysis, the governing differential equations describing the motion of the system are set up directly and are implicitly integrated numerically in time. A simple lumped-nass beam model of the FFTF which includes small clearances between core components is used as a "driver" for a fine mesh model of the PIOTA. The nonlinear forces due to the impact of the core components and their effect on the PIOTA are computed

Gymnostoma tasmanianum sp nov., a fossil Casuarinaceae from the Early Oligocene of Little Rapid River, Tasmania, Australia

Int. J Plant Sci. 164(4):629–634. 2003. © 2003 by The University of ChicagoMacrofossils of Casuarinaceae from Early Oligocene sediments at Little Rapid River, Tasmania, are assigned to a new species, Gymnostoma tasmanianum. This is only the second species of fossil Gymnostoma to be formally described and the first species of Gymnostoma to be described from Tasmania. The species is known from both vegetative and reproductive organs. The new taxon is distinguished from other known species by its small stomata, short article length and tooth width, small length:width ratio of articles, glabrous articles, stomata in two to five rows, and teeth elongate with acute apices and sinuses. The fossil record shows that Gymnostoma once had a much wider distribution in Australia than its current occurrence in far north Queensland.Greg Guerin and Robert S. Hil

Leaf cuticular morphology links Platanaceae and Proteaceae

Int. J. Plant Sci. 166(5):843–855. © 2005 by The University of Chicago.The leaf cuticular morphology of extant species of Platanus was investigated using light and scanning electron microscopy. All species are shown to possess trichome bases of the same type as those commonly found in Proteaceae. Of particular significance are compound forms that consist of an annular surface scar associated with more than one underlying epidermal cell. These are found on the adaxial leaf surfaces of all species of Platanus and are also clearly evident on the abaxial surface of Platanus orientalis. This type of trichome base is therefore interpreted as the first detected nonreproductive morphological synapomorphy linking Proteaceae and Platanaceae. Also, the laterocytic, sometimes paracytic, or anomocytic arrangement of subsidiary cells in Platanus is distinct from the general state in Proteaceae, which is brachyparacytic and presumably derived. In Bellendena, possibly the most basal genus of extant Proteaceae, subsidiary cell arrangements resemble those of Platanus. These results are discussed with respect to leaf fossil records of Proteales, where it is concluded that the combination of brachyparacytic stomata and compound trichome bases is strong evidence for Proteaceae.Raymond J. Carpenter, Robert S. Hill, and Gregory J. Jorda

Implementation experiences of NASTRAN on CDC CYBER 74 SCOPE 3.4 operating system

The implementation of the NASTRAN system on the CDC CYBER 74 SCOPE 3.4 Operating System is described. The flexibility of the NASTRAN system made it possible to accomplish the change with no major problems. Various sizes of benchmark and test problems, ranging from two hours to less than one minute CP time were run on the CDC CYBER SCOPE 3.3, Univac EXEC-8, and CDC CYBER SCOPE 3.4. The NASTRAN installation deck is provided

Length Scales of Acceleration for Locally Isotropic Turbulence

Length scales are determined that govern the behavior at small separations of the correlations of fluid-particle acceleration, viscous force, and pressure gradient. The length scales and an associated universal constant are quantified on the basis of published data. The length scale governing pressure spectra at high wave numbers is discussed. Fluid-particle acceleration correlation is governed by two length scales; one arises from the pressure gradient, the other from the viscous force.Comment: 2 figures, 4 pages. Physical Review Letters, accepted August 200

Photovoltaic array: Power conditioner interface characteristics

The electrical output (power, current, and voltage) of flat plate solar arrays changes constantly, due primarily to changes in cell temperature and irradiance level. As a result, array loads such as dc-to-ac power conditioners must be capable of accommodating widely varying input levels while maintaining operation at or near the maximum power point of the array. The array operating characteristics and extreme output limits necessary for the systematic design of array load interfaces under a wide variety of climatic conditions are studied. A number of interface parameters are examined, including optimum operating voltage, voltage energy, maximum power and current limits, and maximum open circuit voltage. The effect of array degradation and I-V curve fill factor or the array power conditioner interface is also discussed. Results are presented as normalized ratios of power conditioner parameters to array parameters, making the results universally applicable to a wide variety of system sizes, sites, and operating modes

Summary of 1978 Southeastern Virginia Urban Plume study: Aircraft results for carbon monoxide, methane, nonmethane hydrocarbons, and ozone

The characteristics of the Southeastern Virginia urban plume were defined with emphasis on the photon-oxidant species. The measurement area was a rectangle, approximately 150 km by 100 km centered around Cape Charles, Virginia. Included in this area are the cities of Norfolk, Virginia Beach, Chesapeake, Newport News, and Hampton. The area is bounded on the north by Wallops Island, Virginia, and on the south by the Hampton Roads area of Tidewater Virginia. The major axis of the rectangle is oriented in the southwest-northeast direction. The data set includes aircraft measurements for carbon monoxide, methane, nonmethane hydrocarbons, and ozone. The experiment shows that CO can be successfully measured as a tracer gas and used as an index for determining localized and urban plumes. The 1978 data base provided sufficient data to assess an automated chromatograph with flame ionization detection used for measuring methane and nonmethane hydrocarbons in flight

Research and development of a high capacity, nonaqueous secondary battery Final report, Oct. 1964 - Dec. 1965

High capacity nonaqueous secondary batter