AS-206 S-4B restart alternate mission L/V operational flight trajectory, part 3

Saturn S-4B restart alternate mission launch vehicle operational flight trajectory - AS-206 vehicle systems integratio

Hydrographs by Single Linear Reservoir Model

A single linear reservoir (SLR) model is presented which provides a simple means for developing runoff hydrographs for small, urban watersheds. The model only requires one parameter, K, which can be estimated from watershed and precipitation characteristics. Several methods for estimating K and the results of testing the model on various watersheds are presented.Waller Creek Working Grou

Erosion and sedimentation in Lake Ashtabula, southeastern North Dakota

Erosion along the shore of Lake Ashtabula and nearshore and offshore sedimentation were studied from May 1969 to December 1970. The lake, located in the southeastern part of North Dakota, was formed when the Baldhill Dam stopped the flow of the Sheyenne River in 1950. Maximum depth of the lake is 45 feet in the inundated river channel immediately above the dam. The lake is 27 miles long and ranges in width from 1/3 to 1/2 mile. Shoreline erosion, measured at stations located at 100-foot intervals around the margins of the lake, was found to be a major source of sediment filling the lake. The shorelines have attained 6 percent of the projected shoreline erosion based on a stable shelf profile. All incoming wave energy is expended in internal turbulence when a stable shelf is attained. The shape of the profile is dependent on the wave form of deep-water waves, the angle of repose of sediments building the terrace, the slope of the exposed banks adjacent to the shoreline, the valley-wall slope, and the percentage of sand-sized and larger particles in the bank material. The main erosional processes along the shore are slumping, frost weathering, block separation, and collapse of overhangs. The most important conditioning factors are groundwater regime, shoreline orientation, shoreline use, and organic activity. The swelling and contraction of montmorillonitic clays in bank material is important in erosional processes. The role of the conditioning factors was analyzed for all shoreline stations using a number of specially written computer programs. Many turbid-water currents were traced using temperature, specific electrical conductance, and suspended solids. Suspended sediment settling out of turbid water fills the depressions on the lake bottom. The Sheyenne River channel, with 6 percent of the total area, has 19 percent of the total sediment accumulating in the lake. Sediment samples taken along· coring ranges were analyzed for particle size, organic content, total carbonate, mineralogy, and com paction. The total amount of sediment between each coring range was calculated. The accumulating sediment is gelatinous in appearance and has an initial water content of 80 percent. Compaction reduces the water content to 60 percent at 8 inches. Dominant minerals are dolomite, calcite, potassium feldspar, plagioclase, quartz, disordered cristobalite, and the clay minerals. Oxidizable organic content ranges from 8 to 12 percent. At the present 1.5 X 109 pounds (dry weight) of sediment has accumulated in the lake, with at least 5 X 108 pounds coming from shoreline erosion. A thin blanket of sediment is being built into the lake by the Sheyenne River. The lake will be completely filled in 5,000 years, based on the present rate of sediment accumulations. Because erosion rates will decrease as shoreline and other adjustment are made, a life expectancy of 10,000 years is suggested

First-principle density-functional calculation of the Raman spectra of BEDT-TTF

We present a first-principles density-functional calculation for the Raman spectra of a neutral BEDT-TTF molecule. Our results are in excellent agreement with experimental results. We show that a planar structure is not a stable state of a neutral BEDT-TTF molecule. We consider three possible conformations and discuss their relation to disorder in these systems.Comment: 3 pages, 2 figures, submitted to the proceedings of ISCOM 200

DFT calculation of the intermolecular exchange interaction in the magnetic Mn4_4 dimer

The dimeric form of the single-molecule magnet [Mn$_4$O$_3$Cl$_4$(O$_2$CEt)$_3$(py)$_3$]$_2$ recently revealed interesting phenomena: no quantum tunneling at zero field and tunneling before magnetic field reversal. This is attributed to substantial antiferromagnetic exchange interaction between different monomers. The intermolecular exchange interaction, electronic structure and magnetic properties of this molecular magnet are calculated using density-functional theory within generalized-gradient approximation. Calculations are in good agreement with experiment.Comment: 4 page

The Asian red seaweed Grateloupia turuturu (Rhodophyta) invades the Gulf of Maine

We report the invasion of the Gulf of Maine, in the northwest Atlantic Ocean, by the largest red seaweed in the world, the Asian Grateloupia turuturu. First detected in 1994 in Narragansett Bay, Rhode Island, south of Cape Cod, this alga had expanded its range in the following years only over to Long Island and into Long Island Sound. In July 2007 we found Grateloupia in the Cape Cod Canal and as far north (east) as Boston, Massachusetts, establishing its presence in the Gulf of Maine. Grateloupia can be invasive and may be capable of disrupting low intertidal and shallow subtidal seaweeds. The plant\u27s broad physiological tolerances suggest that it will be able to expand possibly as far north as the Bay of Fundy. We predict its continued spread in North America and around the world, noting that its arrival in the major international port of Boston may now launch G. turuturu on to new global shipping corridors

Vibrational signatures for low-energy intermediate-sized Si clusters

We report low-energy locally stable structures for the clusters Si20 and Si21. The structures were obtained by performing geometry optimizations within the local density approximation. Our calculated binding energies for these clusters are larger than any previously reported for this size regime. To aid in the experimental identification of the structures, we have computed the full vibrational spectra of the clusters, along with the Raman and IR activities of the various modes using a recently developed first-principles technique. These represent, to our knowledge, the first calculations of Raman and IR spectra for Si clusters of this size