10,589 research outputs found
The Growth and Survival of Early Instars of \u3ci\u3eBellura Obliqua\u3c/i\u3e (Lepidoptera: Noctuidae) on \u3ci\u3eTypha Latifolia\u3c/i\u3e and \u3ci\u3eTypha Angustifolia\u3c/i\u3e
Larvae of the noctuid moth Bellura obliqua are frequently encountered on Typha latifolia, but less commonly on Typha angustifolia. Experiments were conducted to compare the growth and survivorship of early B. obliqua instars on the two species of cattail. In short-term growth chamber experiments there were no significant differences in the survivorship, relative growth rate (RGR), relative consumption rate (RCR), or the efficiency of conversion of ingested food (ECI) between first-instar larvae reared on leaves of the two species. Third-instar larvae fed stems, however, had a greater RGR and higher ECI when reared on T. lalifolia. Differences in growth are apparently not related to differences in hostplant nitrogen or acid-detergent fiber content. In a long term greenhouse experiment, using transplanted cattails, larvae reared on T. latifolia grew somewhat larger and had a significantly higher survival rate than those reared on T. angustifolia. Host plant structure is postulated to influence larval survivorship. Typha is under consideration for use as a bio-energy crop and planting T. angustifolia may help to reduce infestations in cultivated stands
Origins of Bulk Viscosity at RHIC
A variety of physical phenomena can lead to viscous effects. Several sources
of shear and bulk viscosity are reviewed with an emphasis on the bulk viscosity
associated with chiral restoration and with chemical non-equilibrium. We show
that in a mean-field treatment of the limiting case of a second order phase
transition, the bulk viscosity peaks in a singularity at the critical point.Comment: submitted to PR
Effects of Nutrients on Productivity and Morphology of Typha angustifolia x latifolia
The productivity of natural stands of cattails (Typha latifolia) has been correlated with the amounts of nutrients in the soil and water by Boyd and Hess (Ecology, 51: 296, 1970). The direct effects of varying levels of nitrogen (N), phosphorus (P) and potassium (K) on productivity were examined in our study by growing cattails in Hoagland\u27s nutrient solution. Concentrations of ¼, 1/16, and 1/64 the amount of N present in complete Hoagland\u27s solution (0.01Ml resulted in 63 percent, 48 percent and 26 percent of the dry weight of plants grown in complete solution. Rhizomes used to start plants contained considerable amounts of P and K since growth in solutions with no P or no K resulted in dry weights up to 37 percent of that of plants grown in complete solution. Nutrient availability also affected plant morphology . Reduced N increased root growth up to 75 percent greater than that of plants grown in complete solution
Hydrogen Dissociation and Diffusion on Ni and Ti -doped Mg(0001) Surfaces
It is well known, both theoretically and experimentally, that alloying
MgH with transition elements can significantly improve the thermodynamic
and kinetic properties for H desorption, as well as the H intake by Mg
bulk. Here we present a density functional theory investigation of hydrogen
dissociation and surface diffusion over Ni-doped surface, and compare the
findings to previously investigated Ti-doped Mg(0001) and pure Mg(0001)
surfaces. Our results show that the energy barrier for hydrogen dissociation on
the pure Mg(0001) surface is high, while it is small/null when Ni/Ti are added
to the surface as dopants. We find that the binding energy of the two H atoms
near the dissociation site is high on Ti, effectively impeding diffusion away
from the Ti site. By contrast, we find that on Ni the energy barrier for
diffusion is much reduced. Therefore, although both Ti and Ni promote H
dissociation, only Ni appears to be a good catalyst for Mg hydrogenation,
allowing diffusion away from the catalytic sites. Experimental results
corroborate these theoretical findings, i.e. faster hydrogenation of the Ni
doped Mg sample as opposed to the reference Mg or Ti doped Mg.Comment: 17 pages, 15 figures, to appear in Journal of Chemical Physic
Energy Potential of Cattails (Typha spp.) and Productivity in Managed Stands
Because of their high productivity in both natural and managed stands, cattails are being considered as a potential energy crop . Yields of 40 tons per hectare, including above and below ground biomass, have been reported (Moss et al., 1977). Yields from plants grown in managed paddies on peat are generally 20-30 percent lower. The maximum shoot weight occurs in August while maximum below ground biomass is reached in October. Total biomass increased with increasing rates of fertilizer application but differences were not significant. Differences between the initial nutrient contents of the two peat types used were more important than fertilizer levels. Significant differences in yield were obtained by increasing the planting rate from 12 to 48 rhizomes per plot. Further studies on natural stands are under way at the Carlos Avery Wildlife Area
Advanced analog television study final report, 4 nov. - 19 dec. 1963
Information bandwidth reduction for analog television signals - Description of multiple interlace syste
Polyimide processing additives
A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA
A system of relational syllogistic incorporating full Boolean reasoning
We present a system of relational syllogistic, based on classical
propositional logic, having primitives of the following form:
Some A are R-related to some B;
Some A are R-related to all B;
All A are R-related to some B;
All A are R-related to all B.
Such primitives formalize sentences from natural language like `All students
read some textbooks'. Here A and B denote arbitrary sets (of objects), and R
denotes an arbitrary binary relation between objects. The language of the logic
contains only variables denoting sets, determining the class of set terms, and
variables denoting binary relations between objects, determining the class of
relational terms. Both classes of terms are closed under the standard Boolean
operations. The set of relational terms is also closed under taking the
converse of a relation. The results of the paper are the completeness theorem
with respect to the intended semantics and the computational complexity of the
satisfiability problem.Comment: Available at
http://link.springer.com/article/10.1007/s10849-012-9165-
Automated Data Management Information System (ADMIS)
ADMIS stores and controls data and documents associated with manned space flight effort. System contains all data oriented toward a specific document; it is primary source of reports generated by the system. Each group of records is composed of one document record, one distribution record for each recipient of the document, and one summary record
Early evolution of electron cyclotron driven current during suppression of tearing modes in a circular tokamak
When electron cyclotron (EC) driven current is first applied to the inside of
a magnetic island, the current spreads throughout the island and after a short
period achieves a steady level. Using a two equation fluid model for the EC
current that allows us to examine this early evolution in detail, we analyze
high-resolution simulations of a 2/1 classical tearing mode in a low-beta large
aspect-ratio circular tokamak. These simulations use a nonlinear 3D reduced-MHD
fluid model and the JOREK code. During the initial period where the EC driven
current grows and spreads throughout the magnetic island, it is not a function
of the magnetic flux. However, once it has reached a steady-state, it should be
a flux function. We demonstrate numerically that if sufficiently resolved
toroidally, the steady-state EC driven current becomes approximately a flux
function. We discuss the physics of this early period of EC evolution and its
impact on the size of the magnetic island.Comment: 12 pages, 7 figure
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