Measurements in atmospheric electricity designed to improve launch safety during the Apollo series

Ground test measurements were made during the launches of Apollo 13 and 14 in an effort to better define the electrical characteristics of a large launch vehicle. Of particular concern was the effective electrical length of the vehicle and plume since this parameter markedly affects the likelihood of a lightning stroke being triggered by a launch during disturbed weather conditions. Since no instrumentation could be carried aboard the launch vehicle, the experiments were confined to LF radio noise and electrostatic-field measurements on the ground in the vicinity of the launch pad. The philosophy of the experiment and the instrumentation and layout are described. From the results of the experiment it is concluded that the rocket and exhaust do not produce large-scale shorting of the earth's field out to distances of thousands of feet from the launch pad. There is evidence, however, that the plume does add substantially to the electrical length of the rocket. On this basis, it was recommended that there be no relaxation of launch rules for launches during disturbed weather

Transforming carbon nanotubes by silylation: An ab initio study

We use ab initio density functional calculations to study the chemical functionalization of single-wall carbon nanotubes and graphene monolayers by silyl (SiH3) radicals and hydrogen. We find that silyl radicals form strong covalent bonds with graphene and nanotube walls, causing local structural relaxations that enhance the sp3 character of these graphitic nanostructures. Silylation transforms all carbon nanotubes into semiconductors, independent of their chirality. Calculated vibrational spectra suggest that specific frequency shifts can be used as a signature of successful silylation.Comment: 4 pages, 3 figure

Quantum Films Adsorbed on Graphite: Third and Fourth Helium Layers

Using a path-integral Monte Carlo method for simulating superfluid quantum films, we investigate helium layers adsorbed on a substrate consisting of graphite plus two solid helium layers. Our results for the promotion densities and the dependence of the superfluid density on coverage are in agreement with experiment. We can also explain certain features of the measured heat capacity as a function of temperature and coverage.Comment: 13 pages in the Phys. Rev. two-column format, 16 Figure

Supersymmetric Baryogenesis from Exotic Quark Decays

In a simple extension of the minimal supersymmetric standard model, out-of-equilibrium decays of TeV scale exotic vector-like squarks may generate the baryon asymmetry of the universe. Baryon number and CP violation are present in the superpotential, so this mechanism does not rely on CP violation in supersymmetry breaking parameters. We discuss phenomenological constraints on the model as well as potential signals for the Large Hadron Collider and electronic dipole moment experiments. A variation on the TeV scale model allows the exotic squarks to be the messengers of gauge mediated supersymmetry breaking.Comment: 28 pages, 7 figures, 2 appendices, v2: typos corrected, results unchange

On the validity of mean-field amplitude equations for counterpropagating wavetrains

We rigorously establish the validity of the equations describing the evolution of one-dimensional long wavelength modulations of counterpropagating wavetrains for a hyperbolic model equation, namely the sine-Gordon equation. We consider both periodic amplitude functions and localized wavepackets. For the localized case, the wavetrains are completely decoupled at leading order, while in the periodic case the amplitude equations take the form of mean-field (nonlocal) Schr\"odinger equations rather than locally coupled partial differential equations. The origin of this weakened coupling is traced to a hidden translation symmetry in the linear problem, which is related to the existence of a characteristic frame traveling at the group velocity of each wavetrain. It is proved that solutions to the amplitude equations dominate the dynamics of the governing equations on asymptotically long time scales. While the details of the discussion are restricted to the class of model equations having a leading cubic nonlinearity, the results strongly indicate that mean-field evolution equations are generic for bimodal disturbances in dispersive systems with \O(1) group velocity.Comment: 16 pages, uuencoded, tar-compressed Postscript fil

Managing ponds and lakes for aquaculture and fisheries in Missouri : fish selection and stocking for sport fishing (2014)

Sport fishing is a popular recreational activity among Missouri pond owners (Figure 1). Developing a farm pond for fishing requires several important decisions, including where to get fish; what species to stock; how many, what size and when to stock. Ponds stocked with incorrect combinations of fish can quickly develop unbalanced populations that will become a problem. Small farm ponds and lakes are not natural environments, so they must be carefully managed. Successful pond management involves a combination of practices that promote a healthy and productive pond ecosystem: Ensuring during construction that a pond has enough watershed acreage to maintain water levels ; Monitoring water quality, and adjusting as necessary ; Ensuring food is available for fish ; Controlling harvesting to maintain a balance of predator and prey populations ; Managing aquatic vegetation, and controlling weeds ; Preventing situations that may cause fish kills.New 5/14/Web

Converting unused agriculture facilities for aquaculture use : swine barn conversion for fish culture (2012)

New 7/12/Web

Managing ponds and lakes for aquaculture and fisheries in Missouri : establishing hybrid sunfish in ponds for recreation (2014)

Sunfish -- bluegill, redear and longear sunfish -- are among the most popular species of fish for angling in Missouri (Figure 1). They are relatively easy to catch on a variety of lures and baits and provide a challenge for anglers of all ages, making hybrid sunfish a popular choice for stocking in ponds to improve angling opportunities. Several popular hybrid sunfish crosses are used to stock ponds, including bluegill and green sunfish, bluegill and redear sunfish, and green sunfish and redear sunfish. The most commonly stocked hybrid is a male bluegill crossed with a female green sunfish (Figure 2). These hybrids are exceptionally hardy fish. Bluegill and green sunfish usually inhabit, feed and spawn in shallow areas of the pond. Bluegill and green sunfish are multiple spawners and will frequent nests arranged as colonies over the warm summer months. Redear sunfish, on the other hand, only spawn once a year and normally do so at a cooler temperature than bluegill or green sunfish. Bluegill-green sunfish hybrids and bluegill-redear hybrids are good combinations because they prefer different areas of the pond and have different feeding habits. Some pond owners like these combinations because they offer diverse fishing. Being a mix of two species, hybrid sunfish have attributes of both parents. Such attributes include fast growth, reduced reproduction, ability to eat floating fish feed and an aggressive feeding behavior, which makes them easy to catch. Although hybrid sunfish are not sterile, breeding is greatly reduced because 85 to 95 percent are male. Hybrid sunfish cannot replace bluegill in a pond stocked with bass and bluegill because they do not produce enough offspring to provide enough food for largemouth bass.New 6/14/Web

Bluegill sunfish production in Missouri (2012)

New 4/12/Web

A preliminary report on the contact-independent antagonism of Pseudogymnoascus destructans by Rhodococcus rhodochrous strain DAP96253.

BackgroundThe recently-identified causative agent of White-Nose Syndrome (WNS), Pseudogymnoascus destructans, has been responsible for the mortality of an estimated 5.5 million North American bats since its emergence in 2006. A primary focus of the National Response Plan, established by multiple state, federal and tribal agencies in 2011, was the identification of biological control options for WNS. In an effort to identify potential biological control options for WNS, multiply induced cells of Rhodococcus rhodochrous strain DAP96253 was screened for anti-P. destructans activity.ResultsConidia and mycelial plugs of P. destructans were exposed to induced R. rhodochrous in a closed air-space at 15°C, 7°C and 4°C and were evaluated for contact-independent inhibition of conidia germination and mycelial extension with positive results. Additionally, in situ application methods for induced R. rhodochrous, such as fixed-cell catalyst and fermentation cell-paste in non-growth conditions, were screened with positive results. R. rhodochrous was assayed for ex vivo activity via exposure to bat tissue explants inoculated with P. destructans conidia. Induced R. rhodochrous completely inhibited growth from conidia at 15°C and had a strong fungistatic effect at 4°C. Induced R. rhodochrous inhibited P. destructans growth from conidia when cultured in a shared air-space with bat tissue explants inoculated with P. destructans conidia.ConclusionThe identification of inducible biological agents with contact-independent anti- P. destructans activity is a major milestone in the development of viable biological control options for in situ application and provides the first example of contact-independent antagonism of this devastating wildlife pathogen