The Paleo-ocean of Mars

A Paleo-ocean on the northern plains of Mars is proposed. The hypothetical ocean would have formed very early in Mars' history, during the early period of rapid outgassing and cratering. As the ocean froze and receded, bursting of aquifers along the shoreline would create catastrophic flooding. Analysis of soil at the two Viking landing sites, both of which occur on the floor of the hypothetical ocean, is not inconsistent with an oceanic clay rich in water soluble salts

A Parallelized Method for Solving Large Scale Integer Linear Optimization Problems using Cut-and-Solve with Applications to cGWAS

The commercial solver CPLEX has been one of the top solvers of mixed-integer and purely integer linear problems for some time. Its method of solving, Branch-and-Cut, has been shown to be highly effective, but has its limits in terms of input sizes which are tractable, and cannot be effectively parallelized beyond a small number. Here we present a different method of solution, Cut-and-Solve, which utilizes the power of CPLEX to effectively parallelize any mixed-integer or integer linear problem. We have utilized Cut-and-Solve in a novel way to offer optimal solution guarantees more quickly. We will show comparisons of Cut-and-Solve to CPLEX and show that it has definite promise as a solver of these types of problems. It offers a less memory intensive solution and one with power equal to the limitations only of the hardware it can be parallelized on. This method does not perform better than CPLEX at the level of parallelization tested here, but with some minor adjustments has the potential to solve previously intractable problems. Importantly, our current implementation shows an effective use as an anytime solver

The Use of Ergogenic Aids Among High School Athletes in Eastern Kentucky

A fifteen-question survey was developed to study the use of over-the counter nutrition supplements by high school athletes in eastern Kentucky. Athletic trainers from four local high schools were given one hundred permission forms and surveys. After two weeks only a small number (n=25) completed the requirements to participate in the study. The twenty-five participants consisted of male (n=15) and female (n=10). The athletes with the highest frequency of supplement use were football players (67.7%). The supplements with the highest use were protein powders (n=13) and creatine monohydrate (n=9)

Evolution of highly buoyant thermals in a stratified layer

The buoyant rise of thermals (i.e. bubbles of enhanced entropy, but initially in pressure equilibrium) is investigated numerically in three dimensions for the case of an adiabatically stratified layer covering 6-9 pressure scale heights. It is found that these bubbles can travel to large heights before being braked by the excess pressure that builds up in order to drive the gas sideways in the head of the bubble. Until this happens, the momentum of the bubble grows as described by the time-integrated buoyancy force. This validates the simple theory of bubble dynamics whereby the mass entrainment of the bubble provides an effective braking force well before the bubble stops ascending. This is quantified by an entrainment parameter alpha which is calculated from the simulations and is found to be in good agreement with the experimental measurements. This work is discussed in the context of contact binaries whose secondaries could be subject to dissipative heating in the outermost layers.Comment: 12 pages, 18 figures, A&A (accepted

Paper Session II- B - Alternative Fuel Transport using semi volatile Ammonia

A major constraint to exploring space is the ability to carry the necessary fuel and oxidizer for a return trip. The aerospace community is continuously looking for methods to derive the fuel or oxidizer from In-situ resources. In the case of Mars, one option would be to derive the oxidizer from the C02 rich atmosphere. This process relies on the ability to deliver hydrogen from earth to mars. The weight of the fuel is only 5%-10% of the overall system weight required to transport it. The Space Shuttle and some expendable launch vehicles utilize liquid hydrogen providing a high density storage technique. Alternative storage methods that would achieve hydrogen capacities greater than 10% are much sought after for both terrestrial and space based applications. This paper describes one method of transporting hydrogen to Mars by anhydrous ammonia. By chemically binding the hydrogen in the ammonia a storage capacity greater than 15% (mass of hydrogen to mass of total system) is theoretically possible. The ammonia is then dissociated into hydrogen and nitrogen using a patented microwave electro-thermal plasma reactor. The hydrogen is then available as a feedstock for processing or as a fuel for a fuel cell or propulsion system

Ethanol Based Gel Fuel for a Hybrid Rocket

A cost effective, renewable ethanol-based solid fuel compound, and method of making the fuel for hybrid rocket engines. Gelling agents, preferably methylcellulose can be used in conjunction with calcium acetate or calcium acetate alone make stiff plastic out of ethanol to improve its properties for hybrid rocket engine. The increased stiffness of an ethanol-based fuel gel, increases yield stress that allows rapid acceleration of rockets. The low cost bio-fuel based on solidified ethanol rather than expensive petroleum derived substances lowers the cost of volume rocket launches, lowers the cost of access to orbit and provides safer sounding rocket flights into space. The resulting raw gel can further be mixed with a cross linking compound and water to form a stiffer material. Alternatively, the resulting raw gel can be frozen by liquid nitrogen

The interaction of a giant planet with a disc with MHD turbulence I: The initial turbulent disc models

This is the first of a series of papers aimed at developing and interpreting simulations of protoplanets interacting with turbulent accretion discs. Here we study the disc models prior to the introduction of a protoplanet.We study models in which a Keplerian domain is unstable to the magnetorotational instability (MRI). Various models with B-fields having zero net flux are considered.We relate the properties of the models to classical viscous disc theory.All models attain a turbulent state with volume averaged stress parameter alpha ~ 0.005. At any particular time the vertically and azimuthally averaged value exhibited large fluctuations in radius. Time averaging over periods exceeding 3 orbital periods at the outer boundary of the disc resulted in a smoother quantity with radial variations within a factor of two or so. The vertically and azimuthally averaged radial velocity showed much larger spatial and temporal fluctuations, requiring additional time averaging for 7-8 orbital periods at the outer boundary to limit them. Comparison with the value derived from the averaged stress using viscous disc theory yielded schematic agreement for feasible averaging times but with some indication that the effects of residual fluctuations remained. The behaviour described above must be borne in mind when considering laminar disc simulations with anomalous Navier--Stokes viscosity. This is because the operation of a viscosity as in classical viscous disc theory with anomalous viscosity coefficient cannot apply to a turbulent disc undergoing rapid changes due to external perturbation. The classical theory can only be used to describe the time averaged behaviour of the parts of the disc that are in a statistically steady condition for long enough for appropriate averaging to be carried out.Comment: 10 pages, 23 figures, accepted for publication in MNRAS. A gzipped postscript version including high resolution figures is available at http://www.maths.qmul.ac.uk/~rp