Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

PRACTICAL EXPERIENCE WITH SOLAR CROP DRIERS IN THE CARIBBEAN

Solar crop driers have been used in the Caribbean territories for the past twelve years. Crops dried have included sorrel, bananas, grass, nutmegs, ginger and screw pine. Several types of drier have been employed, varying from the simple wood-and-plastic wire basket drier to the metal-and-glass rock bed drier with chimney-assisted air circulation. Practical experience indicates that the most cost effective design is the wire basket drier with a plastic cover of UV stabilised polyethylene. For crops which require higher or more stable temperatures, the open cycle natural convection rock bed drier may be used. Rock-bed driers have been built in Barbados, Jamaica, Dominica, Grenada and Trinidad & Tobago, wire basket driers have been used in St. Lucia, Dominica, Guyana and Trinidad and Tobago. Simple cabinet driers have also been used, but they lack the simplicity of the wire basket drier and the heat storage capacity of the rock bed driers. ----- Durante los (iltimos doce anos, se ha utilizado secadores solares en el Caribe para secar cultivos tales como la acedera, los bananos, la hlerba, la nuez rnoscada, el jengibre y la pandanea, Se ha empleado variias clases de secadores, del sencillo secador de madera y plastico con red de alambre hasta el secador de vidrio y metal con lecho de piedras y circulaci6n de alre por chimenea, La experiencia practica indica que el diseno mas rentable es la red de alambre con una tapa de plastico hecha de polietileno estabilizado contra los rayos UV. Para los cultivos que necesitan temperaturas mas altas 0 estables, se puede utilizar el secador de lecho de piedras de cicIo abierto y convecci6n natural. Se ha construido secadores de lecho de piedras en Barbados, Jamaica, Dominica, Granada, y Trinidad y Tobago. Se ha utilizado tambien los secadores sencillos en forma de gabiente, pero estos son mils complejos que la red de alambre y no tienen la capacidad de almacenamiento calorifico de los secadores de lecho de piedras

The Crystal Structure of a Bis(2,6-pyridinedicarboxylato)Chromate(III) Anion with an Elaborate Network of Hydrogen Bonding and Pi Stacking

The synthesis, X-ray crystallography, spectroscopic, and electrochemical properties of the title compound, [Hdpa][Cr(dipic)2]·3H2O, 1, are reported. Compound 1 crystallized in the triclinic space group P-1 with a = 7.1057(11) Å, b = 12.965(2) Å, c = 14.269(2) Å, α = 80.306(3)°, β = 82.101(2)°, γ = 83.799(2)°, and V = 1278.6(4) Å3 with Z = 2. The distorted octahedral chromium anions are part of an elaborate network of hydrogen bonding formed by the waters of solvation, the anion, and cation as well as π-stacking interactions

Athabasca oil sands process water : characterization by atmospheric pressure photoionization and electrospray ionization fourier transform ion cyclotron resonance mass spectrometry

The Athabasca oil sands in Canada are a less conventional source of oil which have seen rapid development. There are concerns about the environmental impact, with particular respect to components in oil sands process water which may enter the aquatic ecosystem. Naphthenic acids have been previously targeted for study, due to their implications in toxicity toward aquatic wildlife, but it is believed that other components, too, contribute toward the potential toxicity of the oil sands process water. When mass spectrometry is used, it is necessary to use instrumentation with a high resolving power and mass accuracy when studying complex mixtures, but the technique has previously been hindered by the range of compounds that have been accessible via common ionization techniques, such as electrospray ionization. The research described here applied Fourier transform ion cyclotron resonance mass spectrometry in conjunction with electrospray ionization and atmospheric pressure photoionization, in both positive-ion and negative-ion modes, to the characterization of oil sands process water for the first time. The results highlight the need for broader characterization when investigating toxic components within oil sands process water