48 research outputs found
Wartime scars or reservoirs of biodiversity? The value of bomb crater ponds in aquatic conservation
Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X
Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X
We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases.EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/ EUROfusio
Living ring-opening polymerization of L,L-lactide initiated with potassium t-butoxide and its 18-crown-6 complex
Synthesis of Iminodiacetic Acid in a Cascade Reactor
The present paper deals with the modernization of the manufacturing of iminodiacetic acid, enhancing the conversion and the reactor-intensity, as well as with the elaboration of a procedure permitting continuous production. During the investigation of the industrial synthesis of iminodiacetic acid our important recognition is that glycine, produced together with the desired iminodiacetic acid, can be converted with monochloroacetic acid to iminodiacetic acid after removal of the excess of ammonia from the reaction mixture. For utilization of glycine, an industrial procedure has been elaborated. According to this, production of iminodiacetic acid is carried out in a quadrate cascade reactor, so that the reaction mixture leaving the second reactor element is freed from annnonia, concentrated, and then reacted with an equivalent of monochloroacetic acid calculated on the basis of the glycine-content. In this way, iminodiacetic acid is obtained in the laboratory-scale experimental reactor with a 91 % yield, based on monochloroacetic acid. Calculations for the optimization of the reactor-cascade are also presented. These clearly prove that the required new investment is reimbursed upon manufacturing on an industrial scale