Effect of sampling effort and sampling frequency on the composition of the planktonic crustacean assemblage: a case study of the river Danube

Although numerous studies have focused on the seasonal dynamics of riverine zooplankton, little is known about its short-term variation. In order to examine the effects of sampling frequency and sampling effort, microcrustacean samples were collected at daily intervals between 13 June and 21 July of 2007 in a parapotamal side arm of the river Danube, Hungary. Samples were also taken at biweekly intervals from November 2006 to May 2008. After presenting the community dynamics, the effect of sampling effort was evaluated with two different methods; the minimal sample size was also estimated. We introduced a single index (potential dynamic information loss; to determine the potential loss of information when sampling frequency is reduced. The formula was calculated for the total abundance, densities of the dominant taxa, adult/larva ratios of copepods and for two different diversity measures. Results suggest that abundances may experience notable fluctuations even within 1 week, as do diversities and adult/larva ratios

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

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

Investigation of the Industrially Applicable Synthesis of Iminodiacetic Acid

The present paper deals with the synthesis of iminodiacetic acid, which is the basic material of the production of the plant-protecting agent N-phosphonomethyl glycine. The most economical procedure for the industrial preparation of iminodiacetic acid involves aminolysis of monochloroacetic acid, where the starting materials are monochloroacetic acid, ammonia and Ca(OH)2. We improved the conversion of monochloroacetic acid into the target compound to 91 % from the present 67 % yield. Our results show that the rate-determining step is the formation of iminodiacetic acid, while a considerable amount of glycine is present. 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

Fényemittáló maleinimid tartalmú polimerek előállítása és vizsgálata

Fluoreszcens tulajdonságokkal rendelkező maleimid tartalmú alapláncokat szintetizáltunk. Az előállított monomereket (akril-származékok) gyökös módszerrel polimerizáltuk. A fluoreszcens termékeket tisztítottuk és részletesen karakterizáltuk NMR, GPC és tömegspektrometriás mérésekkel. Az elvégzett optikai vizsgálatok kimutatták, hogy az előállított monomerek és polimerek, az oldat elkészítésénél használt oldószer polaritásától függően, zöld vagy sárga fényt emittálnak