Glucosinolate and folate content in sprouted broccoli seeds

HPLC analysis of broccoli seeds and laboratory-grown broccoli sprouts revealed that three aliphatic glucosinolates (glucoraphanin, glucoiberin and glucoerucin) and a group of indol-glucosinolates including 4-hydroxy-glucobrassicin are preformed in the seeds. In the early stage of sprouting a reduction (approx. 20%) of the aliphatic glucosinolates was measured. During further growing, until day 8, and subsequent cold storage up to the 12th day the amounts of the aliphatic glucosinolates levelled off. While 4-hydroxy-glucobrassicin declined continuously, three minor indole-derivatives increased steadily, but remained at a comparatively low level. Besides glucosinolates, folates were quantified in broccoli sprouts by stable isotope dilution assays (SIDAs). During germination, the contents of total folates increased to 72 μg/100 g fresh mass and 546 μg/100 g dry mass on the 4th day, which was equivalent, respectively, to a 3-fold and a 24-fold increase in the seed’s content. Thereafter, total folates decreased again to 13 μg/100 g fresh mass until the 8th day of germination and remained at this low level. The folate pattern measured by SIDA revealed 5-methyltetrahydrofolate as the predominant vitamer at each stage.     

A Laboratory Reactor for Gas‐Phase Olefin Polymerization

A new reactor system for gas‐phase ethylene/α‐olefin polymerization is described. Good gas‐phase temperature control at high polymerization rates was achieved with the 2‐L semi‐batch reactor. Ethylene/1‐hexene and ethylene polymerization results showing the effects of operating conditions on temperature profiles are presented. Good gas‐phase temperature control is required to obtain reliable activity profiles. A gas‐sampling and analysis system, which allows relatively rapid (< 3 min) and accurate determination of ethylene/1‐hexene contents in the gas‐phase of the reactor, is also described. Rapid and reliable hydrogen contents were also measured with this relatively inexpensive system.     

Korrosionsinhibierende Plasmapolymerschichten auf Stahluntergründen

Plasma polymeric coatings with inhibitory effect on steel surfaces The plasma based surface technique facilitates scientifically and technically, economically and ecologically interesting alternatives to traditional treatment procedures. From that the evolution of a new procedure for the improvement of the corrosion resistance of low‐alloy steel surfaces through ultrathin plasma polymeric coatings was a main topic at the iLF in the last years. After plasma based super cleaning process under oxidized conditions should be produced plasma polymeric coatings with a corrosion inhibiting / passivation effect. For this purpose corrosion inhibitor molecules are implanted into the normally electrochemically inactive coating during the process of the plasma based polymerization of silicon‐organic monomers. Through that it has been proved that the long‐term corrosion protection improves. Besides the surface of the produced plasma polymer shift can be modified by plasma‐technical procedures so that it shows also optimal adhesion promoter characteristics.     

The influence of aluminum alkyls on the polymerization of ethylene with SiO2/MgCl2-supported TiCl4 catalysts

The influence of different aluminum alkyls (diethylaluminum chloride, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum and isoprenylaluminum) on the ethylene polymerization activity of a laboratory prepared high-activity SiO₂/MgCl₂-supported TiCl₄ catalyst has been investigated. A slurry reactor (decane diluent) was used for measuring rates of polymerization. The average molar mass, the breadth of the molar mass distribution, the polymerization activity, and the shapes of the activity-time profiles, were strongly dependent on the nature of the aluminum alkyl. For several of the cocatalysts used, the catalytic activity approached a constant value after a certain amount of time under reaction conditions. In this constant activity region, a first-order dependence of the polymerization rate on the monomer concentration was found for all of the systems examined. However, the activation energy of the polymerization reaction was found to depend strongly on the type of cocatalyst which was used.     

Highly efficient Cu(In,Ga)Se2 solar cells grown on flexible polymer films

Solar cells based on polycrystalline Cu(In,Ga)Se(2) absorber layers have yielded the highest conversion efficiency among all thin-film technologies, and the use of flexible polymer films as substrates offers several advantages in lowering manufacturing costs. However, given that conversion efficiency is crucial for cost-competitiveness, it is necessary to develop devices on flexible substrates that perform as well as those obtained on rigid substrates. Such comparable performance has not previously been achieved, primarily because polymer films require much lower substrate temperatures during absorber deposition, generally resulting in much lower efficiencies. Here we identify a strong composition gradient in the absorber layer as the main reason for inferior performance and show that, by adjusting it appropriately, very high efficiencies can be obtained. This implies that future manufacturing of highly efficient flexible solar cells could lower the cost of solar electricity and thus become a significant branch of the photovoltaic industry.