Prospects of gas supply until 2020 in Europe and its relevance for the power sector in the context of emission trading

With the liberalization of energy markets and the introduction of an emission trading system, electricity production by gas combined cycle power plants has significantly increased in the European Union in recent years. Reasons for the significant increase include the short construction time for gas power plants and the favourable investment costs. One further advantage is the relatively low CO₂ emissions of gas power plants. Thus, a key option for reducing emissions is seen in the increased use of gas for power production. Model calculations from various models show that an increase of gas power production is expected. In general, however, the interdependencies of the different markets (gas, electricity and CO₂) as well as the country-specific gas supply options, determined by pipelines and liquefied natural gas (LNG), are neglected. As the competitiveness of gas power plants mainly depends on the availability of gas and the gas price, a novel model that integrates electricity, gas, and CO₂- emission markets assuming perfect competition will be presented. The objective of this paper is to analyse the long-term relevance of the gas market for the electricity sector in the European Union in the context of CO₂-emission reduction targets.     

Die Lösung von Ermüdungsfragen am Beispiel eines Prozeßkrans in der Stahlindustrie

Solution of fatigue issues in the case of a process crane in the metallurgical industry. Cranes that are used as casting or charging cranes in steel works belong to those steel structures exposed to the highest possible fatigue stress. Such cranes are often designed for over two million loadings and are part of the most essential equipment of a steel mill. Hidden under the roofs of the workshops they are hardly perceived although they perform their work with unshakable calmness and reliability. The following article shall throw a little more light on these burden carriers from the point of view of a structural engineer.     

HF-unterstützte Synthese von Orthoestern und Oxazolinen. [1]

A convenient method is reported to generate the ortho-pivalic acid esters 5 and 7 from meso-erythrit 3 ) and D -mannitol ( 6 ), respectively, using a HF-supported procedure. Furthermore, the α-D -glucopyrano[1,2-d]-2-oxazolines 9 and 10 were prepared from starch and nitriles (pivalonitrile and benzonitrile) by a Ritter-type reaction in anhydrous hydrogen fluoride. The separation of the products 5 , 7 , 9 , and 10 was possible by quenching of their HF-solutions with triethylamine. The structure of the orthoester 7 and the oxazoline 10 was confirmed by X-ray analyses.     

A comparison of 2H and 129Xe NMR as a probe of the effect of crosslinking in rubbery materials

The paper describes the investigation of butadiene rubber networks varying in crosslink density by means of xenon (¹²⁹Xe) and deuteron (²H) NMR spectroscopy. ¹²⁹Xe NMR spectra give an evidence of structural inhomogeneities inside the lower crosslinked network which were already observed in previous deuteron NMR studies under uniaxial deformation. The results are discussed in comparison with theoretical models and simulations. It appears that experiment, theory and also simulation are now coming together to give a detailed picture of the behaviour of these rubbery materials.     

Wechselwirkungen in Kristallen. 136. Protonierte Di(pyrid-2-yl)amin-Salze mit verschiedenen Anionen: Monomeres Tetraphenylborat sowie Bis(trifluormethylsulfonat), dimeres Squarat und polymeres Chlorid-Dihydrat

Interactions in Crystals. 136. Protonated Dipyridylamine Salts with Different Anions: Monomeric Tetraphenylborate as well as Bis(trifluormethylsulfonate), Dimeric Squarate and Polymeric Chloride Dihydrate Di(pyrid-2-yl)amine is monoprotonated by acetic, squaric as well as hydrochloric acid and diprotonated by trifluoromethylsulfonic acid. To explore the anion and hydrogen-bridge dependency of its salts, crystals of the monomeric tetraphenylborate, the dimeric squarate as well as the bis(trifluoromethylsulfonate) and the polymeric chloride hydrate have been grown and their structures determined: Separated by bulky tetraphenylborate anions, pyrid-2-yl(2′-pyridinium) amine cation contains an intramolecular hydrogen bridge N^⊕H…︁N and is slightly folded. The squarate salt dimer exhibits additional bridges, N H…︁O^⊖ and O H…︁O. The severely twisted di(2-pyridinium)amine dication is connected to its trifluormethylsulfonate counter anions by altogether three H-bridges, two N^⊕H…︁O and one N H…︁O. The chloride dihydrate crystallizes in layers of 16-membered rings, formed from three Cl anions and five water molecules. The diversity of the hydrogen-bridge dominated salt structures is discussed based on comparison with selected literature examples and on PM3 calculations.     

Thermoplastic cellulose acetate and cellulose acetate compounds prepared by reactive processing

Novel families of thermoplastic polysaccharides such as cellulose-2,5-acetate were produced by means of reactive processing technology that grafted cyclic lactones simultaneously onto polysaccharide, hydroxyfunctional plasticizer, and optionally also onto hydroxyfunctional fillers. Organosolv lignin, cellulose, starch, and chitin were added to effect reinforcement of the polymer matrix. Mechanical and thermal properties depended upon molecular architecture of the components and process parameters such as temperature, feed ratios, and screw speed. Such blends and composites utilize renewable resources and are of interest in waste disposal via biodegradation. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 213–242, 1997     

Experimental evidence of a linear relationship between inorganic mercury loading and methylmercury accumulation by aquatic biota

Developing effective regulations on mercury (Hg) emissions requires a better understanding of how atmospheric Hg deposition affects methylmercury (MeHg) levels in aquatic biota. This study tested the hypothesis that MeHg accumulation in aquatic food webs is related to atmospheric Hg deposition. We simulated a range of inorganic Hg deposition rates by adding isotopically enriched Hg(II) (90.9% 202Hg) to 10-m diameter mesocosms in a boreal lake. Concentrations of experimentally added ("spike") Hg were monitored in zooplankton, benthic invertebrates, and fish. Some Hg(II) added to the mesocosms was methylated and incorporated into the food web within weeks, demonstrating that Hg(II) deposited directly to aquatic ecosystems can become quickly available to biota. Relationships between Hg(II) loading rates and spike MeHg concentrations in zooplankton, benthic invertebrates, and fish were linear and significant. Furthermore, spike MeHg concentrations in the food web were directly proportional to Hg(II) loading rates (i.e., a percent change in Hg(II) loading rate resulted in, statistically, the same percent change in MeHg concentration). This is the first experimental determination of the relationship between Hg(II) loading and MeHg bioaccumulation in aquatic biota. We conclude that changes in atmospheric Hg deposition caused by increases or decreases in Hg emissions will ultimately affect MeHg levels in aquatic food webs.