Analyse des Erdbeeraromas - Quantifizierung der flüchtigen Komponenten in Kulturerdbeervarietäten und der Walderdbeere

The volatile components of thirteen strawberry varieties and of a wild strawberry were evaluated in the freon-extract of fresh and frozen fruits. With the aid of GC/MS about 120 volatile substances could be identified. The determination of the substantial sensory qualities resulted from AEDA with sniffing technique. In this way 17 key compounds could be attached. The analysis of the key compounds point out significient variety differences.     

Photocatalytic reactors for treating water pollution with solar illumination. III: a simplified analysis for recirculating reactors

A solar photoreactor operated in the batch, recirculating mode is analyzed in terms of very simple observable variables such as the impinging photon flux, the incident area, the initial concentration, the flow rate, the reactor volume and a property defined as the Observed Photonic Efficiency. The proposed equipment is made of a tubular reactor, a tank, a pump and the connecting pipes. The analysis is formulated in terms of the photon input corresponding to an equivalent batch system that is derived as a new reaction coordinate for photoreactions. Employing several plausible approximations, the pollutant concentration evolution in the tank is cast in terms of very simple analytical solutions.Process photonic efficiencies are defined for the system operation and calculated with respect to the maximum achievable yield corresponding to the differential operation of the solar recirculating reactor.     

The potential role of hydrogen energy in India and Western Europe

We used the TIMER energy model to explore the potential role of hydrogen in the energy systems of India and Western Europe, looking at the impacts on its main incentives: climate policy, energy security and urban air pollution. We found that hydrogen will not play a major role in both regions without considerable cost reductions, mainly in fuel cell technology. Also, energy taxation policy is essential for hydrogen penetration and India's lower energy taxes limit India's capacity to favour hydrogen. Once available to the (European) energy system, hydrogen can decrease the cost of CO₂ emission reduction by increasing the potential for carbon capture technology. However, climate policy alone is insufficient to speed up the transition. Hydrogen diversifies energy imports; especially for Europe it decreases oil imports, while increasing imports of coal and natural gas. For India, it provides an opportunity to decrease oil imports and use indigenous coal resources in the transport sector. Hydrogen improves urban air quality by shifting emissions from urban transport to hydrogen production facilities. However, for total net emissions we found a sensitive trade-off between lower emissions at end-use (in transport) and higher emissions from hydrogen production, depending on local policy for hydrogen production facilities.     

Photokatalytische Systeme. XXI. Zum Mechanismus der Photoreduktion von Kaliumchromat in Alkoholen

Photocatalytic Systems. XXI. On the Mechanism of the Photoreduction of Potassium Chromate in Alcohols The photolysis of crown ether complexes of potassium chromate in several alcohols has been investigated by e.s.r.-spectroscopy. Two different relatively long-lived Cr(V) intermediates formed by different reaction pathways have been observed. Radicalic oxidation products of the alcohols (alkoxy and hydroxyalkyl radicals as well as fragmentation products) and of the crown ether have been detected by spin trapping.