Wirkungsgrade in der Welt des Lebens und der Technik

Zusammenfassung Um der oft gehörten Meinung entgegenzutreten, die energetischen Wirkungsgrade lebender Organismen seien wesentlich höher als die technischer Verfahren, werden entsprechende Werte miteinander verglichen. Der sehr niedrige Wirkungsgrad der Photosynthese zusammen mit der kleinen Energiedichte der Sonnenstrahlung erzwang ab einer kritischen Größe die Aufspaltung in Energiesammler, die Pflanzen, und Verbraucher chemischer Energie, den Tieren. Dank den 10 mal höheren Wirkungsgraden in der Technik, lassen sich Solarmobile bauen, die von der auf sie fallenden Sonnenstrahlung angetrieben werden. Wegen des Multiplikationsgesetzes der Teilwirkungsgrade ergeben sich sowohl für die Speicherung der Sonnenenergie in den fossilen Brennstoffen wie in der Nahrungskette extrem niedrige Wirkungsgrade.

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Efficiencies in the world of life and in engineering

One often hears the opinion, that the efficiencies in the world of life are higher than in engineering. To disprove this, many values of efficiency of corresponding processes are compared. The very low efficiency of photosynthesis in living plants together with the low density of solar radiation has led the world of life to split into collectors of energy, the plants, and consumers of chemical energy, the animals. Thanks to the ten times higher efficiencies of solar cells, it is possible, to produce solar mobiles, vehicles that move driven by solar radiation.

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Herrn Prof. Dr.-Ing. U. Grigull zum 75. Geburtstag gewidmet     

Etude de la reactivite d'ylures de sulfonium et de pyridinium stabilises par un groupement cyanoformyle

The sulfonium and pyridinium ylides stabilized by a cyanoformyl group, in an acidic medium, lead to sulfonium and pyridinium salts which are equivalents of pyridinium or sulfonium ketene salts. This originality has been used to prepare new stabilized ylides, or derivatives of substituted arylacetic acids or 4-hydroxy thiazoles.     

Intelligent driving in traffic systems with partial lane discipline

It is a most common notion in traffic theory that driving in lanes and keeping lane changes to a minimum leads to smooth and laminar traffic flow, and hence to increased traffic capacity. On the other hand, there exist persistent vehicular traffic systems that are characterised by habitual disregarding of lane markings, and partial or complete loss of laminar traffic flow. Here, we explore the stability of such systems through a microscopic traffic flow model, where the degree of lane-discipline is taken as a variable, represented by the fraction of drivers that disregard lane markings completely. The results show that lane-free traffic may win over completely ordered traffic at high densities, and that partially ordered traffic leads to the poorest overall flow, while not considering the crash probability. Partial order in a lane-free system is similar to partial disorder in a lane-disciplined system in that both lead to decreased traffic capacity. This could explain the reason why standard enforcement methods, which rely on continuous increase of order, often fail to incur order to lane-free traffic systems. The results also provide an insight into the cooperative phenomena in open systems with self-driven particles.     

Thermodynamical Description of Modified Generalized Chaplygin Gas Model of Dark Energy

We consider a universe filled by a modified generalized Chaplygin gas together with a pressureless dark matter component. We get a thermodynamical interpretation for the modified generalized Chaplygin gas confined to the apparent horizon of FRW universe, whiles dark sectors do not interact with each other. Thereinafter, by taking into account a mutual interaction between the dark sectors of the cosmos, we find a thermodynamical interpretation for interacting modified generalized Chaplygin gas. Additionally, probable relation between the thermal fluctuations of the system and the assumed mutual interaction is investigated. Finally, we show that if one wants to solve the coincidence problem by using this mutual interaction, then the coupling constants of the interaction will be constrained. The corresponding constraint is also addressed. Moreover, the thermodynamic interpretation of using either a generalized Chaplygin gas or a Chaplygin gas to describe dark energy is also addressed throughout the paper.     

9-Methyl-cis-decalin-1,3-dion: Stereochemische Untersuchungen an 9-Methyl-cis-decalin-Derivaten. 5. Mitteilung über cyclische β-Diketone

The synthesis and the spectral properties of the hitherto unknown 9-methyl-cis-decalin-1,3-dione ( 16 ) are described. The keto-enol equilibrium of 16 in various solvents was determined by NMR. spectroscopy. The configuration and conformation of a large number of intermediates and derivatives were determined.     

Synthesis of C-C-bridged bis-isoflavones

Unique C-C-bridged bis-isoflavones 5, 8, and 9 were obtained by reaction of 2-bromomethyl-7,4'-dimethoxyisoflavone 4 with ethyl cyanoacetate anion or tetraethylammonium cyanide or by Pd-catalyzed ethoxycarbonylation, respectively. The phenolic carboxylic acid 7 is available from 5 in two steps.     

Synthesis of the Deuterium Labeled Isoflavone-<Emphasis Type="Italic">O</Emphasis>-glucoside 8,3′,5′-D<Subscript>3</Subscript>-Daidzin

The regio- and stereospecific glycosylation of 8,3′,5′-trideuterodaidzein 1 with α-acetobromoglucose to provide 8,3′,5′-trideuterodaidzein-7-O-β-glucopyranoside 2 is presented.     

Bright Red Organic Electroluminescent Devices Based on a Soluble Rare Earth Complex Eu(TTA)_3 Phen

ＩｎｔｒｏｄｕｃｔｉｏｎＯｒｇａｎｉｃｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｔ（ＥＬ）ｄｅｖｉｃｅｓｈａｖｅｂｅｃｏｍｅｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｓｕｂ－ｊｅｃｔｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎａｓｌ...     

Optimierung einer Kalium-Valinomycin-Diskelektrode

Zusammenfassung Es wird über die Optimierung einer Kalium-Valinomycin-Diskelektrode durch den kombinierten Zusatz verschiedener Weichmacher berichtet. Die Inkorporation dreier Weichmacher (Diphenyläther, Dinonylphthalat, Trisäthylhexylphosphat) in die PVC-Membran führt zu einer Elektrode, die wesentliche Funktionskriterien für eine Anwendung in der klinischen Analytik erfüllt.

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Optimization of a potassium-valinomycin disc electrode

Summary Optimization of a potassium valinomycin disc electrode by adding a combination of several plasticisers is reported. Incorporation of three plasticisers (diphenyl ether, dinonyl phthalate, trisethylhexyl phosphate) into the PVC membrane results in an electrode, which has all qualities for application in clinical analysis.

Wir danken dem Fonds der Chemischen Industrie und der Firma Fresenius Apparatebau KG, Bad Homburg v.d.H., für die Unterstützung dieser Arbeit.