Untersuchung von Fetten und ?len

Ohne Zusammenfassung     

Ebullioskopie

Ohne Zusammenfassung     

Loans,ordering and shortage costs in start-ups: a dynamic stochastic decision approach

Start-up companies are a vital ingredient in the success of a globalised networked world economy. We believe that such companies are interested in maximising the chance of surviving in the long term. We present a Markov decision model to analyse survival probabilities of start-up manufacturing companies. Our model examines the implications of their operating decisions, in particular how their inventory strategy is influenced by purchasing, shortage, transportation and ordering costs, as well as loans to the firm. It is shown that although the start-up company should be more conservative in its component purchasing strategy than if it were a well-established company it should not be too conservative. Nor is its strategy monotone in the amount of capital available.     

Temperature and pressure dependence of the rate coefficient for the reaction between ClO and CH3O2 in the gas-phase

A temperature and pressure kinetic study for the CH(3)O(2) + ClO reaction has been performed using the turbulent flow technique with a chemical ionisation mass spectrometry detection system. An Arrhenius expression was obtained for the overall rate coefficient of CH(3)O(2) + ClO reaction: k(10)(T) = (1.96(?0.24)(+0.28)) × 10(-11) exp[(-626 ± 35)/T] cm(3) molecule(-1) s(-1) where the uncertainty associated with the rate coefficient is given at the one standard deviation level. Over a range of pressure (100-200 Torr) and temperature (298-223 K) no pressure dependence is observed. The smaller rate coefficients measured at lower temperatures compared with both previous low temperature studies are believed to arise through the reduction of secondary chemistry and greater sensitivity in terms of reactant detection (hence much lower initial concentrations were employed). These new data reduce the effectiveness of ozone loss cycles involving reaction of CH(3)O(2) + ClO in the polar stratosphere by around a factor of 1.5 and restrict the importance of the reaction to the tropical and extra-tropical clean marine environments in the troposphere.     

Synthesis and structure of tetrakis(isopropylimino)bis-[tris(dimethylamino)silylamino]alane

A novel cage-type compound tetrakis(isopropylimino)bis[tris(dimethylamino)silylamino]alane, H₆Al₆(NⁱPr)₄[NSi(NMe₂)₃]₂, (1), was prepared by reaction of tris(dimethylamino)silylamine H₂NSi(NMe₂)₃ with poly(isopropyliminoalane) (HAlNⁱPr)₆. The molecular structure of 1 was determined and discussed on the basis of FTIR, NMR and X-ray crystallographic analysis.