Succession, establishment phase

The application of phase-transfer catalysis to the Williamson synthesis of ethers has been exploited widely and is far superior to any classical method for the synthesis of aliphatic ethers. Probably the first example of the use of a quaternary ammonium salt to promote a nucleophilic substitution reaction is the formation of a benzyl ether using a stoichiometric amount of tetraethylammonium hydroxide [1]. Starks mentions the potential value of the quaternary ammonium catalyst for Williamson synthesis of ethers [2] and its versatility in the synthesis of methyl ethers and other alkyl ethers was soon established [3-5]. The procedure has considerable advantages over the classical Williamson synthesis both in reaction time and yields and is certainly more convenient than the use of diazomethane for the preparation of methyl ethers. Under liquidrliquid two-phase conditions, tertiary and secondary alcohols react less readily than do primary alcohols, and secondary alkyl halides tend to be ineffective. However, reactions which one might expect to be sterically inhibited are successful under phase-transfer catalytic conditions [e.g. 6]. Microwave irradiation and solidrliquid phase-transfer catalytic conditions reduce reaction times considerably [7]. 

Pertinent examples of the value of dimensional analysis have been reported in a series of papers by Maa and Hsu (19,37,63). In their first report, they successfully established the scale-up requirements for microspheres produced by an emulsification process in continuously stirred tank reactors (CSTRs) (63). Their initial assumption was that the diameter of the microspheres, <7ms, is a function of phase quantities, physical properties of the dispersion and dispersed phases, and processing equipment parameters ... 

Most of these enzymatic ways to regenerate nicotinamide cofactors have been successfully established in a multitude of synthetic processes. The introduction of organic-water two-phase systems seems to be a useful method to overcome problems with the low solubility of many organic substrates. Bioconversions using whole cells have been well investigated because they show some decisive advantages like increased enzyme stability. The use of recombinant DNA techniques offers a wide field of application. Tailor-made cells can be created to perform whole cell biotransformations efficiently. 

A fast, reliable, and specialized CFD model for PEM fuel cell simulation can be very useful in fuel cell design optimization and operation control. In this project, a unified PEM fuel cell simulation model has been successfully established. This project started in FY 2000 with 2-D single-phase models. In FY 2001, the 2-D models were successfully transformed into a unified 3-D model for hydrogen feed. In FY 2002, this established 3-D model was extended to include reformate feed, accounting for the poisonous effect of carbon monoxide as well as the dilution effect of the reformate gas stream on the anode side. Based on this 3-D model with the geometry of a single fuel cell, a preliminary stack model was established. Extensive experiments in our lab and industry interactions were carried out to improve and calibrate the computation model. 

At the time Murata s study was reported, the solution structure of acyclic portions of the okadaic acid structure were not known despite extensive NOE measurements coupled with distance geometry calculations. Using Jhh coupling constants measured from E. COSY data and "Jch (" = 2, 3), determined predominantly from HETLOC spectra for the contiguous protonated carbon portions of the molecule and phase-sensitive HMBC data for segments containing quaternary carbons, Murata and co-workerswere able to successfully establish the solution structure of okadaic acid. 

It is the advantage of the cholesteric phase that its pitch and thereby the wavelength of the emitted laser light can be tuned by various external stimuli (usually the temperature). Lasers relying on a cholesteric feedback medium have usually a very narrow line width and their emission is circularly polarized. With this concept, rather small lasers can be constructed [97, 98]. They are usually pumped by pulsed solid-state lasers although, after first attempts [99], continuous pump conditions were recently successfully established [100]. Lasing has been mostly observed from low molar mass cholesteric mixtures because they show excellent alignment. The state of the art is reviewed in [98, 101, 102]. 

In the present study, it has been highlighted that SIMS data in association with high-quality structural data and information derived from other complementary techniques allows the crystal chemical properties of difficult mineral phases to be successfully established. Moreover, a SIMS study of inhomogeneous samples at the micrometer scale can provide insightful relationships between their crystal chemistry and the volcanological processes to which they have partaken. 

The resolution of optically active compounds by gas chromatography with chiral phases is a well-established procedure, and the separation of Al-perfluoto-acetylated ammo acid ester enantiomers m 1967 was the first successful application of enantioselective gas-liquid chromatography [39] Ammo acids have been resolved as their A -trifluoroacetyl esters on chiral diamide phases such as N-lauroyl-L-valineferf-butylamideorAl-docosanoyl-L-valme /ez-r-butylamide [40,41,... 

Like other surfactants, alkanesulfonates generate lyotropic liquid-crystalline phases. But the phase equilibria can only be inadequately described because of the enormous experimental difficulties in, for instance, establishing an appropriate equilibrium. Nevertheless, for simple ternary systems the modeling of surfactant-containing liquid-liquid equilibria has been successfully demonstrated [60],... 

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