Reagents introduction

When discussing various methods for the synthesis of protein-like HP-copolymers from the monomeric precursors (Sect. 2.1), we pointed to the possibility of implementation of both polymerization and polycondensation processes. The studies of the potentials of the latter approach in the creation of protein-like macromolecular systems have already been started. The first published results show that using true selected reactions of the polycondensation type and appropriate synthetic conditions (structure and reactivity of comonomers, solvent, temperature, reagent concentration and comonomer ratio, the order of the reagents introduction into the feed, etc.) one has a chance to produce the polymer chains with a desirable set of monomer sequences. 

Depending on the configuration of the device and the method for sample and reagents introduction, it is possible to classify the systems into static (batch or discrete sampling instrument) or flowing stream, both using continuous-flow or stopped-flow systems. 

Fig. 7. Illustration of an automated reagent introduction, reaction and analysis set-up based on the incorporation of a micro-fluidic device into a conventional HPLC system...

Freizer, H., Reactive Groups as Reagents Introduction and Inorganic Applications. In Treatise on Analytical Chemistry, ed. by I.M. Kolthoff and RJ. Elving., 2nd ed. Vol. 3, New York, Interscience Pubishers, 1983. 

To eliminate the effects of external temperature fluctuations in the calorimetric block, the calorimeter has two heat-flow meters, which are connected in opposition. The process under investigation is carried out in one of two identical calorimeter vessels, the other serving as the tare or reference element. This differential arrangement permits the compensation of parasitic phenomena such as external connections and reagent introduction heat, and it provides a good stability of the baseline. (From the development in Section II,A on thermodynamics it follows that for adsorption of gas in a Calvet calorimeter the heat measured corresponds to a differential molar enthalpy of adsorption because all other effects are compensated.)... 

Steel plates surrounding munition protect the 2-in. thick stainless-steel vessel which operates in a vapor containment structure. Detonation and reagent introduction are conducted remotely. Air and liquid effluents are monitored for presence of agent. 

In the first stopped-flow analysers, it was noted that turbulence was approached during the very sudden period of sample and reagent introduction (GO period) and that the reaction medium was stopped (STOP period) for a relatively long time interval [1,3]. Moreover, the authors reported the formation of vortices and their beneficial influence on mixing conditions. It should be stressed that the expression turbulent flow is not appropriate for characterising the flow regime during the GO period because the available time interval is too short to permit the establishment of a steady state situation [155]. 

S.K. Mishra, P.K. Dasgupta, Electrodialytic reagent introduction in flow systems, Anal. Chem. 82 (2010) 3981. 

Electrophoresis, amino acids, ninhydrin, isatin, Sakaguchi reagents. Introduction... 

Another end-column derivatization system involves agap junction reactor, as described byAlbin et al. In the gap junction reactor, two capillaries are separated by a small gap in which the fluorophore is introduced. Careful alignment of the two capillaries ensures that high separation efficiency is maintained at the junction. The gap junction interface is an excellent choice when using high-cost derivates, as smaller volumes can be used for reagent introduction. 

Formation of characteristic fronts macrostructures under liquid flows mixing and fast chemical reactions including polymerization is mainly determined by the ratio of linear speeds of reagents introduction Vi / V2 (Vi - speed of axial flow, V2 - speed of radial flow) and method of their introduction into reaction zone [1,42,44]. 

Figure 2.7. Tubular turbulent apparatus of cylindrical (a, c) and divergent-convergent (b) designs with coaxial (a, b) and radial (c) methods of reagents introduction. Ind - introduction of indicator. Reactors working regimes P - plan front T - torch Z - drift regime.

The method of reception of curves of response to indicator introduction (see 2.2.8) is useful for studying of reagents residence times distribution in reaction zone and estimation of hydrodynamic regime of tubular turbulent apparatus operation with different canal s geometry (cylindrical and divergent-convergent) and reagents introduction way (coaxial and radial). 

The observed dependence of tubular turbulent apparatus work on the way of reagents introduction is explained by the fact that in this case the formation of various reaction fronts macrostructures in mixing zone is possible, in particular planar front (P), torch (T) and drift (Z) etc. (Fig. 2.7c) (see 1.3.1). At that the macrostructure in the form of planar reaction front corresponds to... 

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