Non-in-situ Methods

Some comparisons between the yields of the Mannich reaction of enol silanes using in situ methods for preparation of the iminium salt and non in situ methods are shown in Table 9. Higher yields (20-30%) of P-amino ketones using in situ methods are seen in entries 2 and 4 but not in entry 1. Although a clear advantage of the in situ methods is not evident in these limited examples, in situ methods may be preferred from the standpoint of convenience. With aldehyde enol silanes (entry 3), the in situ method of Miyano et al is less practical due to elimination of the amino group, presumably caused by the strongly basic N,/V,/V, N -tetramethyl(methylene)diamine present in solution. 

Comparison of the Mannich Reactions of Enol Silanes with Af -Dimethyl(methylene)iminium Salts Using In Situ and Non In Situ Methods... 

There are two principal subdivisions in molecular spectroscopy in-situ and non-in-situ methods (2,75). The principal invasive non-in-situ techniques used for soil and aquatic systems are x-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES), and secondary mass spectroscopy (SIMS). Each of these techniques yields detailed information about the structure and bonding of minerals and the chemical species present on the mineral surfaces. 

The chemical stability and electrochemical reversibility of PVF films makes them potentially useful in a variety of applications. These include electrocatalysis of organic reductions [20] and oxidations [21], sensors [22], secondary batteries [23], electrochemical diodes [24] and non-aqueous reference electrodes [25]. These same characteristics also make PVF attractive as a model system for mechanistic studies. Classical electrochemical methods, such as voltammetry [26-28] chronoamperometry [26], chronopotentiometry [27], and electrochemical impedance [29], and in situ methods, such as spectroelectrochemistry [30], the SECM [26] and the EQCM [31-38] have been employed to this end. Of particular relevance here are the insights they have provided on anion exchange [31, 32], permselectivity [32, 33] and the kinetics of ion and solvent transfer [34-... 

Remediation of soil refers to practices of either removing or rendering of contaminants to less mobile - that is, to generate less harmful forms. Methods for remediating metal-polluted soils have been recently broadly investigated and discussed (Adriano et al. 1999, Cunningham and Berti 2000, Iskandar 2001, Knox et al. 2000, Li etal. 2000, Mukherjee 2001, Sparks 1995). The remediation of soils and sites contaminated with radionuclides is of special concern. Several techniques, both in situ and non-in situ, have been applied to clean soils contaminated with trace metals. Due to the complexity of soils and the presence of multiple contaminants, only a few of these techniques... 

The fate of organic contaminants in soils and sediments is of primary concern in environmental science. The capacity to which soil constituents can potentially react with organic contaminants may profoundly impact assessments of risks associated with specific contaminants and their degradation products. In particular, clay mineral surfaces are known to facilitate oxidation/reduction, acid/base, polymerization, and hydrolysis reactions at the mineral-aqueous interface (1, 2). Since these reactions are occurring on or at a hydrated mineral surface, non-invasive spectroscopic analytical methods are the preferred choice to accurately ascertain the reactant products and to monitor reactions in real time, in order to determine the role of the mineral surface in the reaction. Additionally, the in situ methods employed allow us to monitor the ultimate changes in the physico-chemical properties of the minerals. 

Ex situ sampling (non-in situ sampling) is the method (or methods) of sampling coal from a stockpile, a coal train (or other means of transportation), or at the time of entry into the preparation plant, or power plant. 

It is impossible to comprehensively discuss all non-vibrational in situ techniques with a potential application to oxidation catalysts within this chapter. Therefore, we have selected only those methods for a more detailed presentation which have seen a widespread application so far and/or offer unique opportunities for understanding the functioning of real catalysts. For more specific in situ methods, such as the microscopy techniques mentioned above, Mossbauer spectroscopy which is restricted to the viewing of elements only, or thermo-analytical studies using an oscillating microbalance reactor,the reader is referred to the respective reviews. 

In our review we will consider only methods of synthesis of polymer composites. Three main methods were established recently, by which such variety of polymer com K>sites has been obtained The in-situ method or the formation of particles in polymer matrix immersed in aqueous or non aqueous solution involves soluble reagmts trans X)rted into polymer, fixed by matrix containing s )ecific grou s and then reacted with the formation of non-soluble particles the by-products of reaction are extraded by washing. An example of such synthesis is the formation of CuS >artides with the size of 20 nm (SAXS)... 

Another in situ method to access sulfonamides utilises readily accessible aryl and heteroaryl iodides as starting points. In this method, thiobenzoate is coupled with an atyl/heteroatyl iodide to give an aryl/heteroaryl thiobenzoate this intermediate is then oxidised to a sulfonyl chloride under non-acidic conditions (Scheme 18.4). The use of non-acidic oxidising eon-ditions gives the methodology a broad scope as sulfonyl chlorides carrying acid-sensitive funetionalities (such as Boc-protected amine groups) can be readily synthesised (Schemes 18.4 and 18.5). 

Eddy currents The examination of non-ferrous tubing using external coils is a well-tried and successful inspection technique, owing mainly to the pioneering work of Forster in Germany. The adoption of this method for in-situ inspection of condenser tubes, by mounting eddy-current coils in probes (or bobbins) that can be inserted in condenser tubes, was a logical development of the technique. Suitable apparatus was developed in the immediate post-war period more or less independently by several oil and chemical companies. The principle of operation has been described in the literature... 

Non-situ and ex situ studies can provide important information for understanding the properties of metal/electrolyte interfaces. The applicability of these methods for fundamental studies of electrochemistry seems to be firmly established. The main differences between common electrochemical and UHV experiments are the temperature gap (ca. 300 vs. 150 K) and the difference in electrolyte concentration (very high concentrations in UHV experiments). In this respect, experimental research on double-layer properties in frozen electrolytes can be treated as a link between in situ experiments. The measurements of the work functions... 

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