Synergistic phenomena

Synergistic phenomena similar to those described for etching are expected during film formation processes. In particular, the creation of adsorption and nucleation sites, along with the promotion of chemical reactions and the dissociation of adsorbed species because of particle bombardment,... 

Metal ions (C8) such as Co have been studied in conjunction with amino acids and synergistic phenomena have been described (B31). Mg + ions are known to activate many preparations of alkaline phosphatase but this effect differs with the enzyme source. 

Mechanisms of Interaction. The synergistic phenomenon between hindered phenolics and thiodipropionate esters involves free radical scavenging by the phenolic, peroxide decomposition by the sulfide ester and by the products of disproportionation of oxidized forms of the sulfur compound, and finally, regeneration of the phenolic by the disproportionation products. 

In considering these tests it should be remembered that the phenomenon of cavitation-erosion is often accompained by corrosion effects and that a synergistic effect may operate between the mechanically and chemically induced forms of attack. In fact the term cavitation-erosion-corrosion may often be more applicable in describing the requirements of a test procedure. The subject has recently been discussed by Wood etal. °. 

FBAs applied in combination may show a synergistic effect. Synergism is, at present, only of commercial interest with polyester brighteners. This phenomenon is discussed further in section 11.10. Conversely, the presence of a trace impurity in an FBA formulation may greatly reduce its effectiveness. In industrial laboratories much time and effort is expended in developing processes to minimise the content of such impurities or even to eliminate them completely. 

The synergistic action of a phenol and aromatic amine mixture on hydrocarbon oxidation was found by Karpukhina et al. [16]. A synergistic effect of binary mixtures of some phenols and aromatic amines in oxidizing hydrocarbon is related to the interaction of inhibitors and their radicals [16-26]. In the case of a combined addition of phenyl-A-2-naphthylamine and 2,6-bis(l,l-dimethylethyl)phenol to oxidizing ethylbenzene (v, = const, 343 K), the consumption of amine begins only after the phenol has been exhausted [16], in spite of the fact that peroxyl radicals interact with amine more rapidly than with phenol (7c7 (amine) = 1.3 x 105 and /c7 (phenol) = 1.3 x 104 L mol 1 s respectively 333 K). This phenomenon can be explained in terms of the fast equilibrium reaction [27-30] ... 

Dative and synergistic complexation of dihydrogen Direct observation of complexation of molecular H2 at metal centers is a relatively recent phenomenon. Virtually all such complexes exhibit relatively minor elongation of the H—H bond, indicating that description of these species as molecular-H2 complexes (rather than, e.g., metal dihydrides or some intermediary resonance mixture) is well justified. Experimentally observed molecular H2 complexes of the synergistic type are common, but those of simple dative type are not. 

The study of electrosynthetic reactions is not a new phenomenon. Such reactions have been the study of investigation for more than a century and a half since Faraday first noted the evolution of ethane from the electrolysis of aqueous acetate solutions. This reaction is more well known as the Kolbe electrolysis [51]. Since the report of Kolbe, chemists have had to wait nearly a century until the development, in the 1960 s, of organic solvents with high-dielectric which have been able to vastly increase the scope of systems that could be studied [52]. Added to this more recently is the synergistic effect that ultrasound should be able to offer in the improvement of the expected reactions by virtue of its ability to clean of surfaces, form fresh surfaces and improve mass transport (which may involve different kinetic and thermodynamic requirements)... 

Let us now proceed to umami substances. Monosodium glutamate, di sodium inosinate and disodium guanylate exhibit umami. Umami is a Japanese term implying "deliciousness of meat, mushrooms, some vegetables and cheese, but is now acknowledged widely as the fifth taste [5], Umami substances exhibit a very interesting phenomenon, i.e., a synergistic effect. In the coexistence of MSG and IMP, we experience drastic increase in umami. 

Two-way analysis of variance (and higher classifications) leads to the presence of interactions. If, for example, an additive A is added to a lube oil stock to improve its resistance to oxidation and another additive, B, is added to inhibit corrosion by the stock under load or stress, it is entirely possible that the performance of the lube oil in a standard ball-and-socket wear test will be different from that expected if only one additive has present. In other words, the presence of one additive may adversely or helpfully affect the action of the other additive in modifying the properties of the lube oil. The same phenomenon is clearly evident in a composite rocket propellant where the catalyst effect on burning rate of the propellant drastically depends on the influence of fine oxidizer particles. These are termed antagonistic and synergistic effects, respectively. It is important to consider the presence of such interactions in any treatment of multiply classified data. To do this, the two-way analysis of variance table is set up as shown in Table 1.24. 

Synergism A phenomenon in which exposure to more than one chemical can result in health effects greater than expected when the effects of exposure to each chemical are added together. In simple terms 1 + 1 = 3. If chemicals have synergistic properties, the potential hazards of the chemicals should be reevaluated, considering their synergistic properties. 

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