Eutectic local

Continued exposure of the nickel-chromium alloy to more severely sulphurising and reducing atmospheres results in local depletion of chromium to such an extent that nickel sulphide and the eutectic are formed internally. The latter constituents are not often observed in service failures, but the relative instability of nickel sulphide in the presence of chromium sulphide can result in its reduction to nickel during slow cooling on shut down. That nickel sulphide is formed is suggested by the frequent occurrence of blisters, associated with the formation of molten eutectic on the surface of sulphur-attacked specimens . 

Vehicles for local delivery journeys tend to he in use only in the daytime and spend the night static. Cooling systems can run from a mains electricity supply providing they can hold a sufficiently low temperature while on the road. Use is made of eutectic plates (see Section 7.5) and of cooling the vehicle hody only when in the garage, relying on the cold mass of produce and good insulation to... 

Reports of kinetic studies do not always include an explicit statement as to whether or not the reactant melted during reaction or, indeed, if this possibility was investigated or even considered (cf. p. 1). This aspect of behaviour is important in assessing the mechanistic implications of any data since reactions in a homogeneous melt, perhaps a eutectic, usually proceed more rapidly than in a crystalline solid. It is accepted that the detection of partial or localized melting can be experimentally difficult, but, in the absence of relevant information, it is frequently impossible to decide whether a reported reaction proceeds in the solid phase. 

Sn + Pb is a two-phase eutectic system in which fine crystals of Pb with a linear parameter of 0.01 to 0.02 fim are localized along the grain boundaries of large Sn crystals (3 to4//m). A comparison of experimental... 

Similar to Voltaren" Emulgel, oily droplets of an eutectic mixture of lidocaine and prilocaine are dispersed in a hydrogel to provide local anesthesia to the skin for injections and siugical treatment (Emla cream). A further possibility is the dermal administration of a liposome dispersion as a spray (Heparin PUR ratiopharm Spriih-gel "). After administration, water and isopropylic alcohol evaporate partially resulting in an increase of concentration and in a transition from the initial liposome dispersion into a lamellar liquid crystal [32]. The therapeutic effect appears to be influenced favorably by the presence of lecithins rather than by the degree of liposome dispersion. 

Both solid-solid and solid-gas types of reactions lead from solid reactants to a solid product without the use of solvents. Solvent-less processes, however, are not necessarily solid-state processes. Indeed, it has been argued [8d,e] that many solid-state syntheses cannot be regarded as bona fide solid-solid reactions because they occur with the intermediary of a liquid phase, such as a eutectic phase or a melt, or may require destruction of the crystals prior to reaction. This latter situation is often observed, for instance, in the case of reactions activated by co-grinding, since the heat generated in the course of the mechanochemical process can induce local melting at the interface between the different crystals, or when kneading, i.e. grinding in the presence of small amounts of solvent, takes place (vide infra). 

III.b.8.1. Skin. Surface anaesthesia of the skin can be produced with help of a cream containing a eutectic mixture of local anaesthetics (EMLA), which is a water/oil emulsion of equal parts of prilocaine and lidocaine with particularly good penetration capacity. EMLA is applied under occlusion, around 40-60 minutes before the planned intervention. This is an effective way of producing anaesthesia before needle punctures and minor, painful, procedures. The method is excellent, particularly in paediatrics, to reduce fear and pain. 

EMLA cream (lidocaine 2.5% and prilocaine 2.5%) consists of a eutectic mixture of focal anesthetics. It is used to provide topical anesthetic to intact skin. Other topical preparations are effective only on mucosal surfaces. EMLA has been shown to reduce pain on venipuncture and provide substantial anesthesia for skin graft donor sites. No significant local or systemic toxicity has been demonstrated. 

Since the work of Edwards et al. a vast array of molten salts has been studied, including mixtures and eutectics [2-5]. Beyond the binary ionic melt there are two important factors affecting the local order of the system, namely, the covalency of the interaction between unlike ions and the stoichiometry... 

Naturally, the fixed composition phase transformations treated in this section can be accompanied by local fluctuations in the composition field. Because of the similarity of Fig. 17.3 to a binary eutectic phase diagram, it is apparent that composition plays a similar role to other order parameters, such as molar volume. Before treating the composition order parameter explicitly for a binary alloy, a preliminary distinction between types of order parameters can be obtained. Order parameters such as composition and molar volume are derived from extensive variables any kinetic equations that apply for them must account for any conservation principles that apply to the extensive variable. Order parameters such as the atomic displacement 77 in a piezoelectric transition, or spin in a magnetic transition, are not subject to any conservation principles. Fundamental differences between conserved and nonconserved order parameters are treated in Sections 17.2 and 18.3. 

A significant number of studies have characterized the physical properties of eutectic-based ionic liquids but these have tended to focus on bulk properties such as viscosity, conductivity, density and phase behavior. These are all covered in Chapter 2.3. Some data are now emerging on speciation but little information is available on local properties such as double layer structure or adsorption. Deposition mechanisms are also relatively rare as are studies on diffusion. Hence the differences between metal deposition in aqueous and ionic liquids are difficult to analyse because of our lack of understanding about processes occurring close to the electrode/liquid interface. 

The discovery of evidence of liquid water-ammonia eutectics on Titan provides a context for the potential for polar fluids outside what is normally regarded as the habitable zone. The stay of the Cassini-Huygens mission on the surface of Titan was brief, but this moon of Saturn is the locale that is most likely to support exotic life. The committee believes that it is important to consider whether the planned missions to the solar system should be reordered to permit returning to Titan earlier than now scheduled. 

Figure 4. Section of the pseudobinary phase diagram of the sulfuric acid SLP catalytic material. The data were taken from Ref. 16. The data points were derived from anomalies of the conductivity versus temperature curves of the respective mixtures. At the high compositional resolution and in the range of the global eutectic, the formation of a vanadate-sulfato complex causes the local maximum in the solidus curve. It is noted that extreme precision in the experimental procedures was necessary to derive this result illustrating the characteristic of fused systems that compound formation can well occur in the molten state.

Cordoni, A., and Cordoni, L. E. (2001), Eutectic mixture of local anesthetics reduces pain during intravenous catheter insertion in the pediatric patient, Clin. J. Pain, 17, 115-118. 

The troubles we encountered here were predictable and not so drastic as seen in the eutectic crystalline freeze-drying of CET. As a whole, the production in the commercial size dryer went well but a small number of the vials were moved to secondary drying, holding free water locally due to the variation of freezing or drying as described before. The fortuitous occurrence of product defect such as local evacuation or local high-water-content spot was unavoidable. 

Prilocaine is an aminoamide local anesthetic. It can be used on its own, but it is also included in Emla in a eutectic combination with lidocaine (25 mg/ml each), which is widely used as a local anesthetic in topical administration for, for example, superficial surgery and venepuncture. 

Sinisterra S, Miravet E, Alfonso 1, Soliz A, Papazian O. Methemoglobinemia in an infant receiving nitric oxide after the use of eutectic mixture of local anesthetic. J Pediatr 2002 141(2) 285-6. 

Altai N, Brasseur L, Chauvin M, Bouhassira D. Effects of single and repeated applications of a eutectic mixture of local anaesthetics (EMLA) cream on spontaneous and evoked pain in post-herpetic neuralgia. Pain 1999 81(l-2) 203-9. 

A B-rich liquid forms at the reaction interface with the B4C as a result of this temperature rise. The first B-rich liquid in the system outside of molten boron occurs at 2165°C from eutectic reaction of B4C, C, and ZrCl (l. On further local heating (T > 2220°C), a continuous B-rich liquid can form between pure boron and the eutectic liquid. The exact composition of the B-rich liquid is unknown, but it appears to lie somewhere within the triangle formed by B4C, C, and ZrB2. 

---