Zinc matrix

In the couples of the type shown in Fig. 3.12b the cohesion between dissimilar metals after prolonged isothermal annealing was so poor that the nickel or cobalt plate could be taken out without any effort by hand from the zinc matrix. Therefore, more or less acceptable kinetic data were only obtained with the couples of the type shown in Fig. 3.12c, in which the nickel or cobalt plate is seen to be surrounded by the zinc phase. However,... 

Photoelectron spectra of the methyl halides have also been studied in the condensed phase (zinc matrix)78. The ionization bands are broad relative to the gas and are shifted ca 1 eV towards lower ionization energies. This polarization shift is slightly larger for a ionizations than for halogen lone-pair ionizations. 

Aluminium 309.3 nitrous oxide/ acetylene Add 2000Mg ml-1 potassium to sample solutions to suppress ionisation. Use a standard additions procedure to avoid interference from the zinc matrix... 

A neutralization of impurities is probably what takes place when brass and red brass are treated with sodium. The cleanser is usually introduced as a zinc-sodium master alloy. Zinc dissolves not more than 2.8% sodium at 557° C. and this alloy, when solid, is constituted of zinc-sodium compound in a zinc matrix. An action of sodium on sulfides, antimonides, and arsenides, even if these impurities were tied up with zinc, could be expected in these copper alloys. Sodium has been suggested as a desulfurizer for cast iron and shooting it into the metal bath has been proposed. In another proposition the sodium is weighed down with lead within an iron shell with a perforated bottom, which is lowered into the fused cast iron. Evidently sodium-lead alloy would perform as well. 

Linear thin y layer next to the steel with a narrow layer of coherent 8 phase, above which is a region of fragmented 8 in a zinc matrix interspersed above this are large isolated crystals of pronounced idiomorphic habit (e.g., silicon). 

Finally, from x = 0.98 until x = 1.0, a solution of copper in the zinc matrix is observed. The regions of homogeneous solutions are examples of Hume-Rothery s third rule. The higher valent atom (zinc) is more soluble in the lower valent solvent (copper) then vice versa. 

Figure 12.2 Co-deposition of mica flakes in a zinc matrix. ...

The donor concentrations in the order of 10 cm are relatively high but typical for many passive films, and the increase of Njj with the cobalt content is in accordance with the formation of additional inter-band states by alloying of the zinc matrix. The results also show that the properties of passive films of Zn-Co and Zn-Ni alloys are not fully compatible with the simple Mott-Schott-ky relation. The observed deviations may be explained by a distribution of energetically different electronic states within the band gap, according to the theory of Stimming et al. (Dean and Stimming, 1987). These states were not detected by photo-electrochemical measurements. This is another example that demonstrates the effect of inhomogeneities localized at the interface of electrode surfaces. 

Meketa, M.L. and Weinreb, S.M. (2007a) A new total synthesis of the zinc matrix metalloproteinase inhibitor ageladine A featuring a biogenetically patterned 6n-2-azatriene electrocydization. Org. Lett., 9, 853-855. 

In commercial alloys, 2inc is usually dissolved in the magnesium matrix and in the hard magnesium—aluminum phase when aluminum is present. Zinc additions to magnesium—aluminum alloys change the eutectic stmcture to a so-called divorced eutectic, characteri2ed by the presence of massive compound particles surrounded by a magnesium-rich sohd solution. 

A sintered friction material is composed of a metal matrix, generally mainly copper, to which a number of other metals such as tin, zinc, lead, and iron are added. Important constituents include graphite and friction-producing components such as siHca, emery, or asbestos. 

Copper, with its high heat conductivity, resists frictional heat during service and is readily moldable. It is generally used as a base metal, at 60—75 wt %, whereas tin or zinc powders are present at 5—10 wt %. Tin and zinc are soluble in the copper, and strengthen the matrix through the formation of a soHd solution during sintering. 

Metals such as copper, iron, or a combination of the two, usually modified with tin, bismuth, and/or lead ate used as binders of sintered friction materials where deformation under the high forming pressure is requited to lock together the property modifiers within a matrix. Metals such as copper, iron, zinc, aluminum, and occasionally lead are also used as friction modifiers. 

Thus, it can be concluded that in the present iono-mer system, zinc stearate plays a dual role. First, below its melting point it reinforces the matrix and strengthens the ionic aggregates and, second, at a higher temperature it results in solvation of the ionic aggregates and plasticizes the system, thus, facilitating the transition from the rubbery state to the viscous flow state [23]. 

We have carried out impurity calculations for a zinc atom embedded in a copper matrix. We first perform self consistent band theory calculations on pure Cu and Zn on fee lattices with the lattice constant of pure Cu, 6.76 Bohr radii. This yields Fermi energies, self consistent potentials, scattering matrices, and wave functions for both metals. The Green s function for a system with a Zn atom embedded in a Cu matrix... 

The pneumatic tire has the geometry of a thin-wallcd toroidal shell. It consists of as many as fifty different materials, including natural rubber and a variety ot synthetic elastomers, plus carbon black of various types, tire cord, bead wire, and many chemical compounding ingredients, such as sulfur and zinc oxide. These constituent materials are combined in different proportions to form the key components of the composite tire structure. The compliant tread of a passenger car tire, for example, provides road grip the sidewall protects the internal cords from curb abrasion in turn, the cords, prestressed by inflation pressure, reinforce the rubber matrix and carry the majority of applied loads finally, the two circumferential bundles of bead wire anchor the pressnrized torus securely to the rim of the wheel. 

The most satisfactory solution to this problem is to employ a corrosion-resistant alloy, and alloys of the gun-metal type, containing 2-4% zinc, have proved completely satisfactory. The substitution of zinc for phosphorus gives sounder castings and improves the corrosion resistance of the copper-rich matrix. 

Both silicon and aluminium are added to zinc to control the adverse effects of iron. The former forms a ferro-silicon dross (which may be removed during casting). Aluminium forms an intermetallic compound which is less active as a cathode than FeZn,] . Similarly in aluminium and magnesium alloys, manganese is added to control the iron . Thus in aluminium alloys for example, the cathodic activity of, FeAl, is avoided by transformation of FeAlj to (Fe, Mn)Al/. This material is believed to have a corrosion potential close to that of the matrix and is, therefore, unable to produce significant cathodic activity . 

Manganese, D. of - continued with magnesium and zinc, (ti) 334 Mannitol 299, 581 Masking agents 12, 312 Mass action law 16 applications to electrolyte solutions, 23 Matrix effects 733, 794 Maxima in polarography 597 suppression of, 597, 611 Mean deviation 134 relative, 134 standard, 134 Measuring cylinders, 87 flasks, 81... 

Cell suspensions which were exposed to 1.0 ppm zinc were combined, and to this matrix known amounts of Zn were added, to allow measurement of the amount of zinc accumulated by the cells via GFAA. In related work, cells treated with known concentrations of zinc solutions were systematically combined and thereby "diluted" with cells not exposed to zinc, to determine If GFAA and EMI analyses yield confirmatory results. 

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