Meyer hardness

Pavlov GM, Korneeva EV, Jumel K, Harding SE, Meyer EW, Peerlings HWl, Stod-dart JF, Nepogodiev SA (1999) Carbohyd Polym 38 195... 

Id. The Ideal Rubber.—The data available at present as summarized above show convincingly that for natural rubber (dE/dL)T,v is equal to zero within experimental error up to extensions where crystalhzation sets in (see Sec. le). The experiments of Meyer and van der Wyk on rubber in shear indicate that this coefficient does not exceed a few percent of the stress even at very small deformations. This implies not only that the energy of intermolecular interaction (van der Waals interaction) is affected negligibly by deformation at constant volume—which is hardly surprising inasmuch as the average intermolecular distance must remain unchanged—but also that con-... 

Meyer, M. C., Straughn, A. B., Mhatre, R. M., et al. The effect of gelatin cross-linking on the bioequivalence of hard and soft gelatin acetaminophen capsules. Pharm. Res. 17 962-966, 2000. 

In other words there is a tendency to abandon those locations which Prof. Dr. R. van Pelt called the absolute center in the "geography of atrocities (see page 91), or even the Birkenau crematoria altogether, since, according to Meyer the genocide is now supposed to have taken place mainly in those ominous farmhouses or bunkers of which we possess hardly any documentary evidence. 

Hardness and a ductile-to-brittle transition temperature (DBTT) have also been noted to follow a Hall-Petch relationship (Meyers, and Chalwa, 1984). Ductility increases as the grain size decreases. Decreasing grain size tends to improve fatigue resistance but increases creep rate. Electrical resistivity increases as grain size decreases, as the mean free path for electron motion decreases. 

This equation was first used by Born, Huggins, and Meyer and therefore bears their names. The first two terms represent, respectively, the attractive and repulsive potentials. The last two terms represent dipole-dipole and dipole-quadrupole potentials, respectively. In spite of allowing for the dipole interactions, the calculation is still a hard-sphere one, a mean spherical approximation, because the forces are not allowed to change the shape and the position of the particles. Later on, Saboungi et al. 

Hard, W., Beck, C., Roth, M., Meyer, F. and Hempelmann, R. (1997) Berichte Der Eunsen-Gesellschaft-Physical Chemistry Chemical Physics, 101 (11), 1714-17. 

Figure 11.21 Predictions of the dimensionless Frank constants for hard rods as functions of reduced concentration nL"dv/A, using a numerical solution of the Onsager equation. At the concentration v = v, the abscissa has the value n L Ju/4 = 4. (From Lee and Meyer, reprinted with permission from J. Chem. Phys. 84 3443, Copyright 1986, American Institute of Physics.)...

In the Brinell test (Brinell, 1900 Meyer, 1908) the indenter consists of a hard steel ball, though in examining very hard metals the spherical indenter may be made of tungsten carbide or even of diamond. Another type of indenter which has been widely used is the conical or pyramidal indenter as used in the Ludwik (1908) and Vickers (see Smith Sandland (1925)) hardness tests, respectively. These indenters are now usually made of diamond. The hardness behaviour is different from that observed with spherical indenters. Other types of indenters have, at various times, been described, but they are not in wide use and do not involve new principles. 

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