Stresses experimental studies

G04 Y.M. Gupta, Theoretical and Experimental Studies to Develop a Piezoelectric Shear Stress Interface Gage, SRI International Report, 1984. 

The existence of asperity contacts in mixed lubrication causes great many local events and significant consequences. For example, the parameters describing lubrication and contact conditions, such as film thickness, pressure, subsurface stress, and surface temperature, fluctuate violently and frequently over time and space domain. It is expected that these local events would have significant effects on the service life of machine elements, but experimental measurements are difficult because of the highly random and time-dependent nature of the signals. Only a few successes were reported so far in experimental studies of mixed lubrication, mostly limited to the artificially manufactured... 

S. Montes, J.L. White, N. Nakajima, F.C. Weissert, and K. Min, An experimental study of flow and stress fields in a pressurized Mooney viscometer. Rubber Chem. TechnoL, 61, 698-716, 1988. 

The effects of the different stresses mentioned in Sect. 4.1.3 cannot be determined individually by experimental studies, so that only collective conclusions are possible. Of practical interest are the effects of the gas velocity, the geometry of the gas distributor, and the filling height. 

Various types of work in addition to pV work are frequently involved in experimental studies. Research on chemical equilibria for example may involve surfaces or phases at different electric or magnetic potentials [11], We will here look briefly at field-induced transitions, a topic of considerable interest in materials science. Examples are stress-induced formation of piezoelectric phases, electric polarization-induced formation of dielectrica and field-induced order-disorder transitions, such as for environmentally friendly magnetic refrigeration. 

More recently, arguments for the origin of Amontons s law have arisen that are based on experimental studies demonstrating that the shear stress as varies with the local pressure P according to Eq. [4]... 

We wish to stress that comparison of the isotopic effects in biologic and abiologic systems will be most meaningful if experimental conditions are identical, where the only difference is the presence or absence of bacteria. The wide variety of buffers, growth media, and others conditions that are involved in biological experiments raise the possibihty that spurious results may be obtained if these factors are not carefully controlled. Because speciation may exert a strong control on Fe isotope fractionations (Schauble et al. 2001), even small differences across experimental studies may be significant. 

Altinkaynak, A., Gupta, M., Spalding, M.A., and Crabtree, S.L, An Experimental Study on Shear Stress Characteristics of Polymers in Single-Screw Extruders, SPE ANTEC Tech. Papers, 53, 395 (2007)... 

Inflamed tissue associated with an oxidative stress as a consequence of a disbalance in the pro-oxidant/antioxidant homeostasis in chronic wounds is thought to drive a deleterious sequence of events that finally results in the non-healing state [29]. Experimental studies showed that wounds of delayed healing type are accompanied... 

Since fluid shear rates vary enormously across the radius of a capillary tube, this type of instrument is perhaps not well suited to the quantitative study of thixotropy. For this purpose, rotational instruments with a very small clearance between the cup and bob are usually excellent. They enable the determination of hysteresis loops on a shear-stress-shear-rate diagram, the shapes of which may be taken as quantitative measures of the degree of thixotropy (G3). Since the applicability of such loops to equipment design has not yet been shown, and since even their theoretical value is disputed by other rheologists (L4), they are not discussed here. These factors tend to indicate that the experimental study of flow of thixotropic materials in pipes might constitute the most direct approach to this problem, since theoretical work on thixotropy appears to be reasonably far from application. Preliminary estimates of the experimental approach may be taken from the one paper available on flow of thixotropic fluids in pipes (A4). In addition, a recent contribution by Schultz-Grunow (S6) has presented an empirical procedure for correlation of unsteady state flow phenomena in rotational viscometers which can perhaps be extended to this problem in pipe lines. 

Brauer (B14), 1956 Extensive experimental study of film flow outside tube 4.3X130 cm. films of water, water + surfactant, aqueous diethylene glycol solutions, kinematic viscosity 0.9-12.7 cs. Nr = 20-1800. Data on film thicknesses, waves, maximum and minimum thicknesses, characteristic Reynolds numbers of flow, onset of rippling and turbulence, wall shear stress, etc. 

The cuprous-cupric electron transfer reaction is believed to be the rate-limiting step in the process of stress corrosion cracking in some engineering environments [60], Experimental studies of the temperature dependence of this rate at a copper electrode were carried out at Argonne. Two remarkable conclusions arise from the study reviewed here [69] (1) Unlike our previous study of the ferrous-ferric reaction [44], we find the cuprous-cupric electron transfer reaction to be adiabatic, and (2) the free energy barrier to the cuprous cupric reaction is dominated in our interpretation by the energy required to approach the electrode and not, as in the ferrous-ferric case, by solvent rearrangement. 

Tsui, T.Y., Oliver, W.C. and Pharr, G.M. (1996), Influence of stress on the measurement of mechanical properties using nanoindentation Part I. Experimental studies in an aluminium alloy , Journal of Materials Research, 11, 752-759. 

Land (e.g., 198S) has stressed the chemical and structural variations associated with natural dolomites, and has gone so far as to suggest that the name "dolomite" be used in the same way that the mineral name "feldspar" is used. The fact that dolomite is relatively unreactive compared to most other sedimentary carbonate minerals has severely limited experimental studies under temperature and pressure conditions that exist during shallow burial. Consequently, most information on the chemical behavior of dolomite must be obtained from observations of complex natural systems. Such observations are all too often open to multiple interpretations. 

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