Mechanical twinning

The atomic mechanism, based on the previously proposed inhomogeneous shear, leading to the formation of twinning and antiphase boundaries in TiNi with the CsCl-type structure is described. The twinning mechanism described herein explains the electrical resistivity anomaly due to incomplete thermal cyclings observed previously in TiNi. This explanation is in keeping, in a qualitative manner, with the "memory effects observed in relation to the electrical resistivity anomaly. 

I have argued that social norms regulate behavior through the twin mechanisms of shame in the subject and disgust or contempt in the... 

Harry and Sally, twin mechanical engineering graduates, may encounter... 

By combining kinetic and structural data, a vacancy mechanism and a twinning mechanism were deduced for anisotropic O diffusion in the CuO layer between BaO layers. 

Besides dislocation movement, there are other mechanisms of plastic deformation. These are the martensitic transformation we already discussed, diffusion creep at high temperatures (to be covered in chapter 11), and finally the so-called twinning. Mechanical twinning usually contributes only slightly to plastic deformation and is in general more difficult to activate than dislocation movement. Therefore, it will be discussed only briefly. 

The twin mechanisms of coagulation and heterogeneous nucleation (condensation of one materiai to another) tend to accumulate submicrometre aerosol particle mass in this mode (Whitby and Cantrell, 1976 Willeke and Whitby, 1975). Because of the sharp decrease in particles larger than 0.3 pm in diameter, little mass is transferred from the accumulation mode to the coarse particle size range. Sedimentation and impaction tend to increase the relative concentration of the smallest mechanically produced particles, and then accumulate in this mode. Salt from sea spray is typically present as particles in the 1-5 pm size range, outside the normal accumulation mode. 

Early investigations of the deformation modes of various sulfide minerals observed both plastic and brittle behavior [383-386]. Considerable subsequent work established shp and twinning mechanisms in several important sulfide ore... 

Figure 3 (a) [010] zone axis built from experimental ED patterns recorded tilting along b. (b) Twinning mechanism... 

Despite the remarkable variety of polyunsaturated fatty acids found in some protists, there is no evidence that they are sjmthesized in vivo other than by combination of the twin mechanisms of desaturation and two-carbon addition. These reactions are familiar to students of fatty acid biosynthesis in plants and animals. The possibihties which stem from cambination of these two processes have been demonstrated by the studies of Hulanicka, Erwin, and Bloch (1964) on Euglena gracUis. 

Signal processing in mechanical impedance analysis (MIA) pulse flaw detectors by means of cross correlation function (CCF) is described. Calculations are carried out for two types of signals, used in operation with single contact and twin contact probes. It is shown that thi.s processing can increase the sensitivity and signal to noise ratio. 

Penn R L and Banfieid J F 1999 Formation of rutiie nuciei at anatase (112) twin interfaces and the phase transformation mechanism in nanocrystaiiine titania Am. Miner. 84 871... 

The concept of two-state systems occupies a central role in quantum mechanics [16,26]. As discussed extensively by Feynmann et al. [16], benzene and ammonia are examples of simple two-state systems Their properties are best described by assuming that the wave function that represents them is a combination of two base states. In the cases of ammonia and benzene, the two base states are equivalent. The two base states necessarily give rise to two independent states, which we named twin states [27,28]. One of them is the ground state, the other an excited states. The twin states are the ones observed experimentally. 

Properties. Table 1 hsts many of the physical, thermal, mechanical, and electrical properties of indium. The highly plastic nature of indium, which is its most notable feature, results from deformation from mechanical twinning. Indium retains this plasticity at cryogenic temperatures. Indium does not work-harden, can endure considerable deformation through compression, cold-welds easily, and has a distinctive cry on bending as does tin. 

Several commercial products of PVC/TPU blends are available. The BF Goodrich Chemical Group has a PVC/ TPU blend based on their Estane series TPUs. For example, their Estane 54620, a polyester-based TPU with a °ShA 85 hardness, shows excellent compatibility with flexible PVC. The blends are produced by mixing PVC, TPU, plasticizer, stabilizer, and lubricant in a twin-screw extruder. These polymeric blends show intermediate mechanical properties between PVC and TPU. 

---