Dendritic growth: hybrids

Dendritic growth hybrids are prepared using one or more functional groups of a preformed linear chain to effect the stepwise growth of one or more dendritic blocks via divergent synthesis. 

Regardless of the desired architecture, there are three main synthetic approaches to the preparation of diblock, dumbbell or dendronized hybrid copolymers. These involve grafting, polymerization or stepwise dendritic growth... 

Although silver to palladium ratios of 3 1, 4 1, and 6 1 are commonly used in hybrid apphcations, thrifted versions utilizing Pd contents less than 5% have been shown to have good leach resistance in 62% Sn-36% Pb-2% Ag solders. Table 8.4 compares properties of various Ag Pd ratios. These materials meet the requirements of high-conductivity materials needed for circuits with higher speeds and densities. Similar performance can be met by small additions of platinum to silver (1 100). The leach resistance of a 1 % Pt addition is shown to be equivalent to a 10 percent Pd addition with minimum effect on conductivity. However, Ag migration such as dendritic growth and diffusion into resistors or capacitors when used as a termination material is stUl an issue with only minor Pd or E t additions. 

DerMarderosian A, Murphy C (1977) Humidity threshold variations for dendritic growth on hybrid substrate, Proc Int Reliability Phys Symp, Las Vegas, NV... 

Perhaps one of the most exciting areas in neuroscience to which in situ hybridization has made significant contributions in recent years is the discovery that specific mRNA transcripts can be localized to certain compartments of neuronal cells (Steward and Schuman, 2003), such as axons (Tohda, 2003), dendrites (Ma and Morris, 2002 Bockers et al., 2004), cell bodies (Lu et al., 1998), and growth... 

Several hybrid simulations on crystal growth can be found in recent literature. Examples include dendritic solidification by coupling finite-different discretization of a phase field model to a MC simulation (Plapp and Karma, 2000), coupling a finite difference for the melt with a cellular automata for the solidification (Grujicic et al., 2001), a DSMC model for the fluid phase with a Metropolis-based MC for the surface to address cluster deposition onto substrates (Hongo et al., 2002 Mizuseki et al., 2002), a step model for the surface processes coupled with a CFD simulation of flow (Kwon and Derby, 2001) (two continuum but different feature scale models), an adaptive FEM CVD model coupled with a feature scale model (Merchant et al., 2000), and one-way coupled growth models in plasma systems (Hoekstra et al., 1997). Some specific applications are discussed in more detail below. 

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