Three-dimension printing

FIGURE 6.21 Computer generated aggregate assuming particle-partide aggregation. Fractal dimension of 1.5 in two dimensions made to simulate a fractal dimension of 2.5 in three dimensions. Printed, with permission from Sutherland [72]. 

Keep in mind that the geometry is difficult to show on the printed page because the atoms are arranged in three dimensions. 

The term stereochemistry refers to the three-dimensional nature of molecules and to their space-filling properties. Many computer models can give a perception of three dimensions, but printed and hand-drawn representations of molecules are two-dimensional images that are meaningful only to those who understand implicit rules for visualizing the third dimension. Furthermore, such drawings have meanings on many levels. 

Inkjet printing can aheady be used for the production of screens (McCue et al., 1992), and inkjet printing in three dimensions could potentially be used to produce stamps like those used for woodblock printing. Many of the new business opportunities... 

The general aim of future research is the further optimization of droplet generation concerning minimum droplet volume, maximum print frequency, maximum throughput, maximum accuracy and precision, minimum pitches and maximum droplet quality. Due to this, it is essential to understand the basics of droplet generation mechanisms in detail and in three dimensions. Furthermore the development of new applications using different kinds of droplet dispensers is also part of current research work. 

You learned in Chapter 12 that atoms in molecular compounds and polyatomic ions are held together by covalent bonds. Lewis diagrams show, in two dimensions, how the atoms are connected. However, Lewis diagrams do not show how the atoms are arranged n three dimensions-the actual shape of the molecule. In this chapter you will learn how the distribution of atoms leads to the structure and shape of molecules. It begins with the Lewis diagram, and in case it has been a while since you studied Lewis diagrams, we will review them briefly. Important terms are printed in italics. 

Zhao, S., Zhu, M., Zhang, J., Zhang, Y, Liu, Z., Zhu, Y., Zhang, C., 2014. Three dimension-ally printed mesoporous bioactive glass and poly(3-hydroxybutyrate-co-3-hydroxyhexa-noate) composite scaffolds for bone regeneration. Journal of Materials Chemistry B 2 (36), 6106-6118. 

Even the coordinate systems which we employ are vulnerable to intellectual prejudice. It may be clear that we need to make provision for storing atomic coordinates in three dimensions. Yet the standard esthetically pleasing diagrams which we see in journals often have (X,Y) coordinates on the printed page which cannot be related to their (X,Y,Z) coordinates in real space. This is very true of stereochemical representations, where the so-called real shape of the molecule is translated into an unreal flat appearance. 

The quality of pattern transfer differs greatly among the three modes of printing. As an example, a mask with parallel bundles of slits and spaces between slits with dimensions comparable with the slits can be considered. In this case, optical interference results in distorted images. The theoretical minimum dimension (for both space and slit) that allows resolvable interference peaks for contact or proximity printing is approximated by ... 

The authors of a biochemistry text face the problem of trying to present three-dimensional molecules in the two dimensions available on the printed page. The interplay between the three-dimensional structures of hiomolecules and their biological functions will be discussed extensively throughout this hook. Toward this end, we will frequently use representations that, although of necessity are rendered in two dimensions, emphasize the three-dimensional structures of molecules. 

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