The pyramid model

1 Pyramid model for textile recycling categories, by quantity. 

Estimated total used Estimated value textile goods by volume  

Conversion to value added markets 29% Value varies widely depending on product. Sold by weight. 

Landfill and incineration 7% Varies by location and/ or rural/urban. Costs are by weight. 

Not aU used clothing is exported to poorer countries. One informant shared that he has a new market in the United Arab Emirates, one of the richest countries in the world. Used clothes in the United Arab Emirates are not intended for the local 

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Dowell, A.M. 2002. "Getting from Policy to Practices The Pyramid Model (Or What Is this Standard Really Trying to Do )." Process Safety Progress 21(1). March. 

Figure 1 The pyramid model suggests that the structure of successful drug discovery is built on several interrelated technologies. No single technology is more important than any other.

To amplify this point, safety and loss prevention professionals often use the pyramid model to drive home the point that near-misses and other underlying factors, if not addressed, will ultimately lead to an accident. Visualize a pyramid or triangle starting at the bottom, for every 300 equipment damage accidents or... 

Reciprocal salt pair solutions may be represented on an isothermal space model, in the form of either a square-based pyramid or a square prism. Figure 4.30a indicates the pyramidal model the four equilateral triangular faces stand for the four ternary systems AX-AY-W, AY-BY-W, BY-BX-W and AX-BX-W (W = water) for the salt pair represented by the equation... 

Of the two extremes experimental studies indicate that the planar sp model describes the bonding m alkyl radicals better than the pyramidal sp model Methyl rad ical IS planar and more highly substituted radicals such as tert butyl radical are flattened pyramids closer m shape to that expected for sp hybridized carbon than for sp ... 

In 1972 Walton et al. [32] modeled the drug literature as a pyramid with the primary literature forming the base of the pyramid, the secondary literature interfacing and serving as a bridge from the primary literature to reference works (tertiary literature). Reference works (tertiary literature) are the capstone of the pyramid and represent the smallest portion of the total literature volume. 

We see that it is a consequence of the Pauli principle and bond formation that the electrons in most molecules are found as pairs of opposite spin—both bonding pairs and nonbonding pairs. The Pauli principle therefore provides the quantum mechanical basis for Lewis s rule of two. It also provides an explanation for why the four pairs of electrons of an octet have a tetrahedral arrangement, as was first proposed by Lewis, and why therefore the water molecule has an angular geometry and the ammonia molecule a triangular pyramidal geometry. The Pauli principle therefore provides the physical basis for the VSEPR model. 

According to the VSEPR model, NX3E molecules are expected to have a triangular pyramidal geometry. Experimental data for some NX3E molecules are given in Table 8.10 and Figure... 

The pyramidal inversion energies of chalcogen-onium imides were estimated by MO calculations.28 The values for model compounds, dimethyl chalcogen-onium imides, were evaluated to be 34, 44, and 54 kcal mol-1 for S, Se, and Te, respectively, indicating that among the chalcogen-onium imides, telluronium imides are those that are most stable toward pyramidal inversion. 

The LCFC approach provides the basis for the development of an overview of the shapes of AX2 and AX3 molecules. In order to maximize simplicity, we have developed a model which restricts the number of basis set configurations in such a manner that only the key electronic changes accompanying the bending of a linear tri-atomic molecule or the pyramidalization of a flat tetraatomic molecule are considered. The various features of our model are the following ... 

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