Coins double

Diene monomers with suitably disposed double bonds may undergo intramolecular ring-closure in competition with propagation (Scheme 4.12). The term cyclopolymcrization was coined to cover such systems. Many systems which give cyclopolymerization to the exclusion of normal propagation and crosslinking are now known. The subject is reviewed in a series of works by Butler.98 102... 

Olefin metathesis, an expression coined by Calderon in 1967,1 has been accurately described in Ivin and Mol s seminal text Olefin Metathesis and Metathesis Polymerization as the (apparent) interchange of carbon atoms between a pair of double bonds (ref. 2, p. 1). This remarkable conversion can be divided into three types of reactions, as illustrated in Fig. 8.1. These reactions have been used extensively in the synthesis of a broad range of both macromolecules and small molecules3 this chapter focuses on acyclic diene metathesis (ADMET) polymerization as a versatile route for the production of a wide range of functionalized polymers. 

The name silicone was originally coined because of the resemblance of the empirical formulae of silicones, e.g. R2SiO, with ketones, R2CO. However, because of the different nature of the silicon and carbon atoms, in particular that silicon is too large to form stable double bonds, this resemblance is merely superficial. 

Bursters from 155-mm, M110 mustard agent projectiles are transferred by the PMD burster transfer conveyor to the burster size-reduction machine. This is a baseline-system rocket shear machine (RSM) modified to perform burster size reduction. The M6 bursters from these projectiles are cut into three equal-length sections to reduce the time required to separate/deactivate the tetrytol explosive in the COINS. From the burster size-reduction machine, the burster sections drop into the projectile component discharge hopper, through double blast gates, to the projectile component discharge chute... 

The nucleosome is the fundamental repeating structural unit of chromatin. It is composed of two molecules of the core histones H2A, H2B, H3, H4, approximately two superhelical turns of double-stranded DNA, and linker histone HI (H5). In addition to biochemical studies, the existence of the nucleosome was established in electron micrographs (Fig. la) [1,2], and the name nucleosome, coined to incorporate the concept of the spherical nu-bodies [3]. Micrococcal nuclease limit digestion of chromatin established the nucleosome core particle (NCP) as the portion of the nucleosome containing only the core histones surrounded by 1.75 superhelical turns of double-stranded DNA [4,5]. 

The Problem You have a total of 40 coins in nickels and quarters. If you double the number of quarters and add 12, you ll get the same number of coins as you d have if you multiply the number of nickels by 4 and subtract 4. How much money do you have in quarters ... 

Let n represent the number of nickels and q represent the number of quarters. Your first equation is n + q = 40. The second equation sets the two relationships between the number of coins equal to one another. Let double the number of quarters and add 12 be represented by 2q + 12, and... 

VMP, a term coined by Crim and coworkers in 1987 [26], has been applied extensively by him and others since then [27-33], However, some VMP studies were carried out even earlier (see Section 2.3). As mentioned earlier, direct photodissociation, Figure 2.1a, involves electronic excitation of vibrationless ground state parent molecules to an excited PES, while in VMP, Figure 2.1b, excitation of molecules initially prepared in a particular vibrational state is involved. Therefore, in VMP, two- or three-color photons are required to induce a double resonant... 

On the other hand, many of those plates generally considered modern fakes were made by a repousee technique and involved an outer, plain-curved back that was folded over at the rim to form a double-walled hollow plate. Occasionally a separate (cast) piece, usually a raised front leg of the horse, was attached, probably by soldering. These fakes and copies of existing museum plates all have less than 0.6% Au in Ag (in agreement with the fake Sasanian coins, Figure 5) and 14 of the 18 fakes in Figure 6 have less than 94% Ag + Au. 

Carbometallation is a term coined for describing chemical processes involving net addition of carbon-metal bonds to carbon-carbon Jt-bonds [1] (Scheme 4.1). It represents a class of insertion reactions. Whereas the term insertion per se does not imply anything chemical, the term carbometallation itself not only explicitly and clearly indicates carbon-metal bond addition but also is readily modifiable to generate many additional, more specific terms such as carboalumination, arylpalladation, and so on. In principle, carbometallation may involve addition of carbon-metal double and triple bonds, that is, carbene- and carbyne-metal bonds, as well as those of metallacycles. Inasmuch as alkene- and alkyne-metal Jt-complexes can also be represented as three-membered metallacycles, their ring expansion reactions via addition to alkenes and alkynes may also be viewed as carbometallation processes (Scheme 4.1). 

Structures and the recommended names of compounds belonging to the bomane group of bicyclic terpene hydrocarbons are given in Chart 14. Reasons for coining the name bornane and for the necessity of using the norbomane-type names to systematize the nomenclature of the bicyclo 2.2. [] heptane bicyclics have been presented earlier. Examination of the names in Chart 14 reveals that in the systematic bicyclo 2.2.1 ]heptane names and the recommended norbornane names the prefix numbers for substituents and double bonds and the order of names of substituents are identical. 

Based on some interesting reactions in certain inorganic crystalline compounds, Kohlschutter [9,10] proposed that the nature and properties of the products obtained take place on the surface or within the solid state. Indeed, he coined the term topochemistry for such reactions in the solid state. However, systematic investigations of photoinduced reactions in crystals began from 1964 onward by Schmidt and Cohen [11], Their studies on the 2tt + 2tt photoreaction of cinnamic acid derivatives in the crystalline state and correlation with the molecular organization in these crystals led to what are now known as Topochemical Principles. The most important conclusions reached by them are as follows (1) The necessary conditions for the reactions to take place are that the reactive double bonds are parallel to one another and the center-to-center distance be within 4.1 A (2) there is one-to-one correspondence between the stereochemistry of the photoproduct and the symmetry relationship between the reactants. The centrosymmet-ric relationship (called the a-form) leads to centrosymmetric cyclobutane (anti-HT), whereas the mirror symmetric arrangements (called the (5-form) produce mirror symmetric dimer (yy -HH). 

The alloy of zinc with copper is termed brass, pinchbeck, Muntz metal, and tombac. English brass usually contains 70 per cent, of copper and 30 of zinc. It is made by melting the copper and adding the molten zinc. The addition of nickel (Cu 52 per cent., Zn 23 per cent., Ni 13 per cent.) yields German silver, of which spoons, forks, and coins are made. Electroplate has usually a basis of this alloy, and is covered with silver by depositing it from its double cyanide with potassium. Zinc coated over... 

I stepped outside and pulled the door shut, fumbled my way between the outbuildings, and went back to the house, where everything was much as before, except that Lady Essington s mother had joined her at the table and the heap of coins between them had doubled in size. Harford offered me a place, and I sat down and drank glass after glass of wine while I gambled my husband s sovereigns on three hands of quadrille and won every time. 

The present assumptions are that the coins are reasonably homogeneous, that the melt was reasonably homogeneous, that probably two batches of copper were made each day, and that dies were stored over night in a container of some sort (a strong-box). Table VIII contains the analyses for pairs of coins having double die links. Both obverse and reverse dies are the same in some cases this cannot be determined with certainty since some coins are worn or corroded, and on rare occasion two different dies are nearly the same. In all cases the die orientations of the doubly-die linked pair are the same within experimental error, 30 min. The... 

Table VIII- Compositions of Double Die-Linked Coins ...

Half of the eight pairs of doubly die-linked coins have the same chemical compositions, evidently meaning that four of the double die-linked pairs of coins were made from the same four batches of copper ... 

Well coine back to this molecular orbital description of ir bonding in future chapters, pniiiculaxly when we discuss rompuuncls with more than one double bond. 

---