The Broad Outline

In the preface and conclusion of the Shukuk, al-Mas udi informs us of the book s objectives and modus operandi. The preface goes as follows  

These are puzzles shukuk) and dubitations (shubah) that I encountered ara at U) in some places in the Ishdrdt. I have not lost hope of solving 

19 Al-Khayyam, Tarjama, 228. Avicenna s text is also briefly cited by al-Razi Mabahith, 2, 

20 This work is extant in several manuscript copies, for instance, MS Istanbul, Mehmed Asim Bey 238 ( e en, Fihris, 3,108). Al-TabrIzI does not seem to refer to al-Mas udI s commentary. 

22 Echoing part of a hadith Inna ll-rabbl-kum fl ayydm dahri-kum nafahdt (on this hadlth, see, for instance, al-Zahldi, Ithdf, 3,280-281). 

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Once the broad outlines of DNA replication and protein biosynthesis were established scien tists speculated about how these outlines af fected various origins of life scenarios A key question concerned the fact that proteins are re quired for the synthesis of DNA yet the synthesis of these proteins is coded for by DNA Which came first DNA or proteins How could DNA store genetic infor mation if there were no enzymes to catalyze the polymerization of its nucleotide components How could there be proteins if there were no DNA to code for them ... 

Whereas the quasi-chemical theory has been eminently successful in describing the broad outlines, and even some of the details, of the order-disorder phenomenon in metallic solid solutions, several of its assumptions have been shown to be invalid. The manner of its failure, as well as the failure of the average-potential model to describe metallic solutions, indicates that metal atom interactions change radically in going from the pure state to the solution state. It is clear that little further progress may be expected in the formulation of statistical models for metallic solutions until the electronic interactions between solute and solvent species are better understood. In the area of solvent-solute interactions, the elastic model is unfruitful. Better understanding also is needed of the vibrational characteristics of metallic solutions, with respect to the changes in harmonic force constants and those in the anharmonicity of the vibrations. 

In chemical kinetics, one finds linked sets of differential equations expressing the rates of change of the interacting species. Overall, mathematical models have been exceedingly successfiil in depicting the broad outlines of an enormously diverse variety of phenomena in nature. Some scientists have even commented in surprise at how well mathematics works in describing nature. So successful have these mathematical models been that their use has spread from the hard sciences to areas as diverse as economics and the analysis of athletic performance [3]. 

Thus, overall, it is clear that flash photolysis with uv-visible detection is effective in establishing the broad outlines of the photochemistry of a particular metal carbonyl. Intermediates can be identified from their reaction kinetics, and sometimes, with the help of uv-vis data from matrix isolation experiments. Structural information from uv-vis flash photolysis is at best sketchy. Many questions remain unanswered. Time-resolved IR measurements can fill in some of these answers. 

This subcommittee prepared the broad outline for the book, identified the scope and major key references, and selected the title "Guidelines for Chemical Reactivity Evaluation and Application to Process Design" as representative of the concepts desired. The TNO Prins Maurits Laboratory, Rijswijk, The Netherlands, was chosen as the contractor with Dr. A. Henk Heemskerk as the project manager. 

In this chapter, we reviewed the broad outlines of the Big Bang model for the origin of the universe and discussed some of the supporting observations. We showed that the Big Bang gave rise to hydrogen, helium, and some lithium, beryllium, and boron, but that other elements were produced primarily in stars. The rest of the elements were synthesized in stars via the nuclear reactions that cause the stars to shine. To understand stellar nucleosynthesis, it is necessary to understand the characteristics of stars. Astronomers use... 

A simple conclusion follows. Before a silver ion from solution becomes part of the metallic lattice (Fig. 7.123), it has to receive an electron and divest itself of its sheath of hydration water. In short, the deposition of an ion consists of electronation and dehydration. How the ion goes through electronation and dehydration is an interesting story, only the broad outlines of which will be sketched here. 

This book is written for chemistry students who wish to understand how group theory is applied to chemical problems. Usually the major obstacle a chemist finds with the subject of this book is the mathematics which is involved consequently, I have tried to spell out all the relevant mathematics in some detail in appendices to each chapter. The book can then be read either as an introduction, dealing with general concepts (ignoring the appendices), or as a fairly comprehensive description of the subject (including the appendices). The reader is recommended to use the book first without the appendices and then, having grasped the broad outlines, read it a second time with the appendices. 

The broad outline of the mechanism of catalysis of ester hydrolysis by hydroxide ion is not in doubt. The reaction is well known to involve acyl-oxygen cleavage, and seems invariably to be of the second order, being first order in both ester and hydroxide anion. General base catalysis in the usual sense is not a possibility, the partial removal of a proton from water cannot generate a species more reactive than hydroxide ion, so direct nucleophilic attack must be involved. (However, if it is accepted that the high ionic nobility of the hydroxide ion in water is explained by a Grotthus-type mechanism... 

It is now over a decade since the last attempts to survey all of silylene chemistry1-5. While new work continues to be published at a brisk pace, it is fair to state that the field has reached a stage of maturity in which silylenes are tools for answering questions as much as ends in themselves. That implies a belief that the broad outlines of silylene chemistry are known and can be applied. This is not to say that there are no surprises, and indeed there is considerable healthy controversy, extending even to what one means by silylene . 

The broad outlines of eukaryotic protein synthesis are the same as in prokaryotic protein synthesis. The genetic code is generally the same (some microorganisms and eukaryotic mitochondria use slightly different codons), rRNA and protein sequences are recognizably similar, and the same set of amino acids is used in all organisms. However, specific differences exist between the two types of protein synthesis at all steps of the process. 

It used to be supposed by empiricists that the justification of such inference rests upon induction. Unfortunately, it can be proved that induction by simple enumeration, if conducted without regard to common sense, leads very much more often to error than the truth. And if a principle needs common sense before it can be safely used, it is not the sort of principle that can satisfy a logician. We must, therefore, look for a principle other than induction if we are to accept the broad outlines of science, and of common sense in so far as it is not refutable. This is a very large problem. 

Watt shared the broad outline and many of the details of this coherent conception of the chemistry of airs. Watt s long-held belief about the conversion of water into air if high enough temperatures could be attained had meteorological significance. Recall that when he advised Boulton of this idea in December 1782 he noted that it solved the problem of the source of atmospheric air, as Priestley had already observed. 

At face valne, it wonid appear that these providers could supply a total number of compounds well in excess of 3,000,000 however, in reality there is a significant amount of overlap between these simple, and essentially design-free, collections. In fact the total nnmber of nnique, structurally different compounds is something less than 2,000,000 once the overlap is taken into account and, of these, just 700,000-750,000 might be considered drug-like once a set of snitable medchem filters have been applied. (The broad outlines of the cheminformatics methods being nsed to analyse diversity and to apply such filters to these commercial compound collections will be discussed below.)... 

The broad outlines of Earth history during the Hadean are starting to become visible. The solar system originated 4.57 Ga (Allegre et al., 1995). The accretion of small bodies in the solar nebula occurred within lOMyr of the birth of the solar system (Lugmaier and Shukolyukov, 1998). The Earth reached its present mass between 4.51 Ga and 4.45 Ga (Halliday, 2000 Sasaki and Nakazawa, 1986 Porcelli et ah, 1998). The core formed in <30 Ma (Yin et al., 2002 Kleine et aL, 2002). The early Earth was covered by a magma ocean, but this must have cooled quickly at the end... 

Careful and extensive work by Milliet and Lusinchi and Challis and co-workers has confirmed the broad outlines of this proposal. However, the latter investigators found that the extent of acid catalysis was determined overwhelmingly by the structure of the A -substituent, particularly when that substituent was a bulky tertiary group and much less so when a primary group was present. Since the products of hydrolysis by path 2 were the same as those of base-catalyzed a-hydrogen abstraction, it was concluded that the latter method is more effective for hydrolysis of A -primary alkyl derivatives. 

If we are satisfied to omit innumerable details, we can trace, for each of the most important chemical elements concerned, the broad outline of its cycle in nature. The elements and simple compounds principally concerned are carbon (COj), oxygen (O2), nitrogen (Nj, NH3, N02 , N03 ), water (H2O), phosphorous (P04 etc.). .. For the drama of life is like a puppet show in which stage, scenery, actors and all are made of the same stuff. The players, indeed, have their exits and their entrances, but the exit is by way of translation into the substance of the stage and each entrance is a transformation scene. So stage and players are bound together in the close partnership of an intimate comedy and if we would catch the spirit of the piece, our attention must not all be absorbed in the characters alone, but must be extended also to the scene, of which they... 

Note in Figure 4.9 that the low frequency terms of the series, which could correspond to the low resolution X-ray reflections arising from families of planes of large spacings and low Miller indexes, fill out the broad outlines of the synthetic wave. The higher frequency terms, corresponding to families of planes of fine spacings, provide the details. The same... 

In the simplest terms, the broad outlines of a future hydrogen economy run something like this ... 

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