General Characteristics and Properties

Although boron forms borides with many elements, only the borides of the transition metals have been investigated extensively for their CVD characteristics. Boron forms stable borides with the transition metals, and the most refractory of these and those with the greatest potential interest are the borides of the elements of Groups IVa (Ti, Zr, Hf), Va (V, Nb, Ta) and, to a lesser degree. Via (Cr, Mo, W) (see Table 

1 of Ch. 9). Other borides, such as lanthanum and cerium hexaborides (LaBg and CeBg), are of great interest particularly as thermionic emitters but little, if anything, has been reported on their CVD. 

The refractory-metal borides have a structure which is dominated by the boron configuration. This clearly favors the metallic properties, such as high electrical and thermal conductivities and high hardness. Chemical stability, which is related to the electronic 

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Some of the procedures used to synthesize dendritic molecules can be quite involved, and many different methods have been reported. The following three sections provide an overview of some of the pioneering work yielding each of the three main subclasses of dendritic polymers, namely, dendrimers, hyperbranched polymers, and dendrigraft polymers. The general characteristics and properties of these materials are also considered, as well as some of the more recent work including potential applications for these extremely versatile materials. 

Carbides, like all materials, have a well-defined internal electronic structure which governs their behavior and controls their properties. This means that, in order to understand their mechanism of formation and their general characteristics and properties, it is essential to have a clear picture of the electronic configuration of their constituents. The element common to all carbides is, of course, carbon a short review of its structure follows.Pl... 

Note Hydrogen is used in a supplementary role in reactions where reduction is not the primary function, for instance where it is necessary to prevent the formation of oxides or carbides and generally improve the characteristics and properties of the deposited material. 

Versteeg, C. 1979. Pectinesterases from the orange fruit - Their purification, general characteristic and juice cloud destabilizing properties. Ph.D. thesis. Agricultural Univ., The Netherlands. 

As was made clear in the Introduction to this chapter, the characteristics and properties of laminates depend on a variety of factors before going on to consider the special qualities of flame-retardant and postforming materials a number of the more important general features are reviewed as follows. 

The other platinum metals form compounds which arc in general similar to those formed by platinum. Table XLIV gives in tabular form the principal compounds formed by the associated metals. In general their formation, characteristics, and properties will be suggested by comparison with tho corresponding platinum derivatives. The following characteristics are worthy of note-... 

The main focus in this chapter is on two themes On the one hand, the discussion aims at presenting, without many formulae, certain critical characteristics and properties of unstable states in general, and, in particular, of states that are normally represented by multi-particle wavefunctions, such as the ones that are found in the spectra of atoms and small molecules. On the other hand, the discussion aims at demonstrating why and how it is possible to tackle, from first principles and from a many-electron point of view, a large number of problems that have to do with field-free and field-induced unstable states, for which reliable electronic structure calculations are, in principle, feasible. 

We hope that the general concepts and principles reviewed in this article will provide the reader with the necessary background to develop deeper expertise and to create novel O/I hybrid particles and nanocomposites with outstanding characteristics and properties. 

Composites are combined materials created by the synthetic assembly of two or more components - a selected reinforcing agent and a compatible matrix binder - in order to obtain specific and advanced characteristics and properties. The components of composite do not dissolve or otherwise merge completely into each other, but nevertheless do act in concert. The components as well as the interface between them can usually be physically identified, and it is the behavior and properties of the interface that generally control the properties of the composite. The properties of a composite cannot be achieved by any of the components acting alone. 

The structural characteristics and properties of interstitial carbides are generally different fi om those one might expect from a simple solution of carbon atoms in the interstices of the transition metal, reflecting an obvious change in the atomic bonding.l l Some of the major differences between the host metal and the carbide are as follows ... 

Aluminum nitride is a highly stable material with the unusual combination of high thermal conductivity comparable to diat of metals and high electrical insulation comparable to the best insulators. Its characteristics and properties are summarized in Table 13.7 (see Ch. 12 for structural data). The reported property values often vary considerably and the values given here are a general average.t K K ... 

General description and properties. There are several reasons for using titanium alloys according to their properties and characteristics. The chief advantages of titanium alloys that are important to design engineers are, in order of importance ... 

Ion-selective electrodes are widely used in pharmaceutical analysis. Numerous ion-selective electrodes based on poly(vinyl)chloride (PVC) have been constructed in order to determine various pharmacologically active substances in pharmaceutical preparations. The inherent advantages of ISE-s are simple design, construction and manipulation, reasonable selectivity, fast response time, low cost, adequate detection limit and adequate precision and accuracy. Therefore, the ISE potentiometric method is very attractive for pharmaceutical analysis. The first part of this chapter describes the properties and uses of PVC, as well as the general characteristics and preparation of the polymer membranes of ion-selective electrodes. The second part deals with the development of solid contact electrodes formed on non-crystal electrodes with a microporous matrix (e.g., vinyl polychloride dissolved in an appropriate modifier) selective for various nonsteroidal anti-inflammatory drugs (NSAlD-s) and their applications in pharmaceutical research. 

Semichem s partnership with the University of Florida to produce the QSAi QSPR program CODESSA has further enhanced the usability and general applicability of Semichem s software. CODESSA ties AMPAC results (thermodynamic, electrostatic, geometric, and quantum mechanical) to experimental results, making real-life application easier and more intuitive. Together AMPAC and CODESSA can often predict actual product characteristics and properties. Semichem has also added a PREDICT module, which automates the execution of both AMPAC and CODESSA, with the objective of generating predictions for molecules using an already derived correlation. 

From these early studies, dithiocarbamates and their transition metal complexes soon found a host of applications. For example, as a result of their insoluble nature they are widely used in inorganic analysis (3,4). They can also be used to separate different metal ions by high-performance liquid chromatography (HPLC) (5-10) and capillary gas chromatography (GC) (11, 12), and find use as rubber vulcanization accelerators (13), fungicides (14), and pesticides (15). Concomitant with the development of these applications came a burgeoning interest in their general transition metal chemistry and the characteristics and properties of the complexes formed. 

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