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Surface carbonites, carbonates, inorganic carboxylates and sometimes formates (specially at low temperature) were identified by Fourier transform infrared (FUR) [30,31], Step 3 Oxygen diffusion from the bulk sites to the surface... [Pg.237]

Data are exportable in a spreadsheet compatible format. Special software to further process data can be obtained from the vendor as part of the MS/MS system, commercially available from software designers, or produced in house. The data processing systems include calculation of ion ratios based on two m/z values, which in turn is used to calculate concentration based on user-defined values. Furthermore, many programs allow... [Pg.289]

As shown in Table 1 Titavit treatment stimultated to a high extent carotenoid formation, specially p-carotene and red coloured xanthophylls (capsorubin and capsanthin). Esterification of capsanthin with fatty acids increased 1.4 times as a function of Titavit treatment. This was accompanied by structural change on the chromoplast. The fatty bodies disappeared and the fibriles became much thicker in chromoplast from Titavit-treated fruits. [Pg.216]

Corrosion service Carbon dioxide (CO2) or hydrogen sulphide (H2S) in formation tluids will cause rapid corrosion of standard carbon steel and special steel may be required... [Pg.54]

Keywords d rec methods, indirect methods, rock properties, coring, core barrel, standard core analysis, special core analysis, slabbed core, sidewall samples, direct indications, microfossils, sonde, logging unit, invasion, mudcake, formation pressure measurement, fluid sampling, measurement while drilling, formation evaluation while drilling. [Pg.125]

Coring is performed in between drilling operations. Once the formation for which a core is required has been identified on the mud log, the drilling assembly is pulled out of hole. For coring operations a special assembly is run on drill pipe (Fig. 5.33) comprising a core bit and a core barrel. [Pg.126]

Almost all chemical information systems work with tlicir own special type of connection table. They often use various formats distinguishing between internal and external connection tables. In most cases, the internal connection tables arc redundant, thus allowing maximum flexibility and increasing the speed of data processing. The external connection tables are usually non-redundant in order to save disk space. Although a connection table can be cprcsented in many different ways, the core remains the same the list of atoms and the list of bonds. Thus, the conversion of one connection table format into another is usually a fairly straightforward task. [Pg.42]

An alternative and much more flexible approach is represented hy the STAR file format [L48, 149, which can be used for building self-describing data files. Additionally, special dictionaries can be constructed, which specify more precisely the contents of the eorresponding data files. The two most widely used such dictionaries (and file formats) arc the CIF (Crystallographic Information File) file format [150] - the International Union of Crystallography s standard for representation of small molecules - and mmCIF [151], which is intended as a replacement for the PDB format for the representation of macromolecular structures,... [Pg.112]

According to an elegant remark by Davies [5], "Modem scientific data handling is multitechnique, multisystem, and manufacturer-independent, with results being processed remotely from the measuring apparatus. Indeed, data exchange and storage are steps of the utmost importance in the data acquisition pathway. The simplest way to store data is to define some special format (i.e., collection of rules) of a flat file. Naturally, one cannot overestimate the importance of databases, which are the subject of Chapter 5 in this book. Below we discuss three simple, yet efficient, data formats. [Pg.209]

The above simple process cannot be applied to the preparation of the homo-logues a higher temperature is requir (di-n-amyl ether, for example, boils at 169°) and, under these conditions, alkene formation predominates, leading ultimately to carbonisation and the production of sulphur dioxide. If, however, the water is largely removed by means of a special device (see Fig. Ill, 57,1) as soon as it is formed, good 300 of ethers may be obtained from primary alcohols, for example ... [Pg.309]

In conclusion, the special influence of water on the endo-exo selectivity seems to be a result of the fact that this solvent combines in it three characteristics that all favour formation of the endo adduct (1) water is a strong hydrogen bond donor, (2) water is polar and (3) water induces hydrophobic interactions. [Pg.25]

A-4-Thiazoline-2-ones and ring substituted derivatives are usually prepared by the general ring-closure methods described in Chapter II. Some special methods where the thiazole ring is already formed have been used, however. An original synthesis of 4- 2-carboxyphenyl)-A-4-thiazoline-2-one (18) starting from 2-thiocyanato-2-halophenyl-l-3-indandione (19) has been proposed (Scheme 8) (20, 21). Reaction of bicyclic quaternary salts (20) may provide 3-substituted A-4-thiazoline-2-one derivatives (21) (Scheme 9) (22). Sykes et al. (23) report the formation of A-4-thiazoline-2-ones (24) by treatment ef 2-bromo (22) or 2-dimethylaminothiazole (23) quaternary salts with base (Scheme 10). [Pg.373]

Dimerization in concentrated sulfuric acid occurs mainly with those alkenes that form tertiary carbocations In some cases reaction conditions can be developed that favor the formation of higher molecular weight polymers Because these reactions proceed by way of carbocation intermediates the process is referred to as cationic polymerization We made special mention m Section 5 1 of the enormous volume of ethylene and propene production in the petrochemical industry The accompanying box summarizes the principal uses of these alkenes Most of the ethylene is converted to polyethylene, a high molecular weight polymer of ethylene Polyethylene cannot be prepared by cationic polymerization but is the simplest example of a polymer that is produced on a large scale by free radical polymerization... [Pg.267]

By analogy to the hydration of alkenes hydration of an alkyne is expected to yield an alcohol The kind of alcohol however would be of a special kind one m which the hydroxyl group is a substituent on a carbon-carbon double bond This type of alcohol IS called an enol (the double bond suffix ene plus the alcohol suffix ol) An important property of enols is their rapid isomerization to aldehydes or ketones under the condi tions of their formation... [Pg.379]

When we say cycloheptatriene is not aromatic but cycloheptatrienyl cation is we are not comparing the stability of the two to each other Cycloheptatriene is a stable hydrocarbon but does not possess the special stability required to be called aromatic Cycloheptatrienyl cation although aromatic is still a carbocation and reasonably reac tive toward nucleophiles Its special stability does not imply a rock like passivity but rather a much greater ease of formation than expected on the basis of the Lewis struc ture drawn for it A number of observations indicate that cycloheptatrienyl cation is far more stable than most other carbocations To emphasize its aromatic nature chemists often write the structure of cycloheptatrienyl cation m the Robinson circle m a ring style... [Pg.457]

Therefore, if a large quantity of sample is introduced into the flame over a short period of time, the flame temperature will fall, thus interfering with the basic processes leading to the formation and operation of the plasma. Consequently introduction of samples into a plasma flame needs to be controlled, and there is a need for special sample-introduction techniques to deal with different kinds of samples. The major problem with introducing material other than argon into the plasma flame is that the additives can interfere with the process of electron formation, a basic factor in keeping the flame self-sustaining. If electrons are removed from the plasma by... [Pg.97]

We begin our discussion of copolymers by considering the free-radical polymerization of a mixture of two monomers. Mi and M2. This is already a narrow view of the entire field of copolymers, since more than two repeat units can be present in copolymers and, in addition, mechanisms other than free-radical chain growth can be responsible for copolymer formation. The essential features of the problem are introduced by this simpler special case, so we shall restrict our attention to this system. [Pg.424]

Special techniques for experimentation with the actinide elements other than Th and U have been devised because of the potential health ha2ard to the experimenter and the small amounts available (15). In addition, iavestigations are frequently carried out with the substance present ia very low coaceatratioa as a radioactive tracer. Such procedures coatiaue to be used to some exteat with the heaviest actinide elements, where only a few score atoms may be available they were used ia the earHest work for all the transuranium elements. Tracer studies offer a method for obtaining knowledge of oxidation states, formation of complex ions, and the solubiHty of various compounds. These techniques are not appHcable to crystallography, metallurgy, and spectroscopic studies. [Pg.216]

There are numerous variations of the wet process, but all involve an initial step in which the ore is solubilized in sulfuric acid, or, in a few special instances, in some other acid. Because of this requirement for sulfuric acid, it is obvious that sulfur is a raw material of considerable importance to the fertilizer industry. The acid—rock reaction results in formation of phosphoric acid and the precipitation of calcium sulfate. The second principal step in the wet processes is filtration to separate the phosphoric acid from the precipitated calcium sulfate. Wet-process phosphoric acid (WPA) is much less pure than electric furnace acid, but for most fertilizer production the impurities, such as iron, aluminum, and magnesium, are not objectionable and actually contribute to improved physical condition of the finished fertilizer (35). Impurities also furnish some micronutrient fertilizer elements. [Pg.224]


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