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Abundances medium

The hydrogen atom and its spectrum are of enormous importance in astrophysics because of the large abundance of hydrogen atoms both in stars, including the sun, and in the interstellar medium. [Pg.217]

The differences in composition between the two essential oils examined show well, if they be compared with those which exist between the essential oils of the leaves and the inflorescences, that the distribution of the odorous principles between the leaf, the organ of production, and the flower, the organ of consumption, tends to take place according to their relative solubilities. But this tendency may be inhibited, or on the other hand, it may be favoured by the chemical metamorphoses which the substances undergo at any particular point of their passage or at any particular centre of accumulation. Thus, in the present case, some of the least soluble principles, the esters of menthol, are most abundant in the oil of the leaves, whilst another, menthone, is richest in the oil of an organ to which there go, by circulation, nevertheless, the most soluble portions. This is because this organ (the flower) constitutes the. medium in which the formation of this insoluble principle is particularly active. [Pg.22]

Boilers are heat-transfer devices, wherein water, in the form of either liquid water or gaseous steam, is commonly employed as a medium for the transport of heat to some distant point of use. Although other heat-transfer mediums are sometimes utilized, water is particularly suitable because of its relative abundance, low cost, and high heat capacity. It is generally the medium of choice in most boiler applications, whether for domestic, commercial, institutional, or industrial purposes. [Pg.990]

Our first exploration of property space was focused on acetylcholine. This molecule was chosen for its interesting structure, major biological role, and the abundant data available on its conformational properties [15]. The behavior of acetylcholine was analyzed by MD simulations in vacuum, in isotropic media (water and chloroform) [16] and in an anisotropic medium, i.e. a membrane model [17]. Hydrated n-octanol (Imol water/4mol octanol) was also used to represent a medium structurally intermediate between a membrane and the isotropic solvents [17]. [Pg.11]

The use of CIEF in combination with FTICR has been demonstrated in an analysis of the E. coli proteome (Jensen et al., 1999). For these experiments, E. coli was grown in a medium depleted of rare isotopes in order to increase the mass measurement accuracy. The high abundance isotopes are present at approximately 98.89% 12C, 99.63% 14N and 99.985% H. For peptides, the presence of rare isotopes does not significantly change the spectra but with undigested proteins, mass accuracy can be limited by the broadened distribution of ions of any given protein due to the incorporation... [Pg.16]

Shocks were first invoked to explain the unusually high abundance of the radical CH+in diffuse clouds (n 100 cm-3 T = 100 K), where standard chemical models predict far too little of this substance which is reactive both with electrons and with atomic and molecular hydrogen.128 In a high temperature medium, however, the reaction,... [Pg.41]

The proteins of high abundance are often identified by multiple peptides and high statistical confidence. On the contrary, many medium and low abundant proteins are typically identified by only a single peptide. This is a direct result of the semirandom nature of the DDA algorithm (Liu et al., 2004), as discussed above. In addition, these peptide hits often cannot be confirmed by subsequent DDA experiments conducted... [Pg.281]

Without these advances in hard, strong materials based on abundant, and therefore low-cost iron ore, there could have been no industrial revolution in the nineteenth century. Long bridges, sky-scraper buildings, steamships, railways, and more, needed pearlitic steel (low carbon) for their construction. Efficient steam engines, internal combustion engines, turbines, locomotives, various kinds of machine tools, and the like, became effective only when key components of them could be constructed of martensitic steels (medium carbon). [Pg.3]

The simple cycloalkanes (CH2)n with n = 5 to 12 are the compounds most frequently studied by force field calculations (8, 9, 11, 12,17, 21). This preference results from their simple structure, from the abundant available experimental material (structural (46), thermo-chemical (47) and vibrational spectroscopic (27, 48, 49) data), and from the fact that, apart from bond length deformations, all other strain factors (angle deformations, unfavourable torsion angles, strongly repulsive nonbonded interactions) are important for the calculation of their properties. The cycloalkanes are thus good candidates for testing force fields. For a more detailed discussion we choose cyclodecane, a so-called medium-ring compound. [Pg.188]


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Abundances in the interstellar medium

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