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Crystal micro-crystals

For jet fuels, the elimination of free water using filters and coalescers by purging during storage, and the limit of 5 ppm dissolved water are sufficient to avoid incidents potentially attributable to water contamination formation of micro-crystals of ice at low temperature, increased risk of corrosion, growth of micro-organisms. [Pg.250]

Quantum chemical calculations, 172 Quantum chemical method, calculations of the adsorption of water by, 172 Quantum mechanical calculations for the metal-solution interface (Kripsonsov), 174 and water adsorption, 76 Quartz crystal micro-balance, used for electronically conducting polymer formation, 578... [Pg.641]

The irradiation (or ion bombardment) of solid solutions, where a scavenger can be present, should also be explored further. Here it will be important to ensure that the solids are indeed solutions before conclusions can be safely drawn. It is curious to note that the yields observed in frozen solutions are in several cases very similar to the yields in the pure crystalline solutes. This suggests the possibility that the frozen targets had segregated, and that the solute was in fact present as micro crystals. (If this is the case, it may well be that a new method can be developed on this basis for making phase studies at high dilution.)... [Pg.104]

The electron transport properties described earlier markedly differ when the particles are organized on the substrate. When particles are isolated on the substrate, the well-known Coulomb blockade behavior is observed. When particles are arranged in a close-packed hexagonal network, the electron tunneling transport between two adjacent particles competes with that of particle-substrate. This is enhanced when the number of layers made of particles increases and they form a FCC structure. Then ohmic behavior dominates, with the number of neighbor particles increasing. In the FCC structure, a direct electron tunneling process from the tip to the substrate occurs via an electrical percolation process. Hence a micro-crystal made of nanoparticles acts as a metal. [Pg.328]

Silver halide fibres (AgClxBri x) have the widest spectral range in the mid-IR, well into the fingerprint range. Due to their crystalline nature, they have a superior flexibility. Problematic is their tendency to decompose upon contact with UV radiation or base metals. Also sulphides will chemically destroy the fibre material. Other points against are the high intrinsic attenuation due to absorption by impurities or scattering at inclusions or micro-crystals and the non-availability of (applicable) core-clad fibres. [Pg.139]

These incorporate membranes fabricated from insoluble crystalline materials. They can be in the form of a single crystal, a compressed disc of micro-crystalline material or an agglomerate of micro-crystals embedded in a silicone rubber or paraffin matrix which is moulded in the form of a thin disc. The materials used are highly insoluble salts such as lanthanum fluoride, barium sulphate, silver halides and metal sulphides. These types of membrane show a selective and Nemstian response to solutions containing either the cation or the anion of the salt used. Factors to be considered in the fabrication of a suitable membrane include solubility, mechanical strength, conductivity and resistance to abrasion or corrosion. [Pg.238]

Aggregation The reversible coming together of small particles to form larger particles A suspension of micro-crystals forming soon after nucleation... [Pg.513]

The results presumably were distorted by the unavoidable heating of the microcrystals occurring in the electron beam and other side effects. However, if the A a detected in the (111) reflexions is real, then the surface stress or rather surface tension 7S causing the compression of the lattice can be calculated. If R i and R2 in Eq. (37) are supposed to be identical and equal to 0.5 D, see above, then Pc= 4 ys/D. Let k be the compressibility of the micro-crystal, i.e., -dV/V.dp. Then the relative compaction under the pressure, that is -dV/V, is 4 ysk/D. The ratio dV/V may be approximated as 3 A aja. Hence... [Pg.26]

The former value is much greater, and the latter much smaller than those quoted in Section III. 1. The main objection is, however, against Eq. (38) itself rather than its numerical conclusions. To derive Eq. (38) it is necessary to postulate that the diameter D is twice the radius of curvature. This relation is valid for spheres but is entirely wrong for micro-crystals surrounded by nearly flat faces. The two radii of curvature (R t and R2) of a plane interface are each equal to infinity, independently of the actual dimensions of the microcrystal. As long as the surface of separation is... [Pg.26]

EDSA of thin polycrystalline films has several advantages First of all the availability of a wide beam (100-400 pm in diameter) which irradiates a large area with a large amount of micro-crystals of different orientations [1, 2]. This results into a special t5q)e of diffraction patterns (DP) (see Fig.l). Thus it is possible to extract from a single DP a full 3D data set of structure amplitudes. That allows one to perform a detailed structure analysis with good resolution for determining structure parameters, reconstruction of ESP and electron density. [Pg.98]

Probing Metalloproteins Electronic absorption spectroscopy of copper proteins, 226, 1 electronic absorption spectroscopy of nonheme iron proteins, 226, 33 cobalt as probe and label of proteins, 226, 52 biochemical and spectroscopic probes of mercury(ii) coordination environments in proteins, 226, 71 low-temperature optical spectroscopy metalloprotein structure and dynamics, 226, 97 nanosecond transient absorption spectroscopy, 226, 119 nanosecond time-resolved absorption and polarization dichroism spectroscopies, 226, 147 real-time spectroscopic techniques for probing conformational dynamics of heme proteins, 226, 177 variable-temperature magnetic circular dichroism, 226, 199 linear dichroism, 226, 232 infrared spectroscopy, 226, 259 Fourier transform infrared spectroscopy, 226, 289 infrared circular dichroism, 226, 306 Raman and resonance Raman spectroscopy, 226, 319 protein structure from ultraviolet resonance Raman spectroscopy, 226, 374 single-crystal micro-Raman spectroscopy, 226, 397 nanosecond time-resolved resonance Raman spectroscopy, 226, 409 techniques for obtaining resonance Raman spectra of metalloproteins, 226, 431 Raman optical activity, 226, 470 surface-enhanced resonance Raman scattering, 226, 482 luminescence... [Pg.457]

Gouty inflammation of the tissues or joints is associated with local accumulation of urate microcrystals by the phagocytic neutrophils. After sufficient amounts of these crystals have been taken up into the phagolysosomes of the neutrophil, these organelles disrupt and release their degradative enzymes, accumulated micro-crystals (which may be rephagocytized), and chemotac-... [Pg.443]

Haneda T, Tracz A, Saito G, Yamochi H (2011) Continuous and discontinuous water release/ intake of (BED0-TTF)2Br(H20)3 micro-crystals embedded in polymer film. J Mater Chem 21 1621-1626... [Pg.113]

Kawasaki, T., Kobayashi, W., Ikeda, K., Takahashi, S., and Monma, H., High-performance liquid chromatography using spherical aggregates of hydroxyapatite micro-crystals as adsorbent, Eur. J. Biochem., 157, 291, 1986. [Pg.139]

By analogy with the works which dealt with cellulose micro crystal-reinforced nanocomposite materials, microcrystals of starch [95] or chitin [96, 97] were used as a reinforcing phase in a polymer matrix. Poly(styrene-co-butyl acrylate) [95,96], poly(e-caprolactone) [96], and natural rubber [97] were reinforced, and again the formation of aggregates or clustering of the fillers within the matrices was considered to account for the improvement in the mechanical properties and thermal stability of the respective composites processed from suspensions in water or suitable organic solvents. [Pg.119]

Pure thiosemicarbazide is a white crystalline mass, which is very soluble in water and in ethanol. The reported melting point of the material is 181°, but this is not a reliable criterion of purity. The melting point appears to depend on the kind of crystal obtained by re crystallization. The crystals obtained range from those of micro size to long... [Pg.40]

The results described above illustrate the problem of separating effects due to catalysis provided by pyrrhotite from those due to the chemistry of the reduction of pyrite. It must also be borne in mind that reduction of pyrite produces a nearly equivalent amount of l S, which remains available to enter subsequent reactions by mechanisms now only poorly understood. In order to remove these complications, pyrrhotite was prepared by the reduction of pyrite with tetralin, isolated from the reaction residue, and then heated with fresh tetralin. Figures 4 and 5 contain the yields of naphthalene and 1-methylindan, and the ratios of trans- to cis-decalin as a function of concentration. In this case, the pyrite was a hand-picked sample of micro-crystals taken from a coal nodule. As may be seen, the yields of naphthalene and 1-methylindan, and the ratio of trans- to cis-decalin all increase with pyrite concentration. The slope of the line for naphthalene yield is 0.91. A slope of 0.53 is calculated for stoichiometric reduction of FeS to FeS by tetralin to yield naphthalene. Thus, roughly half of the naphthalene produced can be accounted for by the demand for hydrogen in the reduction of pyrite. [Pg.198]


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See also in sourсe #XX -- [ Pg.236 ]




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Infrared micro-spectroscopy crystals

Micro-crystallization

Micro-crystallization

Micro-crystals

Quartz crystal micro balance

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