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Sensitizer, necessary properties

The greater stability of 120 relative to 123 induced us to center our efforts on luzopeptin E2. It seemed logical to examine first a macrolactonization strategy involving cyclodimerization of 125, because we estimated that the coupling of acid 124 with amine 49 would not be subject to the stereochemical difficulties alluded to in the introduction, and that no base treatment would be necessary subsequent to the union of 124 and 49 through peptide bond formation. Recall that peptides incorporating mhv are base-sensitive this property was likely to be carried over into 125. [Pg.23]

The properties of the solids most commonly encountered are tabulated. An important problem arises for petroleum fractions because data for the freezing point and enthalpy of fusion are very scarce. The MEK (methyl ethyl ketone) process utilizes the solvent s property that increases the partial fugacity of the paraffins in the liquid phase and thus favors their crystallization. The calculations for crystallization are sensitive and it is usually necessary to revert to experimental measurement. [Pg.172]

As the safety and quality of industrial components, equipments and constructions is correlated with the inspection sensitivity and this is influenced in radiography by the film system class, a continuous supervision of the film systems on the market seems to be urgently necessary. To support the confidence of the film users in the film properties specified by the film manufacturers such a system for quality assurance for industrial x-ray films is proposed by some manufacturers and BAM. This system will be open to all manufacturers, distributers and users of x-ray films. It will deal with all film systems inclusive those which are not specified by a manufacturer as for instance mixed systems. The system for quality assurance will be based... [Pg.552]

The technological importance of thin films in snch areas as semicondnctor devices and sensors has led to a demand for mechanical property infonnation for these systems. Measuring the elastic modnlns for thin films is mnch harder than the corresponding measurement for bnlk samples, since the results obtained by traditional indentation methods are strongly perturbed by the properties of the substrate material. Additionally, the behaviour of the film under conditions of low load, which is necessary for the measnrement of thin-film properties, is strongly inflnenced by surface forces [75]. Since the force microscope is both sensitive to surface forces and has extremely high depth resolntion, it shows considerable promise as a teclnhqne for the mechanical characterization of thin films. [Pg.1712]

Refrigera.tion in Transportation. Styling is unimportant. The volume of insulation and a low thermal conductivity are of primary concern. Volume is not large, so appHcation methods are not of prime importance. Low moisture sensitivity and permanence are necessary. The mechanical properties of the insulant are quite important owing to the continued abuse the vehicle undergoes. Cost is of less concern here than in other appHcations. [Pg.416]

Electron Level Position. One essential condition of spectral sensitization by electron transfer is that the LUMO of the dye be positioned above the bottom of the conduction band, eg, > —3.23 eV in AgBr or > —4.25 eV in ZnO (108). To provide the desired frontier level position respectively to the valence and conduction bands of the semiconductor, it is necessary to use a polymethine with suitable electron-donor abiHty (Pq. Increasing the parameter (Pq leads to the frontier level shift up, and vice versa. Chain lengthening is known to be accompanied by a decrease of LUMO energy and hence by a decrease of sensitization properties. As a result, it is necessary to use dyes with high electron-donor abiHty for sensitization in the near-ir. The desired value of (Pq can be provided by end groups with the needed topological index Oq or suitable substituents (112). [Pg.499]

The choice between different types of dryers is often guided by the chemicals involved and their physical properties, particularly heat sensitivity. As when selecting other equipment, the designer should first ask if the step is necessary if so, whether this is the correct or safest process step. Does the material being processed have to have all of the liquid removed Can the downstream step or customer use the material in a liquid, slurry or paste form ... [Pg.39]

With nanosecond time resolution, sensitive, accurate detectors, studies of these release waves have proven to be particularly revealing. First-order descriptions of release properties were obtained with rudimentary instrumentation from the earliest studies [65A01] it has required the most sophisticated modern instrumentation to provide the necessary detail to obtain a clear picture of the events. Characteristically different profiles are encountered in the strong-shock, elastic, and elastic-plastic regimes. [Pg.41]

The photophysical properties of porphycenes make these structures potential sensitizers for an application in Photodynamic Tumor Therapy (PDT). To improve the photophysical properties and to modify possible biological activity it is necessary to have porphycenes with an extended chromophore and/or with additional functional groups for further modifications. The Diels-Alder reaction of a vinyl porphycene allows for the preparation of benzoporphycenes with an extended chromophore9 and additional functional groups (cf. Section 1.1.2.4.). [Pg.681]

The chemical literature is rich with empirical equations of state and every year new ones are added to the already large list. Every equation of state contains a certain number of constants which depend on the nature of the gas and which must be evaluated by reduction of experimental data. Since volumetric data for pure components are much more plentiful than for mixtures, it is necessary to estimate mixture properties by relating the constants of a mixture to those for the pure components in that mixture. In most cases, these relations, commonly known as mixing rules, are arbitrary because the empirical constants lack precise physical significance. Unfortunately, the fugacity coefficients are often very sensitive to the mixing rules used. [Pg.145]

How then are these ions/decompositions chosen Before considering this we must define, very carefully, the requirements of the analysis to be carried out. Is a single compound to be determined or are a number of compounds of interest If a single compound is involved, its mass spectrum and MS-MS spectra can be obtained and scrutinized for any appropriate ions or decompositions. If the requirement is to determine a number of analytes, their chromatographic properties need to be considered. If they are well separated, different ions/decompositions can be monitored for discrete time-periods as each compound elutes, thus obtaining the maximum sensitivity for each analyte. If the analytes are not well separated, this approach may not be possible and it may then be necessary to monitor a number of ions/decompositions for the complete duration of the analysis. If this is the case, the analyst should attempt to find the smallest number of ions/decompositions that give adequate performance for all of the analytes (remember the more ions/decompositions monitored, then the lower the overall sensitivity will be). [Pg.269]

NR, styrene-butadiene mbber (SBR), polybutadiene rubber, nitrile mbber, acrylic copolymer, ethylene-vinyl acetate (EVA) copolymer, and A-B-A type block copolymer with conjugated dienes have been used to prepare pressure-sensitive adhesives by EB radiation [116-126]. It is not necessary to heat up the sample to join the elastomeric joints. This has only been possible due to cross-linking procedure by EB irradiation [127]. Polyfunctional acrylates, tackifier resin, and other additives have also been used to improve adhesive properties. Sasaki et al. [128] have studied the EB radiation-curable pressure-sensitive adhesives from dimer acid-based polyester urethane diacrylate with various methacrylate monomers. Acrylamide has been polymerized in the intercalation space of montmorillonite using an EB. The polymerization condition has been studied using a statistical method. The product shows a good water adsorption and retention capacity [129]. [Pg.866]

Fig. 2 shows the temperature as a function of irradiation time of Cu based material under microwave irradiation. CuO reached 792 K, whereas La2Cu04, CuTa20e and Cu-MOR gave only 325, 299 and 312 K, respectively. The performances of the perovskite type oxides were not very significant compared to the expectation from the paper reported by Will et al. [5]. This is probably because we used a single mode microwave oven whereas Will et al. employed multi-mode one. The multi-mode microwave oven is sometimes not very sensitive to sample s physical properties, such as electronic conductivity, crystal sizes. From the results by electric fixmace heating in Fig. 1, at least 400 K is necessary for NH3 removal. So, CuO was employed in the further experiments although other materials still reserve the possibility as active catalysts when we employ a multi-mode microwave oven. [Pg.311]


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See also in sourсe #XX -- [ Pg.467 ]




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