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Second source

The second source of sulfonic acid uses the following reaction scheme alkylation of benzene by a propylene oligomer then sulfonation of the alkylbenzene. [Pg.360]

A second source of standard free energies comes from the measurement of the electromotive force of a galvanic cell. Electrochemistry is the subject of other articles (A2.4 and B1.28). so only the basics of a reversible chemical cell will be presented here. For example, consider the cell conventionally written as... [Pg.365]

This is not the case for stimulated anti-Stokes radiation. There are two sources of polarization for anti-Stokes radiation [17]. The first is analogous to that in figure B1.3.3(b) where the action of the blackbody (- 2) is replaced by the action of a previously produced anti-Stokes wave, with frequency 03. This radiation actually experiences an attenuation since the value of Im x o3 ) is positive (leading to a negative gam coefficient). This is known as the stimulated Raman loss (SRL) spectroscopy [76]. Flowever the second source of anti-Stokes polarization relies on the presence of Stokes radiation [F7]. This anti-Stokes radiation will emerge from the sample in a direction given by the wavevector algebra = 2k - kg. Since the Stokes radiation is... [Pg.1205]

Th c second source of time steps is in dividual sn apshols stored in a snapshot file on disk and analyzed later. The liin iting rate is... [Pg.325]

Tlierc are two major sources of error associated with the calculation of free energies fi computer simulations. Errors may arise from inaccuracies in the Hamiltonian, be it potential model chosen or its implementation (the treatment of long-range forces, e j lie second source of error arises from an insufficient sampling of phase space. [Pg.593]

Two types of scattering affect the motion of electrons and holes. Lattice or phonon scattering, resulting from thermal vibrations of the lattice, gives increasing ampHtude of vibration with temperature. The associated mobihty decreases according to the relationship 2"-3/2 second source of... [Pg.357]

A second source of brine is found in terminal lakes. The Dead Sea in Israel and Jordan is an example of a large terminal lake with almost unlimited supphes of magnesium chloride, potassium chloride, and sodium chloride. Mote than two and a half million tons of potassium chloride ate extracted from the Dead Sea each year. [Pg.406]

A second source of difficulty is caused by the unavoidable empty space in recycle reactors. This limits their usefulness in some studies. Homogeneous reactions in the empty gas volume may interfere with heterogeneous catalytic measurements. Transient experiments could reveal much more information on various steps in the reaction mechanism but material in the empty space can obscure sharp changes. [Pg.145]

Fig. 21-6. Mean annual wind speed averaged through the afternoon mixing layer. Speeds are in meters per second. Source Adapted ftom Holzworth (2). Fig. 21-6. Mean annual wind speed averaged through the afternoon mixing layer. Speeds are in meters per second. Source Adapted ftom Holzworth (2).
There are very few surface mount capacitors with the desired value, voltage rating, and low ESR all in one part. It would be more conservative to parallel two capacitors of no less than one-half the desired capacitance value. This allows many more second sourced capacitors to be used and lowers the ESR. Lets use two 330 pF, 10 V tantalum capacitors in parallel. The Candidates now become ... [Pg.102]

A second source of inspiration for studying the open-chained equivalents of crown ethers was the observation that a number of naturally occurring antibiotics enhance cation transport and bear a structural similarity to open-chained crown ethers. A number of groups have examined neutral synthetic ionophores and a variety of novel cation carriers is now available. This is discussed in Sect. 7.4, below. [Pg.311]

Dehydrogenation of butanes is a second source of butenes. However, this source is becoming more important because isobutylene (a butene isomer) is currently highly demanded for the production of oxygenates as gasoline additives. [Pg.34]

The SO2 in the atmosphere is derived from two sources. Firstly, from the aerial oxidation of H2S produced naturally (see later) and secondly from the combustion of sulphur-containing fuels. In industrialised countries the second source predominates, but on a global scale only about one-fifth of the total sulphur pollution is derived from human activity. In 1969, the total sulphur emission, expressed in terms of SO2, from burnt fuel in the UK was 6-06 X 10 tons. In densely populated countries sulphur pollution levels arc very much related to the domestic heating cycle, and in the UK maximum... [Pg.338]

A second source of plutonium, dispersed more locally, is liquid effluent from fuel reprocessing facilities. One such is the fuel reprocessing plant at Windscale, Cumbria in the United Kingdom where liquid waste is released to the Irish Sea(6). Chemical analysis of this effluent shows that about one percent or less of the plutonium is in an oxidized form before it contacts the marine water(7). Approximately 95 percent of the plutonium rapidly adsorbs to particulate matter after discharge and deposits on the seabed while 5 percent is removed from the area as a soluble component ). Because this source provided concentrations that were readily detected, pioneering field research into plutonium oxidation states in the marine environment was conducted at this location. [Pg.297]

As a second source, Piaget s theory of accommodation has to be mentioned, which greatly influenced the meaning of the term conceptual change . How does conceptual change take place And what are the similarities to the Kuhnian epistemology We will again quote from the Posner et al. (1982) paper (see also Table 10.1) ... [Pg.218]

Parenteral Fluids. During the past ten years interest has been renewed in the total alimentation of the infant by vein (2). The motivation for this is the fact that neonates may suffer from some congenital malformation of the intestinal tract which would require surgical resection. If this is done, then one needs some outside way for alimentation, bypassing the intestine, until the intestine is able to heal and recover its normal function. This may take many weeks. A second source of motivation is the small premature infant weighing less than a kilogram, whose immature central nervous system and gastrointestinal tract make it difficult to establish nutrition by oral intake soon after birth. These also require total intravenous nutrition for a substantial period of time. [Pg.97]

The second source of partitioning data is experimental equilibration of crystals and liquids followed by microbeam analysis of quenched run products. Starting materials can be natural rocks, or synthetic analogues. In either case it is customary to dope the starting material with the U-series element(s) of interest, in order to enhance analytical precision. Of course, doping levels should not be so high as to trigger trace phase saturation (e g.. [Pg.62]

The production of coke from coal is an important activity in the ferrous metallurgical industries. While coal serves as the principal source for coke, a second source, namely, heavy petroleum fractions, is especially important for countries which have large petroleum resources and lack coal deposits. The properties of metallurgical coke are listed in Table 1.29. [Pg.95]

A second source of error may be in the detector. Detector linearity is an idealization useful over a certain concentration range. While UV detectors are usually linear from a few milliabsorbance units (MAU) to 1 or 2 absorbance units (AU), permitting quantitation in the parts per thousand level, many detectors are linear over only one or two decades of operation. One approach in extending the effective linear range of a detector is high-low injection.58 In this approach, an accurate dilution of a stock sample solution is prepared. The area of the major peak is estimated with the dilution, and the area of the minor peak is estimated with the concentrated stock. This method, of course, relies on linear recovery from the column. Another detector-related source of error that is a particular source of frustration in communicating... [Pg.155]

The first source accounts for the largest volume of wastewater but the second source is very acidic and contains high concentrations of iron and heavy metals. [Pg.20]

Having these severe approximations in mind, SCC-DFTB performs surprisingly well for many systems of interest, as discussed above. However, it has a lower overall accuracy than DFT or post HF methods. Therefore, applying it to new classes of systems should be only done after careful examination of its performance. This can be done e.g. by conducting reference calculations on smaller model systems with DFT or ab initio methods. A second source of errors is related to some intrinsic problems with the GGA functionals also used in popular DFT methods (SCC-DFTB uses the PBE functional), which are inherited in SCC-DFTB. This concerns the well known GGA problems in describing van der Waals interactions [32], extended conjugate n systems [45,46] or charge transfer excited states [47, 48],... [Pg.177]

The present description is based on previous publications from this laboratory56-59 and the interested reader will find additional details and references in that work. Two different ion-source reaction chambers are used. One of these sources which operates at room temperature is shown in Figure 4. The second source, a variable temperature source will also be described. The electrospray generator and the ion-source reaction chamber are shown in Figure 4, while the mounting of the ion source and the front end of the mass spectrometer are shown in Figure 5. [Pg.273]


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See also in sourсe #XX -- [ Pg.195 , Pg.245 , Pg.273 ]




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Molecular source, electronic second-order

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