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MIM approach

The work of Burley et al. and Vosoughi treats a number of significant operational conditions such as flow reversal, time delays, and addition (and withdrawal) of dye liquor during the process, in a comprehensive analysis based on sound chemical engineering principles, which is classified as the MIM approach in Section 3.3. It is also supported by robust numerical techniques for treatment of complicated mathematical problems. The simulation model, however, lacks the analysis of various stages of dye absorption, the variable boundary condition due to the variable concentration of dye in liquor, and the variable dispersion coefficient dne to the variable dyeing conditions. [Pg.83]

One major shortcoming of these models is that the flow property during dyeing is not defined in a sonnd mathematical form, since, for both the STM and MIM approaches, an exact solntion of the problem of convective diffusion to a sohd surface first requires the solution of the hydrodynamic equations of motion of the fiuid for boundary conditions appropriate to the mainstream velocity of flow and the shape of the package. Another limitation of their work is that those workers did not consider situations like variable boundary conditions and variable dispersion coefficients, which are quite common situations in dyeing practice, in their numerical simulations. [Pg.83]

Telegin s group" carried out a considerable amount of work on convective dispersion of solute in dyeing. Apart from initial work in 1997, which used the CDE approach, a simplified model of dye transfer, which is similar to McGregor s work but employing the MIM approach " to model the dye transport within the liquor, was used. The model was accompanied by a sound mathematical description of flow based on fluid mechanics. However, his work can only give a description of convective mass transfer from the solution flow to the flbre surface... [Pg.84]

Recently a novel experimental approach using Schottky diodes with ultra-thin metal films (see Fig. 11) makes direct measurement of reaction-induced hot electrons and holes possible. See for example Refs. 64 and 65. The chemical reaction creates hot charge carriers which travel ballistically from the metal film towards the Schottky interface and are detected as a chemicurrent in the diode. By now, such currents have been observed during adsorption of atomic hydrogen and deuterium on Ag, Cu and Fe surfaces as well as chemisorption of atomic and molecular oxygen, of NO and N02 molecules and of certain hydrocarbons on Ag. Similar results have been found with metal-insulator-metal (MIM) devices, which also show chemi-currents for many exothermic surface reactions.64-68... [Pg.404]

The most extensively used theoretical method for the understanding of the MIM tunneling junction is the time-dependent perturbation approach developed by Bardeen (1960). It is sufficiently simple for treating many realistic cases, and has been successfully used for describing a wide variety of effects (Duke, 1969 Kirtley, 1982). [Pg.21]

The various ways to represent MIMs on paper have often been a portrayal of beauty in their own right. In Sect. 3, we tried to engage the beauty of printed molecular representations. There remain many other ways to perceive the beauty of molecular objects, some of them particularly unique to MIMs, but things get messier when we depart from concrete illustrations and images and venture into even more subjective territory. Roald Hoffman, pioneer of molecular aesthetics, has approached beauty in chemistry from the perspective that beauty is built out of individual pleasure around an object or idea [126]. The aesthetic experience of molecular structures is therefore inexorably tied together with our subjective biases. Synthetically derived molecules are retroactively beautified out of a psychological need to associate pleasure with hard work. We find reasons to label a molecule beautiful and experiments elegant, because we invested work, time, and failure to achieve them. Nevertheless, these notions of beauty are common to the experiences of... [Pg.44]

As for the epoxy polymers, a quantitative comparison of the contact fatigue behaviour was attempted on the basis of an estimate of the maximum tensile stress at the edge of the contact. The coefficient of friction of the copolymers increased as the tests proceeded, with a variation which was dependent upon the level of the normal loading. As a first approach, the value of //. at crack initiation was taken into account in the calculation of a . The results are reported in a S-N fatigue diagram giving the maximum applied tensile stress as a function of the number of cycles to crack initiation (Fig. 23). These data show a marked increase in the contact fatigue resistance of the GIM copolymers compared with the MIM material. [Pg.187]

The newest approach to measuring denitrification uses a mass spectrometer that can rapidly measure the N2/Ar ratio in water using membrane inlet mass spectrometry (MIMS, Kana et al., 1994, 1998). In this approach, sediment cores are incubated under continuous flow conditions. The N2/Ar ratio is then measured at the inlet and outlet of the core over time. Advantages of the technique are the short incubation times needed (usually less than 12 h), and the high throughput and small sample size ( 5 ml) of MIMS analysis. [Pg.1255]

Another interesting suite of approaches that undoubtedly wiU be further developed employs SIMS—secondary isotope mass spectrometry (also know as multiple-isotope imaging mass spectrometry (MIMS)). Orphan et al. (2001) applied FISH—SIMS or fluorescent in situ hybridization SIMS to detect isotopicaUy Ught carbon in archaeal ceUs, identifying the Archaea by FISH and using SIMS to quantify the isotopic composition of individual ceUs by ion microprobe. Finzi et al. (2006) applied nanoSIMS to visualize uptake of N2 and C02 by individual ceUs of a... [Pg.1373]

A great diversity of approaches has been followed to develop MIM sensors. We have found it helpful to apply three complementary classifications to these approaches (i) the nature of the transducer employed in the sensor (ii) the nature of the MIM (iii) what is measured a property of the analyte (the MIM serving simply to concentrate the analyte near the transducer), a property of the MIM which changes upon interaction with the analyte, or a second messenger, whose concentration is dependent on the analyte interacting with the MIM. It is often difficult to assign a material as molecularly imprinted or not. Thus, we use the expression MIM here to refer to materials which are designed to rebind the template used in their preparation and refer to other materials where the template and the subsequent analyte differ as templated materials. [Pg.417]

We now describe the different approaches to the combination of MIMs with some of the transducer types outlined above, emphasising especially electrochemical transducers for measurements in solution, since other sensor approaches will be dealt with elsewhere in this volume. [Pg.423]

For R = mim ux,Uy), one can obtain an error estimate also for the Yeh and Berkowitz method, which allows to tune this method. So why should one actually implement the ELC term First of all because it leads to a faster algorithm, normally by a factor of two or more, since the box size can be made smaller due to the smaller gap size, and therefore one can use a smaller mesh size at constant accuracy. In addition, many implementations of P M (such as the ESPResSo one) allow only for cubic simulation boxes. But (18) shows that in fact the ratios A /Aj, rsp. Xz/ dominate the error behaviour, so that one cannot reduce the error in the Yeh and Berkowitz approach with a cubic 3d-method. For such an implementation, ELC is a must. [Pg.205]

AIMD data were used to improve the classical description of C mim Cl] by applying the force matching approach [72], A self-consistent optimization method for the generation of classical potentials of general functional form was presented and applied. A force field that better reproduces the observed first-principles forces was obtained [72],... [Pg.231]

Mims and McCandlish utilized a different approach to study the FTS over 23 wt% Co/Si02 and precipitated iron catalyst containing Si02 plus Cu and K promoters. As in other studies, an isotope switch was made from CO/H2 to CO/H2 and the rate of incorporation in CH4, and C3 to Cg olefins was followed. However, a distinguishing feature of this study was that accumulated products at different time periods during the transient were also subjected to an NMR analysis to obtain the fraction of in the various positions of the olefin products. The results indicated that incorporation of in the C3 to Cg olefin products was the same at the various carbon positions of the olefins. Further, the fraction of in the total olefin content was the same for C3 to Cg olefins. [Pg.126]

The calibration of MIMS requires a simple, preferably linear, relation between 1 and Ca. Such a relation can be derived by setting r in Equation 27.10 so that / approaches a steady-state value /js as follows ... [Pg.596]

Both ester hydrolysis and de novo synthesis should increase the amount of lAA in the tissues. Incorporation experiments, of deuterium from H20 into the indole ring, as measured by MIM [26 and our lab, unpublished data] were exhibiting some labeling into lAA this could be a promising approach for lAA biosynthesis in seedlings. [Pg.443]

The burgeoning of molecular nanotechnology near the turn of the 21 century has brought with it the emergence of new fields in the chemical sciences fueled by the manipulation of atomic-and molecular-scale matter with ever-increasing dexterity and precision. Among them, the fields of mechanically interlocked molecules (MIMs) and synthetic foldamers, both of which assume bottom-up approaches in the construction of functional nano-architectures, have seldom[l-3] crossed paths. [Pg.272]


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