Cloud Chain

The distinction between virtual production units and information processing units is made according to their contribution to creation of the cloud chain s end product or service. The virtual productions units perform primary value-added or critical activities while the information processing units perform supporting activities. The critical activities are those without which the very existence of the supply chain end-product or service would be impossible. 

The supply chain unit selection in cloud chains is affected by a number of different factors than used in traditional supply chain configuration. These factors are related to the Quality of Service (QoS) criteria used in web service selection (Strunk 2010). They include service response time, service availability and service reliability. It is expected that physical supply chain configuration decisions and virtual/information processing supply chain configuration decisions are mutually interdependent. Therefore, the cloud chain configuration includes joint selection of all kinds of supply chains units according to their respective selection criteria. 

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Information processing velocity in supply chains has increased dramatically thanks in part to mobile and cloud based technologies. This chapter demonstrates that many modem supply chains are a combination ot physical and virtual supply chain units. It proposes methods tor evaluating the combined supply chains and introduces a new concept ot cloud chains. 

Fig. 1. A segment of a cellulose chain composed of four P-D-glucopyianose residues (ceUotetiaose), showing (a) the chemical bonds and election clouds around the atoms. The molecule has the twofold hehcal conformation typical of many models of crystalline cellulose, (b) The (Haworth) stmctural formula...

The effect of carbon chain length and high vs. low 2-phenyl isomer distribution on viscosity and solubility (cloud/clear point) of a liquid hand dishwashing formulation is shown in Table 5. Two sets of pure LAS homolog samples ranging from Cl0 to Cl3 were prepared. All samples were prepared with pure olefins, but one set was produced with an HF alkylation catalyst (low 2-phenyl) and the other set was alkylated with A1C13 (high 2-phenyl). Each LAB... 

Note that when the concentration of added salt is very low, Debye length needs to be modified by including the charge contribution of the dissociating counterions from the polyelectrolytes. Because the equilibrium interaction is used, their theory predicts that the intrinsic viscosity is independent of ion species at constant ionic strength. At very high ionic strength, the intrachain electrostatic interaction is nearly screened out, and the chains behave as neutral polymers. Aside from the tertiary effect, the intrinsic viscosity will indeed be affected by the ionic cloud distortion and thus cannot be accurately predicted by their theory. 

FIG. 13 Schematic drawing of possible binding modes of counterions to polyelectrolyte chains. Counterions loosely bind and form a cloud around the polyelectrolyte chains when the interchain distance (d) is greater than 2.4 0.5 nm, while they strongly bind to form nearly neutral polyelectrolytes at smaller distances d < 2.4 0.5 nm). 

The boiling points of alkanes increase with the length of the carbon chain, because a long electron cloud is more polarizable than a short one. 

Methyl ethyl ether is a gas at room temperature (boiling point = 8 °C), but 1-propanol, shown in Figure 11-13. is a liquid (boiling point = 97 °C). The compounds have the same molecular formula, C3 Hg O, and each has a chain of four inner atoms, C—O—C—C and O—C—C—C. Consequently, the electron clouds of these two molecules are about the same size, and their dispersion forces are comparable. Each molecule has an s p -hybridized oxygen atom with two polar single bonds, so their dipolar forces should be similar. The very different boiling points of 1-propanol and methyl ethyl ether make it clear that dispersion and dipolar forces do not reveal the entire story of intermolecular attractions. 

The estimation of f from Stokes law when the bead is similar in size to a solvent molecule represents a dubious application of a classical equation derived for a continuous medium to a molecular phenomenon. The value used for f above could be considerably in error. Hence the real test of whether or not it is justifiable to neglect the second term in Eq. (19) is to be sought in experiment. It should be remarked also that the Kirkwood-Riseman theory, including their theory of viscosity to be discussed below, has been developed on the assumption that the hydrodynamics of the molecule, like its thermodynamic interactions, are equivalent to those of a cloud distribution of independent beads. A better approximation to the actual molecule would consist of a cylinder of roughly uniform cross section bent irregularly into a random, tortuous configuration. The accuracy with which the cloud model represents the behavior of the real polymer chain can be decided at present only from analysis of experimental data. 

If a significant volume of gas (caused by a leak, for example) is exposed to an ignition source and this gas is mixed with air in proportions that are close to stoichiometric, the gas cloud can cause a lot of damage when it gives rise to a detonation. The accident at Flixborough is one example. The lower explosive limit of hydrocarbons is extremely low. If the carbon chain length exceeds 8, the autoinflammation temperature of a linear hydrocarbon is close to 200°C. All these parameters decrease with pressure. The table below shows to which extent pressure influences the AIT of ethylene ... 

Figure 2. The new species added to our chemical models of interstellar clouds. The species range in complexity from 10-64 carbon atoms and comprise the following groups of molecules linear carbon chains, monocyclic rings, tricyclic rings, and fullerenes. The synthetic pathways are also indicated. See ref. 83. Reproduced from the International Journal of Mass Spectrometry and Ion Processes, vol. 149/150, R.P.A. Bettens, Eric Herbst "The interstellar gas phase production of highly complex hydrocarbons construction of a model", pp 321-343 (1995) with kind permission from Elsevier Science-NL, Sara Burgerhartstraat 25,1055 KV, Amsterdam, The Netherlands.

The formation of stable nanoparticles has been studied using various derivatives of thermosensitive PNIPAM, including diblock and graft copolymers, PNIPAM-b-PEO and PNIPAM-g-PEO [165-172], In these copolymers, the role of the PEO chains is to solubilise/stabilise collapsed PNIPAM at temperatures above its cloud point. Both the graft and the block copolymers, PNIPAM-g-PEO and PNIPAM-fr-PEO, form spherical core-shell structures in... 

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