Flexibility mechanisms

In order to understand the multitude of conformations available for a polymer chain, consider an example of a polyethylene molecule. The distance between carbon atoms in the molecule is almost constant 1.54 A. The fluctuations in the bond length (typically 0.05 A) do not affect chain conformations. The angle between neighbouring bonds, called the tetra-hedral angle 9 = 68° is also almost constant. 

The main source of polymer flexibility is the variation of torsion angles [see Fig. 2.1(a)]. In order to describe these variations, consider a plane defined by three neighbouring carbon atoms C, 2, C, i, and C,. The bond 

Any section of the chain with consecutive trans states of torsion angles is in a rod-like zig-zag conformation (see Fig. 2.2). If all torsion angles of the whole chain are in the trans state (Fig. 2.2), the chain has the largest possible value of its end-to-end distance This largest end-to-end distance 

M -irans (zig-zag) conformation of a short polymer with n= 10 main-chain bonds. 

Gauche states of torsion angles lead to flexibility in the chain conformation since each gauche state alters the conformation from the Q)X-trans zig-zag of 

---

Polymer cable anodes are made of a conducting, stabilized and modified plastic in which graphite is incorporated as the conducting material. A copper cable core serves as the means of current lead. The anode formed by the cable is flexible, mechanically resistant and chemically stable. The cable anodes have an external diameter of 12.7 mm. The cross-section of the internal copper cable is 11.4 mm and its resistance per unit length R is consequently 2 mQ m l The maximum current delivery per meter of cable is about 20 mA for a service life of 10 years. This corresponds to a current density of about 0.7 A m. Using petroleum coke as a backfill material allows a higher current density of up to a factor of four. 

Commercial OODBs do not provide a flexible mechanism for multiple views of a common underlying schema. 

The shortcoming of this expression comes from the fact that in the Flory-Huggins lattice model, chain microstructure and real flexibility mechanisms are not taken into account. 

The availability of storage and equivalent alternative flexibility mechanisms as an integrated part of the overall gas supply system is crucial for an efficient operation of the gas system. 

Several reasons are behind the ideas of activation (i) A thin layer or a microdeposit of active but expensive materials enables to keep costs down to an acceptable level (ii) Some materials would be highly resistive if used in bulk form (iii) Certain materials are not suitable to prepare solid electrodes and need to be supported (iv) The support can be made of materials inert to the working conditions, so that even a destruction of the active layer won t produce a collapse of the structure (v) An activated electrode offers more flexible mechanical solutions. 

Pan H. (2005). The cost efficiency of Kyoto flexible mechanisms A top-down study with the GEM-E3 world model. Environmental Modelling <6 Software, 20(11), 1401-1411. 

These numerical simulations provide a useful insight into the magnitude of distortions induced by allocation to the power sector. Since the C02 emissions cap for Europe is fixed, high C02 emissions projections imply increased scarcity and allowance prices. This could induce an increased flow of allowances through the flexible mechanisms of the Kyoto Protocol, including the clean development mechanism (CDM) and joint implementation (JI). The extent to which C02 prices would have to adjust to achieve the same level of European-wide emissions is a question requiring further research. 

It should be taken into account that in very rigid chains, such as those of poly-(alkyl isocyanate)s and para-aromatic polyamides, apart from rotation about valence bonds another mechanism can contribute to flexibility the deformation of valence angles and bonds during thermal chain motion just as it should occur in ladder structures (p. 100). When several flexibility mechanisms exist, the resulting rigidity of the homopolymer chain can be evaluated if the flexibilities, resulting from different mechanisms, are considered to be additive and the following equations are used ... 

Copenhagen Economics and National Environmental Protection Agency 2002. Prices and risks in international markets for flexible mechanisms , November 2002. 

Ireland s National Climate Change Strategy (NCCS) was first published in October 2000, in advance of the seventh conference of the Parties (COP7) to the United Nations Framework Convention on Climate Change (UNFCCC) at Marrakech. While this strategy contained references to the Protocol s flexible mechanisms and a commitment to develop a carbon tax by 2002, it focused on identifying actual measures to reduce emissions in each sector without identifying the policies to be used to ensure that such measures were taken. 

As the NCCS was published before the Marrakech Accords and ETS Directive were agreed it contained no detailed provisions with respect to the use of flexible mechanisms. The lack of a defined policy in this area was a matter of concern to business interests who considered it essential for the Government to engage in international emission trading to remove the need for domestic action, pointing at the activities of the Dutch ERUPT and CERUPT programmes in particular. However, the Department of the Environment did not particularly favour such a... 

This assessment indicated that insufficient cost-effective measures were available domestically for Ireland to meet its BSA obligations and that the purchase of additional credits via the Kyoto Protocol s flexible mechanisms would be the most efficient method of closing the remaining compliance gap. 

Figure 8.2. Trends and targets set in Spain s NAP. KFMs, Kyoto Flexible Mechanisms.

The Marrakech Accords only call upon domestic policies and measures to contribute significantly to a party s emission reduction effort they leave significant margins for flexible mechanism to make up for any remaining compliance gap. 

A measurable variable used as a baseline or reference in evaluating the performance of projects or actions The idea that emissions reductions anywhere within a specific area count toward compliance. The possibility of forming a bubble represents one of the flexible mechanisms included in the Kyoto Protocol... 

Generic term for the flexible mechanisms of the Kyoto Protocol bubbles, JI, CDM and international emissions trading Known planned development Member State of the European Union Megawatt thermal... 

Hence, we have identified two important requirements for flexible cooperation support in dynamic development processes (1) An organization should be able to use powerful and flexible mechanisms for defining the visibility of process information shared with other organizations. (2) Interoganizational cooperation has to be supported insofar as the different processes of the cooperation partners can be integrated with each other not exclusively according to delegation-based relationships between them. A broad set of customizable cooperation relationships has to be supported instead. 

In an attempt to maximize the efficiency of investments and thereby lower the economic costs of emissions reductions, the Kyoto Protocol established three flexibility mechanisms ... 

In addition, Mylar (and PET in general) is a widely used biocompatible material. For this reason many approaches to the modification and functionalization of the polymer surface by wet chemistry, plasma processes, or UV treatment have been reported in the literature [19-22]. These surface modification approaches demonstrate that it is possible to improve the reactivity of the PET surface in order to generate specific groups on the surface, or to immobilize biomolecules. Therefore, possibilities for (bio)chemosensing on a fully flexible mechanical support can be envisioned and are very interesting for innovative applications such as smart packaging and biotechnology. 

---