Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Achievable construction methods

A major impetus for the design and construction of a finite molecular assembly is to create function not realized by the individual components.3 The size, shape, and functionality of each component, which are achieved via methods of organic syntheses, are thus amplified within a final functional structure. The components may be synthesized, e.g., to give an assembly with cavities that host ions and/or molecules as guests.3 The components may also react to form covalent bonds.1 That a molecular assembly is, de facto, larger than a component molecule means that the components may be designed to assemble to form functional assemblies that reach nanometer-scale dimensions, and beyond.4... [Pg.14]

Intramolecular HR has been utilized as a simple construction method for complex skeletons of natural products. Many elegant and efficient total syntheses of natural products with interesting structures have been achieved, showing that HR is a... [Pg.137]

Depending on the bond(s) to be formed several subtypes result from both cases as outlined in Schemes 3 and 4 e.g. ring C formation can be achieved using method (a) or method (b) [= route C(a) or C(b)]. Accordingly, two different pathways are available for the simultaneous construction of rings B and C [= route B/C(a) and B/C(b)]. [Pg.22]

There are methods that exist that address these constraints however, these require additional theory to understand. In the absence of an explicit temperature expression, it is often easier to tackle the problem numerically, with the aid of an automated AR construction scheme. In Chapter 8, a number of AR construction methods are discussed that may be used for nonisothermal systems. Although these methods often do not suggest an optimal reactor structure, knowledge of the limits of achievability for a nonisothermal is often sufficient for setting design targets. [Pg.207]

Perhaps the earliest account of an automated AR construction method appears in the PhD thesis of McGregor (1998). In this work, AR construction is achieved not by a specific technique, but rather by a constructive, trial and error approach, given reaction kinetics and a feed point. In Figure 8.7, McGregor s recommendations are listed as one potential geometric method, although the recommendations are not discussed here. Interested readers are referred to McGregor (1998) for further details. [Pg.246]

At the time of writing, a sufficiency condition for the AR has still not yet been established. Both inside-out and outside-in methods suffer from uncertainty in construction as a result. A stronger result might be achieved if a construction can be validated using two independent construction methods. Validation could be achieved either theoretically or computationally. [Pg.248]

A perfect outside-in method would be able to achieve this. However, this result cannot be validated, in practice, unless it is compared with the results of an alternate construction method. [Pg.248]

The inside-out algorithms discussed in Section 8.4 use information about the current AR to increase the set of achievable states at each construction step. Outside-in methods, by comparison, carry out constructions by initiating construction with a large region that encloses the true AR. The set is then decreased until no further reduction may be carried out. Whereas inside-out methods achieve constructions via an additive procedure, outside-in methods achieve construction via a sequence of eliminations instead. [Pg.262]

Results The results of the computation, using the parallel complement AR construction method, are shown in Figure 9.9(a). Note that the AR computed for this system is smaller than the stoichiometric subspace computed in Section 9.2.7. In particular, although the stoichiometric subspace predicts a maximum CO mass fraction of approximately 0.9, the maximum achievable... [Pg.298]

Two approaches were proposed to overcome the issues presented by standard navigations (see Figure 4.9). The first involved the use of patient-specific templates or frames [76]. Based on the principles of the stereotactic frame, this approach involved the construction of a patient-specific drill guide specific to the patient anatomy and the locations of several preimplanted attachment posts. The constructed template is mounted to the posts, and the drill constrained to the planned path. The use of these frames is currently undergoing clinical evaluation [77]. The second approach involves the use of robotics early work involved the modification of industrial robots [78] however, suitable clinical accuracy could not be achieved and methods for integration into the operating room remained unsolved. [Pg.104]

It is proposed to carry out the second-order reversible reaction (Problem 3.3) in a battery of equal-volume CSTRs connected in series. The space time of each one of the CSTRs is 1 min. Calculate the number of CSTRs required to achieve 62% net conversion of reactant A. Use the graphical construction method. [Pg.154]

An optimal combination between aerodynamic and weight requirements was achieved for the Transrapid by modular hybrid (mixed) construction methods. For example, the glass-fibre-reinforced plastic (GRP) front module is designed for maintaining aerodynamic pressure as well as for stability under cross wind forces of 500 km/h, and is bonded to the front of the aluminium structure of the rail cars with Sikaflex products (Fig. 5). [Pg.359]

Drainage of the subsoil to reduce waiting times in between subsequent fill lifts, and thus minimising the construction period, is a commonly used construction method. Dissipation of the excess pore pressures can be achieved by the installation of vertical drains. In addition, vacuum pressure can be apphed to the system. The vacuum pressure also acts as an additional preload. [Pg.252]

The invention of redispersible powders by Wacker-Chemie in 195 3 made for the first time the production of polymer modified dry mix mortars possible, which are nowadays referred to as one pack or one component system ( bagged materials). New construction methods and building materials, which had the need for more safety, reliability, durability, efficiency and economy, have been achieved by using modern methods like the dry mix mortar technology. As a consequence worldwide the job-site mix technology and the modification of mortars with liquid polymers on job-sites were and are substituted by polymer modified dry mix mortars. The product characteristics are very well adapted to the requirements of modern construction technologies, materials and cHmates. [Pg.332]

A term that is nearly synonymous with complex numbers or functions is their phase. The rising preoccupation with the wave function phase in the last few decades is beyond doubt, to the extent that the importance of phases has of late become comparable to that of the moduli. (We use Dirac s terminology [7], which writes a wave function by a set of coefficients, the amplitudes, each expressible in terms of its absolute value, its modulus, and its phase. ) There is a related growth of literatm e on interference effects, associated with Aharonov-Bohm and Berry phases [8-14], In parallel, one has witnessed in recent years a trend to construct selectively and to manipulate wave functions. The necessary techifiques to achieve these are also anchored in the phases of the wave function components. This bend is manifest in such diverse areas as coherent or squeezed states [15,16], elecbon bansport in mesoscopic systems [17], sculpting of Rydberg-atom wavepackets [18,19], repeated and nondemolition quantum measurements [20], wavepacket collapse [21], and quantum computations [22,23], Experimentally, the determination of phases frequently utilizes measurement of Ramsey fringes [24] or similar" methods [25]. [Pg.96]


See other pages where Achievable construction methods is mentioned: [Pg.485]    [Pg.690]    [Pg.503]    [Pg.314]    [Pg.384]    [Pg.132]    [Pg.144]    [Pg.314]    [Pg.255]    [Pg.171]    [Pg.350]    [Pg.154]    [Pg.247]    [Pg.75]    [Pg.8]    [Pg.209]    [Pg.77]    [Pg.240]    [Pg.153]    [Pg.157]    [Pg.47]    [Pg.170]    [Pg.70]    [Pg.224]    [Pg.174]    [Pg.1101]    [Pg.414]    [Pg.384]    [Pg.370]    [Pg.1958]    [Pg.80]    [Pg.440]    [Pg.481]    [Pg.518]    [Pg.155]   


SEARCH



Achievability

Achievability method

Achievable

Achievement

Achievers

Construction methods

Constructive methods

© 2024 chempedia.info