Big Chemical Encyclopedia

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

Articles Figures Tables About

Structure of limitations

A distinction is made with cell walls between primary cell walls, central lamellae, and secondary cell walls. The primary cell wall contains a large amount of hemicelluloses and only about 8% cellulose and a little pectin. It has a netlike structure of limited orientation of the cellulose molecules (Figure 31-1). The central lamellae form the binder between the primary cell walls, and they are pectinlike. [Pg.577]

Discontinuities such as the lid or other penetration attachments could give a locally stiff element of structure of limited strength which could fail by either adjacent stmctural deformation or high loading (due to decelerations) on their retained masses. [Pg.176]

Temporary systems are structures of limited duration that operate within and between permanent organizations. ... [Pg.522]

All structures are subject to foundation design. In some cases piled foundations are preferable. Heavy structures with very strict specifications regarding (differential) settlement will normally require a piled foundation when constructed on reclaimed land overlying soft subsoil. Small sized structures of limited weight can generally be supported by shallow foundations. Based on a technical and economical evaluation of the structural and reclamation design, the decision whether a piled foundation is required should be made in an early phase of the project. [Pg.400]

Floor structures of limited express type, suburban, for commuting, nongovernmental railroad, and subway electric railcars are shown in O Fig. 47.7b. In them, floor compound material made of epoxy resin and lightweight aggregate is plastered and cured on steel deck, and PVC floor coverings are bonded on the surface of it with nitrile adhesives. [Pg.1218]

Film (substrate) A free-standing flexible structure of limited thickness. Also called a Web. [Pg.614]

Small Scale Structure of Limited Length Chain with Finite Bending Rigidity (Scaling Estimations)... [Pg.56]

Where possible, introducing extraneous materials into the process should be avoided, and a material already present in the process should be used. Figure 4.6h illustrates use of the product as the heat carrier. This simplifies the recycle structure of the flowsheet and removes the need for one of the separators (see Fig. 4.66). Use of the product as a heat carrier is obviously restricted to situations where the product does not undergo secondary reactions to unwanted byproducts. Note that the unconverted feed which is recycled also acts as a heat carrier itself. Thus, rather than relying on recycled product to limit the temperature rise (or fall), simply opt for a low conversion, a high recycle of feed, and a resulting small temperature change. [Pg.101]

Electrochemistry is concerned with the study of the interface between an electronic and an ionic conductor and, traditionally, has concentrated on (i) the nature of the ionic conductor, which is usually an aqueous or (more rarely) a non-aqueous solution, polymer or superionic solid containing mobile ions (ii) the structure of the electrified interface that fonns on inunersion of an electronic conductor into an ionic conductor and (iii) the electron-transfer processes that can take place at this interface and the limitations on the rates of such processes. [Pg.559]

The above classification of structures is made primarily for convenience. In fact, the structures of many compounds cannot be precisely described under any of these classes, which represent limiting, or ideal cases. However, we shall use these classes to examine further the limiting types of bonding found in them. [Pg.27]

Abstract. The overall Hamiltonian structure of the Quantum-Classical Molecular Dynamics model makes - analogously to classical molecular dynamics - symplectic integration schemes the methods of choice for long-term simulations. This has already been demonstrated by the symplectic PICKABACK method [19]. However, this method requires a relatively small step-size due to the high-frequency quantum modes. Therefore, following related ideas from classical molecular dynamics, we investigate symplectic multiple-time-stepping methods and indicate various possibilities to overcome the step-size limitation of PICKABACK. [Pg.412]

A completely new method of determining siufaces arises from the enormous developments in electron microscopy. In contrast to the above-mentioned methods where the surfaces were calculated, molecular surfaces can be determined experimentally through new technologies such as electron cryomicroscopy [188]. Here, the molecular surface is limited by the resolution of the experimental instruments. Current methods can reach resolutions down to about 10 A, which allows the visualization of protein structures and secondary structure elements [189]. The advantage of this method is that it can be apphed to derive molecular structures of maaomolecules in the native state. [Pg.129]

To provide further insight why the SCF mean-field model in electronic structure theory is of limited accuracy, it can be noted that the average value of the kinetic energy plus the attraction to the Be nucleus plus the SCF interaction potential for one of the 2s orbitals of Be with the three remaining electrons in the s 2s configuration is ... [Pg.232]

Another way of predicting liquid properties is using QSPR, as discussed in Chapter 30. QSPR can be used to And a mathematical relationship between the structure of the individual molecules and the behavior of the bulk liquid. This is an empirical technique, which limits the conceptual understanding obtainable. However, it is capable of predicting some properties that are very hard to model otherwise. For example, QSPR has been very successful at predicting the boiling points of liquids. [Pg.303]

The first empirical and qualitative approach to the electronic structure of thiazole appeared in 1931 in a paper entitled Aspects of the chemistry of the thiazole group (115). In this historical review. Hunter showed the technical importance of the group, especially of the benzothiazole derivatives, and correlated the observed reactivity with the mobility of the electronic system. In 1943, Jensen et al. (116) explained the low value observed for the dipole moment of thiazole (1.64D in benzene) by the small contribution of the polar-limiting structures and thus by an essentially dienic character of the v system of thiazole. The first theoretical calculation of the electronic structure of thiazole. benzothiazole, and their methyl derivatives was performed by Pullman and Metzger using the Huckel method (5, 6, 8). [Pg.26]

Linus Pauling (1901-1994) was born in Portland Ore gon and was educated at Oregon State University and at the California Institute of Technology where he earned a Ph D in chemistry in 1925 In addition to re search in bonding theory Pauling studied the structure of proteins and was awarded the Nobel Prize in chemistry for that work in 1954 Paul ing won a second Nobel Prize (the Peace Prize) in 1962 for his efforts to limit the testing of nuclear weapons He was one of only four scientists to have won two Nobel Prizes The first double winner was a woman Can you name her" ... [Pg.15]

The most generally apphcable method for prediction of the property is the method or Seaton, which depends only on the molecular structure of the molecule and utilizes second order (Benson-type) groups to construct the molecule. Equation (2-175) sums the groups number of each type group (/id to get both the upper and lower limits. [Pg.418]


See other pages where Structure of limitations is mentioned: [Pg.507]    [Pg.76]    [Pg.135]    [Pg.277]    [Pg.813]    [Pg.571]    [Pg.507]    [Pg.76]    [Pg.135]    [Pg.277]    [Pg.813]    [Pg.571]    [Pg.226]    [Pg.21]    [Pg.34]    [Pg.1808]    [Pg.1843]    [Pg.2268]    [Pg.197]    [Pg.233]    [Pg.70]    [Pg.475]    [Pg.506]    [Pg.519]    [Pg.537]    [Pg.663]    [Pg.703]    [Pg.117]    [Pg.35]    [Pg.133]    [Pg.215]    [Pg.272]    [Pg.299]    [Pg.378]    [Pg.147]    [Pg.228]    [Pg.269]    [Pg.69]    [Pg.118]   
See also in sourсe #XX -- [ Pg.10 , Pg.84 ]




SEARCH



Limitation of Marine Primary Productivity and Control on Ecosystem Structure

Limiting Unimolecular Nucleophilic Reactions—Effects of Structure and Solvent

Limiting structures

Scattered intensity in the limit of zero concentration intra- and intermolecular structure functions

© 2024 chempedia.info