Semi-extensible

The mill had the choice either to shut the machine or upgrade to improve the stretch and TEA values and the profiles in the cross direction. The mill acted to address the CD profile problems by upgrading the dryer section of the paper machine to improve dryer pocket humidity profiles. At the same time, the mill also decided to upgrade the product quality from flat sack to semi-extensible sack papers. Semi-extensible sack paper is an ideal sustainable packaging solution where high pressure and high-speed filling are... 

Figure 13.33 Layout of retrofitted refining system for semi-extensible sack kraft paper. Table 13.5 Effect of HC and LC refining on fibres for sack papers.

Retrofitting of the existing double-disc refiner used to refine unbleached long-fibre Pinus radiata kraft pulp to make flat sack kraft paper by an HC refining system followed by LC refining enabled the mill to manufacture premium-grade semi-extensible sack kraft papers... 

ENGELL-S0RENSEN K, ST0TTRUP J G and HOLMSTRUP M (2004) Rearing of flounder Platichthys flesus) juveniles in semi-extensive systems. Aquaculture 230 475-491. 

Extensible > 200% elongation. Semi-extensible 25 - 200% elongation, Non-extensible < 25% elongation... 

The flux-flux expression and its extensions have been used to calculate reaction probabilities for several important reactions, including H2+02 H + H2O, by explicit calculation of the action of G in a grid representation with absorbmg potentials. The main power of the flux-flux fomuila over the long mn will be the natural way in which approximations and semi-classical expressions can be inserted into it to treat larger systems. 

Markovic N and Billing G D 1997 Semi-classical treatment of chemical reactions extension to 3D wave packets Chem. Phys. 224 53... 

The MEP at the molecular surface has been used for many QSAR and QSPR applications. Quantum mechanically calculated MEPs are more detailed and accurate at the important areas of the surface than those derived from net atomic charges and are therefore usually preferable [Ij. However, any of the techniques based on MEPs calculated from net atomic charges can be used for full quantum mechanical calculations, and vice versa. The best-known descriptors based on the statistics of the MEP at the molecular surface are those introduced by Murray and Politzer [44]. These were originally formulated for DFT calculations using an isodensity surface. They have also been used very extensively with semi-empirical MO techniques and solvent-accessible surfaces [1, 2]. The charged polar surface area (CPSA) descriptors proposed by Stanton and Jurs [45] are also based on charges derived from semi-empirical MO calculations. 

For small molecules, the accuracy of solutions to the Schrtidinger equation competes with the accuracy of experimental results. However, these accurate a i initw calculations require enormous com putation an d are on ly suitable for the molecular system s with small or medium size. Ah initio calculations for very large molecules are beyond the realm of current computers, so HyperChern also supports sern i-em p irical quantum meclian ics m eth ods. Sem i-em pirical approximate solutions are appropriate and allow extensive cliem ical exploration, Th e in accuracy of the approxirn ation s made in semi-empirical methods is offset to a degree by recourse to experimental data in defining the parameters of the method. 

As presented, semi-empirieal methods are based on a single-eonfiguration pieture of eleetronie strueture. Extensions of sueh approaehes to permit eonsideration of more than a single important eonfiguration have been made (for exeellent overviews, see Approximate Molecular Orbital Theory by J. A. Pople and D. E. Beveridge, McGraw-Hill, New York... 

Apractical introduction to molecular mechanics and semi-empirical quantum mechanics calculations, with extensive examples from the MMP2 (not in HyperChem), MINDO/3, and MNDO methods. One of the more accessible books for new computational chemists. 

In appearance and on handling the material is somewhat intermediate between a wax and a rubber. It is also semi-tacky. Like isotactic polypropylene it is attacked by oxygen but unlike the isotactic material it swells extensively in aliphatic and aromatic hydrocarbons at room temperature. It is also compatible with mineral fillers, bitumens and many resins. 

Requirements for desulfurizing the feed are much the same as in the semi-regenerative process. While the continuous regeneration facilities would permit operation with higher sulfur feeds, extensive HjS corrosion results, making feed... 

Tobacco and its alkaloids have long ceased to have any therapeutic importance, but their extensive use as insecticides and the demand for nicotine for the manufacture of nicotinic acid have stimulated interest in processes of extraction and methods of estimation. On the latter subject there is a voluminous literature, of which critical resumes have been published by various authors.Recent work on this subject has been specially concerned with (1) the development of miero- and semi-miero-methods suitable for estimating nieotine in tobacco smoke and the distribution of nieotine on sprayed garden produce, in treated soils and in tobaeeo leaves,(2) the study of conditions necessary to ensure satisfactory results in using particular processes, " and (3) methods of separation and estimation of nicotine, nomicotine and anabasine in mixtures of these bases. ) In the United States and in Russia considerable interest is being shown in the cultivation of types of tobacco rich in nicotine, in finding new industrial uses for tobacco and its alkaloids, and in possible by-products from tobacco plants such as citric and malic acids, i " Surveys of information on tobacco alkaloids have been published by Jackson, i Marion and Spath and Kuffner. ... 

The radius of the beads and the interactions, Eqs. (8,9), have been chosen such that the chains may not intersect themselves or each other in the course of their movement within the box. Thus entanglement constraints are obeyed automatically and need not be enforced by extra (time consuming ) control. The chains are treated as fully flexible and a potential for bond angles is not considered, although an extension of the model to allow for semi-flexibihty of the chains is straightforward. 

The first Monte Carlo study of osmotic pressure was carried out by Panagiotopoulos et al. [16], and a much more detailed study was subsequently carried out using a modified method by Murad et al. [17]. The technique is based on a generalization of the Gibbs-ensemble Monte Carlo (GEMC) method applied to membrane equihbria. The Gibbs ensemble method has been described in detail in many recent reports so we will only summarize the extension of the method to membrane equilibria here [17]. In the case of two phases separated by semi-permeable membranes... 

Hydrides of the types AnHi (An = Th, Np, Pu, Am, Cm) and AnHs (Pa —> Am), as well as ThaHis (i.e. ThHs.yj) have been so obtained but are not very stable thermally and are decidedly unstable with respect to air and moisture. Borides, carbides, silicides and nitrides (q.v.) are mostly less sensitive chemically and, being refractory materials, those of Th, U and Pu in particular have been studied extensively as possible nuclear fuels.Their stoichiometries are very varied but the more important ones are the semi-metallic monocarbides, AnC, and mononitrides, AnN, all of which have the rock-salt structure they are predominantly ionic... 

---