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Process prerequisites

Since plant material is the product of a predominantly biological process, prerequisite of its productivity is the knowledge on the factors in uencing it, of which the most important ones are... [Pg.65]

The vertex of G corresponds to a quadruplet (structure of a compound, organ, time, concentration), while an edge corresponds to a doublet (denomination of the P process, prerequisites of P process). Here P symbolizes either a transport process or a metabolic reaction. [Pg.74]

Further prerequisites depend on the chemical problem to be solved. Some chemical effects have an undesired influence on the structure descriptor if the experimental data to be processed do not account for them. A typical example is the conformational flexibility of a molecule, which has a profound influence on a 3D descriptor based on Cartesian coordinates. In particular, for the application of structure descriptors with structure-spectrum correlation problems in... [Pg.517]

We conclude that the beneficial effects of water are not necessarily limited to reactions that are characterised by a negative volume of activation. We infer that, apart from the retro Diels-Alder reaction also other reactions, in which no significant reduction or perhaps even an increase of solvent accessible surface area takes place, can be accelerated by water. A reduction of the nonpolar nature during the activation process is a prerequisite in these cases. [Pg.168]

The details of the commercial preparation of acetal homo- and copolymers are discussed later. One aspect of the polymerisation so pervades the chemistry of the resulting polymers that familiarity with it is a prerequisite for understanding the chemistry of the polymers, the often subde differences between homo- and copolymers, and the difficulties which had to be overcome to make the polymers commercially useful. The ionic polymerisations of formaldehyde and trioxane are equiUbrium reactions. Unless suitable measures are taken, polymer will begin to revert to monomeric formaldehyde at processing temperatures by depolymerisation (called unsipping) which begins at chain ends. [Pg.57]

The acceptance of optical data storage iato the mass storage market, which is as yet exclusively dominated by magnetic systems, will be fundamentally boosted if optical drives and media are subject to uniform standards and become fully compatible, and multiuser drives are offered which enable the user to employ alternatively CD-ROM and EOD disks, and maybe WORM disks as well (and CD-R disks, respectively). A prerequisite, however, will be whether rewritable optical memories will use the MOR or the PCR process. This accord especially will be hard to reach. [Pg.164]

These mixing systems offer high flexibility because they can be operated in batch, semibatch, or continuous modes. Adequate mixing is a prerequisite for the success of chemical processes in terms of rninirnizing investment and operating costs. In addition, chemical reactions with... [Pg.419]

Although reduction or elimination of the repulsion barrier is a necessary prerequisite of successful flocculation, the actual flocculation in such a destabilized suspension is effected by particle—particle collisions. Depending on the mechanism that induces the collisions, the flocculation process may be either perikinetic or orthokinetic. [Pg.318]

As mentioned earlier, unmodified polystyrene first found application where rigidity and low cost were important prerequisites. Other useful properties were the transparency and high refractive index, freedom from taste, odour and toxicity, good electrical insulation characteristics, low water absorption and comparatively easy processability. Carefully designed and well-made articles from polystyrene were often found to be perfectly suitable for the end-use intended. On the other hand the extensive use of the polymers in badly designed and badly made products which broke only too easily caused a reaction away from the homopolymer. This resulted, first of all, in the development of the high-impact polystyrene and today this is more important than the unmodified polymer (60% of Western European market). [Pg.462]

Step 1.1 Getting Ready. A thorough preparation for a P2 audit is a prerequisite for an efficient and cost-effective evaluation. Gaining support for the assessment from top-level management, and for the implementation of results, is particularly important. Otherwise, there will be no real action on recommendations. Early in the process, management needs to accept that, at a bare minimum, the audit is a worthwhile exercise and that resources - human and financial - should be diverted from other activities to the task of auditing. [Pg.358]

Understanding the planning processes described in these documents and how the information being assembled will be used is a prerequisite for determining which computer application will best address the specific set of needs involved. [Pg.268]

To produce this kind of grid map by quickly measuring the concentrations at some points for immediate processing and graphical presentation is a simple and often effective way to communicate the results to persons w ho are not trained to analyze primary results of measurements. The method must, however, be used with care since there is a risk that the sampling of data itself may affect the airflow in the studied area. I he equipment needed is relatively expensive, and the method is therefore of interest when the prerequisites are already available for other reasons. [Pg.1116]

Although desulfurization is a process, which has been in use in the oil industry for many years, renewed research has recently been started, aimed at improving the efficiency of the process. Envii onmental pressure and legislation to further reduce Sulfur levels in the various fuels has forced process development to place an increased emphasis on hydrodesulfurization (HDS). For a clear comprehension of the process kinetics involved in HDS, a detailed analyses of all the organosulfur compounds clarifying the desulfurization chemistry is a prerequisite. The reactivities of the Sulfur-containing structures present in middle distillates decrease sharply in the sequence thiols sulfides thiophenes benzothiophenes dibenzothio-phenes (32). However, in addition, within the various families the reactivities of the Substituted species are different. [Pg.396]

Two other factors are noteworthy the deleterious effects on chemical and mechanical properties of small amounts of impurities residual from extraction of the metal, and its toxicity. The first of these factors is obviated by vacuum melting the raw metal (for purification) as an essential prerequisite to further processing. The toxicity of beryllium is essentially a pulmonary problem and great care must be taken in handling the finely divided metal or its compounds. In practice, this type of activity is usually carried out under well-ventilated conditions. Certain tolerance levels for atmospheric beryllium are now internationally accepted and merit careful study before work on beryllium is embarked upon. [Pg.832]

During electrochemical reduction (charge) of the carbon host, lithium cations from the electrolyte penetrate into the carbon and form a lithiated carbon Li rCn. The corresponding negative charges are accepted by the carbon host lattice. As for any other electrochemical insertion process, the prerequisite for the formation of lithiated carbons is a host material that exhibits mixed (electronic and ionic) conductance. [Pg.386]

Strictly speaking, growth refers specifically to an increase in mass. In biological contexts, and increase in mass is often coupled to (and is indeed often a prerequisite for) proliferation (an increase in cell number). Importantly, growth and proliferation are distinct processes that can be both physiologically and experimentally uncoupled. [Pg.565]


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See also in sourсe #XX -- [ Pg.269 ]




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