Factors that influence separation

A number of factors that influence separation are clearly temperature dependent... 

Various authors [90] and researchers have published factors that influence the magnitude of HETP values. The lower the HETP value (i.e., number of feet (or inches) per theoretical plate/tray/stage) the more efficient is the packing (random or structured) for any particular separation system. Other influences include ... 

A review of the available literature allows a hierarchical ranking of the importance of different factors that influence the pre-harvest infection of cereal grains by Fusarium weather/climate (year) > inoculum pressure/tillage/ previous crop > fungicides > available plant nitrogen. The individual factors related to other fungi are described in separate sections below. 

The factors that influence the chemical resolution of sensors are well understood and are not discussed here. This section reviews the factors that control the temporal resolution of sensors to be used for eddy correlation. In the analysis of the design of chemical sensors to be used for eddy correlation it is instructive to consider the different components of chemical sensor systems separately to determine the influences that they have on the temporal response to variations in the atmospheric concentration of a trace constituent. Of course this analysis is an oversimplification because the total systems operate in a more complex fashion, but it is a useful exercise. 

Although not all of the factors that influence homogeneous hydrogenation and hydroboration in sc C02 are fully understood, it is clear that the use of sc C02 can lead to an increase in selectivity for some reactions. Additional work is needed to understand the opportunities for further selectivity enhancements and catalyst separation/recycle strategies. Even sc C02 systems that exhibit similar selectivities to those obtained in organic solvents could offer a practical, environmentally responsible method for the production of many important chiral building blocks. 

Presumably the difference in rates in either direction is the result of steric factors that influence the chemical or thermal stabilities of the two combinations concerned. In any event, after the interaction has continued for a time but has not gone to completion, then more of one active component and less of the other will be found in combination. A partial resolution of the antipodes therefore can be effected by separating the combined and the uncombined portions of the system. Several methods of stepwise resolution have been based upon the effects just described. 

Solid phase micro-extraction (SPME) allows isolation and concentration of volatile components rapidly and easily without the use of a solvent. These techniques are independent of the form of the matrix liquids, solids and gases can be sampled quite readily. SPME is an equilibrium technique and accurate quantification requires that the extraction conditions be controlled carefully. Each chemical component will behave differently depending on its polarity, volatility, organic/water partition coefficient, volume of the sample and headspace, speed of agitation, pH of the solution and temperature of the sample (Harmon, 2002). The techniques involve the use of an inert fiber coated with an absorbant, which govern its properties. Volatile components are adsorbed onto a suitable SPME fiber (which are usually discriminative for a range of volatile components), desorbed in the injection chamber and separated by a suitable GC column. To use this method effectively, it is important to be familiar with the factors that influence recovery of the volatiles (Reineccius, 2002). 

Hybrid framework compounds, including both metal-organic coordination polymers and systems that contain extended inorganic connectivity (extended inorganic hybrids), have recently developed into an important new class of solid-state materials. We examine the diversity of this complex class of materials, propose a simple but systematic classification, and explore the chemical and geometrical factors that influence their formation. We also discuss the growing evidence that many hybrid frameworks tend to form under thermodynamic rather than kinetic control when the synthesis is carried out under hydrothermal conditions. Finally, we explore the potential applications of hybrid frameworks in areas such as gas separations and storage,... 

Ion-exchange (or ion) chromatography uses vertical columns loaded with ionic resins with either mobile anions or mobile cations (typically acidic cations and aminium anions) to separate ionic salts dissolved in water. These resins can separate even rare earth salts from each other and would have been a godsend to Marie Curie The charge, polarizability, and size of the solvated ion and the properties of the anionic or cationic resins are factors that influence the separability. 

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