Potential contact capacity

Inherent potential or capacity of a material to cause chronic effects that occur following long exposure times. For S. capricornutum, whose cell numbers double every 12 h at 24° C, a 3-d contact time with a test sample corresponds to a chronic exposure period allowing for the determination of corresponding chronic toxicity effects. See also Chronic effects and Chronic exposure. Volume 1(3,5), Volume 2(2,5,11). 

N. N. Alexandrov, R. Nussinov, R. M. Zimmer. Fast protein fold recognition via sequence to structure alignment and contact capacity potentials. Pac. Symp. Biocomput. 1996, 53-72. 

Pair potentials vs contact capacity potentials a) a pair potential attributes an energetic contribution to each pair of amino acids a, and aj that are mapped by a sequence-structure alignment onto locations of the amino acids b and b/ of the protein template structure. The contribution depends on the types of residues a, and aj as well as on geometric features of their locations b/, and b/, such as their distance in space or in sequence. Often, only certain pairs of amino acid residues are scored, such as those that are contacting or close in space. The total energy is computed as the sum of all pair contributions, b) a contact capacity potential rates the energetic contribution of an amino acid a, from the protein target... 

These pieces of information can be assembled in a fingerprint that characterizes the environment of location bj. Note that the contact capacity potential is derived from the chemical makeup of the template protein exclusively. In both variations of potentials, the contribution of residue a, as mapped onto location bj is determined via inverse Boltzmann statistics. 

Other advantages of gravity beds include flexibility in gas and sohds flow rates and capacities, variable retention times from minutes to several hours, space economy, ease of startup and shutdown, the potentially large number of contacting stages, and ease of control by using the inlet- and exit-gas temperatures. 

Opiates and opioid derivatives delay the transit of intraluminal content or increase gut capacity, prolonging contact and absorption. The limitations of the opiates are addiction potential (a real concern with long-term use) and worsening of diarrhea in selected infectious diarrheas. 

The right hand side of Fig. A.4.6 is contained in Fig. 3.3. Capacity measurements can readily be made at solid electrodes to study adsorption behavior. For a review see Parsons (1987). As Fig. A.4.7 illustrates, capacity potential curves of three low-index phases of silver, in contact with a dilute aqueous solution of NaF, show different minimum capacities (corresponding to the condition o = 0) and therefore remarkably different potentials of pzc. The closest packed surface (111) has the highest pzc and the least close-packed (110) has the lowest pcz these values differ by 300 mV. Such complications observed with single crystal electrodes, seem likely to have their parallel at other solid surfaces. For example, it is to be expected that a crystalline oxide will have different pzc values at its various types of exposed faces. 

Capacity-potential curves for three low-index planes of silver in contact with aqueous 0.01 M NaF at 25 °C. 

At a semiconductor/solution interface, an n-type semiconductor (carrier density of 10 electrons cm A is in contact with a nonaqueous system using a redox system, i.e., no surface states. The capacity of this interface is 4 pF cm-2. Evaluate the potential differences within the semiconductor. (Bockris)... 

Guanidines are basic molecules (pA of guanidine = 12.5) with a capacity to form intermolecular contacts mediated by H-bonding interactions. Consequently, they are potentially useful pharmacophores in medicinal chemistry, 1 have proven applications as artificial sweeteners,2,3 and are useful as probes in academic studies of intermolecular associations, including su-pramolecular complexes. Expedited access to these molecules via solid-phase synthesis is therefore a worthy goal. This chapter outlines various... 

The properties of lithium metal were described in Chapter 4, where particular note was made of its high specific capacity and electrode potential. However, because of its highly electropositive nature, it is thermodynamically unstable in contact with a wide variety of reducible materials. In particular, lithium reacts with components of most electrolytes to form a passivating layer. Film formation of this type ensures long shelf life for primary lithium cells, but causes severe problems when the electrode is cycled in a secondary cell. 

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