Chemical attraction

Chemically active These filters are similar in design to the non-active depth units but the filtering media used are so chosen that contaminants adhere by chemical attraction. Thus there is a dual action, mechanical and chemical. The materials used include various activated clays. Fuller s earth, charcoal and chemically treated paper. Their cleansing action is much more thorough than that of the purely mechanical devices, for they are capable of removing matter actually in solution in the oil. 

Dodson, C. H. 1970. The role of chemical attractants in orchid pollination. Pages 83-107 in K. L. Chambers (ed.) Biochemical Coevolution. Oregon State University Press, Corvallis. Downie, S. R. 1988. Morphological, cytological, and flavonoid vaiiabihty of the Arnica angusti-folia aggregate (Asteraceae). Can. J. Bot. 64 24-39. 

Electrodialysis units recover plating chemicals differently from the recovery units discussed thus far. In electrodialysis, electromotive forces selectively drive metal ions through an ion-selective membrane (in RO, pressure is the driving force in ion exchange, the driving force is chemical attraction). The membranes are thin sheets of plastic material with either anionic or cationic characteristics.33... 

Biologists have known of these intertwined lives for more than a century, but only more recently have they brought modern tools to bear on the relationship. Along with several other points, the role of chemical signals here is still unsettled. The moths may locate yucca flowers by scent, sight, or both. For such a scientifically well-known interaction, it would be interesting to know more. If yuccas do emit a chemical attractant, the scent apparently attracts only yucca moths, a selectivity suggesting an attractant that mimics some unsuspected moth pheromone. 

The binding constants of selected ligands of class A were determined to obtain their ranking with respect to their affinity to the protein and to select a chemically attractive compound for further detailed characterization of its mode of binding. The compound HUB093 was chosen by medicinal chemists as interesting. Using uniformly 13C-labeled... 

Chemical cues hold considerable promise for manipulating behavior in vertebrates, provided we understand an animal s natural history, biology, and behavior well. However, the development of chemical attractants, stimulants, inhibitors, and repellents for vertebrates has progressed rather slowly for several reasons. First, chemical stimulus and behavior are not connected as rigidly as in insects, for example. Second, the same stimulus may elicit different behaviors, depending on the state of the recipient and the context. Third, chemical cues often are rather complex mixtures of compounds. Fourth, learning, especially early experience plays a major role in vertebrate, notably mammalian behavior. Finally, many behaviors are modulated by several sensory modalities so that chemical stimuli alone trigger only incomplete responses at best. 

Pawson, M. G. (1977). Analysis of a natural chemical attractant for whiting Mcrlangtis mcr-langus L. and cod Gadus morhm L. using a behavioral bioassay. Comparative Biochemical Physiology 56A, 129-135. 

Recent Developments in Chemical Attractants for Tephritid Fruit Flies... 

TERANISHIET AL. Chemical Attractants for Tephiitid Fruit Flks... 

Ions such, as S", HS, T and CN are probably somewhat displaced owing to the chemical attraction they exert for mercury. 

Isaac Newton (1642-1727) was one of the first to speculate on the true nature of chemical attraction. Newton believed an attractive force similar to that of gravity, magnetism, and electricity also applied to matter at the molecular level. Other scientists... 

It seems to be important that there is a distinct chemical attraction between the two guest diastereomers (DSAs) and the adsorption medium (AM) (e.g., via dipole-dipole or hydrogen bonding or other interactions) leading to two distinct adsorption complexes AM—(R,R)-DSA and AM —(S./tf-DSA. The degree of differentiation is driven by ... 

A few years later, in his major lifetime work, he summarized this view as follows. Compounds formed by chemical attractions, possess new properties diflFerent from those of their component parts. By way of elaboration he added... 

The long range orientation of most other Insects In response to chemical attractants Is not nearly as clear. The olfactory orientation of the Colorado potato beetle has been studied In considerable detail by Vlsser and coworkers. 

Concentrated particle suspensions may also show a yield point which must be exceeded before flow will occur. This may result from interaction between irregularly shaped particles, or the presence of water bridges at the interface between particles which effectively bind them together. Physical and chemical attractive forces between suspended particles can also promote flocculation and development of particle network structures, which can be broken down by an applied shear stress [2]. 

Rapusas, H. R., Bottrell, D. G. and Coll, M. (1996). Intraspecific variation in chemical attraction of rice to insect predators. Biological Control 6 394-400. 

Aldrich, J. R. and Barros, T.M. (1995). Chemical attraction of male crab spiders (Araneae, Thomisidae) and kleptoparasitic flies (Diptera, Milichiidae and Chloropidae). Journal of Arachnology 23 212-214. 

Some researchers noticed that some chemicals attract adult of Amblyomma [107,108]. Among these substances many were of natural origin, such as nonanoic acid, methyl salicylate, benzyl alcohol, benzaldehyde, heptadecane and squalene. Other authors exploited this feature to prepare some drugs in which the acaricides were associated to the pheromone-like chemicals to control Amblyomma [109,110]. 

The word adsorb is important here. When a material adsorbs something, it attaches to it by chemical attraction. The huge surface area of activated charcoal gives it countless bonding sites. When certain chemicals pass next to the carbon surface, they attach to the surface and are trapped. 

In the absence of electron donor-acceptor interactions, the London dispersive energy is the dominant contributor to the overall attractions of many molecules to their surroundings. Hence, understanding this type of intermolecular interaction and its dependency on chemical structure allows us to establish a baseline for chemical attractions. If molecules exhibit stronger attractions than expected from these interactions, then this implies the importance of other intermolecular forces. To see the superposition of these additional interactions and their effect on various partitioning phenomena below, we have to examine the role of dispersive forces in more detail,... 

The attraction of coloring matter by charcoal is denominated mechanical, while the attraction of sulphuric acid by baryta is classed with chemical effects. But animal charcoal does not only attract coloring matter it aho decomposes metallic salts, and fixes their base by that same power of retention., Now it is known that chemical combinations and decompositions are produced by differences in intensity of one only chemical attractive force eollod affinity. It is evident that the same force is inherent in animal charcoal. This view is corroborated by the fact thot animal charcoal absorbs different compounds in different bnt determined quantities. Niepce has shown that iodine and chlorine gas ore condensed by the Inked portion of printed paper, while the white portion of the paper dees not retain any of the gases. Charcoal absorbs heat and light most readily.. It.Condenses... 

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