Specific effect

Before concluding this section, there is one additional thermodynamic factor to be mentioned which also has the effect of lowering. Since we shall not describe the thermodynamics of polymer solutions until Chap. 8, a quantitative treatment is inappropriate at this point. However, some relationships familiar from the behavior of low molecular weight compounds may be borrowed for qualitative discussion. The specific effect we consider is that of chain ends. The position we take is that they are foreign species from the viewpoint of crystallization. 

It is less well known, but certainly no less important, that even with carbon dioxide as a drying agent, the supercritical drying conditions can also affect the properties of a product. Eor example, in the preparation of titania aerogels, temperature, pressure, the use of either Hquid or supercritical CO2, and the drying duration have all been shown to affect the surface area, pore volume, and pore size distributions of both the as-dried and calcined materials (34,35). The specific effect of using either Hquid or supercritical CO2 is shown in Eigure 3 as an iHustration (36). 

DDT is highly toxic to fish (LC q for trout and blue gill, 0.002—0.008 ppm), and it is only moderately toxic to birds (oral LD q mallard 1300 and pheasant >2240 mg/kg). However, widespread bird kills have resulted from bioconcentration of DDT through food chains, ie, from fish or earthworms. A significant environmental problem has resulted from the specific effects of DDE on eggshell formation in raptorial birds where accumulation has caused decreases in shell thickness of 10—15%, resulting in widespread breakage. 

There are no hiUy effective therapeutic agents for the treatment of thederiasis. Chlorotetracycline (20) and oxytetracycline (3) have therapeutic activity duting the iacubation period. Pamaquiae (68) was reported to have a specific effect on the erythrocyctic forms. Other dmgs with limited efficacy are imidocarb (19) on T annulata halofugiaone (45) on both T annulata and T parva and the naphthoquiaones menoctone (76), parvaquone (88), and buparvaquone (89) on T parva. Methotrexate (90) has been found to be active in vitro (Table 9). 

A SAPP with intermediate reactivity is used in combination with fast-acting MCP for the manufacturer of industrial baking powder and for retail and wholesale prepared cake mixes. SAPP imparts a bitter aftertaste which is often characterized as a mild burning sensation, especially when used in a product of low sweetness. SAPP is normally used at an NV of 72. However, it may be used at slightly higher or lower NV to obtain specific effects in certain types of baked goods. 

Effect of Various Alloying Elements. The mechanical properties of cast copper alloys are a function of alloying elements and their concentrations. The specific effects of a number of these alloying elements are given in the following sections. 

Quahtative variables can be broken down into two categories. The first consists of those variables whose specific effects ate to be compared directiy eg, comparison of the effect on performance of two proposed preparation methods or of three catalyst types. The requited number of conditions for such variables is generally evident. Such variables are sometimes referred to as fixed effects or Type I variables. 

Unfortunately, no general theory for quantitatively predicting such specific effects has been developed to date. 

Concern Specific effects, therefore increased costs, accident rate reduced productivity Decreased well-being Non-specific respiratory troubles Irritation of eyes, nose and throat Damage to property and vegetation Injury to animals Decrease in amenity Long-term ecological effects... 

The ability to accommodate site-specific effects of terrain can be significant under some circumstances. 

The effect of exposure of plastics to the environment for a length of time. The specific effect and degree depend on the moisture in, and temperature and composition of, the environment, in addition to the length of exposure. 

Organ-spcctfic Defining organ-specific effects and defining chemically induced critical effects... 

Rearrangement studies give an interesting insight into the specific effect of fluonne on the thermodynamic stability and rearrangement kinetics of fluonnated cyclopropanes Fluorine decreases the thermodynamic stability of the cyclopropyl nng, in contrast with the generally observed effect of fluonne increasing the stability of molecules to which it is introduced [124]... 

Because the key operation in studying solvent effects on rates is to vary the solvent, evidently the nature of the solvation shell will vary as the solvent is changed. A distinction is often made between general and specific solvent effects, general effects being associated (by hypothesis) with some appropriate physical property such as dielectric constant, and specific effects with particular solute-solvent interactions in the solvation shell. In this context the idea of preferential solvation (or selective solvation) is often invoked. If a reaction is studied in a mixed solvent. 

The specific effect of actin on myosin ATPase becomes apparent if the product release steps of the reaction are carefully compared. In the absence of actin, the addition of ATP to myosin produces a rapid release of H, one of the products of the ATPase reaction ... 

The photosynthetic COg fixation pathway is regulated in response to specific effects induced in chloroplasts by light. What is the nature of these effects, and how do they regulate this metabolic pathway ... 

Salt effects on the reaction of 2,4-dinitrochlorobenzene with amines or alkoxides have been investigated.Reinheimer et al. have studied decelerative ion pairing of alkali metal methoxides in reaction with this substrate cations and anions in added salts have specific effects on ion pairing. 

The reactivities of 4- and 2-halo-l-nitronaphthalenes can usefully be compared with the behavior of azine analogs to aid in delineating any specific effects of the naphthalene 7r-electron system on nucleophilic substitution. With hydroxide ion (75°) as nucleophile (Table XII, lines 1 and 8), the 4-chloro compound reacts four times as fast as the 2-isomer, which has the higher and, with ethoxide ion (65°) (Table XII, lines 2 and 11), it reacts about 10 times as fast. With piperidine (Table XII, lines 5 and 17) the reactivity relation at 80° is reversed, the 2-bromo derivative reacts about 10 times as rapidly as the 4-isomer, presumably due to hydrogen bonding or to electrostatic attraction in the transition state, as postulated for benzene derivatives. 4-Chloro-l-nitronaphthalene reacts 6 times as fast with methanolic methoxide (60°) as does 4-chloroquinoline due to a considerably higher entropy of activation and in spite of a higher Ea (by 2 kcal). ... 

Attempts have also been made to separate non-specific effects of the local electrical field from hydrogen-bonding effects for a small group of ionic liquids through the use of the k scale of dipolarity/polarizability, the a scale of hydrogen bond donor acidity, and the (i scale of hydrogen bond basicity (see Table 3.5-1) [13, 16]. 

Polymerization of acrylamide is usually performed in aqueous solutions. The principal factors that determine popularity of this polymerization technique are a high rate of polymer formation and the possibility to obtain a polymer with a large molecular weight. The reason for a specific effect produced by water upon acrylamide polymerization lies in protonation of the macroradical, leading to localization of an unpaired electron, which leads to an increase in the reactivity of the macroradical ... 

Heterogeneities associated with a metal have been classified in Table 1.1 as atomic see Fig. 1.1), microscopic (visible under an optical microscope), and macroscopic, and their effects are considered in various sections of the present work. It is relevant to observe, however, that the detailed mechanism of all aspects of corrosion, e.g. the passage of a metallic cation from the lattice to the solution, specific effects of ions and species in solution in accelerating or inhibiting corrosion or causing stress-corrosion cracking, etc. must involve a consideration of the detailed atomic structure of the metal or alloy. 

Numerous references regarding alloying additions have been published, and the reader should look up specific effects for relevant alloying systems. 

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