Controls contradictory

Bubble size control is achieved by controlling particle size distribution or by increasing gas velocity. The data as to whether internal baffles also lower bubble size are contradictory. (Internals are commonly used in fluidized beds for heat exchange, control of soflds hackmixing, and other purposes.)... 

There are two general theories of the stabUity of lyophobic coUoids, or, more precisely, two general mechanisms controlling the dispersion and flocculation of these coUoids. Both theories regard adsorption of dissolved species as a key process in stabilization. However, one theory is based on a consideration of ionic forces near the interface, whereas the other is based on steric forces. The two theories complement each other and are in no sense contradictory. In some systems, one mechanism may be predominant, and in others both mechanisms may operate simultaneously. The fundamental kinetic considerations common to both theories are based on Smoluchowski s classical theory of the coagulation of coUoids. 

Commercial thermoplastics are the engineering materials containing two or more compatibilized polymers that are chemically bounded in a way that creates a controlled and stable morphology with a unified thermodynamic profile. In view of multiplicity and contradictory requirements of various properties for most of the applications, almost all the commercial PBAs are made of two or more thermoplastics, elastomeric modifiers along with a series of compatibilizers with modifiers compounded together. A considerable number of blends have been appearing in the market regularly, some of which are listed in Table 9. 

The sometimes contradictory results from different workers in relation to the elements mentioned above extends to other elements . Some of these differences probably arise from variations in test methods, differences in the amounts of alloying additions made, variations in the amounts of other elements in the steel and the differing structural conditions of the latter. Moreover, the tests were mostly conducted at the free corrosion potential, and that can introduce further variability between apparently similar experiments. In an attempt to overcome some of these difficulties, slow strain-rate tests were conducted on some 45 annealed steels at various controlled potentials in three very different cracking environments since, if macroscopic... 

Though such data are ambiguous, and sometimes even contradictory [12], they can be rationally explained on the basis of qualitative considerations on intermolecular interactions of a polymer with a filler. Of practical importance is the fact that varying the nature of the dispersion medium and the filler and thus controlling the intensity of net-formation, we can vary the yield stress of filled polymers within wide limits and in different directions. 

In the analysis of molecular capacitors, the diffuse layer and elastic capacitors, we have always assumed that the electrode charge density a could be controlled. Under such conditions it is generally possible for C to become negative while the system remains stable. For example, contraction of the gap z in an elastic capacitor proceeds smoothly with cr growing until the plates come in contact, while C becomes negative for z < 2/3. At the same time, as shown in Section II for an EC connected to a battery, the EC collapses after z 0.6 is reached. How can these seemingly contradictory results be reconciled And how can cr-control be related to reality Is C < 0 observable These questions are addressed in this section. 

Matheson and Rabani (1965) measured the rate of the reaction eh + eh— H2 + 20H at pH 13 under 100 atmospheres H2 pressure, where all radicals are converted to eh. From a pure second-order decay, the rate constant was determined as 6 x 109 M 1s 1. There are contradictory views on this reaction. According to some, this rate is too low for a diffusion-controlled reaction between like charges, by a factor of -4 (see Farhataziz, 1976). This factor of 4 can be accounted for by spin considerations, since each electron is a doublet but the end product H2is a singlet. To be consistent, then, one has to consider the rate of reaction eh + O—-O2- as normal for diffusion control. 

After these initial steps, TIQDT was tested for its capacity to screen environmentally relevant compounds. 2,4-Dichlorophenoxyacetic acid (2,4-D), l,l-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT), and 4-nonylphenol (4-NP) were selected as they are usually considered to be TGFDs [52-55]. Reports concerning the effect of methyhnercury (MeHg) on thyroid function are contradictory [56-58]. Two environmentally relevant compounds with no reported effects on the thyroid system, fenoxicarb and atrazine [59, 60], were included as negative controls to assess the specificity of the assay. Our data strongly suggest that TIQDT may be... 

Fibroblasts have another and apparently contradictory capability—namely, the secretion of collagenase, the enzyme that initiates the dissolution of collagen. Mechanisms controlling the creation, extrusion, and deposition of fibrous extracellular components, and the synthesis of dissolution enzymes, are incompletely known. Each of these areas continues to be investigated (Furthmayr, 1982). 

Mayes LC, Horwitz RI, Feinstein AR. A collection of 56 topics with contradictory results in case-control research. Inf Epidemiol 1988 17 680-5. 

It is important to distinguish between acute (e.g., 1 day) and longer term treatment with a BZD. Most of the literature addressing this issue consists of anecdotal reports, retrospective chart reviews, and uncontrolled studies in small patient samples, plus a small number of controlled trials for short-term acute BZD therapy. To our knowledge, at least 12 studies (including more than 450 patients) have evaluated the efficacy of adjunctive BZDs in nonresponsive schizophrenics (Table 5-23). Two of three open studies showed positive results, as did two controlled, single-blind studies ( 343, 344, 345, 346 and 347). In seven double-blind, crossover studies (six with placebo controls), the results are more contradictory, in that five showed no advantage to an adjunctive BZD, and one of the two positive studies had a small sample size (188, 189, 348, 349, 350 and 351). 

When it occurs, onset of therapeutic activity may be rapid (within hours, days, or 1 to 2 weeks). Even in those few patients with good initial response, however, therapeutic effects attributable to BZDs may be temporary. Several controlled studies have found that tolerance developed by the fourth week of treatment ( 172,188, 189, 349, 350, 387). High doses appear to be associated with more favorable response, but data are limited, contradictory, and inconclusive ( 177,190, 347, 362). 

However, there are some contradictory reports on the composition of the products of toluene alkylation or benzene dialkylation at high conversions. In some cases, compositions corresponding to the thermodynamic equilibrium between ortho, meta and para isomers were found, and in other cases, kinetic control of orientation, giving mostly the ortho + para substitution, prevailed. Consecutive isomerisation of the ortho and para isomers to the more stable meta isomer seems to be the cause of the disagreement. More active catalysts gave more meta derivatives than the less active ones [343] and increasing the temperature has the same effect [351]. 

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