Effect Of Kinetic Factors Research Articles

A bibliometric analysis and review on the performance of polymer-modified bitumen

The addition of polymer to a base binder has been documented as a successful approach in terms of improving physical and rheological properties of the base bitumen. However, the main drawbacks of polymer-modified bitumen are incompatibility and degradation of polymer due to aging. This article aims to introduce a bibliometric analysis and review on modifying bitumen with polymers. Additionally, this article intent to highlight the significant gaps and recommendations for future work. Furthermore, another objective of this article is to provide a worth attempt regrading reducing the negative impact of polymer’s drawbacks on the performance of polymer-modified base binder. The findings of this article demonstrated that the test of storage stability for polymer-amended bitumen should be modified, in which the softening point of aluminum tube centerpiece should be measured to introduce a better evaluation for the storage stability of polymer-amended bitumen. In addition, the effects of kinetic factors (mixing sequence, viscosity of blend, shear rate, and time of mixing) on the compatibility of polymer-amended bitumen should be investigated. Moreover, the addition of compatibilizers and stabilizers to polymer-modified binder is recommended to improve compatibility and reduce the effect of aging on degradation of polymer.

FTIRin situ study of supersaturated solutions of MgSO4 and NaClO4 aerosols

The continuous sampling FTIR/AFT (aerosol flow tube) has been constructed in the present work, leading to thein situ observation of the supersaturated solutions of MgSO4 and NaClO4 aerosols. The observation suggests that the MgSO4 aerosol show serious mass transfer limitation at low RH (relative humidity), while the NaClO4 aerosol deliquesce without notable effect of kinetic factors. It is also shown that the v3 band of SO2-4 is very sensitive to the formation of contact ion pairs in the supersaturated solutions of MgSO4 aerosol.

A study on the α-amylase fermentation performed by Bacillus amyloliquefaciens

Abstract α -Amylase fermentation with soluble starch as the limiting substrate was performed by Bacillus amyloliquefaciens . We investigated the influence, of the presence of α -amylase, on the hydrolysis of different starch concentrations. Both the initial and average rates for the hydrolysis of starch under different initial conditions were compared and calculated. The time for the completion of starch hydrolysis was also obtained. Effects of kinetic factors, such as pH of 5.5, 6.3, 7.0 and temperature of 30 °C and 37 °C, on the performance of α -amylase fermentation were studied. The influence of the dynamic variables, such as agitation speed and aeration rate, on this fermentation were also evaluated and are discussed. The variations of cell mass, α -amylase activity, and reducing sugar with regard to the step changes of aeration rates during a batch fermentation are also discussed. The optimal conditions of these variables have been determined.

The effect of substituents (CH3 and NH2) in positions 4 and 6 on the acid-base properties of 2(1H)-pyrimidinethiones

The acid-base properties of 4,6-dimethyl- and 4,6-diamino-2(1H)-pyrimidinethiones (1 and2) were investigated by potentiometric titration. Dissosiation of1 and protonation of its anion occur in two steps, the first of which affords the deprotonated dimer [HA2)−. The relative stability of the dimer depends on the nature of the solvent. The effect of kinetic factors on the acid-base behavior of1 was elucidated by comparing the results of potentiometric titrations carried out under various kinetic conditions. It was concluded that the difference between the acid-base properties of1 and2 results from the electron-donating effect of the amino groups.

Macrokinetics of diffusion mass transport with solid phase reaction in binary metallic systems

A macrokinetic description is presented for diffusion produced by a solidphase reaction in a binary system. The kinetics of processes on the interphase boundary and diffusion with the phase volumes are considered. The effect of kinetic factors on the growth of intermetallic compounds is studied numerically.

The effect of kinetic factors on the thermodynamic evaluations of therapeutic chelating agents

The effect of certain kinetic factors on thermodynamic evaluations of several therapeutic chelating agents is examined. This allows the in vivo behavior of these drugs to be understood in more detail. The main kinetic factors examined are: (a) the pharmacokinetics of the chelating agents in vivo; (b) the kinetics by which the toxic metal ions are distributed between the serum and other organs; and (c) the rates of the reactions between the therapeutic chelating agent and the complexes formed by the toxic metal ion with serum constituents. A new parameter is proposed for predicting the efficacy of metal binding in plasma. This takes into account changes in the chelating agent concentration with time. Predictions of the relative efficacy of the therapeutic agents based solely on thermodynamic calculations are shown to provide a useful differential indicator for spontaneous detoxification processes, whereas kinetic factors become more important in delayed treatments or when the chelating agents exhibit similar thermodynamic behavior.