Influence of manufacturing temperature on the rheological behavior of some vegetable lubricating greases

Lubricant greases from renewable resources are considered as an alternative to those manufactured from mineral or synthetic oils, due to their close-loop supply chain. Low toxicity makes them prone for machinery in food industry. The goal of the present study was to find the optimum parameters for their manufacture from some vegetable oils and calcium stearate soap synthesized in situ. The effect of synthesis temperature (between 80-110 °C) and soap concentration (between 15-25% wt.) on the rheology and consistency of the products was studied. The optimum manufacture resulted to be 100 °C and soap concentration between 20-25% wt. The conclusions of these study can serve as a basis for improving the said greases through additivation.

Control System Strategy Of The Saponification Process Between Ethyl Acetate And Sodium Hydroxide

The research looks into the performance of Proportional (P), Proportional Integral (PI), and Proportional Integral Derivative (PID) controller to maintain soap concentration. To facilitate the study, the mathematical model of saponification process is derived using information cited from literature. Then the model is validated using experimental data. Based on model, the control system using Proportional (P), Proportional Integral (PI) and Proportional Integral Derivative (PID) are designed. In this case, the constant of each controller is tuned using Ziegler Nichols method. The result showed that the PID controller with Integral Square Error (ISE) of 5,77936 E-08 isthe strongest for disturbance rejection among the others. The performance of PID controlleris also good for set point tracking with ISE of 1.28227 E-05.Key words : control, mathematical model, simulation, saponification

Indirekter Nachweis von Assoziaten solubilisierter, polycyclischer, aromatischer Kohlenwasserstoffe in wäßrigen Seifenlösungen durch Lichtabsorption und Fluoreszen / Indirect Evidence for Molecular Association of Polycyclic Aromatic Hydrocarbons in Aqueous Soap Solutions from Light Absorption and Fluorescence

Aqueous solutions of alkyl sulphates containing small amounts of the free alkanol differ in their dissolving properties for polycyclic aromatic hydrocarbons from aqueous solutions of the pure soap in concentrations near the CMC. The differences are observed only near the CMC of the pure soap, where the soap solutions containing free alkanol have a minimum of the surface tension. The observed alterations are deviations from the Lambert-Beer law, energy transfer, and changes of the fluorescence quantum efficiencies, when the soap concentration is varied. The different results are consistent with the assumption that microcristalline molecular van der Waals associations are brought into solution by the soap solutions which were studied.

Magnetic Studies with Copper (II) Soaps in Non-aqueous Solutions

The dispersion states of copper (II) soaps in non-aqueous solutions have been investigated by the determinations of the magnetic susceptibilities and magnetic moments of copper ions in copper soaps in non-aqueous solvents. The binuclear structure of copper soaps persists in hydrocarbons and in alcohols. The values of magnetic moments of copper ions in copper soaps are higher in hydrocarbons as compared with those in alcohols. The magnetic moments of copper ions in alcohols are independent of the chain length of the soap and of the soap concentration.