Free-running properties

In powder metallurgy autohesive and adhesive processes are involved in extrusion and pressing techniques and in the production of finished articles from the original powdered material they also affect the free-running properties of powders. 

The forces of adhesion and autohesion may be reduced by hy-drophobization of the powder surface ( 10), thus increasing the free-running properties. Hydrophobization of the surface of sand may be effected by treatment with suspensions or solutions of wood pitch [447]. 

Specifications for testing the electrochemical properties are given in an appendix to Ref. 33. The test consists of a long-term free-running test with flowing... 

As a necessary preliminary to the study of how compositional heterogeneity affects the properties of the polymers, compositionally heterogeneous and homogeneous co- and terpolymers had to be synthesised. It Is common in copolymerisations for the relative reactivity of the co-monomers to be different (5) so that during polymerisations carried out to high conversion In a free-running batch reactor, the Initially formed polymer Is richer In the more reactive monomer, whereas, at the end of the reaction the polymer produced contains a greater proportion of the less reactive monomer. In such circumstances, compositional... 

For free-running dye jets the viscosity of the liquid solvent must be sufficiently large to ensure the laminar flow necessary for high optical quality of the gain zone. Most jet-stream dye lasers use ethylene glycol or propylene glycol as solvents. Since these alcohols decrease the quantum efficiency of several dyes and also do not have optimum thermal properties, the use of water-based dye solutions with viscosity-raising additives can improve the power efficiency and frequency stability... 

It is essential that the industrial ventilating engineer have a basic understanding of the properties of water and its treatment. This is to ensure an efficiently running and trouble-free plant. Additional to these issues are the problems relating to the discharge of contaminated water to the surrounding environment. 

The vinyl chloride monomer polymerizes via addition polymerization to form polyvinyl chloride. The final polymer has the chemical composition shown in Fig. 22.1. The polymer exhibits limited crystallinity, though this property is not often considered as important in defining its performance. It tends to be atactic or regionally syndiotactic, surrounded by extended atactic runs. When exposed to temperatures above 100 °C, polyvinyl chloride decomposes, creating free radicals that further attack the polymer chain, as we shall discuss in more detail later. For this reason, the degradation of polyvinyl chloride is autocatalytic... 

This property can be used to separate highly volatile and low-viscous mineral oils from oil-water dispersions.To demonstrate this,a dispersion of 20 ml of ligroin or petroleum ether in 200 ml of water is prepared in a 400 ml beaker with a fast-running mixer.Then approx. 5 g of crushed urea/formaldehyde foam are added. After 5 min the solution is filtered through a folded filter.The aqueous filtrates are optically free from dispersed hydrocarbons. In the same way a crude oil/water dispersion can be separated. 

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