Slumping technique

With the slumping technique and the spin casting technique, the material consumed can be reduced drastically in comparison with the conventional technique, especially for workpieces with a large camber. Figure 4.19 shows the most economical manufacturing techniques for different diameters, thicknesses, and apertures. 

Fig. 4.19. The most economical manufacturing techniques for thin menisci for two relative apertures (f l, f 2) (A) conventional technique, (B) slumping technique, (C) spin casting technique...

Recently a decreased level of CE activity has been noticed with a shift of attention towards other separation techniques such as electrochromatography. CE is apparently not more frequently used partly because of early instrumental problems associated with lower sensitivity, sample injection, and lack of precision and reliability compared with HPLC. CE has slumped in many application areas with relatively few accepted routine methods and few manufacturers in the market place. While the slow acceptance of electrokinetic separations in polymer analysis has been attributed to conservatism [905], it is more likely that as yet no unique information has been generated in this area or eventually only the same information has been gathered in a more efficient manner than by conventional means. The applications of CE have recently been reviewed [949,950] metal ion determination by CE was specifically addressed by Pacakova et al. [951]. 

FIGURE 31.15 Sealing a slump hole to a shallow yet operable sump. (Adapted from U.S. EPA, Radon-Resistant Construction Techniques for New Residential Construction—Technical Guidance, EPA/625/ 2-91/032, U.S. Environmental Protection Agency, Washington, DC, February 1991.)... 

Testing techniques for the evaluation of physical properties and other properties of finished margarine products as well as low-fat spreads have been stated to include (4, 91) appearance, oral melting characteristics, oil exudation, slump (collapse), penetrations, spreadability, emulsion viscosity at 35°C (95°F), emulsion drop size, and electrical conductivity. 

Rehabilitation is achieved by overlays such as latex-modified concrete, low-slump concrete, high-density concrete, and polymer concrete. They are commonly used for the rehabihtation of bridge decks. This procedure extends the life of a bridge deck by about 15 years. Impressed-current CP systems on bridge decks are now a routine rehabihtation teehnique because of the cooperative research with industry and states in the development of durable anodes, monitoring devices, and installation techniques. Titanium mesh anode, used in conjunction with a concrete overlay to distribute protective current, serves as a durable anode for use in impressed-current CP of reinforced concrete bridge deeks and widely accepted by state and other transportation agencies. 

All the individual components for a high energy MCP optic are available or will be with modest improvements in manufacturing techniques. What remains to be done is their combination into a square pore, slumped, high L D, low surface roughness element. To this end, ESA have recently approved a program in their... 

Sagging or slumping is a simple method whereby the glass is heated so that it slumps into the mold. The technique can also be used for clay effectively it is pressing, with gravity providing half the press. 

In order to study the effect of SO3 on slump loss in superplasticized cement, Khalil and Ward l adopted the conduction calorimetric technique. The heat effects were used to explain the workability loss. It was concluded that for cements cured at 25°C, the optimum SO3 content was higher in the presence of the superplasticizer. 

The material used in this technique is conventional concrete and epoxy resin bonding agent. The concrete should be the same as the old concrete but with consistency (slump value) within 40 mm. The resin should be of two components, 100 % solid type, meeting the requirements of specification ASTM C-881 (2010) for type II or type V, class B or C (depending on the ambient temperature). Type II can be used for use in non-load-bearing applications to bond fresh to hardened concrete, while for load-bearing applicatimis, type V should be used (ASTM C-881 2010). 

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