Strengthening Plant Parts

The Equisetum genus (horsetail) contains so much silica it was used in the kitchen as scouring rush. Pioneers used it to clean the teeth. According to Prison (94) these plants were used for centuries as abrasives, one type being employed for polishing wood and another for household utensils.  

The above-mentioned microfibrous silica in Equisetum arvense described by Laroche (95) may be formed by the same process by which silica gel is excreted within cells from the inna surface of the membranes in Avina sativa. As shown in electron micrographs by Kaufman et al. (97c), the nlica appears to be extruded as fibers around 120 A in diameter and 120 A apart, from the inner surface of the walls of special silica cells. As the mass of parallel fibers grows away from the membrane surface it seems to undergo syneresis like most freshly formed silica gels. 

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However, because of the oriented structure there is shrinkage in only two directions and the flbers are drawn together into parallel bundles or rods about 600 A in diameter. In the micrograph the dried silica is disrupted but in the living cell the silica forms a lining within thie cell in which the rods project from the surface like a pilecarpet. . - 

The silica, having been formed by polymerization at ordinary temperature, probably consists of close-packed ultimate particles of SiO with surfaces of SiOH groups and with water held tightly in the micropores between these small particles as in microporous silica gels formed in the laboratory. If suitably dried, such gel should have a specific surface area of more than 400-600 m g.  

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Yet more research and development effort concentrates on the diaphragm cell caustic evaporator, finding ways to aid the evaporation of the 10-12% caustic soda in brine to make it into a saleable product. Work is directed into methods of removing the salt products and impurities and preventing corrosion of the equipment. Recovery of the salt from the evaporated caustic soda is an important part of a diaphragm cell plant as the recovered salt is used in the strengthening of the feed brine. 

P G sells over 300 brands of consumer products around the world. In 1993, P G s Operations Research (OR) team undertook a major study, called Strengthening Global Effectiveness, to restructure P G s global supply chain. A major part of the study was to examine the North American supply chain, which had 60 plants, 15 DCs, and more than 1000 customer zones. To be globally competitive, P G decided to consolidate manufacturing plants to reduce cost and improve speed to market. The OR team decomposed the... 

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