Glass regenerators

Sulfates of sodium are iadustriaUy important materials commonly sold ia three forms (Table 1). In the period from 1970 to 1981, > 1 million metric tons were consumed aimuaHy ia the United States. Siace then, demand has declined. In 1988 consumption dropped to 890,000 t, and ia 1994 to 610,000 t (1,2). Sodium sulfate is used principally (40%) ia the soap (qv) and detergent iadustries. Pulp and paper manufacturers consume 25%, textiles 19%, glass 5%, and miscellaneous iadustries consume 11% (3). About half of all sodium sulfate produced is a synthetic by-product of rayon, dichromate, phenol (qv), or potash (see Chromium compounds Fibers, regenerated cellulosics Potassium compounds). Sodium sulfate made as a by-product is referred to as synthetic. Sodium sulfate made from mirabilite, thenardite, or naturally occurring brine is called natural sodium sulfate. In 1994, about 300,000 t of sodium sulfate were produced as a by-product another 300,000 t were produced from natural sodium sulfate deposits (4). 

As a result of the larger flues and the restric ted surface area per unit of gas passed, regenerators employed with this type of furnace exhibit much lower efficiency than would be reahzed with smaller flues. In view of the large amount of iron oxide contained in open-hearth exhaust gas and the alkah fume present in glass-tank stack gases, however, smaller checkerbrick dimensions are considered imprac tical. 

The photoelectrochemical properties of CdS nanoparticles formed in LB films of cadmium arachidate on ITO glass (indium tin oxide-coated glass) were investigated [188]. The CdS particles were formed by exposure to H2S gas, and then the cadmium arachidate structure was regenerated by exposing the gas-treated films with aqueous solutions of CdCL. Gassing/immersion cycling increased the particle size from 2.3 0.7 nm after one cycle to 9.8 2.4 nm after five cycles. The 9.8-nm particles showed UV-visible ab-... 

Cui L, Locatelli L et al (1997) Effect of nucleoside analogs on neurite regeneration and mitochondrial DNA synthesis in PC-12 cells. J Pharmacol Exp Ther 280(3) 1228-1234 Dal Pan GJ, Glass JD et al (1994) Clinicopathologic correlations of HIV-l-associated vacuolar myelopathy an autopsy-based case-control study. Neurology 44(11) 2159-2164 Dalakas MC (2001) Peripheral neuropathy and antiretroviral drugs. J Peripher Nerv Syst 6(l) 14-20 Dalakas MC, Semino-Mora C et al (2001) Mitochondrial alterations with mitochondrial DNA depletion in the nerves of AIDS patients with peripheral neuropathy induced by 2 3 -dideoxycytidine (ddC). Lab Invest 81(11) 1537-1544... 

Membranes UF membranes consist primarily of polymeric structures (polyethersulfone, regenerated cellulose, polysulfone, polyamide, polyacrylonitrile, or various fluoropolymers) formed by immersion casting on a web or as a composite on a MF membrane. Hydrophobic polymers are surface-modified to render them hydrophilic and thereby reduce fouling, reduce product losses, and increase flux [Cabasso in Vltrafiltration Membranes and Applications, Cooper (ed.). Plenum Press, New York, 1980]. Some inorganic UF membranes (alumina, glass, zirconia) are available but only find use in corrosive applications due to their high cost. 

Glass, J.M. Machiavelli s Prince alchemical transformation action archetype of regeneration. Polity 8, no. 4 (Summer 1976) 503-528. 

Bioactive glasses are currently used as granulate for bone and dental grafting in small defects, or as powder incorporated into toothpaste. Although silica-based bioactive glasses meant an extraordinary advance in the field of bone tissue regeneration, their application as pieces for medium and large defects is not possible due to their very poor mechanical properties. 

---