Calcium germanates

HYDRAULICALLY REACTIVE CALCIUM GERMANATES, STANNATES, AND PLUMBATES... 

The hydration rate of dicalcium germanate is significantly slower, but the hydration products are similar to those formed in the hydration of tricalcium germanate. The bonding characteristics of the formed C-G-H phases are better than those of the C-S-H phase formed in calcium silicate hydration. Calcium germanates have no practical use as inorganic cements, because of their prohibitive costs. 

Trettin, R. et al. (1995) The hydration of hydraulically active calcium germanates. 

Calcium—zinc soaps are used in many PVC food container appHcations because these heat stabilizers are universally accepted as safe by the U.S. FDA, German BGA, Japanese JHPA, and other government regulatory groups. 

Naphthalenesulfonic Acid. The sulfonation of naphthalene with excess 96 wt % sulfuric acid at < 80°C gives > 85 wt % 1-naphthalenesulfonic acid (a-acid) the balance is mainly the 2-isomer (P-acid). An older German commercial process is based on the reaction of naphthalene with 96 wt % sulfuric acid at 20—50°C (13). The product can be used unpurifted to make dyestuff intermediates by nitration or can be sulfonated further. The sodium salt of 1-naphthalenesulfonic acid is required, for example, for the conversion of 1-naphthalenol (1-naphthol) by caustic fusion. In this case, the excess sulfuric acid first is separated by the addition of lime and is filtered to remove the insoluble calcium sulfate the filtrate is treated with sodium carbonate to precipitate calcium carbonate and leave the sodium l-naphthalenesulfonate/7J(9-/4-J7 in solution. The dry salt then is recovered, typically, by spray-drying the solution. 

Sodium—lead alloys that contain other metals, eg, the alkaline-earth metals, are hard even at high temperatures, and are thus suitable as beating metals. Tempered lead, for example, is a beating alloy that contains 1.3 wt % sodium, 0.12 wt % antimony, 0.08 wt % tin, and the remainder lead. The German BahnmetaH, which was used ia axle beatings on railroad engines and cars, contains 0.6 wt % sodium, 0.04 wt % lithium, 0.6 wt % calcium, and the remainder lead, and has a Brinell hardness of 34 (see Bearing MATERIALS). 

I German degree. = i part calcium oxide (CaO) per 100,000 parts of water... 

Formation of magnesium and calcium hydride compounds was first recognized by German chemists yet at the end of nineteenth century [95] but it took more than a half a century before a substantial yield of Mg hydride was obtained from direct... 

Insert, in connection with white acetate Of lead, page 44, column 1.—It is a well-known fact among phyto-chemists, that sulphide of lead has a great affinity for coloring matters. Based on this observation, a German chemist proposed to decolor a colored solution of acetate of lead, by the addition of a small quantity of sulphide of potassium or sulphide of calcium. After boiling and filtering, the menstruum is clear and without hue. 

Kramer, R. and Lagoni, H. 1969. Calcium selective electrode for the measurement of calcium ion activity in milk and milk products. Milchwissenschaft 24, 68-70 (German). 

Probably the first scientifically recorded observation of a completely inorganic coordination compound is the formation of the familiar tetraamminecopper(II) ion, [Cu(NH3)4]2+. The 16th century German physician and alchemist Andreas Libavius (15407—1616) noticed that aqua calcis (limewater or saturated calcium hydroxide solution) containing sal ammoniac (ammonium chloride) became blue in contact with brass (an alloy of copper and zinc).8... 

Scapolite is found in the metamoiphic locks, particularly those, rich in calcium also in contact metamorphic deposits in limestones. It has been found in basic igneous rocks, probably as a secondary mineral. Notable localities are Lake Baikal, Siberia Arendal. Norway and Madagascar. In the United States, it is found in Massachusetts, New York, and New Jersey. Greenville, in the Province of Quebec, Canada is an important locality. Superb transparent yellow gem crystals have recently been found in Brazil and Tanzania. Wernente (scapolite) was named in honor of A.O. Werner, a famous German mineralogist (1749-1817). 

German, M.S., Moss, L.G. and Rutter, W.J. (1990) Regulation of insulin gene expression by glucose and calcium in transfected primary islet cultures. J. Biol. Chem., 265, 22063-22066. 

In the normal infant a wide range of calcium retention has been reported by Hoobler (H8), Telfer (Tl), Daniels and Stearns (D2), Flood (F5), Stearns (S10), Jeans et al. (Jla), and Harrison (H4). From these authors we have obtained the results of 24 calcium balances in healthy infants (7-12 months), fed on cow s milk or on evaporated milk, with, so far as can be ascertained, a normal intake of vitamin D. On an average intake of 1.17 g calcium daily, the mean retention of calcium was 32 % (range 0-79 %) or 0.38 g. This agrees very closely with the daily retention of calcium in a similar age group reported by Sherman and Hawley (S3) from their study of German published reports and with the calculated requirements of the body at this age (LI). 

The high calcium content of the younger coals has led to the formation and deposition of calcium carbonate in the liquefaction reactor in the form of wall scale and oolites which were first observed in German operations (10). These deposits form as calcium salts of humic acids in the coal decompose under liquefaction conditions. The deposits continue to grow with time and could lead to unwanted solids accumulation in the reactor itself as well as fouling of downstream equipment (11). Data shown in Figure 7 indicate the accumulation rate of the calcium carbonate in the liquefaction reactor for different coals under typical EDS conditions as well as two methods for controlling the solids build-up. 

---