Germanium accumulation

FIGURE 3. Germanium accumulation by selected microorganisms (modified from Reference 15). Cultures were incubated in a medium containing 10 g gluci>se I 1 and 0.5 g Cief >2 I final pH 7, at 28°C for 20 h... 

Gastrointestinal absorption of germanium oxides and cationic salts is poor. No reports of germanium accumulation in human or animal tissue exist. 

In substitutional metallic solid solutions and in liquid alloys the experimental data have been described by Epstein and Paskin (1967) in terms of a predominant frictional force which leads to the accumulation of one species towards the anode. The relative movement of metallic ion cores in an alloy phase is related to the scattering cross-section for the conduction electrons, which in turn can be correlated with the relative resistance of the pure metals. Thus iron, which has a higher specific resistance than copper, will accumulate towards the anode in a Cu-Fe alloy. Similarly in a germanium-lithium alloy, the solute lithium atoms accumulate towards the cathode. In liquid alloys the same qualitative effect is observed, thus magnesium accumulates near the cathode in solution in bismuth, while uranium, which is in a higher Group of the Periodic Table than bismuth, accumulated near the anode in the same solvent. 

We discuss the dissolution of surface atoms from elemental semiconductor electrodes, which are covalent, such as silicon and germanium in aqueous solution. Generally, in covalent semiconductors, the bonding orbitals constitute the valence band and the antibonbing orbitals constitute the conduction band. The accumulation of holes in the valence band or the accumulation of electrons in the conduction band at the electrode interface, hence, partially breaks the covalent bonding of the surface atom, S, (subscript s denotes the surface site). 

The net charge on albumin appears to be more significant than the nature of the substrate when considering how much protein initially binds to the aqueous/solid interface. More protein adsorbed onto copper, nickel, and germanium substrates at pH 4.8, where albumin has no net surface charge, than at pH 4.0 or pH 7.4. Since no charge effects exist between the macromolecules adsorbed on the surface, high protein densities at the aqueous/solid interface would be expected. Copper and nickel appeared to accumulate the same quantities of albumin independent of the pH studied. 

A rough surface presents more surface area on which physical absorption can occur. More protein might have been expected to adsorb on the copper and nickel films as compared to germanium due to the granular nature of these films. Only at pH 7.4 did copper and nickel accumulate more albumin than did germanium, however. Despite the macroscopic differences in surface morphology copper and nickel appeared to accumulate the same quantity of albumin. 

Carefully swirl to mix. Be certain to cover the bottom evenly, but do not swirl the solution up onto the container walls. The total initial volume is 5.0 mL. Screw the lid on the container and carefully place in position in the germanium gamma-ray detector counting chamber it should be centered and level. Count twice for a sufficient time period to accumulate 2000 counts (typically 100 s). Check to confirm that at least 2,000 counts have been accumulated at each of the peaks used for calibration. Collect the gross gamma-ray count rates for the full-energy peaks in Data Table 2B.1. 

The participation of volcanic material in iron-ore accumulation is confirmed by the distribution of trace elements, in particular germanium (Grigor yev, 1971). The explanation of the formation of banding in the case of a volcanic source of the iron and silica and sedimentary mode of deposition presents considerable difficulties. Usually, pulsating volcanic activity, and as a result of this, periodic entry of iron and silica into solution. 

Grigor yev, V.M., 1971, Regularities in the distribution and Conditions of Accumulation of Germanium in Iron Deposits (in Russian). Izd. Nauka, Moscow, 153 pp. 

One possible explanation for these results and the observation that TCB did not wet the bare germanium disc is that it is the wetting properties of the molten polymer that are important and not that of TCB. The temperature of the surface of all discs used exceeded the melting points of all the polymers investigated for the entire experiment. Furthermore, with the evaporation conditions used for all experiments except the last one mentioned, evaporation of solvent was instantaneous when the droplets reached the disc surface. No liquid accumulation was evident. 

---