Radio-phosphorus

BP is a difficult material to sinter because of the high dissociation pressure of phosphorus. Radio frequency (RF) hot pressing would be applicable (29). The powders were pressed up to 19.6 MPa at room temperature and the temperature was raised to 1000°C by RF heating with a maximum applied pressure of 78.4 MPa. Subsequently, the temperature was kept at sintering temperatures (1500-1800°C) for 1 h and then reduced to room temperature for 1 h. The density of the specimen increases from 60 to 65% of the theoretical value with increasing sintering temperature. 

The radio-phosphorus, a hitherto unknown isotope of ordinary phosphorus, disintegrates with a half period of three minutes and fifteen seconds, according to the following reaction ... 

To determine the effects of the deprivation of specific micronutrients on the water hyacinth (Eichhornia crassipes), Colley et al. (1979) studied the rate of uptake of iron and manganese in comparison with phosphorus. Results indicated that all three elements were actively absorbed by the root systems, but the rates of absorption differed markedly. The rate of absorption of manganese by roots was 13 and 21 times that for radio-iron and -phosphorus, and iron was taken up by the roots at nearly twice the rate of phosphorus. Manganese translocation appeared to be faster than phosphorus translocation by an order of magnitude and 65 times faster than iron translocation. 

Light frequently exerts a considerable influence on the rate of oxidation 1 thus phosphorus trichloride when illuminated undergoes more rapid conversion into the oxychloride 2 than in the dark and iron likewise corrodes more rapidly m similar circumstances. Oxidation may be catalytically accelerated by radio-active substances. Thus thonum-X has been found 3 to assist the oxidation of adrenaline and morphine. 

Atomic hydrogen obtained (i) from dissociation in an electrical discharge, (ii) in a radio-frequency plasma discharge, (iii) photochemically in Hg-sensitized processes, or (iv) at high T reacts with phosphorus or its compounds to form phosphines. Elemental P or P40,Q and atomic H react ... 

The bioavailability of iron from several organic phosphorus-containing compounds appears to be good. The iron in ferripoly-phosphate protein powder (13) and ferric glycerol phosphate Q, 6) was found to be 92-100% as bioavailable as ferrous sulfate in heme repletion assays with anemic rats and chicks. Morris and Ellis (14) have reported that the iron in monoferric phytate was utilized by rats as well as the iron in ferrous ammonium sulfate. While Lipschitz, et al. (15) have reported that dogs absorbed radio-labelled iron from a small dose (1.5 mg iron) of monoferric phytate one-half as well as they absorbed iron from ferrous sulfate. 

The half-value period of the radio-phosphorus was found to be... 

Bora- and further heterofuUerenes (C Si, C Ge) may be produced, among others, by arc discharge methods. To this end, suitably impregnated rods of graphite are employed in typical fullerene reactors. For the preparation of phosphafuUerenes, the simultaneous vaporization of carbon and phosphorus in a radio frequency oven proved its worth. The vaporization of both elements at different positions in the oven, corresponding to different temperatures, was found to be crucial in this... 

MHZ with proton decoupling on a Bruker spectrometer MSL 300 with phosphoric acid (60 wt-%) as reference for the chemical shifts. For the determination of the phosphorus content the free induction decay extrapolated to time zero were compared with those of the standard NH H2PO. For the P CP MAS Investigations a radio frequency field corresponding to a rt/2 puls of 6 fjft was used. The reference samples were AlPO molecular sieve and NH H2PO. ... 

A measrired quantity (normally 0.010 mol) of a volatile halide such as thionyl chloride, silicon tetrachloride, boron chloride, germanium(IV) chloride, or phosphorus(III) chloride is then dosed into the reaction vessel, with liquid nitrogen as a refrigerant. The reaction vessel is isolated from the vacuum manifold and warmed to 0° in an ice bath to bring about liquefaction of the volatile chloride. Intermittent shaking of the ice-bath-cooled reactants for a period of 1 to 4 hours usually ensures complete exchange of the radio-... 

Fig. 2.1. Response of phosphorus nuclei to an applied magnetic field, and to a radio frequency (rf) wave, (a) Nuclear magnetic dipole without applied magnetic field, (b) Applied magnetic field, with applied rf wave, (c) Alignment of dipole with (stable, low energy), (d) Alignment against B (unstable, high energy).

About half of the environmental P NMR experiments reported in the literature used proton decoupling to remove scalar coupling of protons to phosphorus. This is done with an additional radio-frequency pulse at the Larmor frequency for protons. 

Shortly after the JoHot-Curies discovery, Hevesy irradiated 10 liters of carbon disulfide (CS2) with neutrons and produced radio-phosphorus ( P), in a form readily extracted with dilute nitric acid or water (the remainder of the CS2 is recycled). Radio-phosphorus was administered to rats and its uptake in bones and tissues analyzed. Hevesy s later research involved studying the formation and decomposition of glucose-6-phosphate, ATP, and other compounds vital for understanding intermediary metabolism. 

Radiofrequency EDLs. The intensity of these lamps may be lower than that of microwave lamps, but they give better short and long term stability without the need for a thermostat. The radio frequency commonly employed is 27.12 MHz. Radiofrequency EDLs are available for about 15 elements, and they are particularly suitable for routine applications of the volatile elements arsenic, selenium, antimony, tellurium, and phosphorus. 

There is some evidence that vitamin D also has a direct action upon the bone cells effecting an increased deposition of bone salt. In a study of the effect of adding vitamin D to a rachitic low-phosphorus diet, it was observed that deposition of bone in rats was resumed at the expense of tissue phosphorus and that tissue growth was suspended. Deposition of radio-... 

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