Irradiation, natural

The precursor of ° Ru is ° Rh (tip, = 3 years). It is prepared by irradiating natural ruthenium metal with 20 MeV deuterons, " Ru (d, n) Rh. The target is then allowed to decay for several months to diminish the accompanying Rh activity. In a report on ° Ru Mossbauer spectroscopy [111], the authors reported on spectra of Ru metal, RuOa, and [Ru(NH3)4(HS03)2] at liquid helium temperature in standard transmission geometry using a Ge(Li) diode to detect the 127 keV y-rays. The absorber samples contained 1 g of ruthenium per cm. ... 

The two Mossbauer levels of Pt, 99 keV and 130 keV, are populated by either EC of Au(fi/2 = 183 days) or isomeric transition of Pt(fi/2 = 4.1 days). Only a few authors, e.g., [323, 324] reported on the use of Pt, which is produced by thermal neutron activation of " Pt via " Pt(n, y) Pt. The source used in the early measurements by Harris et al. [322, 325] was carrier-free Au diffused into platinum metal. Walcher [326] irradiated natural platinum metal with deuterons to obtain the parent nuclide Au by (d, xn) reactions. After the decay of short-lived isotopes, especially Au(fi/2 = 6.18 days), Au was extracted with ethyl acetate, and the Au/Pt source prepared by induction melting. Buym and Grodzins [323] made use of (a, xn) reactions when bombarding natural iridium with... 

NTD wafers were produced by irradiating natural ultra pure Ge crystals by means of a flux of thermal neutrons (see Section 15.2.2). To realize the electrical contacts, both sides of the wafers (disks, 3 cm in diameter, 3 mm thick) were doped by implantation with B ions to a depth of 200nm. The implanted layers are doped to such a high concentration that the semiconductor becomes metallic. Then a layer of Pd (about 20 nm) and Au (about 400 nm) was sputtered onto the both sides of the wafers. Finally, the wafers were annealed at 200°C for 1 h. The wafers are cut to produce thermistors of length 3 mm between the metallized ends (3x3x1 mm3 typical size) the electrical contacts are made by ball bonding with Au wires. 

Hattori, K., N. Kato, M. Kinoshita, S. Kinoshita, and T. Sunada. Protective effect of ozone in mice against whole-body X-irradiation. Nature 198 1220, 1%3. 

In the following section, the main trends on the influence of experimental conditions, such as atmosphere, irradiation (nature, dose, and dose rate), and composition of the organic and aqueous phases, have been summarized. Generally, radiolysis of... 

Keywords Alkaloids Microwave irradiation Natural products Steroids ... 

D. Ugarte, Curling and Closure of Graphitic Networks under Electron-Beam Irradiation, Nature, 1992, 359, 707. 

Kadhim, M.A., Macdonald, D.A., Goodhead, D.T., Lorimore, S.A., Marsden, S.J., Wright, E.G. (1992). Transmission of chromosomal instability after plutonium alpha-particle irradiation. Nature 355 738 0. 

Osano, Y. T., Uchida, A., and Ohashi, Y. Optical enrichment of a racemic chiral crystal by X-ray irradiation. Nature (London) 352, 510-512 (1991). 

Origins. Most of the radioactive waste at SRP originates in the two separations plants, although some waste is produced in the reactor areas, laboratories, and peripheral installations. The principal processes used in the separations plants have been the Purex and the HM processes, but others have been used to process a variety of fuel and target elements. The Purex process recovers and purifies uranium and plutonium from neutron-irradiated natural uranium. The HM process recovers enriched uranium from uranium—aluminum alloys used as fuel in SRP reactors. Other processes that have been used include recovery of and thorium (from neutron-irradiated thorium), recovery of Np and Pu, separation of higher actinide elements from irradiated plutonium, and recovery of enriched uranium from stainless-steel-clad fuel elements from power reactors. Each of these processes produces a characteristic waste. 

Given other evidence that hydrophobic organic compounds such as DDE sorbed to the NOM aggregates are in a hydrocarbon microenvironmenl (30-34), the results in Table II may be attributable to a solvent effect oi direct photoreaction. This hypothesis is supported by the finding (eq 12) tha only direct photoreaction products were observed in organic extracts of thi irradiated natural water samples. 

To prepare I-DOTATATE, 1 mg of DOTATATE was dissolved in 100 mL of 0.02M acetic acid in redistilled water and dispensed into 1 mL fractions in plastic coated vials. These vials were then freeze dried for 24 h and refrigerated for use in further experiments. A vial containing 10 gg of DOTATATE was added to 40 gL of O.IM phosphate buffer solution at pH7.5. A Na l solution at pH7.5 with high specific activity (>2 x 10" Bq/mg) produced in our laboratory using dry distillation of irradiated natural TeO2 powder was used for the labelling studies. 

Ugarte, D. (1992). Curling and closure of graphitic networks under electron-beam irradiation. Nature, 359, 707-9. 

Spray column contactors were used in the first large-scale solvent extraction plants at Hanford, Washington, for recovering plutonium from irradiated natural uranium and in the first chemical processing plant at Idaho for recovering enriched [L2]. 

U.S. plants. The principal U.S. reprocessing plants are listed in Table 10.3, together with their main process features. All use some form of the Purex process. In 1979, the only ones operating were the Savannah River and Idaho plants of the U.S. Department of Energy (DOE). The Hanford plant had been used primarily for recovery of plutonium and uranium from irradiated natural uranium, but was versatile and had been used, for example, for Thorex... 

Savannah River [P7]. At the Savannah River Purex plant, neptunium in irradiated natural uranium was recovered by the alternative method of forcing most of it into the aqueous waste stream HAW from the first extraction cycle and then recovering it from waste directly by anion exchange. Neptunium in the first extraction step was converted mostly to the inextractable pentavalent state by adding sufficient nitrite to the next-to-the-last mixer-settler stage of the HA section to make the solvent 0.007 M in HNOj. 

The severe degradation of polypropylene following sterilizing doses of irradiation can be characterized mechanically by its failure to undergo the necessary work in practice. Embrittlement increases with time for an irradiated polypropylene, thus rendering an acceptable formulation totally unacceptable a few months after irradiation. Naturally, the decay of radicals can be accelerated by thermal annealing, limited by the geometrical distortion temperature. 

Trial Production of Condoms from Irradiated Natural Rubber Latex on... 

Trial Production of Examination Gloves from Irradiated Natural Rubber... 

TRIAL PRODUCTION OF CONDOMS FROM IRRADIATED NATURAL RUBBER LATEX ON A FACTORY SCALE... 

Several scientists reported that RVNRL or irradiated natural rubber latex is not cytotoxide and free from nitrosamines (4-5), so irradiated natural... 

This paper presents the results of trial production of condom from irradiated natural rubber latex in factory scale, for preparation of commercial production of condom from irradiated latex. 

Apparatus A latex irradiator with activity 110 kCi Co was u.sed for producing the irradiated natural rubber latex. Automatic dipping condom machine with capacity 45-50 gro.ss/hour was used for producing condom. Apparatus for testing latex and condom were pH meter, Instron tester type 1122, etc. 

Figure 6. Thickness distribution of 50 condom from irradiated natural rubber latex... 

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