Search Results

You are looking at 1 - 10 of 22 items for :

  • Refine by Access: All Content x
Clear All

Abstract  

Nondestructive measurements of γ-ray and X-ray emissions are often made to characterize special nuclear materials. Various computer codes are available to determine the relative isotopic composition of uranium or plutonium (along with certain other associated nuclides) from analysis of the spectra resulting from such measurements. MGA (Gunnink, Proceedings of the 9th ESARDA symposium on safeguards and nuclear management 167, 1987) and MGAU (Gunnink et al., Proceedings of the IAEA symposium on international safeguards 541, 1994) are among the major isotopic codes. The purpose of this study was to investigate MGA and MGAU performance versus energy resolution of the counting system.

Restricted access

Summary Proton concentration in SrZr0.95M0.05O3-α (M=Ga, Sc, Y and Nd) was measured with a thermobalance at different temperatures (T=673-973 K) and water vapor pressures (P H2O=0.9-12.8 kPa). At all the pressures and temperatures examined, the amount of proton concentration in these samples is in the order of Sc>Y>Ga>Nd. By an equilibrium evaluation, we estimated the maximum possible proton concentration about 2.0 mol% in these samples. Infrared (IR) absorption spectra are measured in these samples. The absorption bands can be fitted by four (M=Ga, Y, Nd) or three (M=Sc) Gaussian bands.

Restricted access
Acta Veterinaria Hungarica
Authors: Consuelo López-Bayghen, Heidy Zozaya, Luis Ocampo, Gordon Brumbaugh, and Héctor Sumano

The efficacy of melengestrol acetate (MGA) to shorten the vernal transition of mares by synchronising and accelerating the first ovulation of the year after 60 days of phototherapy was determined by ultrasonographic monitoring. Sixteen mares in late transition were fed two doses of MGA (150 mg/mare/day and 100 mg/mare/day, respectively) for 10 days. A luteolytic dose of prostaglandin was administered to each mare one day after the end of MGA treatment. The presence and duration of oestrus, follicular growth, uterine oedema and presence of ovulation were monitored by ultrasonography and the cervical tone was evaluated by rectal palpation. Ovulation was detected in 87.5% of the mares treated with 150 mg MGA/mare/day for 10 days, and in 62.5% of the mares receiving 100 mg MGA/mare/day for 10 days. This was statistically different (P = 0.03) from the untreated control mares having an ovulation rate of 20%. Mares that received 150 mg MGA/day for 10 days had a mean treatment to ovulation interval of 13.1 ± 5.97 days after the end of treatment, while mares that received 100 mg MGA/day for 10 days had a mean of 25.6 ± 10.50 days (P = 0.01) to ovulation. These results suggest that MGA can be used for synchronising and hastening the first ovulation of the year in mares.

Restricted access

The objective of this paper is to report a procedure for the extraction and the determination of five textile dyes (Lanasyn Blue F-L 150, Lanasyn Dark Brown M-GLN, Lanasyn Red M-GA, Nylosan Dark Brown S-MBL, and Nylosan Red N-2RBL) which were not yet studied in literature by high-performance thin-layer chromatography. For SPE of these dyes, four types of Strata cartridges (WAX/NH2, SAX, C18-U and C18-E) were tested. The best results were obtained on Strata WAX/NH2. The dyes were separated on precoated Alugram RP-18W/UV254 plates with the n-butanol-ethyl acetate-5% ammonium hydroxide 4:4:1 (v/v) mobile phase. The densitometric scanning was performed at 550 nm. Linear regression analysis of the calibration data indicated a good linear relationship between the peak area and the dye concentration in the range of 20–60 ng per band. For the HPTLC method, the detection and the quantification limits of the studied dyes were calculated. The obtained detection limits (ng per band) were: 6.6 for Lanasyn Blue F-L 150, 5.90 for Lanasyn Dark Brown M-GLN, 3.38 for Lanasyn Red M-GA, 5.49 for Nylosan Dark Brown S-MBL, and 1.07 for Nylosan Red N-2RBL. The SPE-HPTLC procedure was applied to monitor these textile dyes in the effluent wastewater samples collected from a textile factory from Romania.

Restricted access

Abstract  

The kinetics of the exchange between56Mn-labelled manganese dioxide and cations in aqueous solution was studied by measuring the β activity acquired by the solution. The results of the exchange between a chemical γ MnO2 and a divalent M2+ ion (M=Mn, Co, Cu or Zn) or a trivalent M3+ ion (M=Ga, Fe, In, Rh or Al) indicate a fast initial process followed by a diffusion—controlled exchange. It is assumed that M2+ ions exchange with Mn2+ ions and M3+ ions exchange with Mn3+ ions in MnO2. The process depends on the radii of the host and substituent ions and on consideration of crystal field stabilisation energies. It seems that the γ MnO2 studied contains more Mn3+ than Mn2+ ions. The possibility of the exchange between Mn ions and cations of a different charge cannot be ruled out. The exchange between Co2+ ions and MnO2 was enhanced in presence of pyrophosphate, which stabilises Mn(III) as a complex. The fraction of Mn in different samples of MnO2 exchanged with a given cation depends on the type and not on the surface area of the sample.

Restricted access

Arrold, N. P. (1972): Confirmation of the ability of Pseudomonas putida to cause fruiting of the cultivated mushroom. M.G.A. Bull. , 269 , 200-201. Confirmation of the ability of Pseudomonas putida to cause fruiting of the

Restricted access

. 2001 76 213 L. Canilha, J.B. Almeida, M.G.A. Felipe , and W. Carvalho , Biotechnol. Lett. 25

Restricted access
Agrokémia és Talajtan
Authors: Tibor Szili-Kovács, Ágnes Bárány, Anna Füzy, Tünde Takács, Gergely Krett, Ramóna Kovács, and Andrea Borsodi

-Pearson , V. & Gianinazzi , S. eds., Physiological and genetical aspects of mycorrhizae . INRA , Paris , 217 – 221 . van der Heijden , M.G.A

Restricted access
Restricted access

176 186 Cornelissen, J.H.C., Lavorel, S., Garnier, E., Diaz, S., Buchmann, N., Gurvich, D.E., Reich, P.B., ter Steege, H., Morgan, H.D., van der Heijden, M.G.A., Pausas, J

Restricted access