Singular and Hypersingular Integral Equations Techniques for Gyrotron Coaxial Resonators with a Corrugated Insert

For the first time rigorous theory is developed for eigen traveling TM modes in the resonator of the coaxial cavity gyrotron with a corrugated insert. This mathematical model can be applied for any corrugation parameters and wavelengths. Gyrotron simulation software is developed and allows to calculate mode eigenvalues, electromagnetic field components and Ohmic losses for eigen TE and TM modes. Results of the numerical investigations are presented for the ITER relevant 170 GHz coaxial cavity gyrotron developed in Forschungszentrum Karlsruhe, Germany.     

Sorption of cesium on finely dispersed composite ferrocyanide sorbents

Sorption of microamounts of cesium on finely dispersed composite ferrocyanide sorbents was studied. The sorbents were prepared by precipitation of nickel potassium ferrocyanide in the presence of various mineral supports (chalk, wollastonite, bentonite, clinoptilolite, diatomite, biosilica). The distribution coefficient (K _d) of ¹³⁷Cs on composite ferrocyanide sorbents is considerably higher than on nickel potassium ferrocyanide without support. The K _d values on the composite sorbents increase by a factor of 25–110 when separating the solid phase with a paper filter and by a factor of 4.3–8.2 when using a microfiltration membrane. Considerable increase in K _d of ¹³⁷Cs on composite sorbents is attributed to the formation of a nickel potassium ferrocyanide phase firmly fixed on the support surface and resistant to peptization. Composite ferrocyanide sorbents were tested for the ¹³⁷Cs recovery from a simulated NPP bottom residue in the pH range 8.5–12.0. On the composite sorbents, K _d of ¹³⁷Cs is 2.5–3.0 times higher than on the nickel ferrocyanide precipitate throughout the examined pH range. The composite sorbent based on biosilica and nickel potassium ferrocyanide was tested for treatment of real liquid radioactive waste with a total salt content of 22.0 g dm⁻³ to remove ¹³⁷Cs. The decontamination factor as high as 5190 was attained owing to simultaneous use of the finely dispersed composite ferrocyanide sorbent and an ultrafiltration ceramic membrane.     

Processor curve of a magnetostrictive displacement transducer

A technique is discussed for improving the accuracy of a displacement-sensing primary detector by taking into account the influence of perturbing factors on the coefficients of the so-called processor curve. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 29–30, May, 1999.     

Radiative recombination rate in quantum-well structures in the model without k-selection

The influence of size quantization on the probability of optical transitions without an electron wave-vector selection rule is investigated. It is shown that the inversion current is essentially independent of the thickness of the quantum-well layer in the approximation of a constant injection efficiency. Various approximations for calculating the rate of spontaneous recombination are discussed. Fiz. Tekh. Poluprovodn. 31, 1087–1091 (September 1997)     

Assessment of bioengineering ceramic coatings using the wetting method

The wettability of coatings, including ceramic ones, which show considerable promise for the use on bioengineering products, with physical solution (0.9% NaCl) have been studied. It has been found that the use of coatings of all types under study increases the wetting angles on the surface as compared with the initial metal materials (stainless steel of the 12X18H10T grade, titanium alloy of the BT6-grade, Co-Cr-Mo alloy), which serves as a prerequisite for an improvement in the biocompatibility of implants. The degree of the coating bioinertness increases in the following order: titanium nitride → diamond carbon films → aluminum nitride → titanium oxide (anodic oxide film) → nitride (oxidized) → oxide → titanium oxide (anodic-spark coating).     

X-ray diffraction investigation of diffusion during the sintering of nickel-chromium and iron-chromium powder alloys

Summary The sintering of powder nickel-chromium and iron-chromium alloys was investigated by the x-ray diffraction technique. It was established that the rate of diffusion processes increases with rise in the nickel content of the nickel-chromium alloys, and in the iron content of the iron-chromium alloys, subjected to heat treatment under similar conditions.Translated from Poroshkovaya Metallurgiya, No. 8(56), pp. 22–27, August, 1967.The authors wish to express their gratitude to S. M. Solonin for helpful advice and L. O. Zhenni-Maiskaya for assistance in the investigation.