A new approach to radioactive waste self-burial using high penetrating radiation

The method of self-burial of radioactive waste in geological formations using direct heating of rocks by radiation is proposed in this paper. In the currently known studies, thermal conductivity is considered as a main heat transfer mechanism. Application of high penetrating gamma radiation for direct melting of surrounding rocks will reduce the energy absorption inside the sinking device and will lower maximum temperature and temperature gradients in the elements of the device. In this paper, conditions of realization of the direct heating by radiation mechanism are presented and requirements to heat-generating radionuclides have been derived. Assessments of the spatial distribution of energy release in the surrounding rocks for the point and plane sources with the radionuclide ⁶⁰Co have been performed. Based on these data, the temperature distributions in the surrounding rocks and the expression for determining the descent velocity as a function of ⁶⁰Co surface activity in the sinking device have been obtained. Estimations of energy absorption fraction inside the spherical heat-generating elements filled with ⁶⁰Co and surface activity of ⁶⁰Co, necessary to achieve velocity of about 1 km per year, have been made. The results are given for granite and salt rocks.     

On the combination of heat pump with solar steam turbine

In this paper we present thermodynamic analysis of the heat pump with solar steam and gas turbines.     

Numerical computation of the thermal self-action effect in a subsonic gas flow

Results are obtained on the thermal self-action effect of an initially Gaussian beam in a subsonic weakly-absorbent gas flow in a broad range of similarity parameters.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 8, No. 1, pp. 35–42, January, 1990.     

Photo-thermo-refractive glass co-doped with Nd as a new laser medium

Photo-thermo-refractive (PTR) glass demonstrates refractive index change after exposure to UV radiation followed by a thermal treatment that enables recording of high efficiency holographic optical elements. This work demonstrates feasibility of function of this material as a complex optical medium which posseses both photosensitive and luminescent properties and paves a way for creation of monolythic solid state lasers where resonator components can be holographically recorded inside of a laser medium. It was found, that incorporating of Nd³⁺ ions in PTR glass does not affect photosensitivity required for hologram recording. It was demonstrated that emission wavelength, spectral width, and cross section of Nd³⁺ luminescence in PTR glass are typical for silicate laser glasses and Nd-doped PTR glass can be considered as a promising laser medium for monolithic solid state lasers.     

Comparison of chlorophyll a concentration detected by remote sensors and other chlorophyll indices in inhomogeneous turbid waters

A new analytical approach for retrieval of the vertically weighted chlorophyll a concentration (Chl(rs)) detected by remote sensors is presented. Model calculations were carried out for the turbid waters of Lake Kinneret, Israel, and showed that Chl(rs) may be replaced by the average chlorophyll a concentration (Chl(p)) within the upper "penetration layer" 0-Z(p). The study also showed a high correlation between Chl(rs) and Chl concentration averaged in the other depth layers, namely, the 0-1 m layer, the euphotic layer (0-Z(e)), and the production layer (0-Z(pr)). Our findings are closely related to models developed for the world ocean, with the exception of periods when the dinoflagellate Peridinium gatunense blooms in the lake. We showed the effect of the pattern of vertical Chl distributions within the penetration layer on the difference between Chl(rs) and other Chl indices was conspicuous when the Chl maximum was in the uppermost 0- m layer of the water column. We assume that the presented approaches are instrumental for further development of optimal, locally adapted algorithms for remote sensing of Chl in any type of natural waters.     

如何选择平锻机

平锻机用于长杆类锻件局部多工位成形,可完成镦粗、冲孔、切边、镦挤、切断、弯曲等工作(图1)。平锻机一般有垂直分模式平锻机和水平模式平锻机两种。锻模分模方式给平锻机结构带来了明显的差别。垂直分模式平锻机在最近30～40年虽结构上变化不大,但耐用性逐步提高,表现在其自身的刚性、工艺适应性及能耗指标均有改善;水平分模式平锻机则相比之下仍处于研制和完善过程之中。1两种平锻机的比较(1)垂直分模式平锻机该类平锻机可靠性高,使用寿命长,工作区域操作方便,锻模更换容易,氧化皮易于从工作区域清理,提高了锻模的寿命。但该类平锻机难于…     

Byzantine Agreement Given Partial Broadcast

This paper considers unconditionally secure protocols for reliable broadcast among a set of n players, where up to t of the players can be corrupted by a (Byzantine) adversary but the remaining h = n - t players remain honest. In the standard model with a complete, synchronous network of bilateral authenticated communication channels among the players, broadcast is achievable if and only if 2n/h < 3. We show that, by extending this model by the existence of partial broadcast channels among subsets of b players, global broadcast can be achieved if and only if the number h of honest players satisfies 2n/h < b + 1. Achievability is demonstrated by protocols with communication and computation complexities polynomial in the size of the network, i.e., in the number of partial broadcast channels. A respective characterization for the related consensus problem is also given.