Superconductivity in nearly single-phase Bi-Pb-Sr-Ca-Cu-O samples with different nominal compositions

The preparation conditions, phase composition, and superconducting properties of Bi-Pb-Sr-Ca-Cu oxide materials from different nominal compositions have been investigated. Nearly single-phase samples from Bi₂Pb_0.4Sr₂Ca₃Cu₄O _y , as well as from the proposed compositions Bi_1.8Pb_0.4Sr₂Ca₃Cu₄O _y and Bi_1.8Pb_0.4Sr₂Ca_2.5Cu_3.5O _y were obtained by a solid-state reaction in air. Samples with the third nominal composition showed the best superconducting properties (T _on=111 K and zero resistance atT ₀=103 K). A possible mechanism for the 2223 phase formation in the three investigated compositions has been discussed.     

Computer-intensive methods in statistical analysis

As far back as the late 1970s, the impact of affordable, high-speed computers on the theory and practice of modern statistics was recognized by Efron (1979, 1982). As a result, the bootstrap and other computer-intensive statistical methods (such as subsampling and the jackknife) have been developed extensively since that time and now constitute very powerful (and intuitive) tools to do statistics with. This article provides a readable, self-contained introduction to the bootstrap and jackknife methodology for statistical inference; in particular, the focus is on the derivation of confidence intervals in general situations. A guide to the available bibliography on bootstrap methods is also offered     

Project for the development of an ambulatory and semi-ambulatory community center for the third age

A case of osteoid osteoma of the scaphoid was discovered, in the absence of radiological (conventional and CT-scan) alterations. MRI findings were not conclusive.     

Conservation laws and shock waves in the theory of relaxation heat transfer

A set of divergent forms of heat-transfer equations are presented. New laws are established that govern the behavior of the temperature field behind the front of a strong discontinuity. Comparison of theoretical and experimental data on the propagation of nonlinear waves in a sapphire crystal and liquid helium is carried out. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 2, pp. 318–325, March–April 1997.     

Wideband wattmeter based on RMS voltage measurements

A wideband wattmeter for measuring active power over a frequency range of dc to 500 kHz is described. The wattmeter is based on the three-voltmeter method in which three rms voltage measurements are used to calculate power. The wattmeter active power uncertainty is estimated to be within 0.03% from dc to 20 kHz and within 1.5% to 500 kHz     

The development and creating of new-generation full-scope simulator and new technology of simulation

Set out is a brief account of the two major accomplishments by the Russian Research Center ‘Kurchatov Institute’ in creating the full-scope simulators and mathematical modeling technologies. Presented are the basic specifications of one of the world's largest simulators—the full-scope simulator for the Leningrad NPP which is the new-generation one. Owing to the extended modeling scope accomplished is the possibility of training personnel to act in terms of not only the design-basis but rather beyond the design-basis accidents. To minimize the expenditures for creating the simulators, analyzers and other modeling and control means, the RRC ‘Kurchatov Institute' has created the unique technology of mathmodeling automation. Thanks to its versatility and application at its creation of the ELUD philosophy (easy to learn, use and develop) good use is made of this technology both in nuclear and thermal power engineering, as well as in gas industry.     

Structural allograft in two-stage revisions for failed septic hip arthroplasty

We report 11 patients having revision of total hip arthroplasty using massive structural allografts for failure due to sepsis and associated bone loss. All patients had a two-stage reconstruction and the mean follow-up was 47.8 months (24 to 72). Positive cultures were obtained at the first stage in nine of the 11 patients, with Staphylococcus epidermidis being the most common organism. The other two patients had draining sinuses with negative cultures. There was no recurrence of infection in any patient. The mean increase in the modified Harris hip score was 45 and all the grafts appeared to have united to host bone. Two patients required additional procedures, but only one was related to the allograft. Complications included an incomplete sciatic nerve palsy and one case of graft resorption. Our results support the use of massive allografts in failed septic hip arthroplasty in which there is associated bone loss.     

Tomsk complex for neutron-transmutation doping of silicon

All-Union Scientific-Research Institute of Nuclear Physics at the S. M. Kirov Tomsk Polytechnical University. Translated from Atomnaya énergiya, Vol. 79, No. 1, pp. 38–40, July, 1995.