Design of the PIXIE cryogenic system

The Primordial Inflation Explorer (PIXIE) is a proposed mission to study the polarization of the remnant cosmic microwave background with the goal of finding and understanding primordial gravity waves. The instrument has been designed to capture this information across the entire sky by rejecting foreground signals and suppressing systematic error by multiple differencing methods. The instrument operates at a temperature very close to the cosmic microwave background of 2.7 K, while the detectors operate at 0.1 K. The PIXIE cryogenic system provides this in low Earth orbit by making use of three subsystems. Lightweight, simply deployed shields provide protection against the Earth and Sun while passively cooling wiring and instrument supports at 150 K. A mechanical cryocooler precools wires and supports at 68, 17, and 4.5 K while its compressors operate at room temperature. And finally two adiabatic demagnetization refrigerators cool the instrument from 4.5 to 2.7 K and cool the detectors to 0.1 K. Staged cooling in this manner allows a thermodynamically efficient use of relatively mature technologies that can be fully demonstrated before flight.     

Capital market development and mass privatization are logical contradictions: lessons from Russia and the Czech Republic

The introduction of mass privatization policies in Russia andthe Czech Republic depended on the creation of impersonal capitalmarkets to finance the needs of privatized companies and toprovide a secondary market for the trading of securities. Yet,mass privatization created the contradictory conditions of generatingmillions of poorly informed shareholders, with no efficientmarkets for the sale of the shares. The absence of financialmarkets created systematic pressures to move assets by illegalor non-transparent means to users who value them more. Privatizationcreated the incentives to destroy the financial markets criticalto its success. A comparative case analysis of post-privatizationmarket formation in both these countries demonstrates that thefunctional necessity for these markets does not engender theirown creation. In the absence of institutional mechanisms ofstate regulation and trust, markets become arenas for politicalcontests and economic manipulation. The irony of these policiesis that a principal lesson has been that market reforms cannotcreate viable markets, only institutional formation can.     

Strength Assessment for Butt Joints of Steel 50 by the Fracture Toughness Criteria

We propose an experimental-theoretical engineering procedure for assessing the strength of butt-welded joints using the force (K_Ic) and strain (_c) criteria of the brittle and quasibrittle fracture mechanics, respectively. For this purpose, beam specimens with square and bevel welds and an initial edge crack or notch in the weld metal are tested under three-point bending. The parameter K_Imax controlling fracture of a bent beam with an inclined (Mode I + Mode II) crack is assessed taking into account the values of the stress intensity factors K_I and K_II, and the crack inclination angle ^*. We also studied the plastic zone at the crack tip and the crack propagation kinetics depending on the weld geometry and the V-notch tip radius for butt-welded joints. The data obtained allow one to rate such joints by their strength according to the fracture toughness criteria K_Ic and _c.     

Effect of the ellipticity of a dielectric resonator on the induced whispering gallery modes

The influence of ellipticity of a dielectric resonator on the whispering gallery (WG) oscillation modes induced by a lumped radiation source was studied. Dependence of the spectral characteristics of resonators and the spatial distributions of oscillation fields on the WG mode propagation direction is experimentally determined.     

<Emphasis Type="Italic">G</Emphasis>*-Convergence of Nonlinear Operators in the Theory of Homogenization of Control Objects

To study problems of homogenization of one class of control objects described by nonlinear operator equations, the concept of G*-convergence of nonlinear operators is introduced. The sufficient conditions of identifiability of homogenized objects are obtained. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 42–65, September–October 2005.