Open source: the Russian experience (legislation and practice)

The emergence of so-called free or open-source software and the growth of its economic importance in various industries make questions regarding the legal status of free/open-source licenses especially important. In December 2010, new draft amendments to the Civil Code were published, introducing new concepts in order to reflect the ideas pursued by these types of licenses. This article analyzes existing problems with the legal status of free/open-source licenses, whether proposed amendments may solve them, and what risks they may create. Since Russia is among the first countries trying to include provisions on free/open-source licenses in its legislation, such analysis may be of interest to foreign lawmakers since the concept of open source is universal all over the world.     

Interaction of a shock wave with a turbulent boundary layer on a heated surface

The interaction of a shock wave with a turbulent boundary layer has been studied. A stream has been diagnosed using non-invasive visualization (schlieren method). During the investigation the effect of surface heating on the length of boundary layer separation has been studied. It has been discovered that during surface heating the dependence of the length of separation on the temperature ratio is approximated using a linear law.     

Spontaneous Emission in the Anti-Waveguiding VCSEL

Semiconductors - Spontaneous emission in a vertical cavity surface emitting laser (VCSEL) have been studied. It was estimated that a significant part of the spontaneous emission (~1/3) in a...     

Efficient electro-optic semiconductor medium based on type-II heterostructures

An electro-optic medium based on the type-II semiconductor superlattice is proposed. Electrooptic modulation of the intensity of optical reflectance of the electro-optic medium integrated into a vertical Fabry-Perot cavity is studied by the optical-reflectance-spectroscopy method. The experimental data are approximated using an oscillator model of exciton absorption. The efficiency of the electro-optic medium in the case of detuning from the absorption peak by 50 meV in electric fields of 0–50 kV/cm is 10^?9 m/V at a medium filling factor of 100%.     

Near-infrared photorefractive polymer composites based on carbon nanotubes

A photorefractive effect at the wavelength of 1064 nm is demonstrated for a composite consisting of an aromatic polyimide and carbon single wall nanotubes. The two-beam gain coupling coefficient and the net gain coefficient are equal to 90 and 65 cm⁻¹, respectively, at 80 V/μm for a nanocomposite containing 0.25 wt% crude nanotube material. The refractive index modulation measured at E₀ = 50 V/μm is close to Δn = 0.004.     

Synthesis and structural peculiarities of 1,1‐dimethylhydrazine‐based polyurethanes

Novel polyurethanes (PUs) based on poly(oxytetramethylene glycol), 4,4′‐methylenediphenyl diisocyanate, and 1,1‐dimethylhydrazine (DMH) were prepared. Stoichiometric (1 : 1) and nonstoichiometric (2 : 1 to 20 : 1) prepolymer/DMH ratios were studied. The number‐average molecular masses and possible structures of the obtained polymers were evaluated by potentiometric nonaqueous titration analysis of terminal groups, the Kieldal method (the evaluation of the nitrogen atom content), the aminolysis method, viscosimetry, IR spectroscopy, rheology, and small‐angle X‐ray scattering. Only in the case of the stoichiometric (1 : 1) ratio was a low‐molecular‐mass PU with a linear structure formed, whereas for all studied nonstoichiometric ratios, PUs with branched structures were formed. The level of hard and flexible block segregation increased with the increase in the prepolymer/DMH ratio. Dielectric results for the dynamic glass transition and water sorption measurements provided additional support to the structural studies. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Generator of chaotic microwave oscillations based on a high-power bipolar transistor

A chaotic microwave autooscillatory system has been designed, implemented on a high-power bipolar transistor (2T 982 A-2), and studied. The experiments showed stable generation of chaotic oscillations in a 5.26?C5.44 GHz range with a spectral power density of 1.3 × 10^?3 W/MHz.     

On the gain properties of “thin” elastically strained InGaAs/InGaAlAs quantum wells emitting in the near-infrared spectral region near 1550 nm

The results of experimental studies of the gain properties of “thin” (3.2 nm thick) elastically strained InGaAs/InGaAlAs quantum wells emitting in the near-infrared spectral region near 1550 nm are presented. The results of studying the threshold and gain characteristics of stripe laser diodes with active regions based on “thin” quantum wells with a lattice–substrate mismatch of +1.0% show that the quantum wells under study exhibit a high modal gain of 11 cm^–1 and a low transparency current density of 46 A/cm² per quantum well.     

Whispering Gallery Modes and Spontaneous Emission in Compact VCSEL Structures

Semiconductors - The radiation power from active area into the planar waveguide has been studied theoretically in order to model VCSEL characteristics. Exact and simple quantitative connection...     

Enhancing the Heat Exchange Efficiency of a Delayed Coking Unit

Chemistry and Technology of Fuels and Oils - Heat integration of oil refining processes is an effective instrument in the technological modernization of industrial facilities. A more rational use...