Silicon nanoparticles and interstellar extinction

To examine a recently proposed hypothesis that silicon nanoparticles are the source of extended red emission (ERE) in the interstellar medium, we performed a detailed modeling of the mean Galactic extinction in the presence of silicon nanoparticles. For this goal we used the appropriate optical constants of nanosized Si, essentially different from those of bulk Si due to quantum confinement. It was found that a dust mixture of silicon nanoparticles, bare graphite grains, silicate core-organic refractory mantle grains and three-layer silicate-water ice-organic refractory grains works well in explaining the extinction and, in addition, results in the acceptable fractions of UV/visible photons absorbed by silicon nanoparticles: 0.071-0.081. Since these fractions barely agree with the fraction of UV/visible photons needed to excite the observed ERE, we conclude that the intrinsic photon conversion efficiency of the photoluminescence by silicon nanoparticles must be near 100%, if they are the source of the ERE.Comment: Latex2e, uses emulateapj.sty (included), multicol.sty, epsf.sty, 6 pages, 3 figures (8 Postscript files), accepted for publication in ApJ Letters, complete Postscript file is also available at http://physics.technion.ac.il/~zubko/eb.html#SNP

Stress-strain state of the mine massif around the chambers of the second stage of mining

A stress-strain state of the rock mass around the chambers of the second stage of mining was analyzed with the help of thermodynamic method. This study is the question of the day as the ore reserves in the chambers of the second stage of mining are, as a rule, extracted being surrounded by the filling mass, and due to this the highest rates of the ore losses and contamination with the filling mass are observed. In connection with this, the study of the stress-strained state of the filling mass and establishment of a method for improving the massif stability presents a great interest today. A calculation scheme for modeling thermodynamic processes in the rock mass around the chambers was developed with the purpose to study the stress field and determine principles of radial stress changing in the filling mass of the surrounding chamber. A chamber in the layer at the depth of 740-840 m was simulated with the following average geotechnical conditions: depth of the extraction chamber, angle of the deposit depression, horizontal thickness of deposit, rock strength in the hanging layer against uniaxial compression, rock strength in the bottom layer against uniaxial compression, and stowing strength against uniaxial compression. The study determined areas with tensile stress in the rocks of the bottom layer, ore mass and filling mass, and their parameters (size, maximum tension) and formulated empirical equations for the dependences between radial tensions and distance to the chambers L of the second stage of mining. The areas of destructive deformation and their dimensions in the stowing mass around the chambers of the second stage of mining at the level 740-840 m were established. Maximum values are defined for the stresses acting in the stowing mass which, exceeding the ultimate strength, cause the mass failure into the space of the chamber of the second stage. In order to prevent the stowing mass failure it is recommended to make a consolidating layer of the solid stowing at the 2/3 height of the chamber in order to resist the high tensile stresses and to ensure the mass stability

Institutional tool of financial policy : contractual policy

Under the market conditions, the most important role in economic subject belongs to the financial aspect – therefore, effective decisions at the micro-level are predetermined by financial policy, as realization of the strategy in the tactics of finances management is not possible if there’s none. Finances of economic subject are a component of the financial system of the Russian Federation. Together with the state financial policy, which is aimed at overcoming of consequences of the global financial crisis, there is financial policy of separate economic subjects and corporate structures. For the purpose of study of financial policy, the authors deem it expedient to clarify the definition of “policy”. According to M. Weber, policy is “striving for participation in authority or influencing the distribution of authority, be it between states or within a state between groups of people”.peer-reviewe

Диэлькометрический метод контроля и диагностики электрических свойств полимерных материалов электротехнического назначения

A dielcometric methods and techniques for monitoring and diagnosis of the electrical properties of polymer composites are developed. The electrical properties of the composites according to the content and type of filler is conducted in the frequency range of the electric field of 50 Hz-1 MHz.Целью данной статьи является разработка диэлькометрического метода и методики для контроля и диагностики электрических свойств полимерных композитов. Исследование электрических свойств композитов в зависимости от содержания и типа наполнителя проведено в диапазоне частот электрического поля 50 Гц - 1 МГц

Dust Grain-Size Distributions From MRN to MEM

Employing the Maximum Entropy Method algorithm, we fit interstellar extinction measurements which span the wavelength range 0.125-3 micron. We present a uniform set of MEM model fits, all using the same grain materials, optical constants and abundance constraints. In addition, we are taking advantage of improved UV and IR data and better estimates of the gas-to-dust ratio. The model fits cover the entire range of extinction properties that have been seen in the Galaxy and the Magellanic Clouds. The grain models employed for this presentation are the simplistic homogeneous spheres models (i.e., Mathis, Rumpl, & Nordsieck 1977) with two (graphite, silicate) or three (graphite, silicate, amorphous carbon) components. Though such usage is only a first step, the results do provide interesting insight into the use of grain size as a diagnostic of dust environment. We find that the SMC Bar extinction curve cannot be fit using carbon grains alone. This is a challenge to the recent observational result indicating little silicon depletion in the SMC.Comment: 24 pages, 5 figures, accepted for publication in the Astrophysical Journa

ИМПЕДАНСНЫЙ МЕТОД КОНТРОЛЯ И ДИАГНОСТИКИ КАЧЕСТВА ЭЛЕКТРОИЗОЛЯЦИОННЫХ МАТЕРИАЛОВ, ИСПОЛЬЗУЕМЫХ В ЭЛЕКТРОТЕХНИЧЕСКОЙ ПРОМЫШЛЕННОСТИ

A method of impedance control and diagnostics of quality of insulating materials, used in electrotechnical industry, is proposed. Electric-capacitive transmitters are created. Formulas to make monitoring and diagnostics of dielectric parameters of insulating materials, such as relative permittivity, dielectric loss tangent, and relevant standards are developed.Разработан импедансный метод контроля и диагностики качества электроизоляционных материалов, используемых в электротехнической промышленности. Созданы электроемкостные измерительные преобразователи, разработана методика, получены формулы, проведен контроль и диагностика диэлектрических показателей электроизоляционных материалов, таких как относительная диэлектрическая проницаемость, тангенс угла диэлектрических потерь, соответствующих нормам, регламентированным стандартам

The Vega Debris Disk -- A Surprise from Spitzer

We present high spatial resolution mid- and far-infrared images of the Vega debris disk obtained with the Multiband Imaging Photometer for Spitzer (MIPS). The disk is well resolved and its angular size is much larger than found previously. The radius of the disk is at least 43" (330 AU), 70"(543 AU), and 105" (815 AU) in extent at 24, 70 and 160 um, respectively. The disk images are circular, smooth and without clumpiness at all three wavelengths. The radial surface brightness profiles imply an inner boundary at a radius of 11"+/-2" (86 AU). Assuming an amalgam of amorphous silicate and carbonaceous grains, the disk can be modeled as an axially symmetric and geometrically thin disk, viewed face-on, with the surface particle number density following an r^-1 power law. The disk radiometric properties are consistent with a range of models using grains of sizes ~1 to ~50 um. We find that a ring, containing grains larger than 180 um and at radii of 86-200 AU from the star, can reproduce the observed 850 um flux, while its emission does not violate the observed MIPS profiles. This ring could be associated with a population of larger asteroidal bodies analogous to our own Kuiper Belt. Cascades of collisions starting with encounters amongthese large bodies in the ring produce the small debris that is blown outward by radiation pressure to much larger distances where we detect its thermal emission. The dust production rate is >~10^15 g/s based on the MIPS results. This rate would require a very massive asteroidal reservoir for the dust to be produced in a steady state throughout Vega's life. Instead, we suggest that the disk we imaged is ephemeral and that we are witnessing the aftermath of a large and relatively recent collisional event, and subsequent collisional cascade.Comment: 13 pages, 17 figures, accepted for publication in ApJ. (Figures 2, 3a, 3b and 4 have been degraded to lower resolutions.

Perspectives on Interstellar Dust Inside and Outside of the Heliosphere

Measurements by dust detectors on interplanetary spacecraft appear to indicate a substantial flux of interstellar particles with masses exceeding 10^{-12}gram. The reported abundance of these massive grains cannot be typical of interstellar gas: it is incompatible with both interstellar elemental abundances and the observed extinction properties of the interstellar dust population. We discuss the likelihood that the Solar System is by chance located near an unusual concentration of massive grains and conclude that this is unlikely, unless dynamical processes in the ISM are responsible for such concentrations. Radiation pressure might conceivably drive large grains into "magnetic valleys". If the influx direction of interstellar gas and dust is varying on a ~10 yr timescale, as suggested by some observations, this would have dramatic implications for the small-scale structure of the interstellar medium.Comment: 13 pages. To appear in Space Science Review

The corporate management of intellectual capital of company

Гончаров В. Н. Корпоративное управление интеллектуальным капиталом компании / В. Н. Гончаров, В. А. Зубко // Вісник Приазовського державного технічного університету : зб. наукових праць / ПДТУ. - Маріуполь, 2013. - Вип. 26. - С. 91-95. - (Серія : Економічні науки).В проведенном исследовании проанализировано текущее состояние корпоративного управления интеллектуальным капиталом компаний как части развития интеллектуальной экономики и предложен механизм корпоративного управления интеллектуальным капиталом компании, процессы которого направлены на стойкую мотивацию успешного развития бизнеса субъекта хозяйствования.У проведеному дослідженні проаналізовано поточний стан корпоративного управління інтелектуальним капіталом компаній як частини розвитку інтелектуальної економіки та запропоновано механізм корпоративного управління інтелектуальним капіталом компанії, процеси якого спрямовані на стійку мотивацію успішного розвитку бізнесу суб’єкта господарювання.The conducted research analyzes the current state of the corporate intellectual capital management companies as part of the development of the knowledge-based economy and the mechanism of the corporate intellectual capital management company its processes being aimed at sustainable motivation successful business entity

Methodological approaches for producing doubled haploids in sugar beet and red beet (Beta vulgaris L.)

The in vitro production of doubled haploids is a biotechnological path of an accelerated development of parental lines in F1-hybrid breeding programs. Unlike the traditional inbreeding method requiring 5 to 6 generations to reach a suf­ficient homozygosity of lines, the number of generations to produce pure lines of beet by haploid technologies is reduced to 2. The production of doubled haploids by gynogenesis is the most common biotechnological approach in sugar and red beets. Protocols for the production of doubled haploids for B. vulgaris species are few and have been developed mainly for sugar beets. There are no protocols for the production of doubled haploids for red beet (B. vulgaris convar. esculenta Salisb.), and the protocols developed for sugar beet (B. vulgaris convar. saccharifera Alef.) are ineffective for red beet, even though these two crops belong to the same species. The greatest success has been achieved in the production of doubled haploids by gynogenesis through isolated ovule culture, especially in sugar beet. Studies on the production of doubled haploids by androgenesis were actively carried out in the 1970s and 1980s and did not lead to the production of regenerated plants. However, at present, there is renewed interest among researchers in this approach, and scientists in different countries are conducting studies of Beta vulgaris androgenesis through isolated microspore culture. This article provides an overview of studies devoted to the production of doubled haploids, addressing the main problems of doubled haploid technologies, and methods to increase the frequency of embryogenesis and doubled haploid plant formation in B. vulgaris crops