Systems Studies of Nuclear Energy Development in the USSR

It is one of the goals of the Energy program not only to do in-house research but to promote and pursue collaborative research and exchange of information with other institutions. One may view this interest as an attempt for a broader IIASA Energy program that encourages a wider vision of energy problems. Indeed, the number of groups that closely cooperate with the program is increasing; given our premise, reports of those groups may well be seen as an output of this broader Energy program. The present paper is a major contribution of the Institute of High Temperatures, Moscow, and the Siberian Power Institute, Irkutsk, USSR. It points to the systems implications of the development and future trends of the nuclear option against the background of the fuel resource situation in the USSR. Tangible contributions of this kind add to the understanding of actual systems problems. It is IIASA's intention to continue with such collaborative papers and to try to follow up on this line of activities

Imaging of buried 3D magnetic rolled-up nanomembranes

Increasing performance and enabling novel functionalities of microelectronic devices, such as three-dimensional (3D) on-chip architectures in optics, electronics, and magnetics, calls for new approaches in both fabrication and characterization. Up to now, 3D magnetic architectures had mainly been studied by integral means without providing insight into local magnetic microstructures that determine the device performance. We prove a concept that allows for imaging magnetic domain patterns in buried 3D objects, for example, magnetic tubular architectures with multiple windings. The approach is based on utilizing the shadow contrast in transmission X-ray magnetic circular dichroism (XMCD) photoemission electron microscopy and correlating the observed 2D projection of the 3D magnetic domains with simulated XMCD patterns. That way, we are not only able to assess magnetic states but also monitor the field-driven evolution of the magnetic domain patterns in individual windings of buried magnetic rolled-up nanomembranes

Propagation of wave packets in randomly stratified media

The propagation of a narrow-band signal radiated by a point source in a randomly layered absorbing medium is studied asymptotically in the weak-scattering limit. It is shown that in a disordered stratified medium that is homogeneous on average a pulse is channelled along the layers in a narrow strip in the vicinity of the source. The space-time distribution of the pulse energy is calculated. Far from the source, the shape of wave packets is universal and independent of the frequency spectrum of the radiated signal. Strong localization effects manifest themselves also as a low-decaying tail of the pulse and a strong time delay in the direction of stratification. The frequency-momentum correlation function in a one-dimensional random medium is calculated.Comment: 11 pages, 3 figures, Revtex-4. Submitted to Phys. Rev.

Memory Function versus Binary Correlator in Additive Markov Chains

We study properties of the additive binary Markov chain with short and long-range correlations. A new approach is suggested that allows one to express global statistical properties of a binary chain in terms of the so-called memory function. The latter is directly connected with the pair correlator of a chain via the integral equation that is analyzed in great detail. To elucidate the relation between the memory function and pair correlator, some specific cases were considered that may have important applications in different fields.Comment: 31 pages, 1 figur

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ДИНАМИКИ ДВИЖЕНИЯ ЮБКИ ПОРШНЯ В ЦИЛИНДРЕ ДВИГАТЕЛЯ ВНУТРЕННЕГО СГОРАНИЯ

There examined method theoretical research of sectional piston skirt hydrodynamic lubrication, and influence of piston and connection rod groups options on it.В статье рассмотрена методика проведения теоретического исследования гидродинамической смазки юбки составного поршня, и влияние на нее конструктивных параметров деталей поршневой и кривошипно-шатунной групп

Surgical treatment of severe deformities of cervico-thoracic junction

In this study, the outcomes of surgical treatment of severe spinal cervico-thoracic deformities are evaluated. An analysis of 8 patients who underwent surgery between 2012 and 2015 is presented. Mean age was 11,2 years (range from 2 to 18 y.o.). In 6 patients KFS with cervico-thoracic kyphosis was observed. In 2 patients, both 2-year-old girls, there was anterior displacement at the Th1 vertebra, most likely due to congenital dislocation. In 2 cases type I neurofibromatosis was observed. All the patients with KFS presented with neurological deficit: four patients presented with inferior paraparesis and two patients – with tetraparesis due to cervical myelopathy. In all cases staged surgical treatment was performed: halo-traction for 10-14 days, then occipito-cervico-thoracic instrumented fixation as the 2nd stage. In one case, anterior cervical multilevel fusion with autografting was performed as the 3rd stage. In all but one patient full-scale 3D models of the vertebral column at the deformity level was manufactured based on CT-scans. Mean follow-up time was 18,8 months (range 12-36). In all cases, sufficient correction was achieved. In two cases, there was improvement in neurological status. In two cases fractures of one of the 2,5 mm rods in occipito-cervical instrumentation were observed. This condition requires reoperation and additional reinforcing occipito-cervical fixation using cortical peroneal autograft. Conclusion. Due to the severity and complexity of congenital deformities of the cervico-thoracic junction, full-scale 3-D models are indispensable for understanding anatomical relationships and for surgery planning. Halo-traction is recommended for preoperative correction and neurological complication prevention

Application of full-scale three-dimensional models in patients with severe spine deformities

Introduction. Correction of severe spinal deformities remains challenging. Our objective was to describe our experience using three-dimensional (3D) models and individual implants for the correction of severe spinal deformities. Methods. Full-scale 3D models were custom-made for 20 patients with different types of spinal deformities: 5 patients with severe spondylolisthesis, 3 patients with upper cervical deformities, 2 patient with neurofibromatosis, 2 patients with paralytic scoliosis, 7 patients with severe congenital deformities of spine, one patient with tumor of sternum. 3D models were manufactured using rapid prototyping from CT data. In all cases 3D models were used for planning surgical interventions. Using models as a template, individual implants were created for the fixation of the spine in 11 patients. In 2 patients with C1-C2 deformity, anterior transoral C1-C2 fixation using individual plates was performed. In one 9 yrs patient with neurofibromatosis, secondary deformity and sacral hypoplasia, and in 4 patients with paralytic and congenital scoliosis instrumental deformity correction was performed combined with lumbo-pelvic fixation using individual iliac plates. In 4 patients with spondylolisthesis, additional anterior L5-S1 fixation using individual plates and long threaded cages was performed, in one patient with tumor of sternum a custom-made sternum substitute implant was manufactured. Results. The follow-up period was 2 years, with neurological restoration and stable fixation in all cases. Conclusion. Full-scale 3D models offer a useful tool in preoperative planning, allowing full-scale stereoscopic recognition from any direction and distance with tactile feedback. Full-scale 3D models can be effectively used for creating individual implants

Catalog of Nearby Isolated Galaxies in the Volume z<0.01

We present a catalog of 520 most isolated nearby galaxies with radial velocities V_LG<3500 km/s covering the entire sky. This population of "space orphans" makes up 4.8% among 10900 galaxies with measured radial velocities. We describe the isolation criterion used to select our sample, called the "Local Orphan Galaxies" (LOG), and discuss their basic optical and HI properties. A half of the LOG catalog is occupied by the Sdm, Im and Ir morphological type galaxies without a bulge. The median ratio M_gas/M_star in the LOG galaxies exceeds 1. The distribution of the catalog galaxies on the sky looks uniform with some signatures of a weak clustering on the scale of about 0.5 Mpc. The LOG galaxies are located in the regions where the mean local density of matter is approximately 50 times lower than the mean global density. We indicate a number of LOG galaxies with distorted structures, which may be the consequence of interaction of isolated galaxies with massive dark objects

Silicon carbide for solar energy

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.SiC is a wide-bandgap semiconductor that possesses quite a number of interesting properties and is promising for application in power, high-temperature, and radiation hard electronics. Several areas can be distinguished in which SiC is also a promising material for solar power engineering. SiC high temperature power devices and UV detectors can be used at solar energy stations and also SiC can be used as a substrate for growth III-N materials and graphene. New results obtained at the Ioffe Institute, Nitride Crystals Co and National Research University of Information Technologies, Mechanics and Optics in all the above areas of research will be presented in the reportcf201

Terahertz transverse-magnetic-polarized waves localized on layered superconductor defect in photonic crystals

We theoretically study eigenstates of electromagnetic field inside a one-dimensional photonic crystal containing a defect slab of layered superconductor. Basing on the transfer matrix formalism along with the electrodynamics of Josephson plasma, we obtain the dispersion relations describing the THz electromagnetic modes localized on defect. We consider both symmetric and antisymmetric configuration of defect in photonic crystal. The comparison of the dispersion spectra of the localized states for the layered-superconducting defect and the pure insulating defect reveals the features of the studied system.Теоретически исследованы собственные состояния электромагнитного поля в одномерном фотонном кристалле, содержащем дефектную пластину из слоистого сверхпроводника. Основываясь на методе трансфер-матрицы, с использованием электродинамики джозефсоновской плазмы, получены дисперсионные соотношения, описывающие терагерцевые электромагнитные моды, локализованные на дефекте. Рассмотрены симметричная и антисимметричная конфигурации дефекта в фотонном кристалле. Сравнение дисперсионных спектров локализованных состояний для сверхпроводящего и диэлектрического дефектов позволяет выявить особенности изучаемой системы.Теоретично вивчені власні стани електромагнітного поля в одновимірному фотонному кристалі, що містить дефектну пластину з шаруватого надпровідника. Ґрунтуючись на методі трансфер-матриці, з використанням електродинаміки джозефсонівської плазми, отримані дисперсійні співвідношення, які описують терагерцові електромагнітні моди, що локалізовані на дефекті. Розглядаються симетрична і антисиметричну конфігурації дефекту в фотонному кристалі. Порівняння дисперсійних спектрів локалізованих станів для надпровідного і діелектричного дефектів дозволило виявити особливості системи, що досліджується