91 research outputs found
Geotechnical consulting at the stages of design and full repair: A case study of village school in Minusinsk region, Russia
No full textIR SPECTROSCOPY OF LONG CARBON CHAINS AND THEIR DERIVATIVES IN CRYOGENIC MATRICES: SPECIES IDENTIFICATION BY CC ISOTOPIC SUBSTITUTION
No full textAuthor Institution: Max-Planck-Institut fur Kernphysik, D-69029 Heidelberg, PO Box 103980, Germany\maketitle Along with matrix gas, we co-deposited carbon vaporfrom two separated carbon evaporation sources, namely a C-source and a C-source. Under the applied conditions the C molecules are the most abundant species in both carbon sources. We observed that in the formation process of long carbon chains the C units play a major role. This finding was used to establish a new species identification method based on isotopic replacement. The old technique of atomic CC substitution can be reasonably applied only for molecules with a small number of carbon atoms (n9). Using the new method of molecular CC substitution, quite simple distributions having small number of isotopomeric IR absorptions were obtained also for larger species. We present data for C and CO (n6)
Selective Laser-Induced Oxidation of Carbon Chain Molecules in Cryogenic Matrices
No full textWe have tested and applied a laser-induced oxidation method for identifying IR-absorptions of those carbon molecules which have known UV/VIS absorptions. For this purpose we trapped the molecules of carbon vapor in non-inert matrices(O2, Ar-O2). Upon matrix annealing, molecular growth took place leading to a mixture of linear carbon species up to C17. The output of an excimer-dye laser was employed to photo-bleach selectively the strong UV/VIS absorptions of these trapped carbon molecules. Correlations of the changes in IR and UV/VIS spectra were observed. After successful tests performed on C9, C11, C13 for which the UV/VIS as well as the IR absorptions are known we applied the method to the C15 molecule for which the UV/VIS absorption is at around 450 nm but the IR absorptions are unknown. In the course of this research we found that the 1819, 1816 cm^-1 pattern of absorptions in an O2-matrix (1818 cm^-1 in an Ar-matrix) can be assigned to the most intense IR-active C13 stretching mode. The pattern of absorption lines at 1721, 1714, 1707 cm^-1 and 1695 cm^-1 can be assigned as site peaks of C15 in an O2-matrix (1713, 1700, 1695 cm^-1 in an Ar-O2-matrix). To obtain information about infrared absorptions of carbon chain oxides of the type CnO and OCnO, oxygen matrices with replaced ^16O -> ^18O isotopes were applied. There we found that two absorptions at 1803 and 1844 cm^-1 in an Ar-matrix (1800 and 1840 cm^-1 in O2) belong to oxides of a carbon chain rather than to a pure carbon species. The absorption at 2180 cm^-1 in an O2-matrix was assigned to the C6O2 molecule. Our data revise some of the assignments existing in the literature
Experience in designing and operating the buildings located on subsiding and heaving soils of the Minusinsk Hollows
No full textThe article presents the experience of design, expert research within the period of construction and operation of the buildings located on subsiding soils. It describes the experiment in conducting the organized soaking of a mounted house made of reinforced-concrete slabs and claydite-concrete panels. It shows the absence of danger of frost heaving while soaking the subsiding soils. There are tables demonstrating the expert studies during the inspections of deformable buildings and long-term observations over their behavior in freezing and thawing depending on the groundwater level and pressures under the bottom of the foundations. As a result of the analysis of long-term studies it has been established that the building load contributes to the reduction of frost heaving for sandy soils (fine and dust sands). In case of clayey soils, in contrast to the views on this problem emerged at the end of the 20th century, it is impossible to extinguish the migration process using pressure. If the migration flow slows down under the foundation bottom, it occurs due to the higher rate of soil freezing arising from the high thermal conductivity of the foundation body and the formation of vertical ice lenses on the borders of tension zones. The most important thing showed herein is that the thawing process in these lenses provokes the process of stability loss, where the soil protrudes from the foundation bottom. The long-term studies of frost heaving in a severe continental climate of the Minusinsk hollows enabled the development of the most effective direction of the anti-heave stabilization
Boundary triples for integral systems on finite intervals
No full textThe author is grateful to professor V. Derkach for constant attention to this work
Boundary triples for integral systems on finite intervals
No full textThe author is grateful to professor V. Derkach for constant attention to this work
ECONOMIC GROUNDS FOR CREDIT RISK MANAGEMENT UNDER UNCERTAINTY
No full textThis article examines modern financial insurance techniques with the use of credit default swaps for covering bond default risk. The author examines several mathematical models and specifies variables necessary to determine the swap spread depending on the structure of a swap contract and conditions for a set-off. The author suggests implementing J. Hull’s risk model based on default probability and loss ratio estimates
Quantum interference between two phonon paths and reduced heat transport in diamond lattice with atomic-scale planar defects
No full text
The Influence of Tthe Grinding Grains Shape and Orientation on Performance of Coated Abrasive Tools
No full textThe issues of the influence of the orientation and shape of grinding grains of coated abrasive tools on their basic performance characteristics are considered in the article. The advantages of machining with flexible grinding tools are listed. The features of the abrasive grains contained in tools on a flexible basis are presented. The low efficiency of using standard tools is justified. A method is described for increasing the efficiency of the grinding process with tools on a flexible basis due to an integrated approach to the design of new tool designs. It is proposed to use abrasive grains of a given shape and oriented in a certain way relative to the surface of the tool base. The main stages of work related to the development of new tool designs and studies of their operational characteristics are presented. Experimental data of the dependencies of cutting capability, wear, temperature in the cutting zone, power spent on cutting, and the cut surface quality on the shape and the orientation angle of grinding grains are presented. Practical recommendations for the application of tools containing in their structure certain varieties of grinding grains are proposed
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