Krasnoyarsk, Russia
Krasnoyarsk, Russia

Siberian Federal University is a modern multidisciplinary university located in the eastern part of Russia, Krasnoyarsk, that combines fundamental and applied research and teaching.The University holds top positions in Russian universities' rankings: 12—14 place in the total National Rating of Universities , 7—8 place in the section "Innovations and Entrepreneurship", 6—10 place in the section "Education". The Siberian Federal University was ranked #14 among Russian universities in the international rankings "Web of Science" and "Ranking Web of World Universities". The Siberian Federal University participates in the international collaboration and integration into international research and education space.The Universities' fundamental and applied research is closely connected with Institutions of the Siberian Branch of the Russian Academy of science ; many scienties from these institutions are professors and lecturers in the SibFU. The Siberian Federal University has its own large university press, which includes the Scientific Journal of the Siberian Federal University.The University was established in 2006 by merging four large universities of Krasnoyarsk city that had been training professionals in the most competitive sectors of economy in Siberia and the Far East: Krasnoyarsk State University, Krasnoyarsk State Technical University, Krasnoyarsk State Academy of Architecture and Construction and Krasnoyarsk State University of Non-Ferrous Metals and Gold.Today Siberian Federal University is the largest higher educational institution in Siberia and consists of 19 Institutes with more than 3,000 faculty staff teaching 41,000 students. The Chairman of the University Board of Trustees is Dmitry A. Medvedev, the Prime Minister of the Russian Federation. Wikipedia.

Time filter

Source Type

Vyunishev A.M.,Siberian Federal University | Chirkin A.S.,Moscow State University
Optics Letters | Year: 2017

We study the frequency doubling in a quadratic nonlinear photonic crystal consisting of periodically poled structures mediated by uniform layers with random lengths. These structures can be formed by new local impact methods for ferroelectric crystal structuring. The statistical frequency doubling theory is developed for such structures. The effect of the number of random layers and variation in their thicknesses on the second-harmonic conversion efficiency is clarified. It is demonstrated that a proper choice of the intermediate layer thickness can enhance or suppress the conversion efficiency. A new type of the Makerfringes-like second-harmonic intensity oscillations is predicted. © 2017 Optical Society of America.

News Article | May 20, 2017

During the research, the scientists were to answer the following questions which are currently considered to be important in the realm of radiobiology: What are the peculiarities of low-dose gamma radiation`s effect on living creatures? What are the differences between gamma and alpha, beta radiation in terms of their effect on living creatures? Photobacterium phosphoreum, which is quite suitable for a comprehensive analysis of a radiation effect, was used as a test organism. In the course of the experiment, the luminous bacteria were put into an experimental capsule where they were undergoing the effect of different radiation capacity and duration under the temperatures of +5 °C, +10 °C, +20 °C. Research concerning gamma radiation is a significant issue, since, compared to alpha- and beta radiation, it is much more dangerous. The level of its spreading and penetrating the objects is quite high, and one cannot simply cover themselves in order to protect from radiation. For example, to prevent from being harmed by alpha radiation a sheet of paper is enough, while gamma radiation can be prevented only by using heavy metals, such as lead. The differences in effects produced by radiation of alpha-, beta- and gamma-rays are connected with the very nature of those kinds of radiation. While alpha and beta radiation are the beams of charged particles -- the nuclei of helium atoms and electrons respectively, gamma radiation is electromagnetic radiation, characterized by low ionizing power. These distinctive features are supposed to influence biological effects in case of both high-dose and low-dose radiation. As low-dose effects are currently being less analyzed, they are the subject of interest for many scientists. As a result of experiments conducted and all the data compared with the previously known information, the researchers have come to a number of significant conclusions: First, if the influence of low-intensity alpha and beta radiation on living creatures can be described applying the model of hormesis (according to which radiation can have both negative and positive influence), low-intensity gamma-radiation under the same circumstances can be only destructive, and is described as a linear correlation in dose-effect coordinates. Second, the scientists have found out that if the radiation is low-intense, the dose absorbed is not as important as its duration, which is the most significant factor in terms of toxic effect on organisms. Third, the influence of low-dose gamma radiation under the temperatures of +5 °C and +10 °C did not seem to have any harmful radiation effect during the experiment (under 175 hours). However, under the temperature of +20 °C, luminous bacteria intrinsic glow was suppressed, which indicated the presence of toxic radiation. According to the scientists, high temperatures lead to the increase in a speed of a metabolic process, thus making bacteria more sensitive to radiation. Fourth, if the danger of radiation impact is usually connected with some changes on genetic level, then in case of a low-dose gamma radiation the scientists have not found any genetic changes, which could have been responsible for the main functions of bacteria. According to one of the co-authors of a publication by the Siberian Federal University professor and a scientist of the Institute of Biophysics SB RAS, Nadezhda Kudryasheva, the results achieved have both a fundamental role and practical applications, ""These results help to comprehend the nature of low intensity radiation`s biological impact at the cell level. The cells of luminous bacteria are a suitable object for such kind of research. The practical aspect is connected with an opportunity to use luminous bacteria in order to monitor the levels of toxicity in environment in the event of chemical pollution. Our research has shown that usage of luminous bacteria for this purpose is quite prospective." "

Shuvaev A.,Siberian Federal University
Cell Biochemistry and Biophysics | Year: 2014

Fitness cost is the measure of the metabolic burden of unneeded gene expression. It is defined as the lag in bacterial cells growth harboring unneeded genes relative to unburdened cells. Separate cells can concurrently adapt to the burden, demonstrating a decrease in or even a disappearance of the lag. The precise mechanisms of this adaptation are not clearly understood. One possibility is that an increased amount of free ribosomes "absorb" the unnecessary burden. In this work, the mechanism by which an increased concentration of ribosomes could result in faster growth and mask the unneeded gene expression burden is discussed. The initiation time of chromosome replication by the initiator protein DnaA, for which the accumulation speed depends on the ribosomes amount, is taken into account. © 2014 Springer Science+Business Media New York.

Discharges from the Mining-and-Chemical Combine (MCC) of Rosatom, downstream from Krasnoyarsk, resulted in radioactive contamination of sediments of the River Yenisei. The concentration of artificial gamma-emitting radionuclides ( 137Cs, 60Co, 152Eu, and 241Am) was determined with the objective to analyze the migration processes leading to the transport of these radionuclides. The content of artificial radionuclides in the surface layers of the study area varied in wide ranges: 137Cs-318- 1,800 Bq/kg, 60Co-87-720 Bq/kg, 152Eu-12- 287 Bq/kg and 241Am-6-76 Bq/kg. There was a sequence of migration of radionuclides investigated in the surface layer of sediments that were collected in the near zone of influence of the MCC: 241Am≈ 152Eu> 60Co> 137Cs. Radionuclide species have been found to be directly related to sediment structure and composition. © Springer Science+Business Media B.V. 2011.

Gavrikov V.L.,Siberian Federal University
European Journal of Forest Research | Year: 2014

A geometrical model of a forest stand has been analyzed. A forest stand has been modeled as a population of cones which was described by the change of total bole surface area with density $$\hat{S}(N)$$S^(N), relation between density and a horizontal dimension (radius r) r(N), and the relation between vertical dimension (generatrix l) and radius l(r). It has been shown that there are close relationships between $$\hat{S}(N)$$S^(N), l(r) and r(N). In case of $$\hat{S}(N) = const$$S^(N)=const, power exponent of l(r) can be predicted from the power exponent of r(N) and vice versa. A comparison of the model analysis with the data available on Scots pine (Pinus sylvestris L.) stands has been performed. In spite of the model simplicity, its inferences proved to be workable in many cases where the data can be interpreted as a dynamics of an even-aged forest stand. In particular, if the estimation of total bole surface area is constant, the power exponent in the relation of diameter and stand density DBH(SD) can be calculated on the basis of the power exponent in the relation of height and diameter H(DBH) and vice versa. Possible limitations and the meaning of the analysis are discussed. © 2014, Springer-Verlag Berlin Heidelberg.

Kozlova S.A.,RAS Institute of Chemistry and Chemical Technology | Kirik S.D.,Siberian Federal University
Microporous and Mesoporous Materials | Year: 2010

The influence of different types of post-synthetic treatment (exposure at calcination, at boiling treatment in neutral, acidic and alkaline aqueous solutions, treatment in hydrofluoric acid) on the state of the silanol surface of the mesostructured mesoporous silicate materials MCM-41 and SBA-15 has been studied. The material alteration has been monitored by X-ray diffraction, IR-spectroscopy, thermal analysis and nitrogen adsorption. It has been shown that post-synthetic treatment changes the concentration of silanol groups on the material surface. The limit value has been established by experiment: about 3-4 OH/nm 2 for MCM-41 and 5-6 OH/nm 2 for SBA-15, with its excess resulting in the material destruction. The distribution of the re-formed Si-OH groups over the surface is of irregular focal nature. In spite of the destruction, the specific characteristics of the material (inner surface, volume, and lattice parameter) remain the same. The treatment type and medium content influence the material destruction rate, but not the limit density of the silanol covering. Based on the molecular model of MCM-41 and percolation theory an interpretation has been proposed due to the mechanism of fragmentary material decay. Fragments of the surface with the concentration of the OH-groups exceeding the limit eliminate from material because the concentration of OH-groups is correlated with concentrations of the broken silaxane bonds (Si-O-Si), which responsible for the surface connectivity. © 2010 Elsevier Inc. All rights reserved.

Zakhvataev V.E.,Siberian Federal University
Biophysics (Russian Federation) | Year: 2015

Possible scenarios for synchronization of some biological processes with variations in the lunisolar gravitational tide acceleration are considered with regard to the trigger influence of the tidal force on the geological environment and the relevant modulation of the emanation and activity fields of radon and other radioactive elements. Mechanisms and models of the sensitivity of living systems to tidal variations of natural background radiation, including mitochondrial permeability transition, generation of reactive oxygen and nitrogen species, bystander factors, secondary biogenic radiation, modulation of cell signaling, and rhythmic gene expression, are discussed. © 2015, Pleiades Publishing, Inc.

Styugin M.,Siberian Federal University
Cybernetics and Systems | Year: 2014

In our study we analyze information restrictions determined by researchers when creating ideal objects of the real world and we classify types of researchers and describe methods of protection against system research. © 2014 Taylor & Francis Group, LLC.

Schroter M.,University of Rostock | Ivanov S.D.,University of Rostock | Schulze J.,University of Rostock | Polyutov S.P.,University of Rostock | And 4 more authors.
Physics Reports | Year: 2015

The influence of exciton-vibrational coupling on the optical and transport properties of molecular aggregates is an old problem that gained renewed interest in recent years. On the experimental side, various nonlinear spectroscopic techniques gave insight into the dynamics of systems as complex as photosynthetic antennae. Striking evidence was gathered that in these protein-pigment complexes quantum coherence is operative even at room temperature conditions. Investigations were triggered to understand the role of vibrational degrees of freedom, beyond that of a heat bath characterized by thermal fluctuations. This development was paralleled by theory, where efficient methods emerged, which could provide the proper frame to perform non-Markovian and non-perturbative simulations of exciton-vibrational dynamics and spectroscopy. This review summarizes the state of affairs of the theory of exciton-vibrational interaction in molecular aggregates and photosynthetic antenna complexes. The focus is put on the discussion of basic effects of exciton-vibrational interaction from the stationary and dynamics points of view. Here, the molecular dimer plays a prominent role as it permits a systematic investigation of absorption and emission spectra by numerical diagonalization of the exciton-vibrational Hamiltonian in a truncated Hilbert space. An extension to larger aggregates, having many coupled nuclear degrees of freedom, becomes possible with the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method for wave packet propagation. In fact it will be shown that this method allows one to approach the limit of almost continuous spectral densities, which is usually the realm of density matrix theory. Real system-bath situations are introduced for two models, which differ in the way strongly coupled nuclear coordinates are treated, as a part of the relevant system or the bath. A rather detailed exposition of the Hierarchy Equations Of Motion (HEOM) method will be given in terms of a stochastic decoupling ansatz. This method has become the standard in exciton-vibrational theory and illustrative examples will be presented as well as a comparison with ML-MCTDH. Applications will be shown for generic model systems as well as for small aggregates mimicking those formed by perylene bisimide dyes. Further, photosynthetic antenna complexes will be discussed, including spectral densities and the role of exciton-vibrational coupling in two-dimensional electronic spectroscopy. © 2014 Elsevier B.V.

News Article | February 21, 2017

The reason for the scientific interest in the eruption of the volcano Samalas is that it is considered the largest in the last thousand years throwing as much as 10 cubic miles of rock into the atmosphere, which lead to destroying Pamatan, the capital of the ancient Kingdom of Lombok. The ice cores in Greenland evidence this as the study of their chemical composition in the 1980s pointed out that there was one of the largest in history volcanic eruptions in the XIII century. The volcano itself has long remained unknown, and scientists have searched for it all over the world. After studying the writings on the palm leaves in Old Javanese, in 2003 Franck Lavigne found that this volcano could be Samalas located on the island of Lombok in Indonesia. Lake Segara Anak formed in the crater later and made it difficult to detect the volcano. One of the existing scientific theories in climatology over the impact of the eruption Samalas volcano on global climatic conditions in the XIII century says that this event may be the cause of the abnormal cold weather (chronicles describe the following year as the "year without a summer"), widespread crop failure, famine, and social upheavals in Europe after 1257. In January 2017 a paper under the title "Climate response to the Samalas volcanic eruption in 1257 revealed by proxy records" was published in the British scientific journal Nature Geoscience with high impact factor among the nature journals (12.508 for 2 years). The international writing team includes scientists from Switzerland, Russia, France, Britain, the United States, China and Canada. Vladimir Myglan (School of the Humanities of Siberian Federal University) and Olga Churakova (Sidorova) (University of Bern, Institute of Geological Sciences, V.N. Sukachev Institute of Forest, SB RAS) are the Krasnoyarsk scientists who took part in the research. In the scientific world, the leading hypothesis is that the eruption of the volcano Samalas in 1257 was the cause of the Little Ice Age, and more than a hundred years of social crisis in Europe. Based on the analysis of reliable sources the paper refutes this hypothesis. The international team of scientists base their studies on the chronicles of European cities (Speyer, Worms and others) and Siberia, chronicles of harvests and climate data of the annual rings of trees. During the interdisciplinary analysis of data sources, it was found that the impact of the volcanic eruption Samalas on the European climate and the severe cooling after 1257 is greatly exaggerated as the heterogeneity of climate change occurs in the places of distribution of volcanic sediments. Vladimir Myglan: "Western Europe, Siberia and Japan experienced the strongest cooling, which coincided with warmer than normal conditions in Alaska and Northern Canada. It is assumed that in North America volcanic radiation was modeled on the positive vibrations of the warm phase of the El Niño. Historical data confirm a severe famine in England and Japan, but it had started before the eruption. We believe that the eruption of the volcano Samalas only aggravated an existing crisis but it was not the cause".

Loading Siberian Federal University collaborators
Loading Siberian Federal University collaborators