Time-delayed feedback control of coherence resonance near subcritical Hopf bifurcation: theory versus experiment

Using the model of a generalized Van der Pol oscillator in the regime of subcritical Hopf bifurcation we investigate the influence of time delay on noise-induced oscillations. It is shown that for appropriate choices of time delay either suppression or enhancement of coherence resonance can de achieved. Analytical calculations are combined with numerical simulations and experiments on an electronic circuit

Investigation of genetic structure in mesomorphic bluegrasses, Poa section Stenopoa dum, by using ISSR markers

A morphological and genetic analysis of five mesomorphic bluegrasses populations, Poa section Stenopoa, from a range of geographical locations were performed. We have established that all the populations have different level of the morphological and genetic diversity. A total of 79 DNA bands were obtained from six ISSR primers, including 61 polymorphic bands. Molecular data have shown no clear difference between morphologically homogeneous populations and hybrid populations P. palustris and P. nemoralis. This result may be due to the high genetic diversity of the populations studied

Experimental Comparisons of Derivative Free Optimization Algorithms

In this paper, the performances of the quasi-Newton BFGS algorithm, the NEWUOA derivative free optimizer, the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), the Differential Evolution (DE) algorithm and Particle Swarm Optimizers (PSO) are compared experimentally on benchmark functions reflecting important challenges encountered in real-world optimization problems. Dependence of the performances in the conditioning of the problem and rotational invariance of the algorithms are in particular investigated.Comment: 8th International Symposium on Experimental Algorithms, Dortmund : Germany (2009

Chronotope of Engineering and Pedagogical Thinking

The article is devoted to engineering and pedagogical thinking as a kind of professional thinking that exists due to specific reasons and necessary and sufficient conditions. The “assembly” of these causes and conditions takes place in a certain time-and-place (chronotope), the conceptual reconstruction of which opens the way to overcoming the traditions of haphazard enumerative descriptions of various properties that have developed in the literature and to reaching the construction of the theory of engineering and pedagogical thinking, which, in turn, will help to reasonably update the content and organization of training engineers-teachers, on whom a lot depends in the near technological future of Russia. A review of the characteristics of engineering-pedagogical and related engineering and pedagogical thinking presented in scientific publications is proposed. It shows the need for greater certainty in understanding the nature, foundations, essence and features of heterogeneous engineering and pedagogical thinking. Heterogeneity requires actualization of the potential not only of pedagogy and technical sciences, but also of philosophy, cultural studies, sociology, and psychology. Such actualization shows the heuristic of the communicative interpretation of the nature and essence of thinking. In its light, engineering-pedagogical thinking appears simultaneously as an articulated and unarticulated, discrete and continuous communication of engineers-teachers with students, within which the competencies required by the profession and the impulse developing engineering and technical flair and ingenuity are transmitted, “infecting” (V. Shklovsky2) and charging them, thanks to which communication overcomes the boundaries of the chronotope, gaining continuum features, demonstrating its pulsating situational-suprasituative (corpuscular-wave) dualism. The scientific novelty lies in the justification, by the example of advancing to the theory of engineering and pedagogical thinking, of supplementing the competence approach with consideration of no less significant cultural and subcultural factors, including latent ones, which sometimes manifest themselves in very weak signals about the features of the chronotope of training engineers and technicians by engineers–teachers, not so much by virtue of official regulations as by virtue of singular acts of everyday life communication

Composition and physico-chemical properties of aqueous extracts of lydites of the North Onega synclinorium in Karelia

Relevance. The need to obtain reliable information on chemical composition of aqueous extracts of lydites. There is lack of such information, but it is so important both for understanding dispersion of elements and their impact on natural waters of a region. It is necessary to study the composition of aqueous extracts as a result of water–rock interaction to determine possible sources of water pollution with toxic elements. Mineral composition of lydites of the North Onega synclinorium contains organic carbon and mist pyrite, which may contain increased concentrations of trace elements "harmful" for drinking water. To determine the ability of such elements to pass into a dissolved state, it is necessary to study aqueous extracts of lydites. Aim. To determine trace element composition and physico-chemical properties of aqueous extracts of lydites selected from two districts of the North Onega synclinorium to assess their environmental hazard. Objects. Geological section of the shungite-lidite-dolomite complex of the Zaonezhskaya formation of the Paleoproterozoic age of the North Onega synclinorium. Samples of lidites were taken at the Tetyugino (LT) and Shunga (LSh) sites of the Medvezhyegorsk district of the Republic of Karelia. Methods. Field studies, including investigation of stratigraphic position of lydites in geological sections of the Tetyugino and Shunga sites and sampling, laboratory experiment, aqueous extraction, scanning electron microscopy, Raman spectroscopy, X-ray fluorescence analysis, Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results. Mineralogical composition of the lydites of both sites is similar. Taking into account high content of SiO2 and negligible content of other petrogenic oxides in chemical composition of lydites, it is possible to consider them as a source for obtaining pure quartz raw materials. The structure of lydites is clot-cryptocrystalline and clot-globular. Lydite extracts environment acidity depends on the totality of the minerals extracted from it, either basic (dolomite) or acidic (pyrite oxidation products). This factor is decisive in formation of chemical composition of lydite extracts, regardless of the location of the samples within a given geological object. Many elements extracted by water from the lydite samples of two regions under consideration are characterized by varying degrees of their extraction from the massive and veined parts of the sample. The cure coefficients of chemical elements in the form of the ratio of element average concentrations in the extract and lydite solid phase show the predominant intake of Cd, Mn, Mo, Sr, Rb, Li, Ni, Co, Li from Tetyugino lydites into water. Mo, Sb and W are predominantly extracted into the solution from the Shunga lydites. Average concentrations of most elements of the extracts of the Shunga samples satisfy the requirements for drinking water and, unlike shungite, they are not sources of harmful components in water. Therefore, it is advisable to carry out work on the possibility of their use for water purification for drinking purposes

Features Smelting of Iron and Silicate Materials in the Solid Fuel Low Shaft Furnace

Рассмотрен процесс плавки чугуна и силикатных материалов в твердотопливной низкошахтной печи (вагранке) при замене кокса антрацитом и тощими углями. Приведено теоретическое и практическое обоснование основных технологических параметров процесса. Установлен оптимальный уровень загрузки материалов при плавке чугуна и силикатных материалов в твердотопливной низкошахтной печи, способ подачи дутья в кислородную зону печи и температура дутьяThe process of smelting iron and silicate materials in the solid fuel low shaft furnace (cupola) by replacing coke by anthracite and lean coal. The theoretical and practical study of the basic technological parameters of the process. The optimal level of loading of materials in the smelting of iron and silicate materials in the solid-low shaft oven, a method of supplying oxygen into the blast zone of the furnace and the blast temperatur

A novel chromatin-remodeling complex variant, dcPBAF, is involved in maintaining transcription in differentiated neurons

The Polybromo-associated BAF (BRG1- or BRM-associated factors) (PBAF) chromatin-remodeling complex is essential for transcription in mammalian cells. In this study, we describe a novel variant of the PBAF complex from differentiated neuronal cells, called dcPBAF, that differs from the canonical PBAF existing in proliferating neuroblasts. We describe that in differentiated adult neurons, a specific subunit of PBAF, PHF10, is replaced by a PHF10 isoform that lacks N- and C-terminal domains (called PHF10D). In addition, dcPBAF does not contain the canonical BRD7 subunit. dcPBAF binds promoters of the actively transcribed neuron-specific and housekeeping genes in terminally differentiated neurons of adult mice. Furthermore, in differentiated human neuronal cells, PHF10D-containing dcPBAF maintains a high transcriptional level at several neuron-specific genes

Conversion of the Organic Matter of Domanic Shale and Permian Bituminous Rocks in Hydrothermal Catalytic Processes

© 2017 American Chemical Society. Comparative studies of hydrothermal transformation of organic matter samples of bituminous rocks from Domanic and Permian deposits of the Tatarstan Republic (Russian Federation) have been carried out. The experiments have been taken at a temperature of 300 °C in a vapor-gas carbon dioxide environment, with a content of 30% water in the reactionary system and an initial pressure of carbon dioxide of 2 MPa. It is shown that the distinguishing features of the organic matter of the analyzed species according to thermal analysis data are most prominent in the loss of its mass at various temperature intervals. Also, changes take place in group and structural composition and hydrocarbon composition, which have an impact on the composition of the initial products of experiments. Hydrothermal effects on the Domanic rock sample result in the destruction of structural polymer fragments of kerogen. It results in an increase in the contents of asphaltenes and their modified structures in the form of carben-carboids, insoluble in solvents characteristic of asphaltenes, thus reducing the relative content of saturated hydrocarbons in the products of the experiment. Under similar hydrothermal conditions, changes in the physical composition of the Permian rock are less significant. For the investigation of activation processes of the transformation of organic matter of the Permian rock, an experiment was conducted using catalysts. As catalysts, a composition of oil-soluble iron(II), cobalt(II), and copper(II) carboxylates with an additive of propanol was used. The use of the catalyst has increased the output of light fractions and reduced the content of resins and asphaltenes as part of Permian rock