500 research outputs found

    Review of man-made mineral formations accumulation and prospects of their developing in mining industrial regions in Ukraine

    Get PDF
    Purpose. Analysis of the man-made mineral formations of ore mining and smelting, fuel and energy complexes development accumulation, location and prospects amount in the Dnipropetrovsk region. Methods. Comprehensive approach, including analysis of state statistics, waste handling sites (WHSs), regional environmental report, environmental passport of the region, as well as data from other information sources is used in the work. Aerial photographs of man-made formations were obtained using the Google Earth 7.1.8 satellite program. Findings. The analysis of the main man-made mineral formations of ore mining and smelting, fuel and energy complexes accumulation in Ukraine (coal and mining industry waste heaps, tailing dumps, ash dumps, smelter slag dumps) was conducted, their amount and occupied areas were estimated. According to the densest location of man-made formations, they are divided into 4 regions: the Prydniprovsk region, the Kryvyi Rih region, the Nikopol region, the Pavlohrad region. According to information sources, the content of some valuable components in man-made formations has been established. Based on the world market prices of technogenic deposits components research, it was proposed to grade them according to the cost of valuable components. The promising directions have been proposed for the use of mineral resources in various economic sectors. It is noted that from the perspective of development of mineral and raw materials potential, the bulk formations are of interest because of their large reserves in the minimum area. But from the perspective of environmental protection and the interests of the Ukrainian people, the bulk technogenic formations occupying significant areas of agricultural land and having smaller mineral reserves are of great interest. Originality. The conception of man-made raw material mineral fund for further industrial development as an alternative to natural deposits is extended and systematized. For the first time, an integrated and detailed analysis has been performed of technogenic waste of the largest waste storage region in Ukraine, as well as the grouping has been proposed of mining and energy sector waste by density of location and by the contained components value. Practical implications. A sketch-map of the man-made objects location was drawn up and their gradation was carried out according to the preliminary prospects of their development. This will provide a more objective approach to the concept of industrial waste development and planning the strategy for the development of mineral and raw materials potential both at the state and regional levels.утворень гірничо-металургійного й паливно-енергетичного комплексів Дніпропетровської області. Методика. У роботі використано комплексний підхід, що включає аналіз даних державної статистики, місць видалення відходів (МВВ), регіональної доповіді про стан навколишнього середовища, екологічного паспорта регіону, а також даних інших інформаційних джерел. Аерофотознімки техногенних утворень отримані за допомогою супутникової програми Google Earth 7.1.8. Результати. Проведено аналіз накопичення основних техногенних утворень гірничо-металургійного та паливно-енергетичного комплексів України (породні відвали вугільної й гірничорудної галузей, хвостосховища, золошлаковідвали, відвали металургійних шлаків), оцінені їх об’єми та займані площі. За найбільш щільним розташуванням техногенних утворень їх запропоновано розділити на 4 райони: Придніпровський, Криворізький, Нікопольський і Павлоградський. За даними інформаційних джерел встановлено вміст деяких цінних компонентів у різних техногенних відходах. На підставі вивчення світових ринкових цін компонентів техногенних родовищ запропоновано районувати їх за вартістю цінних компонентів у 1 т відходів. Запропоновано перспективні напрями використання мінерально-сировинних ресурсів у різних галузях економіки. Відзначено, що з позиції освоєння мінерально-сировинного потенціалу інтерес представляють насипні відходи в силу їх значних запасів на мінімальній площі, а з позиції охорони навколишнього середовища та інтересів українського народу – наливні техногенні відходи, що займають значні площі сільськогосподарських угідь і мають менші запаси мінеральної сировини. Наукова новизна. Розширено та систематизовано уявлення щодо мінерально-сировинного фонду техногенної сировини Дніпропетровської області для подальшого освоєння як альтернатива природним родовищам. Вперше здійснено комплексний та детальний аналіз техногенних відходів найбільшого регіону-накопичувача України і запропоновано групування відходів гірничодобувного та енергетичного сектору за щільністю розташування й вмістом цінних компонентів. Практична значимість. Складена схематична карта розташування техногенних відходів та проведена градація за попередньою перспективністю їх освоєння. Це дозволить більш об’єктивно підходити до концепції промислового освоєння техногенних відходів і планування стратегії розвитку мінерально-сировинного фонду на державному та регіональному рівнях.Цель. Анализ объемов накопления, мест расположения и перспектив промышленной разработки техногенных образований горно-металлургического и топливно-энергетического комплексов Днепропетровской области. Методика. В работе использован комплексный подход, включающий анализ данных государственной статистики, мест удаления отходов (МУО), регионального доклада о состоянии окружающей среды, экологического паспорта региона, а также данных других информационных источников. Аэрофотоснимки техногенных образований получены с помощью спутниковой программы Google Earth 7.1.8. Результаты. Проведен анализ накопления основный техногенных образований горно-металлургического и топливно-энергетического комплексов Украины (породные отвалы угольной и горнорудной отраслей, хвостохранилища, золошлакоотвалы, отвалы металлургических шлаков), оценены их объемы и занимаемые площади. По наиболее плотному расположению техногенных образований их предложено разделить на 4 района: Приднепровский, Криворожский, Никопольский и Павлоградский районы. По данным информационных источников установлено содержание некоторых ценных компонентов в разных техногенных отходах. На основании изучения мировых рыночных цен компонентов техногенных месторождений предложено районировать их по стоимости ценных компонентов в 1 т отходов. Предложены перспективные направления использования минерально-сырьевых ресурсов в различных отраслях экономики. Отмечено, что с позиции освоения минеральное-сырьевого потенциала интерес представляют насыпные отход по причине их больших запасов на минимальной площади, а с позиции охраны окружающей среды и интересов украинского народа – наливные техногенные образования, занимающие значительные площади сельскохозяйственных угодий и имеющие меньшие запасы минерального сырья. Научная новизна. Расширено и систематизировано представление о минерально-сырьевом фонде техногенного сырья Днепропетровской области для дальнейшего промышленного освоения как альтернатива природным месторождениям. Впервые осуществлен комплексный и детальный анализ техногенных отходов наиболее крупного региона-накопителя Украины и предложено группирование отходов горнодобывающего и энергетического сектора по плотности расположения и ценности содержащихся компонентов. Практическая значимость. Составлена схематическая карта размещения техногенных отходов и проведена градация по предварительной перспективности их освоения. Это позволит более объективно подходить к концепции промышленного освоения техногенных отходов и планирования стратегии развития минерально-сырьевого фонда на государственном и региональном уровнях.This work has been performed in the framework of tasks of a research project funded by the state budget by the Ministry of Education and Science of Ukraine (GP-500), and is also consistent with the “Dnipropetrovsk Regional Complex Program (Strategy) on Environmental Safety and Prevention of Climate Change for 2016 – 2025”

    Event--related desynchronization in diffusively coupled oscillator models

    Get PDF
    We seek explanation for the neurophysiological phenomenon of event related desynchronization (ERD) by using models of diffusively coupled nonlinear oscillators. We demonstrate that when the strength of the event is sufficient, ERD is found to emerge and the accomplishment of a behavioral/functional task is determined by the nature of the desynchronized state. We illustrate the phenomenon for the case of limit cycle and chaotic systems. We numerically demonstrate the occurrence of ERD and provide analytical explanation. We also discuss possible applications of the observed phenomenon in real physical systems other than the brain.Comment: Accepted in Physical Review Letter

    Group Analysis of Variable Coefficient Diffusion-Convection Equations. I. Enhanced Group Classification

    Full text link
    We discuss the classical statement of group classification problem and some its extensions in the general case. After that, we carry out the complete extended group classification for a class of (1+1)-dimensional nonlinear diffusion--convection equations with coefficients depending on the space variable. At first, we construct the usual equivalence group and the extended one including transformations which are nonlocal with respect to arbitrary elements. The extended equivalence group has interesting structure since it contains a non-trivial subgroup of non-local gauge equivalence transformations. The complete group classification of the class under consideration is carried out with respect to the extended equivalence group and with respect to the set of all point transformations. Usage of extended equivalence and correct choice of gauges of arbitrary elements play the major role for simple and clear formulation of the final results. The set of admissible transformations of this class is preliminary investigated.Comment: 25 page

    New results on group classification of nonlinear diffusion-convection equations

    Full text link
    Using a new method and additional (conditional and partial) equivalence transformations, we performed group classification in a class of variable coefficient (1+1)(1+1)-dimensional nonlinear diffusion-convection equations of the general form f(x)ut=(D(u)ux)x+K(u)ux.f(x)u_t=(D(u)u_x)_x+K(u)u_x. We obtain new interesting cases of such equations with the density ff localized in space, which have large invariance algebra. Exact solutions of these equations are constructed. We also consider the problem of investigation of the possible local trasformations for an arbitrary pair of equations from the class under consideration, i.e. of describing all the possible partial equivalence transformations in this class.Comment: LaTeX2e, 19 page

    Delay-induced Synchronization Phenomena in an Array of Globally Coupled Logistic Maps

    Get PDF
    We study the synchronization of a linear array of globally coupled identical logistic maps. We consider a time-delayed coupling that takes into account the finite velocity of propagation of the interactions. We find globally synchronized states in which the elements of the array evolve along a periodic orbit of the uncoupled map, while the spatial correlation along the array is such that an individual map sees all other maps in his present, current, state. For values of the nonlinear parameter such that the uncoupled maps are chaotic, time-delayed mutual coupling suppress the chaotic behavior by stabilizing a periodic orbit which is unstable for the uncoupled maps. The stability analysis of the synchronized state allows us to calculate the range of the coupling strength in which global synchronization can be obtained.Comment: 8 pages, 7 figures, changed content, added reference

    Physicochemical mechanism of structure formation and strengthening in the backfill massif when filling underground cavities

    Get PDF
    The strength and microstructural properties of the backfill massif have been studied and assessed when filling underground cavities that pose a threat of mine rocks collapsing in the process of mining mineral deposits. It is suggested that due to a tendency to mechanical destruction by crushing Ca–O ionic bonds rather than Si–Î covalent ones, the backfill mixture composition is saturated with a large amount of Ca2+ ions. This leads to the formation of a highly-basic type of hydrated calcium silicates and a decrease in the massif strength properties. To study the mineral composition of the components of the mixture and solidified massif and to investigate the microstructure and chemical composition of new formations in the backfill massif, infrared spectroscopy and scanning electron microscopy were used. Laboratory studies of the strength properties of backfill massif were also conducted. The minerals of the mixture components, melilite and pseudowollastonite, have been revealed that perform the main function of the new formations occurrence. It was found that the strength of the backfill massif is by 16% less than the required standard value of 7.0 MPa at the age of 90 days. It was determined that highly-basic jellylike hydrated silicates of tobermorite type of the group CSH (II) with variable composition and a ratio of CaO/SiO2=2–3 are formed in the studied structure of the backfill massif after 90 days of hardening. There are no strong low-basic hydrated calcium silicate bonds that could have a reinforcing effect. Providing the conditions for occurrence of low-basic hydrated calcium silicates in the structure is one of the ways to create a hard backfill massif

    Symmetry Analysis of Barotropic Potential Vorticity Equation

    Full text link
    Recently F. Huang [Commun. Theor. Phys. V.42 (2004) 903] and X. Tang and P.K. Shukla [Commun. Theor. Phys. V.49 (2008) 229] investigated symmetry properties of the barotropic potential vorticity equation without forcing and dissipation on the beta-plane. This equation is governed by two dimensionless parameters, FF and β\beta, representing the ratio of the characteristic length scale to the Rossby radius of deformation and the variation of earth' angular rotation, respectively. In the present paper it is shown that in the case F0F\ne 0 there exists a well-defined point transformation to set β=0\beta = 0. The classification of one- and two-dimensional Lie subalgebras of the Lie symmetry algebra of the potential vorticity equation is given for the parameter combination F0F\ne 0 and β=0\beta = 0. Based upon this classification, distinct classes of group-invariant solutions is obtained and extended to the case β0\beta \ne 0.Comment: 6 pages, release version, added reference for section

    The study of the lifetime of ZnS-based luminescent films by using the devices of LMS series

    No full text
    The development of the device to measure the lifetime of ZnS luminescent films with different dopants has been presented. The devices have been designed to operate under semiautomatic ( LMS 01) and program mode (LMS 02) of measuring the parameters of films with setting the input ones. The data are transmitted to a computer and processed by a specialized program that, in its turn, controls the operation of the device, on the whole

    Encoding via conjugate symmetries of slow oscillations for globally coupled oscillators

    Get PDF
    Peter Ashwin and Jon Borresen, Physical Review E, Vol. 70, p. 026203 (2004). "Copyright © 2004 by the American Physical Society."We study properties of the dynamics underlying slow cluster oscillations in two systems of five globally coupled oscillators. These slow oscillations are due to the appearance of structurally stable heteroclinic connections between cluster states in the noise-free dynamics. In the presence of low levels of noise they give rise to long periods of residence near cluster states interspersed with sudden transitions between them. Moreover, these transitions may occur between cluster states of the same symmetry, or between cluster states with conjugate symmetries given by some rearrangement of the oscillators. We consider the system of coupled phase oscillators studied by Hansel et al. [Phys. Rev. E 48, 3470 (1993)] in which one can observe slow, noise-driven oscillations that occur between two families of two cluster periodic states; in the noise-free case there is a robust attracting heteroclinic cycle connecting these families. The two families consist of symmetric images of two inequivalent periodic orbits that have the same symmetry. For N=5 oscillators, one of the periodic orbits has one unstable direction and the other has two unstable directions. Examining the behavior on the unstable manifold for the two unstable directions, we observe that the dimensionality of the manifold can give rise to switching between conjugate symmetry orbits. By applying small perturbations to the system we can easily steer it between a number of different marginally stable attractors. Finally, we show that similar behavior occurs in a system of phase-energy oscillators that are a natural extension of the phase model to two dimensional oscillators. We suggest that switching between conjugate symmetries is a very efficient method of encoding information into a globally coupled system of oscillators and may therefore be a good and simple model for the neural encoding of information
    corecore