Computer Simulation and Comparison of the Efficiency of Conventional, Polymer and Hydrogel Waterflooding of Inhomogeneous Oil Reservoirs

The oil displacement in a layered inhomogeneous reservoir using two types of physical-chemical technologies (polymer flooding and hydrogel flooding) is the subject of this research. In the first case the aqueous polymer solution of the desired concentration is injected into the porous reservoir creating the high-viscous moving fields. Unlike this technology, the hydrogel flooding is characterized by creation and evolution of the moving hydrogel field directly in porous medium in result of chemical reaction between the water solutions of two gel-forming components which one after another are injected into the oil reservoir with given time interruption. The first component is sorbed more intensively and moves slower than the second one, so when it gradually overtakes the first solution, they begin chemically react with creation of hydrogel. Special numerical methods, algorithms and computer software are developed to solve these systems of nonlinear equations, study and compare an efficiency of the oil field development at the different type of waterflooding. It is shown that creations of the moving polymer or hydrogel fields significantly increases the uniformity of oil displacement in all layers of reservoir and improve their basic exploitation parameters due to the cross-flows between layers and creation of the moving structures in the velocity field of two-phase flow. In doing so, hydrogel technology may be much more effectiveness in comparison with polymer flooding

Observation of nonlinearity-controlled switching of topological edge states

We report the experimental observation of the periodic switching of topological edge states between two dimerized fs-laser written waveguide arrays. Switching occurs due to the overlap of the modal fields of the edge states from topological forbidden gap, when they are simultaneously present in two arrays brought into close proximity. We found that the phenomenon occurs for both strongly and weakly localized edge states and that switching rate increases with decreasing spacing between the topological arrays. When topological arrays are brought in contact with nontopological ones, switching in topological gap does not occur, while one observes either the formation of nearly stationary topological interface mode or strongly asymmetric diffraction into the nontopological array depending on the position of the initial excitation. Switching between topological arrays can be controlled and even completely arrested by increasing the peak power of the input signal, as we observed with different array spacings.Comment: 8 pages, 6 figure

Observation of nonlinear disclination states

Introduction of controllable deformations into periodic materials that lead to disclinations in their structure opens novel routes for construction of higher-order topological insulators hosting topological states at disclinations. Appearance of these topological states is consistent with the bulk-disclination correspondence principle, and is due to the filling anomaly that results in fractional charges to the boundary unit cells. So far, topological disclination states were observed only in the linear regime, while the interplay between nonlinearity and topology in the systems with disclinations has been never studied experimentally. We report here bon the experimental observation of the nonlinear photonic disclination states in waveguide arrays with pentagonal or heptagonal disclination cores inscribed in transparent optical medium using the fs-laser writing technique. The transition between nontopological and topological phases in such structures is controlled by the Kekul\'e distortion coefficient $r$ with topological phase hosting simultaneously disclination states at the inner disclination core and spatially separated from them corner, zero-energy, and extended edge states at the outer edge of the structure. We show that the robust nonlinear disclination states bifurcate from their linear counterparts and that location of their propagation constants in the gap and, hence, their spatial localization can be controlled by their power. Nonlinear disclination states can be efficiently excited by Gaussian input beams, but only if they are focused into the waveguides belonging to the disclination core, where such topological states reside.Comment: 11 pages, 6 figure

Observation of π\pi solitons in oscillating waveguide arrays

Floquet systems with periodically varying in time parameters enable realization of unconventional topological phases that do not exist in static systems with constant parameters and that are frequently accompanied by appearance of novel types of the topological states. Among such Floquet systems are the Su-Schrieffer-Heeger lattices with periodically-modulated couplings that can support at their edges anomalous $\pi$ modes of topological origin despite the fact that the lattice spends only half of the evolution period in topologically nontrivial phase, while during other half-period it is topologically trivial. Here, using Su-Schrieffer-Heeger arrays composed from periodically oscillating waveguides inscribed in transparent nonlinear optical medium, we report experimental observation of photonic anomalous $\pi$ modes residing at the edge or in the corner of the one- or two-dimensional arrays, respectively, and demonstrate a new class of topological $\pi$ solitons bifurcating from such modes in the topological gap of the Floquet spectrum at high powers. $\pi$ solitons reported here are strongly oscillating nonlinear Floquet states exactly reproducing their profiles after each longitudinal period of the structure. They can be dynamically stable in both one- and two-dimensional oscillating waveguide arrays, the latter ones representing the first realization of the Floquet photonic higher-order topological insulator, while localization properties of such $\pi$ solitons are determined by their power.Comment: 10 pages, 6 figures, to appear in Science Bulleti

Evaluation of the PV cell operation temperature in the process of fast switching to open-circuit mode

A procedure for measuring the overheating temperature (ΔT ) of a p-n junction area in the structure of photovoltaic (PV) cells converting laser or solar radiations relative to the ambient temperature has been proposed for the conditions of connecting to an electric load. The basis of the procedure is the measurement of the open-circuit voltage (VO C ) during the initial time period after the fast disconnection of the external resistive load. The simultaneous temperature control on an external heated part of a PV module gives the means for determining the value of VO C at ambient temperature. Comparing it with that measured after switching OFF the load makes the calculation of ΔT possible. Calibration data on the VO C = f(T ) dependences for single-junction AlGaAs/GaAs and triple-junction InGaP/GaAs/Ge PV cells are presented. The temperature dynamics in the PV cells has been determined under flash illumination and during fast commutation of the load. Temperature measurements were taken in two cases: converting continuous laser power by single-junction cells and converting solar power by triple-junction cells operating in the concentrator modules

Observation of edge solitons in topological trimer arrays

We report the experimental observation of nonlinear light localization and edge soliton formation at the edges of fs-laser written trimer waveguide arrays, where transition from nontopological to topological phases is controlled by the spacing between neighboring trimers. We found that, in the former regime, edge solitons occur only above a considerable power threshold, whereas in the latter one they bifurcate from linear states. Edge solitons are observed in a broad power range where their propagation constant falls into one of the topological gaps of the system, while partial delocalization is observed when considerable nonlinearity drives the propagation constant into an allowed band, causing coupling with bulk modes. Our results provide direct experimental evidence of the coexistence and selective excitation in the same or in different topological gaps of two types of topological edge solitons with different internal structures, which can rarely be observed even in nontopological systems. This also constitutes the first experimental evidence of formation of topological solitons in a nonlinear system with more than one topological gap.The authors acknowledge funding of this study by RSF (grant 21‐12‐00096). Also, support by CEX2019‐000910‐S [funded by MCIN/AEI/10.13039/501100011033], Fundació Cellex, Fundació Mir‐Puig, and Generalitat de Catalunya (CERCA) is acknowledged.Peer ReviewedPostprint (author's final draft

Observation of linear and nonlinear light localization at the edges of moiré arrays

We observe linear and nonlinear light localization at the edges and in the corners of truncated moiré arrays created by the superposition of periodic mutually twisted at Pythagorean angles square sublattices. Experimentally exciting corner linear modes in the femtosecond-laser written moiré arrays we find drastic differences in their localization properties in comparison with the bulk excitations. We also address the impact of nonlinearity on the corner and bulk modes and experimentally observe the crossover from linear quasilocalized states to the surface solitons emerging at the higher input powers. Our results constitute the first experimental demonstration of localization phenomena induced by truncation of periodic moiré structures in photonic systems.This research is funded by the research Project No. FFUU- 2021-0003 of the Institute of Spectroscopy of the Russian Academy of Sciences and partially funded by the RSF Grant No. 21-12-00096. F. Y. acknowledges support from Shanghai Outstanding Academic Leaders Plan (Grant No. 20XD1402000) and the NSFC (Grant No. 91950120). S. K. I. and L. T. acknowledge support by Grants No. CEX2019-000910-S and No. PGC2018-097035-B-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, Fundació Cellex, Fundació Mir-Puig, and Generalitat de Catalunya (CERCA).Peer ReviewedPostprint (published version

ИНТЕНСИВНОСТЬ ТРАНСПИРАЦИИ ЛИСТЬЕВ GLYCINE MAX (L.) MERR. В ЗАВИСИМОСТИ ОТ ФАЗЫ РОСТА И ЯРУСНОГО РАСПОЛОЖЕНИЯ НА РАСТЕНИИ

The thematic core facilities plan, CCU of Orel state agrarian university "Genetic resources of plants and their use" for a joint program with Shatilovskay of Institute of leguminous and cereal crops, of field and vegetation experiments on the study of specific features of manifestation of the activity of transpiration leaves of soybean are achieved. The object of the study were 10 varieties of soybeans that were grown on plots of 15 m2 in four replications. Seeding was carried out breeding seeder calculated 600 thousand of viable seeds per hectare. the way the plots were allocated systematically with offset. The care of crops was carried out in accordance with the recommended regional events. It was demonstrated that leaf transpiration activity of the culture increases sharply in the transition of plants to the generative period of development, reaching a maximum in the phase of mass fruit formation, when the most active growth and, consequently, the demand for assimilate. The intensity of transpiration of leaves during this period of plant development was by 8.22 mmol H2O/m2c. The highest transpiration activity was typical for the upper leaves located in the generative sphere of plants, the lowest - activity was fount for the lowerst leaves. On the 5th node from the bottom, its value was 2.2 times lower compared to the assimilating leaves at the top of the plants (3-4 knots top). Thus, the most intensive evaporation of the water by leaves are held from 9:00 to 13:00 hours Moscow time. The intensity of transpiration in this period amounted to an average of 5.42 mmol H2O/m2c, which was 19.9% higher than in the morning (from 7:00 to 8:00) and 42.3% in the afternoon (from 15:00 to 17:00).В рамках тематического плана ЦКП Орловского ГАУ «Генетические ресурсы растений и их использование» по совместной программе с Шатиловской СХОС ФГБНУ ВНИИ зернобобовых и крупяных культур, проведены полевые и вегетационные опыты по изучению видовых особенностей проявления активности транспирации листьями сои. Объектом изучения служили 10 перспективных сортов сои, которые выращивали на делянках площадью 15 м2 в четырехкратной повторности. Посев осуществляли селекционной сеялкой из расчета 600 тыс. всхожих семян на га. Способ размещения опытных делянок – систематический со смещением. Уход за посевами выполняли в соответствии с рекомендуемыми для региона мероприятиями. Установлено, что транспирационная активность листьев культуры резко возрастает при переходе растений к генеративному периоду развития, достигая максимума в фазу массового образования плодов, когда отмечается наиболее активный их рост и, соответственно, спрос на ассимиляты. Интенсивность транспирации листьев в данный период развития растений составляла 8,22 mmol H2O/m2c. Самой высокой активностью транспирации отличались верхние листья, расположенные в генеративной сфере растений, а самую низкую имели нижние. На 5 узле снизу ее величина была в 2,2 раза меньше, по сравнению с ассимилирующими листьями в верхней части растений (3-4 узлы сверху). При этом наиболее интенсивное испарение воды листьями проходило с 9:00 до 13:00 часов по московскому времени. Интенсивность транспирации в этот период составляла в сред- нем 5,42 mmol H2O/m2c, что было на 19,9% выше, чем в утренние часы (с 7:00 до 8:00) и на 42,3% – в послеобеденные (с 15:00 до 17:00)