Energy Redistribution Research Articles

Changing the paradigm in modelling the Bray-Liebhafsky oscillatory chemical reaction.

The Bray-Liebhafsky (BL) reaction is one of the simplest chemical oscillators consisting initially of only three components. Despite this, its mechanism is unknown for more than 100 years due to the absence of selective, sensitive, and fast experimental techniques for following all of the involved intermediates. The modeling of the BL mechanism assumes presumably mass action kinetics "adjustable" to oscillatory solutions by the application of mathematical stability analysis and treating the system as homogeneous. Such a basically mathematical approach need not suggest physically realistic kinetic parameters and is not unique since a number of models can be proposed. Based on recent experimental and computational results, a new model of the BL oscillatory reaction mechanism is constructed by including heterogeneous processes occurring in the system. The same set of equations is able to demonstrate not only the oscillatory evolution but also mixing effects on the oscillatory dynamics, and non-oscillatory stepwise-iodine oxidation and can rationalize other effects described in literature. Thus, the paradigm of treating the BL oscillatory system as a homogeneous one, described by formal kinetics only, is extended for a better understanding of the chemistry of this apparently simple system. The introduced ideas of energy redistribution may contribute to establishing an improved conceptual base for considering other complex oscillators in various fields of science.

Development of an untraditional technique to control the structure of the output flow from a vortex chamber

A technique of using coherent vortex formations of the dead-end zone of the vortex chamber of the end type as a controlling factor influencing the structure and characteristics of the output flow has been developed. The kinematic parameters of the flow relative to chambers with elongated and extremely short dead-end parts in the range of Reynolds numbers according to the parameters of the nozzle Re=47080–86530 were investigated. The reaction of the flow structure in the output sections of the vortex chambers was determined experimentally using thermoanemometry. Profiles of time-averaged transversal and axial velocity projections, as well as corresponding values of the relative intensity of velocity pulsations, were obtained. It was found that at Re=86530, the elongation of the dead-end part of the chamber leads to a decrease in the initial cross-section of the transversal component by 15 % with an increase in the axial component by 19.7 %, and, at Re=47080, to a decrease in the transversal component by 21 % with an increase in the axial component by 8.5 %. This indicates the redistribution of kinetic energy from transversal to axial energy motion, which is confirmed by the analysis of the corresponding intensity profiles of the velocity pulsations in the output section of the chamber in the near-wall and near-axis zones of the flow. The integral intensity of the velocity pulsations along the initial cross-section of comparable chamber designs increases in a chamber with an elongated dead-end part with almost no additional energy losses. The obtained results form the basis of a rational method of controlling the macro- and microstructure of flows, which determines the efficiency of mass exchange and heat exchange processes in vortex chambers of the end type. Such designs are characteristic of vortex mixers, burners of industrial furnaces, furnace devices of hot water and steam boilers, and other technological and power equipment

Quantum Chaos in the Dynamics of Molecules.

Quantum chaos is reviewed from the viewpoint of "what is molecule?", particularly placing emphasis on their dynamics. Molecules are composed of heavy nuclei and light electrons, and thereby the very basic molecular theory due to Born and Oppenheimer gives a view that quantum electronic states provide potential functions working on nuclei, which in turn are often treated classically or semiclassically. Therefore, the classic study of chaos in molecular science began with those nuclear dynamics particularly about the vibrational energy randomization within a molecule. Statistical laws in probabilities and rates of chemical reactions even for small molecules of several atoms are among the chemical phenomena requiring the notion of chaos. Particularly the dynamics behind unimolecular decomposition are referred to as Intra-molecular Vibrational energy Redistribution (IVR). Semiclassical mechanics is also one of the main research fields of quantum chaos. We herein demonstrate chaos that appears only in semiclassical and full quantum dynamics. A fundamental phenomenon possibly giving birth to quantum chaos is "bifurcation and merging" of quantum wavepackets, rather than "stretching and folding" of the baker's transformation and the horseshoe map as a geometrical foundation of classical chaos. Such wavepacket bifurcation and merging are indeed experimentally measurable as we showed before in the series of studies on real-time probing of nonadiabatic chemical reactions. After tracking these aspects of molecular chaos, we will explore quantum chaos found in nonadiabatic electron wavepacket dynamics, which emerges in the realm far beyond the Born-Oppenheimer paradigm. In this class of chaos, we propose a notion of Intra-molecular Nonadiabatic Electronic Energy Redistribution (INEER), which is a consequence of the chaotic fluxes of electrons and energy within a molecule.

Програмно-інформаційний комплекс моделювання систем теплопостачання

Software and information complex for modeling of the heat supply systems functioning, which allows ensuring the optimal selection of aggregates and their operation modes. It will ensure the production and redistribution of energy in accordance with the schedule of consumers. Simulation of optimized operating modes of a self-sufficient heat supply system for a cottage village based on local energy resources and with minimal use of external energy sources was performed. The use of the software and information complex made it possible to calculate the parameters that provide optimized coverage of the heat load schedule of the cottage village based on local energy resources. The simulation performed using the example of the predicted values of the installed thermal capacity of the power units and the actual ambient temperature schedule. The developed new software and information complex provides an opportunity for hourly simulation and research of optimal modes of operation of heat units of autonomous heat supply systems. In the developed software and information complex, a model of optimization of operating modes is applied, which belongs to the class of problems of optimal loading of generating capacities of power systems with the criterion of minimizing costs for production, accumulation and consumption of heat and electricity. An example of simulation results using the heat load schedule for the selected day of March 20, 2018 is given. The obtained results indicate a decrease in the specific cost of hourly heat supply with an increase in the part of thermal energy supplied at the expense of renewable energy sources, and accordingly, a decrease in the part of gas, and in the general case of any other generation based on fossil fuel technologies, in the total volume of heat supply. Thus, the effectiveness of the use of renewable energy sources based on local energy resources as part of the heat supply system of the cottage village confirmed. Keywords: autonomous heat supply, efficiency of renewable energy sources based on local energy resources

Broadband nonlinear optical response of titanium nitride in the visible spectral range

Epsilon-near-zero (ENZ) materials, a new class of materials with vanishing permittivity, which can significantly enhance the interaction between incident light and matters. Here, we investigated the third-order nonlinear optical response of titanium nitride (TiN), an ENZ material, in the visible range by using Z-scan method, and obtained a maximum nonlinear absorption coefficient β of −3.78 × 103 cm/GW at its ENZ wavelength. Furthermore, the carriers dynamic characteristics of TiN are revealed by time-resolved pump-probe measurement, including the intraband and interband excitation, the former is mainly derived from laser-induced to form a non-equilibrium distribution of hot electrons, resulting in the electron energy redistribution process in the conduction band, and the latter is the electrons located in the valence band being promoted to the conduction band, increasing the total free carrier density and thus causing a change in the optical properties. Our results indicate the great potential applications of TiN in nonlinear optical and all-optical modulation devices.

Constraining 3-D variations in mantle attenuation using normal modes: forward modelling and sensitivity tests

SUMMARY Robust estimates of the Earth’s temperature, composition and partial melt are difficult to obtain from seismic tomography models based only on wave velocities. Seismic attenuation is able to add crucial additional information and allows us to constrain 3-D variations in temperature as well as answer fundamental questions regarding the presence of water and partial melt within the mantle. A major problem with measuring attenuation is that scattering and focusing effects need to be included in order to distinguish between intrinsic attenuation (transformation of energy to heat) and scattering (redistribution of energy). Here, we will use whole Earth oscillations or normal modes, exploiting the fact that small scale scattering becomes less important at longer periods. In addition, focussing is implicitly included by simultaneously measuring the elastic and anelastic splitting function of a given normal mode. Normal mode data has rarely been used before to constrain 3-D variations in attenuation, hence we first need to assess the feasibility of using whole Earth oscillations to image 3-D variations in attenuation in Earth’s upper and lower mantle. Here, we use simple models in forward calculations to evaluate the sensitivity of normal modes to 3-D attenuation variations, and find observable differences in normal mode spectra when 3-D variations in mantle attenuation are included. We also test if 3-D attenuation variations can be recovered using splitting function measurements for synthetic normal mode spectra and investigate potential problems with unaccounted earthquake magnitude variations, noise and wide-band cross-coupling between modes. We find that we are able to recover input synthetic anelastic splitting functions, even when they are an order of magnitude smaller than the elastic splitting functions. Biases in the earthquake seismic moment solutions may lead to ‘ghost’ anelastic splitting functions being recovered, especially for high degree structure. However, this ‘ghost’ signal is only relevant if the size of the input anelastic splitting function is 50 per cent smaller than the scaled amplitude signal of expected upper mantle attenuation. Random noise and normal mode coupling also lead to spurious effects in the anelastic splitting functions. However, they manly affect high degree anelastic structure in a non-branch consistent manner. Thus, we are able to robustly recover low anelastic degree structure (smax ≤ 4) in all tested cases.

Exact time-dependent solution of the Schrödinger equation, its generalization to the phase space and relation to the Gibbs distribution

Using the simplest but fundamental example, the problem of the infinite potential well, this paper makes an ideological attempt (supported by rigorous mathematical proofs) to approach the issue of ≪understanding≫ the mechanism of quantum mechanics processes, despite the well-known examples of the EPR paradox type. The new exact solution of the Schrödinger equation is analyzed from the perspective of quantum mechanics in the phase space. It is the phase space, which has been extensively used recently in quantum computing, quantum informatics and communications, that is the bridge towards classical physics, where understanding of physical reality is still possible. In this paper, an interpretation of time-dependent processes of energy redistribution in a quantum system, probability waves, the temperature and entropy of a quantum system, and the transition to a time-independent ≪frozen state≫ is obtained, which is understandable from the point of view of classical physics. The material of the paper clearly illustrates the solution of the problem from the standpoint of continuum mechanics, statistical physics and, of course, quantum mechanics in the phase space.

Enantioselective sensing by collective circular dichroism.

Quantitative determination and in situ monitoring of molecular chirality at extremely low concentrations is still challenging with simple optics because of the molecular-scale mismatch with the incident light wavelength. Advances in spectroscopy1-4 and nanophotonics have successfully lowered the detection limit in enantioselective sensing, as it can bring the microscopic chiral characteristics of molecules into the macroscopic scale5-7 or squeeze the chiral light into the subwavelength scale8-17. Conventional nanophotonic approaches depend mainly on the optical helicity density8,9 by localized resonances within an individual structure, such as localized surface plasmon resonances (LSPRs)10-16 or dielectric Mie resonances17. These approaches use the local chiral hotspots in the immediate vicinity of the structure, whereas the handedness of these hotspots varies spatially. As such, these localized resonance modes tend to be error-prone to the stochasticity of the target molecular orientations, vibrations and local concentrations18,19. Here we identified enantioselective characteristics of collective resonances (CRs)20 arising from assembled 2D crystals of isotropic, 432-symmetric chiral gold nanoparticles (helicoids)21,22. The CRs exhibit a strong and uniform chiral near field over a large volume above the 2D crystal plane, resulting from the collectively spinning, optically induced dipoles at each helicoid. Thus, energy redistribution by molecular back action on the chiral near field shifts the CRs in opposite directions, depending on the handedness of the analyte, maximizing the modulation of the collective circular dichroism (CD).

Host-guest doping induced excited state energy transfer for efficient room temperature phosphorescence emission

The 1,8-naphthalimide derivatives as the guest and the benzophenone (BP) analogues bis(4-chlorophenyl)methanone (BP2C) and bis(4-fluorophenyl)methanone (BP2F) benzophenone derivatives as the host, we constructed a series of novel doping systems with fluorescence and room temperature phosphorescence (RTP) dual emission. The steady-state spectroscopy, ultrafast spectroscopy techniques, and theoretical calculations indicate that Förster resonance energy transfer (FRET) between singlet states between host and guest components enables energy redistribution in doped systems. At the same time, the Dexter energy transfer (DET) between the triplet states realizes the obvious absorption of the excited triplet state of the guest, resulting in the long-lived room temperature phosphorescence of the doped system. Doping materials have unlimited potential for information storage and anti-counterfeiting by exploiting the properties of photo activation.

Estimating Aerodynamic Properties of Planetary Surfaces using Drone Attitude

Measuring the wind profile near a planet’s surface provides a way to estimate friction velocity and the surface’s aerodynamic roughness length, parameters key for understanding and predicting aeolian activity. In this study, we demonstrate the feasibility of measuring the wind profile using only the attitude of a small drone. Such an approach may be particularly advantageous in planetary exploration where instrument payload, data volume, and power are all limited. Indeed, estimates of Martian winds and the wind profile are likely already feasible with telemetry from Mars 2020 Ingenuity. Given the enormous influence of wind in energy and sediment redistribution on Mars, such measurements are critical to understanding aeolian processes and to constraining parameters used in geologic and climate models (such as dust lofting rates). Future work should explore how to expand on and improve the measurement approach discussed here and whether the already collected telemetry from Ingenuity might be used.

Differential IL18 signaling via IL18 receptor and Na-Cl co-transporter discriminating thermogenesis and glucose metabolism regulation.

White adipose tissue (WAT) plays a role in storing energy, while brown adipose tissue (BAT) is instrumental in the re-distribution of stored energy when dietary sources are unavailable. Interleukin-18 (IL18) is a cytokine playing a role in T-cell polarization, but also for regulating energy homeostasis via the dimeric IL18 receptor (IL18r) and Na-Cl co-transporter (NCC) on adipocytes. Here we show that IL18 signaling in metabolism is regulated at the level of receptor utilization, with preferential role for NCC in brown adipose tissue (BAT) and dominantly via IL18r in WAT. In Il18r-/-Ncc-/- mice, high-fat diet (HFD) causes more prominent body weight gain and insulin resistance than in wild-type mice. The WAT insulin resistance phenotype of the double-knockout mice is recapitulated in HFD-fed Il18r-/- mice, whereas decreased thermogenesis in BAT upon HFD is dependent on NCC deletion. BAT-selective depletion of either NCC or IL18 reduces thermogenesis and increases BAT and WAT inflammation. IL18r deletion in WAT reduces insulin signaling and increases WAT inflammation. In summary, our study contributes to the mechanistic understanding of IL18 regulation of energy metabolism and shows clearly discernible roles for its two receptors in brown and white adipose tissues.

Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions.

Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green algae, a mobile pool of light-harvesting complex II (LHCII) associates with PSI, increasing its absorption cross-section and restoring the excitation balance. This is called state 2. Upon PSI overexcitation, this LHCII pool moves to PSII, leading to state 1. Whether the association/dissociation of LHCII with the photosystems occurs between thylakoid grana and thylakoid stroma lamellae during state transitions or within the same thylakoid region remains unclear. Furthermore, although state transitions are thought to be accompanied by changes in thylakoid macro-organisation, this has never been observed directly in functional leaves. In this work, we used confocal fluorescence lifetime imaging (FLIM) to quantify state transitions in single Arabidopsis (Arabidopsis thaliana) chloroplasts in folio with sub-micrometre spatial resolution. The change in excitation-energy distribution between PSI and PSII was investigated at a range of excitation wavelengths between 475 nm and 665 nm. For all excitation wavelengths, the PSI/(PSI + PSII) excitation ratio was higher in state 2 than in state 1. We next imaged the local PSI/(PSI + PSII) excitation ratio for single chloroplasts in both states. The data indicated that LHCII indeed migrates between the grana and stroma lamellae during state transitions. Finally, fluorescence intensity images revealed that thylakoid macro-organisation is largely unaffected by state transitions. This single chloroplast in folio imaging method will help in understanding how plants adjust their photosynthetic machinery to ever-changing light conditions.

Direct numerical simulation of turbulent open channel flows at moderately high Reynolds numbers

Well-resolved direct numerical simulations of turbulent open channel flows (OCFs) are performed for friction Reynolds numbers up to $Re_\tau =2000$ . Various turbulent statistics are documented and compared with the closed channel flows (CCFs). As expected, the mean velocity profiles of the OCFs match well with the CCFs in the near-wall region but diverge notably in the outer region. Interestingly, a logarithmic layer with Kárman constant $\kappa =0.363$ occurs for OCF at $Re_\tau =2000$ , distinctly different from CCF. Except for a very thin layer near the free surface, most of the velocity and vorticity variances match between OCFs and CCFs. The one-dimensional energy spectra reveal that the very-large-scale motions (VLSMs) with streamwise wavelength $\lambda _x>3 h$ or spanwise wavelength $\lambda _z>0.5 h$ contribute the most to turbulence intensity and Reynolds shear stress in the overlap and outer layers (where h is the water depth). Furthermore, the VLSMs in OCFs are stronger than those in CCFs, resulting in a slightly higher streamwise velocity variance in the former. Due to the footprint effect, these structures also have significant contributions to the mean wall shear stress, and the difference between OCF and CCF enlarges with increasing $Re_\tau$ . In summary, the free surface in OCFs plays an essential role in various flow phenomena, including the formation of stronger VLSMs and turbulent kinetic energy redistribution.

EMReact: a tool for modelling electromagnetic field induced effects in chemical reactions by solving the discrete stochastic master equation

The effects of electromagnetic fields (EMF) have been widely debated concerning their role in chemical reactions. Reactions, usually took hours or days to complete, have been shown to happen a thousand times faster using EMF radiations. This work develops a formalism and a computer program to evaluate and quantify the EMF effects in chemical reactions. The master equation employed in this program solves the internal energy of the reaction under EMFs while including collisional effects. Multiphoton absorption and emission are made possible with the transitioning energy close to the EMF and are influenced by the dielectric properties of the system. Dimethyl Sulfoxide and Benzyl Chloride are simulated under different EMF intensities. The results show that EMF absorption is closely related to the collisional redistribution of energy in molecules. The EMF effect can be interpreted as a shift of the thermodynamic equilibrium. Under such nonequilibrium energy distribution, the ‘temperature’ is not a reliable quantity for defining the state of the system.

Ceramic composites toughened by vat photopolymerization 3D printing technology

High strength and high toughness are mutually exclusive in structural materials. In ceramic materials, increasing toughness usually depends on the introduction of a ductile phase that reduces the strength and high-temperature stability of the material. In this work, vat photopolymerization 3D printing technology was used to achieve toughening of ceramic composite material. The friction sliding of the 3D-printed ceramic macrolayer structure results in effective energy dissipation and redistribution of strain in the whole structure, and macroscale toughening of the ceramic material is realized. In addition, the bridging and elongation of the crack in situ amorphous ceramic whiskers were significant microscopic toughening results, coupled with the toughening of the crack tip of nano-ZrO2. Multiscale collaborative toughening methods based on 3D-printed ceramics should find wide applications for materials in service at extreme high temperatures.

Renewable Energy Re-Distribution via Multiscale IoT for 6G-Oriented Green Highway Management

While recent works on investigating renewable energy sources for powering the highway offer promising solutions for sustainable environments, they are often impeded by unequal distribution of sources across the region due to variations in solar exposure and road intensity that electromagnetically and mechanically generate the energy. By exploiting viable gathering of massive renewable energy data using the Internet of Things (IoT), this paper proposes a framework for improved highway-energy management based on the unmanned aerial vehicle-assisted wireless energy re-distribution of the harvested renewable energy. Combining both massive low-rate sensing with high-speed 6G-envisioned transmission for data aggregation, the IoT architecture is of multi-scale, consisting of: i) global data exchange and analytics for energy mapping, re-distribution planning and forecasting, and ii) local data sensing and processing at individual highway lampposts for micro-energy management. The feasibility of the networked energy system is analyzed via analytical cost-reliability analyses. The cost analysis demonstrates the cost-effectiveness through the lowest Requirement of Energy and Cost of Energy for the setup and maintenance. The reliability analysis reveals the energy plus (E+) feature of the system in certain conditions with enhanced reliability in adverse weathers that impact energy generation. With multi-scale data connectivity to intelligently manage standalone renewable energy, this work puts forward a viable idea of 6G use cases with massively networked energy sensors with a vision of achieving super-connected and intelligence-equipped highways.

Ефективність використання сопел типу Вентурі при отриманні водних рослинних екстрактів

Technologies for obtaining extracts from plant raw materials require constant improvement due to the significant variety of species, composition and physical and chemical properties of plant raw materials. The constant increase in the volume of manufacturing products and preparations using plant extracts ma¬keit actual to search for individual approaches. Currently, cavitation technologies are considered to be one of the most effective in the treatment of gaseous, solid, and liquid media and are used in various industries. The transformation and redistribution of energy, which occur during the formation and collapse of steam-gas bubbles due to the creation of a high difference in pressure, temperature, and potential, corre¬spondd to their maximum values and contribute to increasing the active dynamic influence on the complex heterogeneous systems. During extraction, the use of hydrodynamic cavitation is allowed to effectively carry out the process of active destructtion of plant cell walls, increase the contact area between phases and intensify mass exchange processes. The design of the equip¬ment, the performance profile of the working devices, the flow parameters (absolute pressure and velocity), the critical pressure Pcav, as well as the material properties have a significant impact on the hydrodynamic conditions of the cavitation treatment. The results of research on determination the effectiveness of the use of venturi nozzles in the extraction of dry flowers of calendulaare presented in the article. The research was carried out with cavitation reactor nozzle neck with diameters of 0.006 m, 0.008 m, 0.01 m and 0.012 m. The nozzle with the minimum diameter of the neck (0.006 m) corresponds to the lowest cavitation number, which indicate the highest dispersion efficiency, but the high dispersity of the suspension makes it difficult to separate insoluble substances from the extract. In theresearch, it was established that a nozzle with diameters of 0.008 m and 0.01 mm is rational to be used. The duration of processing should be no more than 60 cycles to avoid overheating of the mixture and to prevent a critical dispersity index at which the process of filtering and separating the extract from the exhausted raw materials is significantly complicated.

Effect of heat source on kinetic energy transfer in compressible homogeneous shear turbulence

The effects of heat sources on kinetic energy transfer in compressible homogeneous shear turbulence are studied using numerical simulations at turbulent Mach numbers 0.1 and 0.4 for two levels of heat source. It is found that the strong heat source can significantly enhance both positive and negative components of subgrid-scale (SGS) kinetic energy flux and pressure–dilatation. After adding a strong heat source, compression motions enhance the positive SGS flux, and expansion motions enhance the negative SGS flux at a low turbulent Mach number. According to the Helmholtz decomposition, we found that the solenoidal and dilatational components of pressure–dilatation and SGS kinetic energy flux are increased greatly by a strong heat source at a low turbulent Mach number. The solenoidal mode plays a dominant role in the kinetic energy transfer process, but the contribution of the dilatational mode is not negligible. The dilatational component of the production term is increased by a strong heat source at a low turbulent Mach number, providing the main source of kinetic energy to the dilatational mode. The strong heat source also enhances the kinetic energy exchange between solenoidal mode and dilatational mode through nonlinear advection at a low turbulent Mach number. Moreover, the strong heat source enhances pressure anisotropy, redistribution of the kinetic energy of two transverse components, and energy transfer from internal energy to the kinetic energy through pressure–dilatation term. At a high turbulent Mach number, the strong heat source has little impact on the solenoidal and dilatational components of kinetic energy transfer terms.

Quasi-ductile to brittle transitional behavior and material properties gradient for additively manufactured SLA acrylate

• Quasi-ductile to brittle transitional behavior investigation of SLA acrylate. • Low curing energy leads to a ductile behavior and clean fracture surface. • High curing energy promotes a brittle behavior and rough fracture surface. • UV-curing creates a thickness-dependent material properties gradient. • Strain rate sensitivity is both a curing- and thickness-dependent variable. This research investigates the correlation between post-curing conditions, thickness, stress–strain, and fracture behaviors of additively manufactured SLA acrylate polymer, utilizing tensile tests and scanning electron microscopic fractography analysis. Due to poor polymerization, low curing energy resulted in a quasi-ductile behavior and low strain rate sensitivity. In contrast, high energy promotes the redistribution of the fracture energy from failure strain to failure stress, leading to increased sensitivity. Furthermore, poorly cured specimens show clean fracture surfaces, contrasting with their quasi-ductile behavior, whereas highly cured specimens present rough surfaces, generally associated with ductile fracture. Therefore, increasing curing energy promotes a transition from a quasi-ductile to an almost perfectly brittle behavior and influences the material's elastic, plastic, and fracture behaviors, which appear to be non-uniform throughout the thickness, especially for thicker structures.

Damage detection in beam-like structures using static shear energy redistribution

Damage detection in beam-like structures using static shear energy redistribution