Multi-element System Research Articles

In-situ infrared spectroscopic study of the mechanism of the low temperature selective catalytic reduction of NO surface by Mn/ bastnaesite concentrate

The Mn/bastnaesite concentrate and Mn/Al2O3 catalysts were prepared by impregnation method, and their NH3-SCR denitrification performance was tested. The results showed that the Mn/bastnaesite concentrate catalyst achieved up to 95% NO conversion rate at 150 °C, and the Mn/Al2O3 catalyst reached 76% at 300 °C. A series of characterisation results showed that the bastnaesite concentrate can better interact with MnOx species and promote mutual dispersion compared to Al2O3. The Mn/bastnaesite concentrate has a stronger redox capacity, and good NH3 and NO adsorption capacity at low temperatures. The multi-element coexistence system of bastnaesite concentrate itself is a significant advantage of its use as a carrier. In-situ Fourier transform infrared (FTIR) results showed that the Mn/bastnaesite concentrate catalyst follows an L-H mechanism throughout the reaction, with NH4+ species in the Brønsted acidic site on the catalyst surface being the main reactant species. Most of NO is converted to monodentate nitrite, which is formed by bonding with Mn3+ provided by the supported Mn species, rare earth elements and transition metal ions contained in the carrier itself to form O–N–O–Mn3+ intermediates, which participate in the reaction together, and then combined with the adsorbed NH4+/NH3 species to produce N2 and H2O. An E-R mechanism was also present on the catalyst surface, NO participates directly in the reaction in gaseous form, and the NO [NH2](ads) intermediate species produced by interaction with NH4+ species in the acidic position of Brønsted was further decomposed to N2 and H2O. By comparing the reaction mechanism with the commonly used catalyst carrier Al2O3 for NH3-SCR, it can be concluded that bastnaesite concentrate as a carrier not only has the performance of conventional carriers, but also has certain catalytic activity and can interact with the active components to give it excellent performance, which provides a theoretical basis for rare earth minerals as denitrification catalysts.

Improved accuracy for calibrated mass distribution measurements of bimetallic nanoparticles

Implementation of hybrid nanoparticles (HNPs), consisting of two different metal components, into applied systems has been hindered by an incomplete understanding of structural and chemical properties responsible for their enhanced, yet inconsistent performance. To address this persistent need, our work focused on using the electrospray differential mobility analyzer hyphenated to inductively coupled plasma mass spectrometry (ES-DMA-ICP-MS) to determine mass distributions across the entire NP distribution. Although previous work had applied similar hyphenated measurements to HNP systems, no efforts to develop accurate calibration methods for quantifying NP, and especially HNP, masses have been reported. We chose gold titania catalyst HNPs (Au@TiO2: 4 nm gold NPs adsorbed on 100 nm–300 nm TiO2 NPs) as a representative system because a large body of research exists on this topic. When we used ionic standards and compared it to our Au@TiO2 control, a reproducible difference in the slope was observed that led to an overestimation of both gold (Au) and titanium (Ti) by nearly a factor of four for the HNPs, demonstrating the complexity of quantification and the need to both develop a validated calibration method and identify the major sources for uncertainty in quantification. We determined the mass quantification discrepancy derived from the metal oxide NPs (independent of the presence of Au) and was caused by the DMA and ES (not the ICP-MS). Corrections were made for multiple charging that significantly improved the agreement between the ionic standard and Au@TiO2 metal quantification. Discussion on material properties for improved accuracy across different shapes, sizes, compositions, and surface chemistries is also included to demonstrate the general utility of the calibration across a broad number of fields. ES-DMA-ICP-MS is a powerful technique that provides statistically significant data for simultaneous determination of mass distributions of multi-element HNP systems across the entire sample population and should enhance characterization and development of HNPs when coupled with current core methods.

Generalized design variables in rod system optimization under pulse loading

The paper presents the comparative analysis of optimization of the multi-element rod system under static and pulse loads at a variable number of design parameters. It is shown that the design concept of generalization of design variables can significantly reduce not only the complexity of solving the optimization problem, but also the quality of the optimum solution. Approaches are proposed for generalizing the multidimensional design parameters for the twodimensional case at the restrictions of the maximum equivalent stress and strain. The proposed optimization of the frame structure proves the effectiveness of these approaches.

Source Localisation Using Wavefield Correlation-Enhanced Particle Swarm Optimisation

Particle swarm optimisation (PSO) is a swarm intelligence algorithm used for controlling robotic swarms in applications such as source localisation. However, conventional PSO algorithms consider only the intensity of the received signal. Wavefield signals, such as propagating underwater acoustic waves, permit the measurement of higher order statistics that can be used to provide additional information about the location of the source and thus improve overall swarm performance. Wavefield correlation techniques that make use of such information are already used in multi-element hydrophone array systems for the localisation of underwater marine sources. Additionally, the simplest model of a multi-element array (a two-element array) is characterised by operational simplicity and low-cost, which matches the ethos of robotic swarms. Thus, in this paper, three novel approaches are introduced that enable PSO to consider the higher order statistics available in wavefield measurements. In simulations, they are shown to outperform the standard intensity-based PSO in terms of robustness to low signal-to-noise ratio (SNR) and convergence speed. The best performing approach, cross-correlation bearing PSO (XB-PSO), is capable of converging to the source from as low as −5 dB initial SNR. The original PSO algorithm only manages to converge at 10 dB and at this SNR, XB-PSO converges 4 times faster.

Exploring the Patterns of Resident Resettlement in Rural and Suburban Areas and Their Influence on the Passenger Trip Generation

The region is a complex multi-element and heterogeneous dynamic system. Regional public transport systems are characterized by heterogeneity and incompleteness of information about the processes that take place in them. The factors determining the demand for public passenger transport services, the structure of suburban population transit and the economic consequences of changing this structure have not yet been sufficiently investigated. There is no quantitative assessment of the control factors’ influence on the results of the passenger transport system functioning in suburban traffic, which complicates the effective management in this field.In order to determine the mutual influence of objects with unclear functional connection, one of the methods of computational geometry is considered, which allows quantifying and obtaining tabulated functions of various components and parameters of settlements' interaction and centers of gravity. The numerical characteristics obtained by the described method are further used in the modeling of the processes of efficient functioning and collaboration of urban passenger transport with other external transport types, in particular at interchanges.As a result of the proposed operations, we obtain a tabulated function of the investigated parameter for the area of spatial interaction of infrastructure objects and visualize the calculated parameters in the form of graphical dependencies or in the form of a three-dimensional surface. Thus, using the method of computational geometry, with constructing a Voronoi diagram and executing the Delaunay triangulation, it is possible to obtain tabulated characteristic parameters for inhomogeneous zones of mutual influence where infrastructure objects with unclear functional connection are located.

Peculiarities of the Edaphic Cyanobacterium Nostoc linckia Culture Response and Heavy Metal Accumulation from Copper-Containing Multimetal Systems.

Soil and water pollution is a major problem that has a negative impact on ecosystems and human health in particular. In the bioremediation processes, the application of photosynthetic microorganisms, including cyanobacteria, is a direction of action addressed with increasing frequency in the context of further development and improvement of environmentally friendly techniques needed for detoxification of soils and waters polluted with low concentrations of toxic elements, since they pose a challenge for traditional treatment methods. In the present study, the removal of copper and other metal ions from multielement systems by three generations of Nostoc linckia is discussed. Changes in the biochemical composition of the nostoc biomass, which accumulates metal ions, were monitored. Neutron activation analysis was applied to assess Cu, Fe, Ni, and Zn accumulation by biomass, as well as to determine the biochemical composition of biomass after specific biochemical methods were used. The capacity of the accumulation of copper and other metal ions from multi-elemental systems by cyanobacteria Nostoc linckia was high and increased over two cycles of biomass growth in the systems Cu-Fe-Ni and Cu-Fe-Zn and over three cycles in Cu-Fe and Cu-Fe-Ni-Zn systems. It constituted 1720–10,600 µg metal/g depending on the system and cycle of cultivation. The accumulation of Fe, Ni, and Zn also increased over the generations of nostoc. The process of metal accumulation was demonstrated by a significant change in the biomass biochemical composition. Cyanobacteria Nostoc linckia possess a pronounced capacity of copper and other metal ion accumulation from multimetal systems and showed an increased resistance in environments polluted with heavy metals.

Surrogate Model of the Optimum Global Battery Pack Thermal Management System Control

The control of the battery-thermal-management-system (BTMS) is key to prevent catastrophic events and to ensure long lifespans of the batteries. Nonetheless, to achieve a high-quality control of BTMS, several technical challenges must be faced: safe and homogeneous control in a multi element system with just one actuator, limited computational resources, and energy consumption restrictions. To address those challenges and restrictions, we propose a surrogate BTMS control model consisting of a classification machine-learning model that defines the optimum cooling-heating power of the actuator according to several temperature measurements. The la-belled-data required to build the control model is generated from a simulation environment that integrates model-predictive-control and linear optimization concepts. As a result, a controller that optimally controls the actuator with multi-input temperature signals in a multi-objective optimization problem is constructed. This paper benchmarks the response of the proposal using different classification machine-learning models and compares them with the responses of a state diagram controller and a PID controller. The results show that the proposed surrogate model has 35% less energy consumption than the evaluated state diagram, and 60% less energy consumption than a traditional PID controller, while dealing with multi-input and multi-objective systems.

Urbanized Environment Quality Assessment Methodology

Urbanized environment is a complex multi-element system. Urbanization has negative effects on the urban environment and necessitates finding balance to optimize the development of urbanized spaces. This paper proposes an urbanized environment quality assessment method based on evaluating the architecture, nature, development, technogenic effects, and infrastructure. All the aspects of urbanized development are split into positive and negative. The assessment of these aspects helps conclude how favorable urbanized environment is. The assessments must be analyzed to conclude on the quality of development. Then the aspects that score the worst should be addressed in order to improve the quality of the urbanized environment. Ranking can be done by comparing against the scores of other urbanized systems.

Railway track support condition assessment—Initial developments on a vehicle-based monitoring solution through modal analysis

Nowadays, there are multiple initiatives showing a renewed interest on railway transport of goods and passengers around the world. Thus, an efficient management of railway infrastructures, both at the operational level and in terms of economic profitability, is not only desirable but also corresponds to an area of ongoing research. In order to contribute to these efforts, an alternative and novel methodology to evaluate railway track support conditions is presented here, based on modal analysis of the characteristic frequencies of the multi-element system composed by a railway infrastructure and an instrumented vehicle moving over it. This methodology belongs to the group of vibration-based structural damage identification methods, and is focused on observing the characteristic frequencies of this multi-element system, which can be correlated with changes in the physical properties of the railway infrastructure under analysis. An important feature of the proposed methodology is that it should enable the collection of information regarding the conditions of the substructure of a railway infrastructure. By performing this assessment of a railway infrastructure over its length, and over time by comparing different rides over the same railway stretch, important information can be gathered regarding the support conditions of the track. This paper presents a complete description on the current stage of development of the proposed methodology, along with the theoretical model that serves as the basis to interpret the collected data. Preliminary verification of this methodology is performed through the analysis of two case studies regarding the passage of an instrumented vehicle over two underpasses. The results obtained so far show that the proposed methodology can provide relevant information regarding the support conditions of railway tracks.

Decision Games as an Element of Managerial Improvement in Crisis Management

In order to ensure effective counteraction to contemporary security threats, maximum limitation of human losses, property and natural environment losses, a multi-level and multi-element system of crisis management has been organized in Poland, covering all levels of government and local government administration as well as specialist services, guards, separate inspections and non-governmental organisations. The effectiveness of this system, most of whose participants are not full-time employees, depends, among other things, on proper training and preparation of managerial staff. One of the most important contemporary methods of training and improvement of managerial staff is the method of “decision games”, which should be aimed at training the managers of crisis management systems in solving complex problems and shaping intellectual features that affect the efficiency of action and creative thinking of decision-makers, especially during the search for rational solutions to problems, in conditions of difficult to determine risk. This method has many advantages, including the possibility of implementing theoretical knowledge about crisis management into practical solutions, practising in conditions which decision-makers may encounter in reality, the coverage of practically the whole area of decision-making in crisis management, or the implementation of the acquired knowledge and skills into practical actions but on “paper” in conditions free from the risk of human losses or property or natural environment losses due to wrong decisions.

Influence of Surface Preparation on Cracking Phenomena in TIG-Welded High and Medium Entropy Alloys

Multi-element systems with defined entropy (HEA—high entropy alloy or MEA—medium entropy alloy) are rather new material concepts that are becoming increasingly important in materials research and development. Some HEA systems show significantly improved properties or combinations of properties, e.g., the overcoming of the trade-off between high strength and ductility. Thus, the synthesis, the resulting microstructures, and properties of HEA have been primarily investigated so far. In addition, processing is crucial to achieve a transfer of potential HEA/MEA materials to real applications, e.g., highly stressed components. Since fusion welding is the most important joining process for metals, it is of vital importance to investigate the weldability of these materials. However, this has rarely been the subject of research to date. For that reason, in this work, the weldability depending on the surface preparation of a CoCrFeMnNi HEA and a CoCrNi MEA for TIG welding is investigated. The fusion welding of longer plates is described here for the first time for the CoCrNi alloy. The welds of both materials showed distinct formation of cracks in the heat affected zone (HAZ). Optical and scanning electron microscopy analysis clearly confirmed an intergranular fracture topography. However, based on the results, the crack mechanism cannot be conclusively identified as either a liquid metal embrittlement (LME) or hot cracking-like liquid film separation.

Fifth-order aberration for soft x-ray and vacuum ultraviolet multi-element optical systems.

Based on the recently developed fifth-order intrinsic aberration of a soft x-ray and vacuum ultraviolet single-element optical system, this paper proposes a fifth-order aberration (including intrinsic aberration and extrinsic aberration) calculation method for this kind of optical system with multiple elements. First, the fifth-order intrinsic aberration expressions of soft x-ray and vacuum ultraviolet multi-element optical systems are studied; second, the extrinsic aberration calculation method of this kind of optical system is discussed, and corresponding calculation expressions are derived; third, to improve aberration calculation accuracy, the modification of aberration expressions due to the transfer relationship of aperture-ray coordinates with second-order accuracy on the reference exit wavefront between adjacent optical elements is obtained. Finally, the resultant aberration expressions are applied to calculate the aberration of two design examples of soft x-ray and vacuum ultraviolet double-element optical systems with large apertures, and their images are compared with ray-tracing results using Shadow software to validate the aberration expressions. The study shows that the accuracy of the aberration expressions derived in this paper is satisfactory.

A Unified Dissertation on Bearing Rigidity Theory

This work focuses on bearing rigidity theory, namely the branch of knowledge investigating the structural properties necessary for multi-element systems to preserve the inter-unit bearings under deformations. The contributions of this work are twofold. The first one consists in the development of a general framework for the statement of the principal definitions and properties of bearing rigidity. We show that this approach encompasses results existing in the literature, and also provides a systematic approach for studying bearing rigidity on any differential manifold in SE(3)^n, where n is the number of agents. The second contribution is the derivation of a general form of the rigidity matrix, a central construct in the study of rigidity theory. We provide a necessary and sufficient condition for the infinitesimal rigidity of a bearing framework as a property of the rank of the rigidity matrix. Finally, we present two examples of multi-agent systems not encountered in the literature and we study their rigidity properties using the developed methods.

High-Lift Computational Strategy for Slotted, Natural-Laminar-Flow Airfoils

This work uses a computational fluid dynamics approach to evaluate the ability of the aft element of a slotted, natural-laminar-flow airfoil, designed for transonic applications, to function as a high-lift device. The analysis is based on the Reynolds-averaged Navier–Stokes equations with a laminar–turbulent transition model for subsonic flow at representative flight conditions and a fully turbulent model for the aft-element optimization. Results obtained at angles of attack near maximum lift contribute to the understanding of stall characteristics and show that maximum aerodynamic efficiency is obtained with a constant slot width between the flap and main element. Results indicate that the microflap can augment the effectiveness of the aft element. Drag calculations when compared with angle of attack and lift show insight on the aerodynamic efficiency of the microflap system in landing as a lift effector, as well as a drag device. Pitching-moment data are also presented for completeness. Results obtained with Fowler flaps are consistent with other studies of extended-flap configurations; more specifically, the aforementioned velocity ratio decreases toward the aft-element trailing edge, indicating that the multi-element high-lift system is operating as intended.

Free-moving Quantitative Gamma-ray Imaging

The ability to map and estimate the activity of radiological source distributions in unknown three-dimensional environments has applications in the prevention and response to radiological accidents or threats as well as the enforcement and verification of international nuclear non-proliferation agreements. Such a capability requires well-characterized detector response functions, accurate time-dependent detector position and orientation data, a digitized representation of the surrounding 3D environment, and appropriate image reconstruction and uncertainty quantification methods. We have previously demonstrated 3D mapping of gamma-ray emitters with free-moving detector systems on a relative intensity scale using a technique called Scene Data Fusion (SDF). Here we characterize the detector response of a multi-element gamma-ray imaging system using experimentally benchmarked Monte Carlo simulations and perform 3D mapping on an absolute intensity scale. We present experimental reconstruction results from hand-carried and airborne measurements with point-like and distributed sources in known configurations, demonstrating quantitative SDF in complex 3D environments.

Observations of interplanetary scintillation of the 2005 May 13 coronal mass ejection: numerical models

ABSTRACT The 2005 May 13 eruption was an Earth-directed coronal mass ejection (CME) observed using the Multi-Element Radio-Linked Interferometer Network telescope system in the UK as it traversed the Interplanetary Medium on 2005 May 14. Observations of interplanetary scintillation (IPS) provide information on the solar wind conditions, which include velocities and density. In addition, it is also possible to calculate other parameters related to the turbulence and geometry of density irregularities in the solar wind from observations of IPS. Previous analyses have shown that IPS information can be difficult to interpret when a complex structure is crossing the line of sight since the physical properties of the plasma may change quite drastically with distance from the Sun. In order to compare and relate the internal structure of a CME and its physical changes, with the results from observations of IPS obtained previously, we carried out a numerical simulation of the 2005 May 13 eruptive event as it propagates into the IPM, adapting the geometrical properties derived by IPS analysis. In this work, we give a possible explanation of some signatures of CME sub-structure from the point of view of the IPS technique combined with what the modelling reveals.

Modeling stress-strain state of the section of human dental apparatus with the account of contact interaction between the teeth and their partial absence

Complex interaction of incisors of the multi-element system “jaw – tooth – periodontium – enamel – dentinˮ is considered in the present work. The model was created on the basis of tomographic images taking into account previous studies of the human dental apparatus for a simplified model of three molars. The aim of the work is to determine the stress-strain states of the “jaw – periodontium – tooth – dentinˮ system for a different number of incisors and their location using three-dimensional computer finite-element modeling. The results of the study allow obtaining a more complete and accurate assessment of the state of the human dentofacial apparatus as a whole and each of its elements separately in order to improve the technologies and methods of prosthetics.

Serial disparity in the carnivoran backbone unveils a complex adaptive role in metameric evolution

Organisms comprise multiple interacting parts, but few quantitative studies have analysed multi-element systems, limiting understanding of phenotypic evolution. We investigate how disparity of vertebral morphology varies along the axial column of mammalian carnivores — a chain of 27 subunits — and the extent to which morphological variation have been structured by evolutionary constraints and locomotory adaptation. We find that lumbars and posterior thoracics exhibit high individual disparity but low serial differentiation. They are pervasively recruited into locomotory functions and exhibit relaxed evolutionary constraint. More anterior vertebrae also show signals of locomotory adaptation, but nevertheless have low individual disparity and constrained patterns of evolution, characterised by low-dimensional shape changes. Our findings demonstrate the importance of the thoracolumbar region as an innovation enabling evolutionary versatility of mammalian locomotion. Moreover, they underscore the complexity of phenotypic macroevolution of multi-element systems and that the strength of ecomorphological signal does not have a predictable influence on macroevolutionary outcomes.

Integrated Energy System Planning Optimization Method and Case Analysis Based on Multiple Factors and A Three-Level Process

Now that China has outlined its goals of “carbon peak and carbon neutrality”, the development of clean energy will accelerate, the connection between different energy systems will be closer, and the development prospects of the integrated energy service industry will be broader. Integrated energy services are promoting energy transformation and services. “Carbon peaking, carbon neutrality” and other aspects will also have multiple values and far-reaching significance. Before implementing integrated energy services, the top-level design of integrated energy system planning must be carried out, and how to achieve the optimal allocation of capacity in the field of integrated energy systems is an urgent problem to be solved in integrated energy system planning. This paper combines practical engineering experience and the latest theoretical research results to creatively introduce, for the first time, a comprehensive evaluation into the initial planning stage, and proposes, also for the first time, a three-level multi-element comprehensive energy system planning optimization method which combines multi-element requirements to carry out comprehensive energy system planning and optimization. The three-tier planning and optimization solution results in the optimal planning scheme of the integrated energy system, thereby making the scheme more specific and reliable. According to the demand data of an industrial park, this method was applied to complete a case analysis of integrated energy system planning, which verified the feasibility and effectiveness of the method. This method is easy to popularize, and it will guide the planning of integrated energy systems, promote integrated energy services, promote energy transition, and make positive contributions to achieve carbon neutrality as soon as possible.

Study of Synergistic Effects in Complex Stochastic Systems

In this paper, a method for detecting synergistic effects of the interaction of elements in multi-element stochastic systems of separate redundancy, multi-server queuing, and statistical estimates of nonlinear recurrent relations parameters has been developed. The detected effects are quite strong and manifest themselves even with rough estimates. This allows studying them with mathematical methods of relatively low complexity and thereby expand the set of possible applications. These methods are based on special techniques of the structural analysis of multi-element stochastic models in combination with majorant asymptotic estimates of their performance indicators. They allow moving to more accurate and rather economical numerical calculations, as they indicate in which direction it is most convenient to perform these calculations.