bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disturbance rejection control of multiple integrators system by bounded linear extended observer based output feedback
Authors: Zhang Kai , Zhou Bin , Yang Xuefei 
Published: December 2022

SummaryThis paper is concerned with the disturbance rejection control problem of multiple integrators systems subject to actuator saturation and external disturbance. By using the solutions to a class of parametric Lyapunov equations (PLEs), extended observer based bounded linear output feedback controller is designed to solve the considered problem. By constructing a novel Lyapunov function and using the properties of the PLE, the stability of the closed‐loop system is proved and the domain of attraction is estimated. In order to improve control performance, bounded linear time‐varying output feedback controller is also proposed such that the state of the closed‐loop system tends to zero as the time approaches to the prescribed setting time which is independent of the initial conditions and can be assigned in advance. In addition, some comparisons of the proposed methods to existing results are given. Finally, numerical examples verify the effectiveness of the proposed methods.
An Extreme‐Environment‐Resistant Self‐Healing Anti‐Icing Coating
Authors: Li Ruiqi , Tian Shu , Tian Yunqing , Wang Jiancheng , Xu Sijia , Yang Kai , Yang Jing , Zhang Lei 
Published: December 2022

AbstractAnti‐icing coatings on outdoor infrastructures and transportations inevitably suffer from surface injuries, especially in extreme weather events (e.g., freezing weather or acid rain). The coating surface damage can result in anti‐icing performance loss or even icing promotion. The development of anti‐icing coatings that enables self‐healing in extreme conditions is highly desired but still challenging. Herein, an extreme‐environment‐resistant self‐healing anti‐icing coating is developed by integrating fluorinated graphene (FG) into a supramolecular polymeric matrix. The coating exhibits both anti‐icing and deicing performance (ice nucleation temperature is ≈−30.3 °C; ice shear strength is ≈48.7 kPa), mainly attributable to the hydrophobic FG and silicone‐based supramolecular material. Notably, owing to the crosslinking polymeric network with various dynamic bonds, this coating can sustain anti‐icing/deicing performance after autonomous self‐healing under harsh conditions including low temperature (−20 °C), strong acid (pH = 0), and strong alkali (pH = 14) environments. This coating paves the way to meet the anti‐icing demand in open air, especially for the infrastructures in polar regions or acid/alkali environments.
Research Advances in Amorphous‐Crystalline Heterostructures Toward Efficient Electrochemical Applications
Authors: Jin Yachao , Zhang Mengxian , Song Li , Zhang Mingdao 
Published: December 2022

AbstractInterface engineering of heterostructures has proven a promising strategy to effectively modulate their physicochemical properties and further improve the electrochemical performance for various applications. In this context related research of the newly proposed amorphous‐crystalline heterostructures have lately surged since they combine the superior advantages of amorphous‐ and crystalline‐phase structures, showing unusual atomic arrangements in heterointerfaces. Nonetheless, there has been much less efforts in systematic analysis and summary of the amorphous‐crystalline heterostructures to examine their complicated interfacial interactions and elusory active sites. The critical structure‐activity correlation and electrocatalytic mechanism remain rather elusive. In this review, the recent advances of amorphous‐crystalline heterostructures in electrochemical energy conversion and storage fields are amply discussed and presented, along with remarks on the challenges and perspectives. Initially, the fundamental characteristics of amorphous‐crystalline heterostructures are introduced to provide scientific viewpoints for structural understanding. Subsequently, the superiorities and current achievements of amorphous‐crystalline heterostructures as highly efficient electrocatalysts/electrodes for hydrogen evolution reaction, oxygen evolution reaction, supercapacitor, lithium‐ion battery, and lithium‐sulfur battery applications are elaborated. At the end of this review, future outlooks and opportunities on amorphous‐crystalline heterostructures are also put forward to promote their further development and application in the field of clean energy.
Remarkably Selective Propylene–Propane Separation Using a Copper Scorpionate
Authors: Noonikara‐Poyil Anurag , Cui Hui , Wang Bin , Shi Yanshu , Chen Banglin , Dias H. V. Rasika 
Published: December 2022

AbstractPropylene is a crucial building block to produce many industrial‐scale chemicals including polypropylene. The separation of propylene from propane to reach the high‐purity levels needed for downstream applications is a difficult task due to the close similarities in their physical properties. The olefin/paraffin separation including that involving propylene mainly relies on highly energy‐intensive distillation processes and accounts for nearly 0.3% of the global energy consumption. The utility of a copper complex supported by a fluorinated bis(pyrazolyl)borate is demonstrated to accomplish the separation of propylene from propane repeatedly, under mild conditions with high selectivity. Complete characterization of a rare, copper(I) propylene complex is also reported including the molecular structure.
Universal Capacitance Boost—Smart Surface Nanoengineering by Zwitterionic Molecules for 2D MXene Supercapacitor
Authors: Děkanovský Lukáš , Azadmanjiri Jalal , Havlík Martin , Bhupender Pal , Šturala Jiří , Mazánek Vlastimil , Michalcová Alena , Zeng Lunjie , Olsson Eva , Khezri Bahareh , Sofer Zdeněk 
Published: December 2022

AbstractTwo‐dimensional nanomaterials, as one of the most widely used substrates for energy storage devices, have achieved great success in terms of the overall capacity. Despite the extensive research effort dedicated to this field, there are still major challenges concerning capacitance modulation and stability of the 2D materials that need to be overcome. Doping of the crystal structures, pillaring methods and 3D structuring of electrodes have been proposed to improve the material properties. However, these strategies are usually accompanied by a significant increase in the cost of the entire material preparation process and also a lack of the versatility for modification of the various types of the chemical structures. Hence in this work, versatile, cheap, and environmentally friendly method for the enhancement of the electrochemical parameter of various MXene‐based supercapacitors (Ti3C2, Nb2C, and V2C), coated with functional and charged organic molecules (zwitterions—ZW) is introduced. The MXene‐organic hybrid strategy significantly increases the ionic absorption (capacitance boost) and also forms a passivation layer on the oxidation‐prone surface of the MXene through the covalent bonds. Therefore, this work demonstrates a new, cost‐effective, and versatile approach (MXene‐organic hybrid strategy) for the design and fabrication of hybrid MXene‐base electrode materials for energy storage/conversion systems.
Experimental study on seismic behavior of circular steel tube confined reinforced self‐stressing steel slag concrete columns
Authors: Bu Shuangshuang , Yu Feng , Chen Taiyao , Fang Yuan , Qin Yin 
Published: December 2022

AbstractLow‐cycle reversed loading test were conducted on 10 circular steel tube confined reinforced self‐stressing steel slag concrete columns and four circular steel tube confined reinforced steel slag concrete (SSC) columns, to investigate the influence of the shear span ratio, axial compression ratio, diameter‐thickness ratio and expansion ratio of SSC on the seismic performance of the specimens. The results indicated that the crushing of core SSC at the bottom of columns and yielding of longitudinal reinforcement dominated the specimens damage. Fine circumferential tensile cracks without development trend along the height direction appeared at the non‐shear plane of the columns. The hysteretic curves were generally full, which denoted that the specimens had good seismic behavior. With the increase of the axial compression ratio, diameter‐thickness ratio, or decrease of the shear span ratio, the strength degradation was more severe and the ductility reduced. The stiffness degradation rate was accelerated with the increase of the axial compression ratio, or reduction of the expansion ratio of SSC or shear span ratio. In addition, as the axial compression ratio or expansion ratio of SSC raised, or the shear span ratio reduced, the ductility of the specimens decreased and the growth of the energy dissipation coefficient was accelerated.
Impact behavior of low strength concrete slab strengthened with fan type anchored carbon fiber‐reinforced polymer strips
Authors: Çalışkan Özlem , Aras Murat , Yılmaz Tolga , Anıl Özgür , Erdem R. Tuğrul 
Published: December 2022

AbstractThis study investigated the behavior of slabs produced with low compressive strength concrete without reinforcements under the effect of sudden dynamic impact loading. In addition, an experimental study was conducted by proposing a strengthening method with anchored carbon fiber‐reinforced polymer (CFRP) strips to strengthen the nonreinforced slabs with low‐strength concrete against sudden dynamic impact loads to improve their performance. The variables examined in the experimental study were the placement of the CFRP strips adhered to the concrete slabs for strengthening purposes and anchors in the strips. A constant energy level of impact loading was applied to the concrete slab test specimens with the authors' free weight drop test setup. The acceleration‐time, displacement‐time, strain‐time, and applied impact loading‐time measurements on the concrete slabs were examined, and comments were made about the strengthening method applied to the slab test specimens. In addition, numerical analysis of the tested concrete slabs with ABAQUS finite element software was performed, and the results were compared with the experimental results. In the comparison, it was investigated to what extent numerical analysis and this type of impact analysis can be done realistically and compatible with the experimental results. Within the scope of the study, the strengthening method applied with fan‐type anchored CFRP strips significantly improved and increased the impact performance of concrete slabs produced with low‐strength concrete.
Assessment and strengthening of reinforced concrete bridges with half‐joint deterioration
Authors: Granata Michele Fabio , La Mendola Lidia , Messina Davide , Recupero Antonino 
Published: December 2022

AbstractExisting Niagara‐type concrete cantilever bridges, which in Italy are called Gerber bridges, suffer from degradation due to reinforcement corrosion and a consequent reduced load‐bearing capacity. The assessment of these structures is therefore an important part of the procedures for analyzing the state of existing bridges and any interventions required for their retrofitting. In particular, safety against failure of the half‐joint must be evaluated with respect to the behavior of the entire bridge and its state of conservation, determining what the conditions are that lead to failure, in terms of loads, state of stress, and possibly cracking state. This evaluation has to be carried out considering the configuration of the bridge through local and global models, in the presence of the crossbeam between the main girders or the prestressing tendons that can modify the behavior of the Gerber saddle, compared to that expected for a simple dapped‐end beam. To do this, it is necessary to combine the in situ investigations with reliable analytical and numerical models, which can correctly interpret the structural behavior of the bridge, determining the critical aspects for safety. The approach followed in this study was to combine the strut‐and‐tie models with nonlinear finite element models that can provide reliable information to the engineer who deals with the assessment and subsequently the conception of rehabilitation, in combination with in situ investigations and material tests. This was carried out through two different case studies in which the shape of the Gerber saddle, the presence of the crossbeam, and the presence of prestressing characterize the behavior and highlight the degree of safety and that of structural robustness. The results of the analyses carried out show that the presence of prestressing and a careful design with the use of large amounts of reinforcement can lead in some cases to high safety factors and consequently to a good level of robustness. They also show that the structural behavior can vary significantly according to the level of reinforcement corrosion: this is an aspect that can only be correctly assessed with the use of different models with different degrees of refinement. Finally, a proposal for global structural rehabilitation is presented by closing saddles, changing the static scheme to the continuous beam, and supplying external prestressing to strengthen the deck.
Cadmium induces mitochondrial dysfunction via SIRT1 suppression‐mediated oxidative stress in neuronal cells
Authors: Wen Shuangquan , Xu Mingchang , Zhang Wenhua , Song Ruilong , Zou Hui , Gu Jianhong , Liu Xuezhong , Bian Jianchun , Liu Zongping , Yuan Yan 
Published: December 2022

AbstractCadmium is a widespread environmental contaminant and its neurotoxicity has raised serious concerns. Mitochondrial dysfunction is a key event in Cd‐induced nervous system disease; however, the exact molecular mechanism involved has not been fully elucidated. Increasing evidences have shown that Sirtuin 1 (SIRT1) is the key target protein impaired in Cd‐induced mitochondrial dysfunction. In this study, the role of SIRT1 in Cd‐induced mitochondrial dysfunction and cell death and the underlying mechanisms were evaluated in vitro using PC12 cells and primary rat cerebral cortical neurons. The results showed that Cd exposure caused cell death by inhibiting SIRT1 expression, thus inducing oxidative stress and mitochondrial dysfunction in vitro. However, inhibition of oxidative stress by the antioxidant puerarin alleviated Cd‐induced mitochondrial dysfunction. Furthermore, activation of SIRT1 using the agonist Srt1720 significantly abolished Cd‐induced oxidative stress and mitochondrial dysfunction and ultimately alleviated Cd‐induced neuronal cell death. Collectively, our data indicate that Cd induced mitochondrial dysfunction via SIRT1 suppression‐mediated oxidative stress, leading to the death of PC12 cells and primary rat cerebral cortical neurons. These findings suggest a novel mechanism for Cd‐induced neurotoxicity.
Level set‐based shape optimization approach for the inverse optical tomography problem
Authors: Belhachmi Zakaria , Dhif Rabeb , Meftahi Houcine 
Published: December 2022

AbstractWe consider the inverse problem of recovering piecewise scattering and piecewise absorption jump sets from boundary measurements and from a single measurement of the absorbed energy. We propose a reconstruction method based on a shape optimization approach combined with the level set techniques. Our main result includes the partial shape derivatives of two different shape functionals, using differentiability properties of the min‐sup combined with a function space parameterization technique. In particular, it reveals the expression of the distributed partial shape derivative in tensor form. Based on the computed distributed partial shape derivatives, we introduce and implement a numerical approach based on the gradient approach and level set method. We present several numerical experiments to show the efficiency of the method both for exact reconstruction data and for realistic data with noise.
Transforming Navier‐stokes equation to a fourth order nonlinear differential equation for the study of electrolyte flow in a circular microchannel
Authors: Layeghi Mohammad , Gorji Mohammad 
Published: December 2022

AbstractIn this paper, analytical solutions are derived for the study of steady‐state electrolyte flow in a circular microchannel under the simultaneous effects of an external electric field and uniform wall injection. The Navier‐Stokes equations containing an axial linear electric body force are transformed to a fourth‐order nonlinear differential equation and solved analytically using a series solution method. The most important results are presented and discussed in terms of radial Reynolds number and a fundamental non‐dimensional electric field parameter. The Electrical Double Layer theory is employed to model the effects of external electric field. Analytical relations are given for velocity profiles, exit flow rate, and total pressure drop in the microchannel. The results show that a high‐intensity electric field can completely reverse the velocity profile or make it more flat in the presence of wall injection. This electric effect can be used in practical applications to control the shear stress, heat, or mass transfer in microchannels or microelectromechanical systems. In addition, various graphs are presented showing simultaneous effects of electric field and wall injection of the same fluid on the flow physics.
Quadratic regression analysis of the unsteady Ag+TiO2/H2O, Ag+TiO2/CH3OH and Ag+TiO2/H2O‐C2H6O2 hybrid nano‐fluids flow along a deformable cylinder with oblique Lorentz force: A comparative approach
Authors: Nandi Susmay , Nadeem Sohail 
Published: December 2022

AbstractQuadratic regression analysis on the stagnation point flow of Ag+TiO2/H2O, Ag+TiO2/CH3OH and Ag+TiO2/H2O‐C2H6O2 hybrid nano‐fluids past a stretching cylinder placed in a porous medium with multiple slips has been explored numerically. The flow regulating boundary layer equations consider the inclined Lorentz force, viscous‐Ohmic dissipation, heat source, nonlinear way varying thermal radiation, and first‐order chemical reaction. The continuity, energy, and concentration governing equations of tiny‐particles are transformed into a set of ordinary differential equations using the appropriate transformations. The Runge‐Kutta‐Fehlberg method and the well‐known shooting methodology were used to illuminate the numerical for the nonlinear differential equations with the associated boundary conditions. The impact of various controlling factors on velocity, temperature, tiny‐particle concentration, surface drag coefficient, heat transfer rate, and mass transfer rate is then illustrated using numerical analysis. In the absence of a velocity ratio parameter, the hybrid nano‐fluid moves more quickly than when it is present. The temperature and concentration fields, however, show the opposite pattern. Additionally, the temperature profile is highlighted, while the velocity profile fell as the magnetic parameter increased. Moreover, velocity slip reduces the fluid velocity profile, whereas the temperature profile declines for growing values of the temperature jump parameter. The proposed model is useful because it may be used in a variety of fields, such as biomedical sciences, glassblowing, cancer therapies, metal spinning, microelectronics, filament cooling, industrial production processes, biology, etc. Quadratic regression has been statistically used to analyze the effects of pertinent parameters on the drag coefficient and heat and mass transfer rates.
Positivity bounds in vector theories
Authors: de Rham Claudia , Engelbrecht Laura , Heisenberg Lavinia , Lüscher Alice 
Published: December 2022

Abstract
Assuming unitarity, locality, causality, and Lorentz invariance of the, otherwise unknown, UV completion, we derive a new set of constraints on the effective field theory coefficients for the most general, ghost-free Generalized Proca and Proca Nuevo massive vector models. For the Generalized Proca model, we include new interactions that had not been previously considered in the context of positivity bounds and find these additional terms lead to a widened parameter space for the previously considered interactions. Although, the Generalized Proca and Proca Nuevo models are inequivalent, we find interesting analogues between the coefficients parameterizing the two models and the roles they play in the positivity bounds.
Determining the spin of light primordial black holes with Hawking radiation
Authors: Calzà Marco , Rosa João G. 
Published: December 2022

Abstract
We propose a method to determine the mass and spin of primordial black holes (PBHs) in the mass range 5 × 107–1012 kg (Hawking temperatures ~ 10 MeV–200 GeV), based on measuring the energy of specific features in the photon Hawking emission spectrum, including both primary and secondary components. This is motivated by scenarios where PBHs in this mass range spin up as they evaporate, namely the string axiverse, where dimensionless spin parameters $$ \overset{\sim }{a} $$

a
~

~ 0.1–0.5 can be achieved through the Hawking emission of hundreds or even thousands of light axion-like particles. Measuring the present PBH mass-spin distribution may thus be an important probe of physics beyond the Standard Model. Since the proposed method relies on the energy of the photons emitted by a given PBH, rather than on the associated flux, it is independent of the PBH-Earth distance and, as a byproduct, can also be used to infer the latter.
An Index Theorem for Quarter-Plane Toeplitz Operators via Extended Symbols and Gapped Invariants Related to Corner States
Authors: Hayashi Shin 
Published: December 2022

AbstractIn this paper, we discuss index theory for Toeplitz operators on a discrete quarter-plane of two-variable rational matrix function symbols. By using Gohberg–Kreĭn theory for matrix factorizations, we extend the symbols defined originally on a two-dimensional torus to some three-dimensional sphere and derive a formula to express their Fredholm indices through extended symbols. Variants for families of (self-adjoint) Fredholm quarter-plane Toeplitz operators and those preserving real structures are also included. For some bulk-edge gapped single-particle Hamiltonians of finite hopping range on a discrete lattice with a codimension-two right angle corner, topological invariants related to corner states are provided through extensions of bulk Hamiltonians.
Long-range seed dispersal enables almost stationary patterns in a model for dryland vegetation
Authors: Eigentler L. , Sherratt J. A. 
Published: December 2022

AbstractSpatiotemporal patterns of vegetation are a ubiquitous feature of semi-arid ecosystems. On sloped terrain, vegetation patterns occur as stripes perpendicular to the contours. Field studies report contrasting long-term dynamics between different observation sites; some observe slow uphill migration of vegetation bands while some report stationary patterns. In this paper, we show that long-range seed dispersal provides a mechanism that enables the occurrence of both migrating and stationary patterns. We utilise a nonlocal PDE model in which seed dispersal is accounted for by a convolution term. The model represents vegetation patterns as periodic travelling waves and numerical continuation shows that both migrating and almost stationary patterns are stable if seed dispersal distances are sufficiently large. We use a perturbation theory approach to obtain analytical confirmation of the existence of almost stationary patterned solutions and provide a biological interpretation of the phenomenon.