bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive constrained control for automotive electronic throttle control system with experimental analysis
Authors: He Youguo , Liu Xin , Wang Dapeng , Yuan Chaochun , Shen Jie 
Published: February 2022

Abstract
This article proposes an adaptive constrained control strategy with state constraints and uncertain parameters for an electronic throttle control (ETC) system. Compared with the current control strategies for an ETC system, state constraints and parameter uncertainties are adequately considered in the proposed control strategy. First, the nonlinear dynamic model for control of an ETC is described. Second, the asymmetric Barrier Lyapunov Function (BLF) and a backstepping control algorithm are used to ensure that the throttle opening does not exceed the constrained boundary. A parameter adaptive law is given to estimate the unknown parameter and external disturbances with an ETC system. Third, the proposed BLF controller is compared with the existing Quadratic Lyapunov Function (QLF) controller by simulation and experiment. The results show that the proposed control algorithm not only ensure fast transient performance in the control response, but also avoid the out of bounds of the throttle opening. The proposed constrained control strategy can provide excellent control performance for an ETC system.
Learning Petri net models from sensor data of conveying systems based on the merging of prefix and postfix trees
Authors: Windmann Stefan 
Published: February 2022

Abstract
Petri nets are a common modeling approach for parallel processes such as transport operations in conveying systems. In industrial applications, the Petri net models are usually created manually, which involves a lot of effort, especially if the modeled systems change frequently. This paper introduces a new learning method to automatically generate Petri nets from sensor data acquired in conveying systems. The underlying approach is to create prefix and postfix trees of possible event sequences and to merge them into a compact graph, which can be transformed into a deterministic Petri net model of the conveying system. Experimental results show that the proposed method produces realistic Petri net models even for conveying systems with ambiguous events.
Regulation of early growth response-1 (Egr-1) gene expression by Stat1-independent type I interferon signaling and respiratory viruses
Authors: Ramana Chilakamarti V. , Das Bikul 
Published: February 2022

Abstract
Respiratory virus infection is one of the leading causes of death in the world. Activation of the Jak-Stat pathway by Interferon-alpha/beta (IFN-α/β) in lung epithelial cells is critical for innate immunity to respiratory viruses. Transcriptional factor profiling in the transcriptome and RNA analysis revealed that Early growth response-1 (EGR1/Egr-1) was rapidly induced by IFN-α/β and Toll-like receptor (TLR) ligands in multiple cell types. Studies in mutant cell lines lacking components of the interferon-stimulated gene factor complex (ISGF-3) revealed that IFN-β induction of Egr-1 was independent of Stat1, Stat2, or Irf9. Activation of the Mek/Erk-1/2 pathway was implicated in the rapid induction of Egr-1 by IFN-β in serum-starved mouse lung epithelial cells. Interrogation of multiple microarray datasets revealed that respiratory viruses including coronaviruses induced IFN-β and regulated Egr-1 expression in human lung cell lines. Furthermore, bioinformatic analysis revealed that type I interferon-stimulated genes and Egr-1 inducible genes including transcription factors, mediators of cell growth, and chemokines were differentially regulated in the human lung cell lines after coronavirus infection, and in the lung biopsies of COVID-19 patients.
Study on manganese volatilization behavior of Fe–Mn–C–Al twinning-induced plasticity steel
Authors: Lan Fang-jie , Zhuang Chang-ling , Li Chang-rong , Chen Jing-bo , Yang Guang-kai , Yao Han-jie 
Published: February 2022

Abstract
In the smelting process of high manganese steel, the volatilization of manganese will be accompanied. In this article, the volatilization of manganese in high manganese steel was studied by simultaneous thermal analyzer. The results show that the volatilization rate of manganese in high manganese steel increases with increasing temperature and holding time. It is proved by experimental study and data analysis that manganese volatilization follows the first-order kinetics model, and the empirical formula of manganese evaporation is derived. The volatile products of manganese were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the volatile components of manganese mainly consisted of MnO, Mn3O4, Mn2O3, and MnO2. Combined with thermodynamics, the mechanism of manganese volatilization is further analyzed, and two forms of manganese volatilization in high manganese steel are revealed. One is that manganese atoms on the surface of high manganese steel and oxygen atoms in the gas form different types of manganese oxides and then volatilize at high temperature. The other way is that Mn atoms vaporize into Mn vapor and evaporate in high temperature environment, and then are oxidized into different types of manganese oxides. The results of theoretical calculation and experiment show that manganese volatilization is mainly in the first form.
Dependence of the microstructure, residual stresses and texture of AA 6013 friction stir welds on the welding proces
Authors: Lima E. B. F. , Wegener J. , Donne C. Dalle , Goerigk G. , Wroblewski T. , Buslaps T. , Pyzalla A. R. , Reimers W. 
Published: February 2022

Abstract
The microstructure, the residual stresses and the texture of friction stir welds of 4 mm thick samples made of a 6013 Al –Mg– Si –Cu alloy in T4 state were investigated in order to study the influence of the friction stir welding process on the material and in order to determine the influence of different welding parameters. The results of the investigations reveal the influence of the process parameters (welding speed, tool diameter and rotational speed) on the weld properties such as the microstructure, the precipitation state, the hardness, the texture and the residual stresses. The formation of the residual stresses and their distribution is explained based on an existing, simple thermal model for the friction stir welding and on a classical model for the formation of the residual stresses in conventional fusion welding.
Thermal loading of steel in molten aluminium
Authors: Tušek J. , Taljat B. , Košnik A. , Klobčar D. 
Published: February 2022

Abstract
A test stand for thermal loading of steels was developed for the simulation of die casting of Al products. Special specimens were made which were subjected to automatic immersion into molten Al and a cooling emulsion (water + graphite). At the inside, the specimens were water-cooled. In the course of repeated cycles, the temperature inside the specimens was measured at two different points. A computer program permitted the calculation of temperature, stress and deformation distributions in the specimens. A comparison of the measured and calculated temperatures is shown for two points in the specimen. After 6000 cycles, the surface and the interior of the specimens were examined. The number, length and depth of cracks were determined. It was found that major damages occurred at the specimen edges. The damages included edge rounding, cracks, and material hardening just beneath the surface.
Nano-scratch testing on thin diamond-like carbon coatings for microactuators: friction, wear and elastic-plastic deformation
Authors: Küster Rolf L. A. , Schiffmann Kirsten I. 
Published: February 2022

Abstract
In micromechanical systems the mechanical and tribological requirements for the materials in use are getting rapidly higher. The aim is to find out the fundamental frictional and wear behavior of thin coatings by using the hitherto knowledge in mechanical characterization of coatings and selective experiments. Nanoindentation and linear oscillating microwear experiments have been performed on micro-actuator components and on thin diamond-like carbon coatings, using diamond tips and loads in the range of some millinewtons. The wear depth and friction coefficients were determined as a function of load and number of wear cycles. New methods of data analysis will be discussed, which allow a separation of the different contributions of wear due to material loss, and elastic and plastic deformation. The friction coefficient shows deviations from Amonton’s law because of the dependence of the contact area on the normal load.
Effects of an external electric field applied during the solution heat treatment of the Al-Mg-Si-Cu alloy AA6111
Authors: Conrad Hans , Jung Kang 
Published: February 2022

Abstract
The application of an external dc electric field during the solution heat treatment (SHT) of AA6111 Al alloy increased the as-quenched resistivity ρ and hardness H
v. The increases represented reductions in SHT of 10–20 K required for a constant ρ or H
v. Analysis of the results gave that the field reduced both the enthalpy and entropy of solution. The resulting reduction in Gibbs free energy gave increases of 0.03–0.04 at.% in solubility of Mg2Si (or Al –Mg– Si – (Cu)-vacancy complexes) at 400 –600 °C, amounting to a factor of 33% increase in solubility at 400 °C and 6% at 600 °C.
Microstructure evolution in immiscible alloys during rapid directional solidification
Authors: Zhao J.Z. , He J. , Hu Z.Q. , Ratke L. 
Published: February 2022

Abstract
A model has been developed by taking into account the common action of the nucleation, the diffusional growth, the collisions and coagulations of the minority phase droplets and the spatial phase segregation to describe the microstructure evolution in a rapidly directionally solidified immiscible alloy. Numerical solutions have been performed to investigate the microstructure evolution in a directionally solidified hypermonotectic Al –Pb alloy. It has been shown that an undercooled region appears in front of the solid/liquid interface and the liquid –liquid decomposition takes place there. If the solidification velocity is high enough, a steady state of solidification can be established and a fine dispersion of minority phase particles in a hypermonotectic alloy can be obtained.
The creep performance of a sand-cast Mg–2.8 Nd–0.8 Zn–0.5 Zr–0.3 Gd alloy at 241 to 262°C
Authors: Bell A. , Srivastava V. , Greenwood G. W. , Jones H. 
Published: February 2022

AbstractSecondary creep rates of sand-cast Mg–2.8 Nd–0.8 Zn–0.5 Zr –0.3 Gd (wt.%) alloy at 242.5 ± 1.5 °C and 40 to 90 MPa applied tensile stress are shown to be a factor of ~ 24 smaller than reported earlier for chill-cast Mg–2.4 Nd–0.4 Zn–0.3Mn at 240 °C. The relative contributions of grain/cell size and of alloying in achieving this improved creep resistance are discussed. Additionally, preliminary results at 248 and 262 °C indicate an activation energy for creep somewhat larger than that for the earlier alloy at 150 to 240 °C and that for lattice self-diffusion in magnesium.
Punch-shear tests and size effects for evaluating the shear strength of machinable ceramics
Authors: Bao Yiwang , Zhang Haibin , Zhou Yanchun 
Published: February 2022

Abstract
Various sample thicknesses and punch diameters were used in punch-shear tests for investigating the size effects in evaluating the shear strength of machinable ceramics. The ratio of the sample thickness to the punch diameter was defined as the relative thickness that strongly affects the measured shear strength in a certain range. It was found that there was a threshold value in the relative thicknesses (~ 0.1 for Ti3AlC2 and ~ 0.13 for Ti3SiC2) above which the measured shear strength increased linearly with increasing thickness. The threshold provided a thickness-requirement for valid punch-shear tests, and stable shear strength was obtained under this requirement using 3 mm and 1.8 mm punch diameters, respectively. Experiments using various loading rates suggested that the shear strength measured by the punch-shear test was almost immune from the loading rates. The mechanism of the size effects was analysed through optical and SEM observations.
Study of Ti–Si in situ composite processing by multi-stage eutectic solidification
Authors: Mazur Alexander V. , Gasik Michael M. , Mazur Vladislav I. 
Published: February 2022

Abstract
A titanium composite alloy (Ti –Al –Si – Zr) manufacturing process using eutectic solidification was studied by simultaneous thermal analysis up to 1480 °C. Phase transformations predicted by sections of the phase stability diagram (ThermoCalc optimisation) have been observed. The structure of the alloy was also studied by scanning electron microscopy (SEM), light optical microscopy (LOM) and X-ray microanalysis. Several patterns, unexplained on the basis of the stable phase diagrams of the system, are revealed to be associated with metastable phase transformations. The results can be used for a determination of composite applications and the optimisation of its casting technology.
Grain growth kinetics in 2D polycrystals: impact of triple junctions
Authors: Novikov Vladimir Yu. 
Published: February 2022

Abstract
Grain growth in random and textured 2D polycrystals is modeled under the supposition that all the triple junctions possess limited mobility. In the random polycrystal, the growth kinetics is at first linear and becomes parabolic at later stages if both the triple-junction mobility and the initial grain size are low. The experimental data on triple-junction mobility are used to show that such an effect could be observed in nanocrystalline materials. In the textured polycrystal, triple junctions with limited mobility are found to shift the evolution of the growth process toward abnormal grain growth.
Thermal stability of polycrystalline nanowires
Authors: Klinger Leonid , Rabkin Eugen 
Published: February 2022

Abstract
The equilibrium shape of a polycrystalline cylindrical nanowire with bamboo microstructure is determined. It is shown that for a certain ratio of grain boundary and surface energies a critical grain length exists above which the integrity of a nanowire cannot be preserved. Numerical calculations of the kinetics of nanowire shape evolution controlled by surface diffusion are performed. It is shown that the rate of thinning of unstable nanowires in the region of grain boundaries diverges as a break-up event is approached.
Room-temperature grain boundary diffusion data measured from historical artifacts
Authors: Kremer Raymond J. , Dayananda Mysore A. , King Alexander H. 
Published: February 2022

Abstract
Diffusion processes in typical metals are considered to be slow at room temperature but there are many applications for which very long-term use is envisaged and stability needs to be assured over a timescale of 10 000 years, where even slow processes can be important. It is clearly impractical to make diffusion measurements under controlled conditions for this length of time, so it is common to perform accelerated tests at higher temperatures and extrapolate the necessary information from the measurements so obtained. We have tested the validity of this type of extrapolation for room-temperature, grain boundary diffusion in the copper –silver system, by measuring low-temperature diffusion profiles in antique samples of Sheffield Plate. We present experimental measurements and analysis, along with a comparison to modern diffusivity data extrapolated in the usual manner.
Grain boundary segregation and fracture
Authors: Faulkner R. G. 
Published: February 2022

Abstract
This paper describes a combined thermodynamic and micro-mechanical model for the propagation of a grain boundary crack through a solid in which stress concentrations ahead of the crack and plastic deformation around the crack tip are considered. It is shown that critical factors are impurity segregation concentration, grain boundary structure, reflected in the Σ value of the boundary, and temperature. Comparisons of the model predictions are made with other models of grain boundary binding by Sutton. Additionally, the model predictions are compared with several experimental observations of grain boundary fracture strength. It is shown that ductile to brittle transition temperature data for steels are a valuable source of experimental grain boundary fracture information for this important range of commercial materials.
Quantitative evaluation of nanoindents: Do we need more reliable mechanical parameters for the characterization of materials?
Authors: Naimi-Jamal M. R. , Kaupp G. 
Published: February 2022

Abstract
Various sources of errors in the standard procedure according to the ISO 14577 draft for the iteration of elastic modulus and hardness of solid materials, with reference to fused quartz with its particular and unique indentation response, are pointed out on the basis of practical examples. Similar objections exist towards the use of the S
2
F
N
– 1 parameter, where S is the stiffness and F
N is the normal force. It is suggested to use unambiguous mechanic characterization (at least additionally) by quantitative analysis of the loading curves in nanoindentations. These exhibit a general dependence between normal force and (displacement)3/2, the proportionality constant k being a non-iterated nanoindentation coefficient with dimension [force/length3/2] and unit [μN/nm3/2] that depends on the indenter tip geometry (pyramidal or conospherical) and is a characteristic material’s property. The validity has been demonstrated for virtually all types of materials (metals, semimetals, oxides, salts, organic molecular crystals, polymers) independent of their different bonding states. Pressure-induced phase transitions are detected by kinks in the linear plots for the loading curves well in the nanoindentation region. Crystalline materials, such as strontium titanate, exhibit far-reaching anisotropic effects along lattice axes that would strongly forbid the reference to an amorphous standard. The nanoindentation coefficient characterizes the different polymorphs and the face anisotropies. Another unambiguous mechanical characterization is given by the full work of indentation (as differentiated from the less secure plastic work of indentation). It also characterizes the face anisotropies with high precision for a given indenter as it is found proportional to (normal force)3/2, which allows for useful extrapolations.
On the pressure dependence of the indentation modulus
Authors: Wolf B. , Göken M. 
Published: February 2022

Abstract
The influence of the pressure distribution beneath a spherical indenter onto the resulting penetration depth and consequently its impact onto the derived apparent indentation modulus has been modelled theoretically. It turns out that the pressure distribution has the same effect as a constant hydrostatic pressure of one half of the contact pressure within the entire sample. The effect is particularly important in situations of high contact pressure as during elastic indentation loading before the occurrence of the first popin. Furthermore, for all materials with a high ratio between hardness and elastic modulus the indentation modulus should differ from the “zero-pressure elastic modulus” in an experimentally verifiable way. A quantitative assessment delivers a possible increase up to 15 %.
A usable concept for the indentation of thin porous films
Authors: Puschmann René , Schwarzer Norbert , Richter Frank , Frühauf Swantje , Schulz Stefan E. 
Published: February 2022

Abstract
The paper deals with the application of Pharr’s concept of the effectively shaped indenter as well as an extension of that concept – referred to as extrapolation method – on the determination of the yield strength of porous thin films. As an example, a 1066 nm thick porous SiO2 xerogel film having a porosity of about 50% and an average pore size in the range 3 – 4 nm was investigated. Three different spherical indenters with radii of 1.4, 3.11 and 110 lm were used in this investigation. Depending on the indenter radius and the applied load the physical nature of the sample deformation was different making the one or the other of the two methods more suitable for analysis. We found that the data received with the large indenter could be well analysed using Pharr’s concept, while for the two smaller indenters the extrapolation method had to be used. The yield strength values obtained with the two methods were in remarkable agreement (109 vs. 99 MPa).
Analysis of the ductile/brittle transition during a scratch test performed into polymeric film deposited on a PMMA substrate
Authors: Heck G. , Riche A. , Bardon J. , Pelletier H. 
Published: February 2022

Abstract
Indentations and scratch tests using a Nano Indenter ®XP have been carried out to characterize the mar and wear resistance properties of polymeric bilayer systems. These systems were composed of a transparent coating on a thermoplastic polymer (PMMA) substrate. The different thin films were deposited using several coating technologies. Nanoindentation tests with a Berkovich indenter were performed at different peak loads from 0.625 to 10 mN, to determine the mechanical properties both of thin films and of the PMMA substrate, such as the elastic modulus and the hardness. A new analysis of the loading curve was applied to extract the viscoplasticity index. Then, scratch tests using a conical indenter truncated with a spherical tip (radius R = 5 μm) were realized with increasing progressively applied load (from 0 to 40 mN) to create irreversible damages (crack or delamination). The distinction between ductile and brittle behaviour in a scratch process leads to the definition of some specific parameters. For all tested specimens, we estimated the average contact pressure, the strain rate and the average strain beneath the indenter at which the fracture occurs. We propose a complete method to estimate with accuracy these differents parameters, from data supplied experimentally by the depth sensing instrument. This method takes into account the piling-up phenomenon and the viscoelastic recovery of the polymeric surface at the rear of the contact. No direct relationship was found between the viscoplasticity index and the ductile/brittle transition determined by the scratch test. Different criterions related to mar and scratch resistance were tested and compared to results obtained with macroscopic tests.
Nanomechanical and nanotribological properties of polymeric ultrathin films for nanoimprint lithography
Authors: Ekwińska M. , Landis S. , Ekwiński G. , Nowek A. , Chaix N. , Rymuza Z. 
Published: February 2022

AbstractUltrathin polymeric films devoted for nanoimprint lithography were tested. Atomic force microscopy was used to study the surface topography, and the adhesive and nanomechanical/tribological behaviour. The wetting properties of the films were also evaluated, using a special test rig for the contact angle measurements.
Influence of Ce, K, and Na on spheroidization of eutectic carbides in low-tungsten white cast iron
Authors: Zou De-Ning , Fu Han-Guang 
Published: February 2022

AbstractTungsten alloy white cast iron (TAWCI) exhibits strong brittleness and a narrow application scope. The influences of Ce, K and Na on the microstructure and performance of TAWCI have been studied, and the idea to estimate the spheroidization effect of carbides using circular degree (C.D.) is put forward. The results show that eutectic carbides turn from network into sphericity after the modification. Carbide is refined and uniformly distributed and theC.D. of eutectic carbides increases. The mechanism of carbide spheroidization has been analyzed. The impact toughness and wear resistance of TAWCI obviously improves with the rise ofC.D. of carbides. The service life of a modified TAWCI roll is 35 % higher than that of high-chromium cast-iron roll, its production cost is reduced by 25 %.