bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical and Tribological Properties of Ni-B and Ni-B-W Coatings Prepared by Electroless Plating
Authors: Zhao Fan , Hu Hong , Yu Jiaxin , Lai Jianping , He Hongtu , Zhang Yafeng , Qi Huimin , Wang Dongwei
Published: January 2023

Ni-B binary coating and Ni-B-W ternary coating were successfully prepared on titanium alloy (TC4) substrates by electroless plating to improve the hardness and wear resistance, followed by annealing treatment for better mechanical properties and tribological properties. The morphology, composition, microstructure, mechanical properties, and tribological behaviors of the coatings were characterized. Both as-plated coatings were amorphous, while the composition and morphology of the Ni-B-W coating differed from those of the Ni-B coating. Additionally, the Ni-B-W coating had better mechanical and tribological properties with a more considerable hardness (13.5 GPa), a minor friction coefficient (0.42), and a lower wear rate (0.10 × 10−7 cm3/(N·m)). After annealing, both coatings were crystalline. In parallel to the as-plated coating, the annealed coatings showed larger hardness values because of the formation of hard phases. Moreover, the crystalline grain of the coatings grew as the annealing temperature rose from 350 °C to 650 °C. Accordingly, the coatings showed a minor hardness value, a major friction coefficient, and severe wear under the same conditions. Above all, the Ni-B-W coating annealed at 350 °C showed the best performance, with an average grain size of 26.3 nm, hardness of 15.9 GPa, friction coefficient of 0.34, and wear rate of 0.09 × 10−7 cm3/(N·m).
A Validated Computational Study of Lubricants under White Etching Crack Conditions Exposed to Electrical Fields
Authors: Holweger Walter , Bobbio Luigi , Mo Zhuoqiong , Fliege Joerg , Goerlach Bernd , Simon Barbara
Published: January 2023

The problem of White Etching Cracks (WEC) leading to failures in the life cycle of industrial and automotive drive trains has existed for more than 30 years. Many parameters leading to WEC, such as the presence of electricity, unfavorable lubricants, and other factors, have been identified by the use of test rigs. However, since (a) within lifecycle operation these impacts appear incidentally, and (b) the identified impacts stimulate each other as stated in WEC research, the appearance of WEC in a drive train is impossible to predict for any given application. This difficulty causes WEC to be a serious problem. Obtaining reliable failure prediction rates using construction guidelines is still impossible, resulting in warranty claims. The aim of this paper is, first, to establish a routine to determine if and how lubricants could be described numerically with respect to their susceptibility toward electrical fields and to see how this factor could be added in a later stage to construction guidelines. Second, this paper aims to give advice to the applicant in terms of countermeasures. Currently, as predictors are missing, extensive and time-consuming testing is required. Contradictory test results in the field of application, indicate the need for fundamental parameters to determine in which circumstances the application is exposed to WEC risk and to suggest countermeasures. The current study presents a simulation method based solely on the chemical structure of lubricant components, investigating the appearance of WEC and their response to increasing electrical fields. The results show a clear pattern in WEC criticality with respect to lubricants: if two or more components present in the lubricant create clusters through their dipolar interaction, an apparent WEC risk could be accurately predicted apart from test rig results. These clusters are charged like one big particle in an early stage of electrical field exposure. As a result, the surface area increases, facilitating a higher uptake of charge. The incidental breakdown of this charge is assumed. As the charge of a cluster is higher than that of single molecules, WEC critical lubricants are subjected to this pattern. The study validates these results by comparing them using lubricants known to be critical with respect to WEC, suggesting further tests in the near future. Despite the fact that some lubricants seem more critical than others related to WEC, each lubricant clearly might lead to WEC under given conditions. Thus, constructing guidelines for a prediction routine is essential.
Effect of Y on Microstructure and Properties of Al0.8FeCrCoNiCu0.5 High Entropy Alloy Coating on 5083 Aluminum by Laser Cladding
Authors: Li Yanzhou , Shi Yan , Wang Hongxin , Zhou Binjun , Li Defa , Lin Hua , Wang Junqi
Published: January 2023

To improve the surface properties of 5083 aluminum, Al0.8FeCrCoNiCu0.5Yx (x = 0, 0.05, 0.1, and 0.2) high-entropy alloy coatings were prepared by laser cladding. The phase structure and microstructure of the Al0.8FeCrCoNiCu0.5Yx coatings were characterized by XRD and SEM. The tribological properties of the coating were tested by a friction and wear tester. An electrochemical workstation tested the corrosion resistance of the coating. The results show that when Y content is less than 0.2, the Al0.8FeCrCoNiCu0.5Yx coating is in the FCC1, BCC1, and BCC2 phases. When Y is added to 0.2, the coating appears rich in the Y phase. With the increased Y content, the hardness of the coating can increase. The average hardness of Y0, Y0.05, Y0.1, and Y0.2 are 479HV0.2, 517HV0.2, 532HV0.2, and 544HV0.2, respectively. Microstructure evolution leads to an increase in the hardness of the coating. The effect of Y on the wear resistance of the Al0.8FeCrCoNiCu0.5Yx coatings is consistent with the hardness. Al0.8FeCrCoNiCu0.5Y0.2 coating has the lowest wear rate, at is 8.65 × 10−6 mm3/Nm. The corrosion current density of Al0.8FeCrCoNiCu0.5Y0.05 and Al0.8FeCrCoNiCu0.5Y0.1 coatings is in the order of 10−8, which is less than Al0.8FeCrCoNiCu0.5Y0.2 and Al0.8FeCrCoNiCu0.5. The performance of each component coating is superior to that of the substrate.
Window Shape Estimation for Glass Façade-Cleaning Robot
Authors: Nemoto Takuma , Nansai Shunsuke , Iizuka Shohei , Iwase Masami , Itoh Hiroshi
Published: January 2023

This paper presents an approach to the estimation of a window shape for increasing the adaptability of glass façade-cleaning robots to different buildings. For this approach, a window scanning robot equipped with a 2D laser range scanner installed perpendicularly to a window surface is developed for the testbed, and a method for the window shape estimation is proposed, which consists of the robot’s pose estimation with an extended Kalman filter (EKF) and the loop closure based on the robot’s pose estimated. The effectiveness of the proposed approach is demonstrated through an experiment that is carried out on a window placed on a floor. The experimental results show that the window scanning robot can acquire a window shape, moving on a window surface, and the proposed approach is effective in increasing the accuracy of the window shape estimation.
Tribological Properties and Wear Mechanism of C/C Composite Applied in Finger Seal
Authors: Lu Fei , Lu Liang , Liu Jian , Pang Xianjuan , Song Chenfei
Published: January 2023

The application of C/C composites in finger seals can effectively solve the problem of seal wear due to its excellent tribological and mechanical behaviors. However, the designable characteristics of composites, such as the density and orientation of fabric on the friction plane, have a very important influence on the tribological properties and service life of sealing materials. In order to obtain a better material design scheme for the C/C composite on the finger seal, it is necessary to conduct research on the tribological properties and wear mechanism of the C/C composite based on the working conditions of the finger seal. Therefore, a reciprocating tribo-tester was used to conduct the test by abrading the C/C composite disk with a pin made of 1045,080M46. The effects of material density, fabric orientation, and load and sliding velocity on the tribological properties and wear mechanism of the C/C composite were studied. The results show that the friction coefficient and wear rate of the composite with a perpendicular orientation (non-woven cloth perpendicular to the friction plane) were lower than those with a parallel orientation (non-woven cloth parallel to the friction plane). The tribological properties with higher density are better than those of material with a lower density. The friction coefficient of low-density material increases with the load, whereas it decreases gradually with high-density material. The wear rate increases with the load for two-density materials. With the increase in the sliding velocity, the friction coefficient decreases. The wear rate of low-density material decreases significantly, whereas it changes little with high-density material. The influence of the sliding velocity on the friction and wear properties of the C/C composite is greater than that of the load. This study provides a feasible material design idea for effectively alleviating the wear of finger seals.
Mean Square Finite-Approximate Controllability of Semilinear Stochastic Differential Equations with Non-Lipschitz Coefficients
Authors: Mahmudov Nazim I.
Published: January 2023

In this paper, we present a study on mean square approximate controllability and finite-dimensional mean exact controllability for the system governed by linear/semilinear infinite-dimensional stochastic evolution equations. We introduce a stochastic resolvent-like operator and, using this operator, we formulate a criterion for mean square finite-approximate controllability of linear stochastic evolution systems. A control is also found that provides finite-dimensional mean exact controllability in addition to the requirement of approximate mean square controllability. Under the assumption of approximate mean square controllability of the associated linear stochastic system, we obtain sufficient conditions for the mean square finite-approximate controllability of a semilinear stochastic systems with non-Lipschitz drift and diffusion coefficients using the Picard-type iterations. An application to stochastic heat conduction equations is considered.
A New Method for Free Vibration Analysis of Triangular Isotropic and Orthotropic Plates of Isosceles Type Using an Accurate Series Solution
Authors: Papkov Stanislav , Banerjee Jnan Ranjan
Published: January 2023

In this paper, a new method based on an accurate analytical series solution for free vibration of triangular isotropic and orthotropic plates is presented. The proposed solution is expressed in terms of undetermined arbitrary coefficients, which are exactly satisfied by the governing differential equation in free vibration. The approach used is based on an innovative extension of the superposition method through the application of a modified system of trigonometric functions. The boundary conditions for bending displacements and bending rotations on the sides of the triangular plate led to an infinite system of linear algebraic equations in terms of the undetermined coefficients. Following this development, the paper then presents an algorithm to solve the boundary value problem for isotropic and orthotropic triangular plates for any kinematic boundary conditions. Of course, the boundary conditions with zero displacements and zero rotations on all sides correspond to the case when the plate is fully clamped all around. The convergence of the proposed method is examined by numerical simulation applying stringent accuracy requirements to fulfill the prescribed boundary conditions. Some of the computed numerical results are compared with published results and finally, the paper draws significant conclusions.
Internal Categorical Structures and Their Applications
Authors: Martins-Ferreira Nelson
Published: January 2023

While surveying some internal categorical structures and their applications, it is shown that triangulations and internal groupoids can be unified as two different instances of the same common structure, namely a multi-link. A brief survey includes the categories of directed graphs, reflexive graphs, links, multi-links, triangulations, trigraphs, multiplicative graphs, groupoids, pregroupoids, internal categories, kites, directed kites and multiplicative kites. Most concepts are well-known, and all of them have appeared in print at least once. For example, a multiplicative directed kite has been used as a common generalization for an internal category and a pregroupoid. The scope of the notion of centralization for equivalence relations is widened into the context of digraphs while providing a new characterization of internal groupoids.
Weighted Radial Basis Collocation Method for the Nonlinear Inverse Helmholtz Problems
Authors: Hu Minghao , Wang Lihua , Yang Fan , Zhou Yueting
Published: January 2023

In this paper, a meshfree weighted radial basis collocation method associated with the Newton’s iteration method is introduced to solve the nonlinear inverse Helmholtz problems for identifying the parameter. All the measurement data can be included in the least-squares solution, which can avoid the iteration calculations for comparing the solutions with part of the measurement data in the Galerkin-based methods. Appropriate weights are imposed on the boundary conditions and measurement conditions to balance the errors, which leads to the high accuracy and optimal convergence for solving the inverse problems. Moreover, it is quite easy to extend the solution process of the one-dimensional inverse problem to high-dimensional inverse problem. Nonlinear numerical examples include one-, two- and three-dimensional inverse Helmholtz problems of constant and varying parameter identification in regular and irregular domains and show the high accuracy and exponential convergence of the presented method.
Assessing the Impact of Digital Finance on the Total Factor Productivity of Commercial Banks: An Empirical Analysis of China
Authors: Wu Cisheng , Liu Teng , Yang Xiaoxian
Published: January 2023

With the development of technologies such as big data and artificial intelligence, digital technology and finance are becoming increasingly intertwined. At present, digital finance has altered the competitive environment of commercial banks, and the traditional competitive edges in service scenarios and channels, customer information, and capital have been challenged. Based on perfect competition and technology spillover effects, this study attempted to measure the impact of digital finance on commercial banks’ total factor productivity (TFP) and its mediating and moderating mechanisms. We have used the data envelopment analysis-based Malmquist productivity index to measure the total factor productivity of 132 commercial banks in China between 2011 and 2019. The results show that (a) digital finance significantly enhances the TFP of commercial banks; (b) risk taking partially mediates the relationship between digital finance and TFP. The study further tests the effect of the nature of property rights and the moderating effect of diversification. The findings suggest that digital finance significantly improves the TFP of non-state-owned commercial banks but has no significant effect on the TFP of state-owned commercial banks. Additionally, the implementation of diversification can strengthen the effect of digital finance on TFP.
Exploring the Contagion Effect from Developed to Emerging CEE Financial Markets
Authors: Davidescu Adriana , Manta Eduard , Hapau Razvan , Gruiescu Mihaela , Vacaru (Boita) Oana
Published: January 2023

The paper aims to analyze the contagion effect coming from the developed stock markets of the US and Germany to the emerging CEE stock markets of Romania, Czech Republic, Hungary, and Poland using daily data for the period April 2005–April 2021. The paper also captures the level of integration of these emerging stock markets by analyzing the volatility spillover phenomenon. The quantification of the contagion effect coming from the developed to the emerging stock markets consisted of an empirical analysis based on the DCC-GARCH (Dynamic Conditional Correlation) model. Through this multivariate model, the time-varying conditional correlations were analyzed, both in periods of normal economic development and in times of economic instability, when there was a significant increase in the correlation coefficients between developed and emerging stock market indices. Furthermore, the level of connectedness between these markets has been analyzed using the volatility spillover index developed by Diebold and Yilmaz. The empirical results surprised the high level of integration of the analyzed stock markets in Central and Eastern Europe, with the intensity of volatility transmission between these markets increasing significantly during times of crisis. All stock market indices analyzed show periods during which they transmit net volatility and periods during which they receive net volatility, indicating a bidirectional volatility spillover phenomenon. Mostly, the BET, PX, and WIG indices are net transmitters of volatilities, whereas the BUX index is net recipient, except during the COVID-19 crisis, when it transmitted net volatility to the other three indices. Finally, using a Markov switching-regime VAR approach with two regimes, we explored the contagion effect between emerging CEE and developed stock markets during the COVID-19 pandemic. The empirical results proved a shift around the outbreak of the health crisis, after which the high volatility regime dominates the CEE markets. The contagion effects from developed stock markets to emerging CEE markets significantly increased during the first stage of the health crisis.
Computer Simulation of Coke Sediments Burning from the Whole Cylindrical Catalyst Grain
Authors: Yazovtseva Olga S. , Gubaydullin Irek M. , Peskova Elizaveta E. , Sukharev Lev A. , Zagoruiko Andrey N.
Published: January 2023

The article is devoted to the development of the mathematical model of oxidative regeneration of the cylindrical catalyst grain. The model is constructed using a diffusion approach to modeling catalytic processes. The model is based on the equations of material and thermal balance. Mass transfer in the catalyst grain is carried out due to diffusion and the Stefan flow resulting from a decrease in the reaction volume during sorption processes. Chemical transformations of substances are taken into account as a source term in the equation. The thermal balance of the catalyst grain is described by a thermal conductivity equation, with an inhomogeneous term responsible for heating the grain during exothermic chemical reactions. The effective coefficients of heat capacity and thermal conductivity of the catalyst grain, which are determined taking into account the porosity of the grain depending on temperature, were used to calculate the thermal balance of the catalyst grain. The dependencies are approximated using the method of least squares based on experimental data. Different boundary conditions for the developed model allow calculating the main characteristics of the oxidative regeneration process for a whole catalyst grain under different conditions. The mathematical model of oxidative regeneration of a cylindrical catalyst grain is described by a stiff system of differential equations. Splitting by physical processes is applied to avoid computational difficulties. The calculation of flows is carried out sequentially: first, chemical problems are solved using the Radau method, then the diffusion and thermal conductivity equations are solved by the finite volume method. The result of the algorithm implemented in C++ is a picture of the distribution of substances and temperature along the cylindrical grain of the catalyst.
Progressive Hybrid-Modulated Network for Single Image Deraining
Authors: Yu Xiaoyuan , Zhang Guidong , Tan Fei , Li Fengguo , Xie Wei
Published: January 2023

Rainy degeneration damages an image’s visual effect and influences the performance of subsequent vision tasks. Various deep learning methods for single image deraining have been proposed, obtaining appropriate recovery results. Unfortunately, most existing methods ignore the interaction between rain-layer and rain-free components when extracting relevant features, leading to undesirable results. To break the above limitations, we propose a progressive hybrid-modulated network (PHMNet) for single image deraining based on the two-branch and coarse-to-fine framework. Specifically, a hybrid-modulated module (HMM) with a two-branch framework is proposed to blend and modulate the feature of rain-free layers and rain streaks. After cascading several HMMs in the coarsest reconstructed stage of the PHMNet, a multi-level refined module (MLRM) is adopted to refine the final deraining results in the refined reconstructed stage. By being trained using loss functions such as contrastive learning, the PHMNet can obtain satisfactory deraining results. Extended experiments on several datasets and downstream tasks demonstrate that our method performs favorably against state-of-the-art methods in quantitative evaluation and visual effects.
Smart Traffic Shaping Based on Distributed Reinforcement Learning for Multimedia Streaming over 5G-VANET Communication Technology
Authors: Ahmed Adel , Malebary Sharaf , Ali Waleed , Barukab Omar
Published: January 2023

Vehicles serve as mobile nodes in a high-mobility MANET technique known as the vehicular ad hoc network (VANET), which is used in urban and rural areas as well as on highways. The VANET, based on 5G (5G-VANET), provides advanced facilities to the driving of vehicles such as reliable communication, less end-to-end latency, a higher data rate transmission, reasonable cost, and assured quality of experience (QoE) for delivered services. However, the crucial challenge with these recent technologies is to design a real-time multimedia traffic shaping that maintains smooth connectivity under the unpredictable change of channel capacity and data rate due to handover for rapid vehicle mobility among roadside units. This research proposes a smart real-time multimedia traffic shaping to control the amount and the rate of the traffic sent to the 5G-VANET based on distributed reinforcement learning (RMDRL). The proposed mechanism selects the accurate decisions of coding parameters such as quantization parameters, group of pictures, and frame rate that are used to manipulate the required traffic shaping of the multimedia stream on the 5G-VANET. Furthermore, the impact of the aforementioned three coding parameters has been comprehensively studied using five video clips to achieve the optimal traffic rate value for real-time multimedia streaming on 5G communication. The proposed algorithm outperforms the baseline traffic shaping in terms of peak-signal-to-noise-ratio (PSNR) and end-to-end frame delay. This research will open new comfortable facilities for vehicle manufacturing to enhance the data communication system on the 5G-VANET.
Novel Design of Co-Poly(Hydrazide Imide) and Its Complex with Cu(I) for Membrane Separation of Methanol/Dimethyl Carbonate Mixture
Authors: Polotskaya Galina , Tian Nadezhda , Faykov Ilya , Goikhman Mikhail , Podeshvo Irina , Loretsyan Nairi , Gofman Iosif , Zolotovsky Konstantin , Pulyalina Alexandra
Published: January 2023

Poly(2,2′-biquinoline-6,6′-dicarbohydrazide)-co-(bistrimelliteimide)methylene-bisanthranylide (PHI) and its metal–polymer complex PHI-Cu(I) containing several types of functional groups (hydrazide, carboxyl, amide, and imide fragments) were synthesized to prepare two types of dense nonporous membranes. The study on morphology using scanning electron microscopy (SEM), measurements of mechanical, thermal, and transport properties of the membrane samples was carried out. The main mechanical properties of both membranes do not differ significantly, but the values of ultimate deformation differ palpably as a result of a non-uniform character of the deformation process for the PHI membrane. The thermal analysis based on the curves of thermogravimetric (TGA) and differential thermal (DTA) analyses of the PHI and PHI-Cu(I) membranes revealed peculiarities of the membrane structure. Transport properties were studied in pervaporation (PV) of methanol (MeOH) and dimethyl carbonate (DMC) mixtures including an azeotropic point. Intrinsic properties of the penetrant–membrane system were also determined. It was found that the total flux is higher through the PHI membrane, but the PHI-Cu(I) membrane exhibits a higher separation factor. Calculation of the pervaporation separation index (PSI) allowed to conclude that the PHI-Cu(I) membrane exhibits better transport properties as compared with the PHI membrane.
Membranes for Osmotic Power Generation by Reverse Electrodialysis
Authors: Rahman Md. Mushfequr
Published: January 2023

In recent years, the utilization of the selective ion transport through porous membranes for osmotic power generation (blue energy) has received a lot of attention. The principal of power generation using the porous membranes is same as that of conventional reverse electrodialysis (RED), but nonporous ion exchange membranes are conventionally used for RED. The ion transport mechanisms through the porous and nonporous membranes are considerably different. Unlike the conventional nonporous membranes, the ion transport through the porous membranes is largely dictated by the principles of nanofluidics. This owes to the fact that the osmotic power generation via selective ion transport through porous membranes is often referred to as nanofluidic reverse electrodialysis (NRED) or nanopore-based power generation (NPG). While RED using nonporous membranes has already been implemented on a pilot-plant scale, the progress of NRED/NPG has so far been limited in the development of small-scale, novel, porous membrane materials. The aim of this review is to provide an overview of the membrane design concepts of nanofluidic porous membranes for NPG/NRED. A brief description of material design concepts of conventional nonporous membranes for RED is provided as well.
Impact of Pollutant Ozone on the Biophysical Properties of Tear Film Lipid Layer Model Membranes
Authors: Keramatnejad Mahshid , DeWolf Christine
Published: January 2023

Ozone exposure from environmental smog has been implicated as a risk factor for developing dry eye disease (DED). The tear film lipid layer (TFLL), which is the outermost layer of the tear film and responsible for surface tension reduction while blinking, is in direct contact with the environment and serves as the first line of defense against external aggressors such as environmental pollution. The impact of exposure to ozone on the biophysical properties of three TFLL model membranes was investigated. These model membranes include a binary mixture of cholesteryl oleate (CO) and L-α-phosphatidylcholine (egg PC), a ternary mixture of CO, glyceryl trioleate (GT) and PC, as well as a quaternary mixture of CO, GT, a mixture of free fatty acids palmitic acid and stearic acid (FFAs) and PC. Biophysical impacts were evaluated as changes to the surface activity, respreadability, morphology and viscoelastic properties of the films. Expansion to higher molecular areas was observed in all the TFLL model membrane films which is attributable to the accommodation of the cleaved chains in the film. Significant morphological changes were observed, namely fluidization and the disruption of the phase transition behaviour of GT, and multilayer formation of CO. This fluidization reduces the hysteresis loops for the model membranes. On the other hand, the viscoelastic properties of the films exhibited differential impacts from ozone exposure as a function of composition. These findings are correlated to chemical changes to the lipids determined using ESI-MS.
Electrochemical Conversion of CO2 to CO Utilizing Quaternized Polybenzimidazole Anion Exchange Membrane
Authors: Li Jingfeng , Cao Zeyu , Zhang Bo , Zhang Xinai , Li Jinchao , Zhang Yaping , Duan Hao
Published: January 2023

CO is a significant product of electrochemical CO2 reduction (ECR) which can be mixed with H2 to synthesize numerous hydrocarbons. Membranes, as separators, can significantly influence the performance of ECR. Herein, a series of quaternized polybenzimidazole (QAPBI) anion exchange membranes with different quaternization degrees are prepared for application in ECR. Among all QAPBI membranes, the QAPBI-2 membrane exhibits optimized physico-chemical properties. In addition, the QAPBI-2 membrane shows higher a Faraday efficiency and CO partial current density compared with commercial Nafion 117 and FAA-3-PK-130 membranes, at −1.5 V (vs. RHE) in an H-type cell. Additionally, the QAPBI-2 membrane also has a higher Faraday efficiency and CO partial current density compared with Nafion 117 and FAA-3-PK-130 membranes, at −3.0 V in a membrane electrode assembly reactor. It is worth noting that the QAPBI-2 membrane also has excellent ECR stability, over 320 h in an H-type cell. This work illustrates a promising pathway to obtaining cost-effective membranes through a molecular structure regulation strategy for ECR application.
Mechanosensitive Ion Channels and Their Role in Cancer Cells
Authors: Karska Julia , Kowalski Szymon , Saczko Jolanta , Moisescu Mihaela G. , Kulbacka Julita
Published: January 2023

Mechanical forces are an inherent element in the world around us. The effects of their action can be observed both on the macro and molecular levels. They can also play a prominent role in the tissues and cells of animals due to the presence of mechanosensitive ion channels (MIChs) such as the Piezo and TRP families. They are essential in many physiological processes in the human body. However, their role in pathology has also been observed. Recent discoveries have highlighted the relationship between these channels and the development of malignant tumors. Multiple studies have shown that MIChs mediate the proliferation, migration, and invasion of various cancer cells via various mechanisms. This could show MIChs as new potential biomarkers in cancer detection and prognosis and interesting therapeutic targets in modern oncology. Our paper is a review of the latest literature on the role of the Piezo1 and TRP families in the molecular mechanisms of carcinogenesis in different types of cancer.
Separation Properties of Plasmid DNA Using a Two-Stage Particle Adsorption-Microfiltration Process
Authors: Katagiri Nobuyuki , Shimokawa Daisuke , Suzuki Takayuki , Kousai Masahito , Iritani Eiji
Published: January 2023

Plasmid DNA is used as a vector for gene therapy and DNA vaccination; therefore, the establishment of a mass production method is required. Membrane filtration is widely employed as a separation method suitable for the mass production of plasmid DNA. Furthermore, the separation of plasmid DNA using microfiltration and ultrafiltration membranes is being investigated. Because plasmid DNA has a circular structure, it undergoes significant deformation during filtration and easily permeates the membrane, hindering the selection of separation membranes based on molecular weight. In this study, we applied affinity microfiltration to plasmid DNA purification. α-Fe2O3 with an isoelectric point of approximately 8 and a particle size of 0.5 μm was selected as the ligand for two-stage affinity microfiltration of plasmid DNA. In the first stage of microfiltration, the experiment was conducted at a pH of 5, and a cake of α-Fe2O3 with bound plasmid DNA was obtained. Next, liquid permeation (pH 9 and 10) through the cake was performed to elute the bound plasmid DNA. Plasmid DNA was eluted during the early phase of liquid permeation at pH 10. Furthermore, agarose gel analysis confirmed the usefulness of the two-stage affinity microfiltration method with adsorption and desorption for plasmid DNA purification.
Hybrid Inorganic Organic PSF/Hap Dual-Layer Hollow Fibre Membrane for the Treatment of Lead Contaminated Water
Authors: Mansur Sumarni , Othman Mohd Hafiz Dzarfan , Ismail Nurul Jannah , Sheikh Abdul Kadir Siti Hamimah , Puteh Mohd Hafiz , Abdullah Huda , Jaafar Juhana , Rahman Mukhlis A. , Kusworo Tutuk Djoko , Ismail Ahmad Fauzi , Ahmad Abdul Latif
Published: January 2023

Lead (Pb) exposure can be harmful to public health, especially through drinking water. One of the promising treatment methods for lead contaminated water is the adsorption-filtration method. To ensure the cost-effectiveness of the process, naturally derived adsorbent shall be utilised. In this study, hydroxyapatite particles, Ca10(PO4)6(OH)2 (HAP) derived from waste cockle shell, were incorporated into the outer layer of polysulfone/HAP (PSf/HAP) dual-layer hollow fibre (DLHF) membrane to enhance the removal of lead from the water source due to its hydrophilic nature and excellent adsorption capacity. The PSf/HAP DLHF membranes at different HAP loadings in the outer layer (0, 10, 20, 30 and 40 wt%) were fabricated via the co-extrusion phase inversion technique. The performance of the DLHF membranes was evaluated in terms of pure water flux, permeability and adsorption capacity towards lead. The results indicated that the HAP was successfully incorporated into the outer layer of the membrane, as visibly confirmed by microscopic analysis. The trend was towards an increase in pure water flux, permeability and lead adsorption capacity as the HAP loading increased to the optimum loading of 30 wt%. The optimized DLHF membrane displayed a reduced water contact angle by 95%, indicating its improved surface hydrophilicity, which positively affects the pure water flux and permeability of the membrane. Furthermore, the DLHF membrane possessed the highest lead adsorption capacity, 141.2 mg/g. The development of a hybrid inorganic–organic DLHF membrane via the incorporation of the naturally derived HAP in the outer layer is a cost-effective approach to treat lead contaminated water.
Effect of Solution Treatment on Microstructure Evolution of a Powder Metallurgy Nickel Based Superalloy with Incomplete Dynamic Recrystallization Microstructure
Authors: Liu Yanhui , Wang Miao , Sun Pengwei , Yang Guang , Song Wenjie , Wang Xiaofeng
Published: January 2023

In this paper, the powder metallurgy (P/M) Ni-based superalloy FGH4096 with an incomplete dynamic recrystallization structure was treated by a solution treatment at different temperatures, cooling methods, and holding times. The size, morphology, and distribution of grains and γ′ precipitates were characterized by an optical microscope (OM) and a scanning electron microscope (SEM). Research results showed that with the increase of solution temperature from 1060 °C to 1100 °C, the degree of recrystallization increased continuously, the distribution of grain became uniform, and a large number of annealing twins were found. At the same time, the degree of redissolution of the primary γ′ precipitates at the grain boundary increased, and the size of secondary γ′ phase reprecipitated within the grain decreased. The morphology of the secondary γ′ precipitates is mainly spherical with a single distribution under air cooling (AC), while the morphology is near-spherical, cuboids, octets, petaloid, and dendrites with a bimodal distribution under furnace cooling (FC). The size of the γ′ precipitates decreased and the volume fraction increased with the extension of holding time at a higher solution temperature (1100 °C).
Diffusion between Ti6Al4V and Cemented Carbide with Different Compositions
Authors: Li Mingxing , Yue Caixu , Liu Xianli , Zang Wenhai , Jiang Zhipeng
Published: January 2023

Titanium alloys have been widely used in the aerospace industry because of their excellent properties, such as light weights, high strengths, and corrosion resistance. In this research, the element diffusion between tungsten–cobalt cemented carbide and Ti6Al4V was analyzed using thermodynamic solution theory. First, it was observed that W, Co, and Ti elements diffused under a high temperature and high pressure. Then, by analyzing the diffusion of the different elements, it was found that the amount and depth of the W and Co elements diffusion from the cemented carbide increased with increases in the Co element content and the WC grain size, while the diffusion of the Ti element decreased with increases in the Co element content and decreases in the WC grain size. It was also found that the diffusion amount and depth of the elements increased with increases in the holding temperature and holding time. Finally, the milling experiment was conducted, and an analysis of the cutting-edge section found the existence of Ti in the cemented carbide substrate, which proved the occurrence of the diffusion phenomenon. No Co was found during a chip analysis, but the W element was there. The higher hardness of the WC grains caused the W element to etch onto the chip surface during the milling experiment.
High Gradient Magnetic Separation of Pure Gd2O3 Particles from Pure La2O3 Particles
Authors: Chen Liu , Wu Yongxiang , Nhung Nguyen , He Chunlin , Chen Hao , Dodbiba Gjergj , Otsuki Akira , Fujita Toyohisa
Published: January 2023

Rare earth oxides such as La2O3 and Gd2O3 are abundant in waste optical glass. The separation of rare earth oxides is beneficial to the recycling of rare earth resources. In this study, the rare earth oxide Gd2O3 particles were separated from La2O3 particles using high gradient magnetic separation, and the influence of different fluid media (i.e., water, anhydrous ethanol, and their mixture) on the separation results was investigated. By using the measured zeta potential of oxide particles in water/ethanol of different pH and water with different dispersants (Na2SiO3 9H2O, citric acid, Na2CO3, and sodium hexametaphosphate), the DLVO (Derjaguin–Landau–Verwey–Overbeek) potential calculations and their analysis applied to high gradient magnetic separation results were also performed. The results showed that using anhydrous ethanol or adding a dispersant in water as a fluid medium can promote the separation of magnetic Gd2O3 particles under a high-gradient magnetic field. Among the different conditions, anhydrous ethanol can improve the grade of Gd2O3 to 95% from 70% with water. Furthermore, ethanol can be reused after filtration, making it an environmentally friendly fluid medium. Among the four dispersants, sodium hexametaphosphate, Na2SiO3, and Na2CO3 can also increase the separation rate of La2O3 and Gd2O3 to about 95%. The effect of citric acid on the separation performance is slightly worse, and the recovery rate of Gd2O3 is 80%. This study provides a new reference for selecting a fluid medium for magnetic separation.
Structure–Property Relationship in High-Strength Aluminum Alloys/Stainless Steel Brazed Joints
Authors: Fedorov Vasilii , Uhlig Thomas , Wagner Guntram
Published: January 2023

In many industrial sectors, for example, aerospace, automotive and high-performance electronic industries, there is a significant need to join dissimilar materials. In the case of medium-strength aluminum alloys, joints are commonly manufactured using Al-Si brazing fillers with a melting temperature of 575 °C. In comparison to medium-strength aluminum alloys, high-strength aluminum alloys exhibit lower melting temperatures. Therefore, the joining possibilities are limited. Due to the lower melting temperature of about 500 °C, Al-Ag-Cu brazing fillers allow the joining of these alloys. In this study, high-strength aluminum alloys/stainless steel joints were produced via induction brazing and vacuum furnace brazing. The mechanical properties of the joints were determined using tensile shear tests as well as fatigue tests at ambient temperature. The joints produced via induction brazing at 520 °C without holding time reached a maximum tensile shear strength of 32 MPa. The joints failed in the braze metal close to the reaction zone. The joints brazed in the vacuum furnace at 540 °C for 10 min reached a maximum tensile shear strength of 18 MPa. The fractures occurred in the reaction zone, especially inside the Al7Fe2Si intermetallic layer. The thickness of the intermetallic layers as well as the reaction zone had a significant influence on the joining strength and the fracture mechanism of the brazed joints. The results of the fatigue tests showed that the joints brazed without holding time achieved the defined limited number of cycles of 1 × 107 at a stress amplitude of 4 MPa. For all the fatigue-tested samples, the fracture occurred in the braze metal, especially in the eutectic. Hence, the reaction zone does not significantly influence the fracture mechanism of high-strength aluminum alloy/stainless steel brazed joints during cyclic loading.
Roles of Sc and Ag Microalloying Elements in the Mechanical Properties of Al-Zn-Mg-Cu (Al7xxx) Alloy
Authors: Won Sung-Jae , So Hyeongsub , Han Jung-Woo , Oh Soong Ju , Kim Kyou-Hyun
Published: January 2023

In this study, we use microstructural investigation to examine the effects of Sc and Ag microalloying elements on the mechanical properties of Al-Zn-Mg-Cu-based (7050) alloy. Macroscopically, Sc and Ag microalloying elements significantly reduce the formation of intermetallic particles of S (Al2CuMg) and T (Mg32(Al, Zn)49) and of stable η (MgZn2) phase in Al7050 alloy. In addition, Sc microalloying element facilitates the precipitation of the η’ (MgZn2) hardening phase, while Ag microalloying element impedes the formation of the η’ (MgZn2) hardening phase. As a result, trace addition of Sc enhances the σUTS value of the Al7050 alloy from 552 MPa to 594 MPa without lowering the elongation of the Al7050 alloy (15.0% → 15.5%). In contrast, the tensile strength of the Al7050 alloy decreases from 552 MPa to 456 MPa with the addition of Ag microalloying element, while the elongation increases from 15.0% to 21.0%.
Mechanical Response of CNT/2024Al Composite to Compression and Tension at Different Strain Rates
Authors: Xiang Jiajie , Zheng Yuxuan , Li Jiang , Tan Zhanqiu
Published: January 2023

Compressive and tensile properties of a carbon nanotube (CNT) reinforced 2024Al composite are investigated under quasi-static and dynamic compression as well as quasi-static tension, along three different directions (extrusion, normal and transverse directions). Upon compression, yield and fracture strengths of the composite show negligible strain rate effect and mechanical anisotropy as manifested in the compressive stress–strain curves. Fractography and profilometry show that fracture surfaces are rough shear fracture planes for quasi-static compression; however, smooth conical fracture surfaces are observed for dynamic compression as a result of more homogeneous damage nucleation and growth, leading to high ductility under high strain rate loading. Pronounced mechanical anisotropy is observed for the composite under quasi-static tensile loading. Ductility or fracture strain is the highest along the normal direction, because debonding along the particle and lamellar interfaces is suppressed along this direction. In situ optical imaging along with digital image correlation is utilized to obtain the deformation dynamics of the composite along the three different directions. Stripe-shaped strain localizations appear in the strain fields along the extruded and tangential directions, while the strain fields are approximately uniformly distributed along the normal direction, consistent with the stress–strain curves.
Impact of the Ultrasonic-Assisted Casting of an AlSi7Mg Alloy on T6 Heat Treatment
Authors: Gomes Inês V. , Grilo José , Carneiro Vitor H. , Puga Hélder
Published: January 2023

In this work, the effect of ultrasonic vibration during solidification on the aging kinetics of an AlSi7Mg alloy is investigated. With the ultrasonic equipment coupled to the mold walls, melt treatment was performed by two approaches: (i) fully above liquidus (>635 °C); and (ii) in the full range between liquidus and solidus (630 °C→ 550 °C). Cast samples were then subjected to T6 heat treatment for different aging times. It is shown that indirect ultrasound treatment increases the cooling rate while active. The eutectic Si was refined and further modified when ultrasound treatment was performed in the semisolid state. Due to the significant release of solute during the decomposition of π-Al8FeMg3Si6 into fine β-Al5FeSi, this has a significant impact in the solution stage. Ultrasound treatment fully above liquidus decreased the underaging time to 50% and peak aging time to 25% without compromising strength. The results suggest aging kinetics are correlated with a higher vacancy density and solute enrichment which favors Guinier–Preston (GP) zone formation. These findings show a promising route to tailor the aging kinetics in these alloys by selectively modifying phases and cooling rates.
Effect of Boron Addition on the Oxide Scales Formed on 254SMO Super Austenitic Stainless Steels in High-Temperature Air
Authors: Ren Junyu , Zhang Yi , Yang Song , Ma Jinyao , Zhang Caili , Jiang Zhouhua , Li Huabing , Han Peide
Published: January 2023

Focusing on the serious volatilization of MoO3 in super austenitic stainless steel with a high Mo content, the influence of B on the formation of oxide film and the distribution of Cr and Mo was investigated at 900 °C and 1000 °C. Without the addition of B, Mo tends to diffuse to the surface, forming porous Cr/Mo-rich oxides, causing the volatilization of Mo. The addition of B can inhibit the diffusion of Mo to the surface, facilitate the diffusion of Cr to the surface and combines with O, providing conditions for the nucleation of Cr2O3. A large amount of Cr2O3 accumulated on the surface to form a dense passive film, which inhibited the diffusion of Mo to the surface, reduced the loss of Mo, and formed Mo/Cr-rich precipitates at grain boundaries that are close to the surface. However, it was difficult to form Mo-rich precipitates at the grain boundaries of a sample without B, which aggravated the volatilization of Mo from grain boundary to surface. Therefore, the addition of B can improve the oxidation resistance of 254SMO and inhibit the volatilization of Mo.
Analysis of Cold Composite Sheet Rolling Considering Anisotropic Effect and Position-Dependent Friction Model
Authors: Liu Jiageng , Wu Jiang , Liu Qian , Ji Shuai , Zheng Xinlu , Wang Feng , Wang Jiang
Published: January 2023

The large difference in mechanical properties and plastic deformation ability of each layer will have a great impact on the overall performance of a composite sheet prepared by cold-roll bonding. The effect of rolling and material variables on the stress distribution and bonding state in the rolling deformation zone should be studied. In this work, an accurate cold-rolling deformation model considering the anisotropic effect and position-dependent friction model is established using the slab method. Effects of different process and material variables are analyzed. Related experiments were performed on Ti-Al clads and calculation results from the deformation model were compared with the experimental results. This model can well predict the Ti/Al thickness ratio after rolling, and the smaller the initial aluminum strength, the more accurate the predicted value; the minimum error is within 1%. The deformation coordination between the titanium and aluminum layers becomes better with the increase in rolling reduction and initial aluminum strength. At 50% reduction, the deformation ratio of titanium and aluminum increases from 93.8% to 98.1%, which is consistent with the trend of the results calculated using this model.