bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Interaction Behaviors of Cement-Emulsified Asphalt Based on Micro-Morphological and Macro-Rheological Approaches
Authors: Hu Ganghua , Yang Qing , Qiu Xin , Liu Huiqiong , Qian Yanfeng , Xiao Shanglin
Published: January 2022

Cement emulsified asphalt composite binder (CEACB) plays a determining role in the construction of cold recycled asphalt pavements. Understanding the interaction behaviors of cement-emulsified asphalt is very essential to promote the serviceability of CEACB. The objective of this study was to explore the interaction behaviors and mechanism of cement-emulsified asphalt associated with microstructural characteristics and to assess the interaction ability of cement-emulsified asphalt by performing macro-rheological measurements. Firstly, the physico-chemical interaction of cement-emulsified asphalt was qualitatively discussed by analyzing the difference of characteristic peaks based on Fourier transform infrared (FTIR) spectrometer. Secondly, the micro-morphological evolution behaviors of CEACB attributing to the cement-emulsified asphalt interaction were investigated by using a fluorescence microscope (FM) and laser particle size analyzer (LPSA). Thirdly, the microstructural characteristics of CEACB were studied by observing the spatial network structure through the scanning electron microscopy (SEM). Finally, the macro-rheological index based on dynamic rheological shear (DSR) test was proposed to evaluate the interaction ability of cement-emulsified asphalt. The results show that the cement-emulsified asphalt interaction is merely a physical blending process due to the occurrence of no new characteristic peaks in the FTIR spectrum except for cement hydration products. The cement-emulsified asphalt interaction in early-age CEACB could be reflected by the aggregation process among asphalt droplets and the adsorption action of cement particles to asphalt droplets. A reasonable ratio of cement to emulsified asphalt could promote the formation of the denser spatial network structure of CEACB along with cement hydration products growing and interweaving with asphalt films. The K-B-G* index based on macro-rheological properties of CEACB with full consideration of cement hydration process is very suitable for evaluating the interaction ability of cement-emulsified asphalt under the condition of different cement proportions and curing time. The research would provide the support for understanding the natural properties of CEACB and promote the improvement of the mechanical performance of cold recycled asphalt pavements.
Estimation of Thermal Properties of Straw-Based Insulating Panels
Authors: Czajkowski Łukasz , Kocewicz Robert , Weres Jerzy , Olek Wiesław
Published: January 2022

Cereal straw is an environmentally friendly, rapidly renewable, and sustainable raw material for manufacturing insulating panels for building engineering. Credible data on thermal properties of insulating panels are crucial for appropriate and accurate design of building envelopes. The objective of the study was to determine and validate thermal properties of the panels made of cereal straw. Specific heat was measured with the calorimetric method. Thermal conductivity was determined with the inverse method and Isomet 2114 instrument, respectively. Both approaches accounted for the temperature influence. The specific heat of the panels was as high as 1600 J/(kg·K), while the thermal conductivity varied in the range from 0.025 to 0.075 W/(m·K) depending on the applied experimental method. The studied properties were validated and their credibility was assessed. High accuracy of heat transfer modeling was obtained for the properties measured with the calorimetric method and identified with inverse modeling.
On the Microstructure, Microhardnessand Wear Behavior of Gray Cast Iron Surface Layer after Laser Strengthening
Authors: Feldshtein Eugene , Devojno Oleg , Wojciechowski Szymon , Kardapolava Marharyta , Kasiakova Iryna
Published: January 2022

Cast iron is one of the most common structural materials and is widely used in mechanical engineering production. Taking into account its rather low mechanical properties, different technologies are currently used in industry, among other areas, for the mechanical and thermal strengtheningof the surface layer, as well as surface alloying of workpieces. The aim of this study was a comprehensive analysis of changes in the microstructure, microhardness of the surface layer and its wear resistance under lubrication friction conditions and changed surface energy density in order to ensure the effectiveness of laser strengthening of gray cast iron. In this research, the efficiency of gray cast iron GJL200 laser strengthening was described. The basic properties of the surface layer of gray cast iron under laser strengthening, including the microstructure, microhardness, tribological and wear behavior, were compared with the properties of cast iron in the initial state. It was found that laser strengthening under the right choice of the surface energy density ensured a five-to-tenfold increase in the wear resistance of gray cast iron in comparison with the initial state. This was due to forming unconventional pseudo-vermicular graphite shapes at the friction zone, as well as a spongy-capillary effect appearance. The appropriate selection of surface energy density values provided stable and low coefficients of friction and a very significant increase in the wear resistance compared with the values reached for a cast iron in the initial state. This fact is new and very important for the engineering practice. The values of the surface energy density can be easily controlled, which means that different parts can be operated efficiently after laser strengthening.
Reutilisation of Water Contaminated by Mining Waste for the Encapsulation of Potentially Toxic Elements
Authors: Suárez-Macías Jorge , Terrones-Saeta Juan María , Bernardo-Sánchez Antonio , Ortiz-Marqués Almudena , Castañón Ana Maria , Corpas-Iglesias Francisco Antonio
Published: January 2022

Mining activities are essential for a population’s development; however, they also produce negative effects such as the production of waste, an impact on flora and water pollution. On the other hand, construction is one of the sectors which is most demanding of raw materials, with one of the main such materials being water. For this reason, this research evaluates the feasibility of incorporating water contaminated by mining waste into ceramic materials for bricks. In this way, the use of water is reduced and, on the other hand, the contaminating elements of the mining water are encapsulated in the ceramic matrix. To achieve this, the clay used and the contaminated water were first analysed, then different families of samples were conformed with different percentages of contaminated water. These samples were tested to determine their physical and mechanical properties. At the same time, leachate tests were carried out to determine that the ceramic material created did not cause environmental problems. The test results showed that the physical and mechanical properties of the ceramics were not influenced by the addition of contaminated water. On the other hand, the leachate tests showed that encapsulation of most of the potentially toxic elements occurred. However, the use of contaminated water as mixing water for ceramics could only be performed up to 60%, as higher percentages would leach impermissible arsenic concentrations. Accordingly, a new way of reusing water contaminated by mining activities is developed in this study, taking advantage of resources, avoiding environmental pollution and creating economic and environmentally friendly end products.
Effects of La Addition on the Microstructure, Thermal Conductivity and Mechanical Properties of Mg-3Al-0.3Mn Alloys
Authors: Liu Huafeng , Zuo Jing , Nakata Taiki , Xu Chao , Wang Guisong , Shi Hailong , Tang Guangze , Wang Xiaojun , Kamado Shigeharu , Geng Lin
Published: January 2022

The effects of La addition on the microstructure, thermal conductivity and mechanical properties of as-cast and as-extruded Mg-3Al-xLa-0.3Mn (x = 1, 3 and 5 wt.%) alloys were studied. The results showed that the thermal conductivity of the alloys increased with the addition of La element, which was due to the formation of the Al11La3 phases by consuming the solute Al and the added La element. The yield strength of the as-cast Mg-3Al-xLa-0.3Mn alloys increased with the increase in La concentration. The thermal conductivity of the as-extruded alloys was lower than that of as-cast counterparts owing to lots of defects generated in the process of hot extrusion deformation, particularly the grain boundaries. The anisotropy of thermal conductivity was discovered in the as-extruded alloys on account of the formation of texture. As the La content increases, the tensile strength and yield strength of the as-extruded alloys decreased gradually. In contrast, the elongation first increased and then decreased, resulting from the combined effect of the texture strengthening and second phase strengthening.
High-Frequency ac Susceptibility of Iron-Based Superconductors
Authors: Ghigo Gianluca , Fracasso Michela , Gerbaldo Roberto , Gozzelino Laura , Laviano Francesco , Napolitano Andrea , Cao Guang-Han , Graf Michael J. , Prozorov Ruslan , Tamegai Tsuyoshi , Shi Zhixiang , Xing Xiangzhuo , Torsello Daniele
Published: January 2022

A microwave technique suitable for investigating the AC magnetic susceptibility of small samples in the GHz frequency range is presented. The method—which is based on the use of a coplanar waveguide resonator, within the resonator perturbation approach—allows one to obtain the absolute value of the complex susceptibility, from which the penetration depth and the superfluid density can be determined. We report on the characterization of several iron-based superconducting systems, belonging to the 11, 122, 1144, and 12442 families. In particular, we show the effect of different kinds of doping for the 122 family, and the effect of proton irradiation in a 122 compound. Finally, the paradigmatic case of the magnetic superconductor EuP-122 is discussed, since it shows the emergence of both superconducting and ferromagnetic transitions, marked by clear features in both the real and imaginary parts of the AC susceptibility.
Effect of Doping on the Electronic Structure of the Earth’s Lower Mantle Compounds: FeXO3 with X = C, Al, Si
Authors: Chernov Evgeniy D. , Dyachenko Alexey A. , Lukoyanov Alexey V.
Published: January 2022

The effect of the mutual doping of C, Si, and Al atoms on the electronic structure and magnetic properties of FeXO3 (X = C, Al, Si) compounds, which are constituent compounds of the Earth’s lower mantle, was studied. In our first principles calculations, it was found that doping with carbon for both FeSiO3 and FeAlO3 leads to the transition of the compound from a half-metallic state to a metallic one. The values of the magnetic moments of Fe were obtained for pure and doped compounds. For the doped compounds, there is a tendency of the Fe magnetic moment to increase with the growth in the number of substituted ions in the case of replacing Si with C and Si for Al; on the contrary, in the case of replacing Al with C and Si, a decrease in the magnetic moment was revealed. For FeXO3 (X = C, Al, Si), the obtained magnetic moment values were found to be in a good agreement with the known experimental data.
Dynamic Performance Improvement of Solenoid Screw-In Cartridge Valve Using a New Hybrid Voltage Control
Authors: Liu Zengguang , Li Linfei , Yue Daling , Wei Liejiang , Liu Chao , Zuo Xiukun
Published: January 2022

Digital hydraulic technology as an emergent and important branch of fluid power offers good prospects for intelligence, integration, and energy saving of hydraulic systems. The high-speed on-off valve (HSV) that is a critical component of digital hydraulics has the drawbacks of specific design, narrow scope of application and high price compared to the commercial solenoid screw-in cartridge valve (SCV) widely used in the hydraulic industry at present. In this paper, a hybrid voltage control strategy composed of the preloading voltage, positive pulse voltage, holding voltage and negative pulse voltage is proposed to enhance the dynamic characteristics of the SCV, which makes it meet the demands of the digital hydraulics and achieve the end of replacing the HSV. Based on the structural analysis of the SCV, a mathematical model of the SCV is deduced. Subsequently, the simulation model of the SCV is developed in AMESim and validated by experimental measurements. The effects of the different duty ratios of the preloading voltage and holding voltage on the dynamic characteristics of SCV are studied, and the dynamic responses of the SCV under the normal voltage, positive and negative pulse and hybrid voltage control strategies are compared. The simulation results indicate that the increment of the preload voltage duty ratio and the reduction of the holding voltage duty ratio are conducive for decreasing the total opening and closing time of the SCV, especially the opening delay and closing delay time. The hybrid voltage control proposed has a better effect in dynamic characteristics than the other two strategies, using which the total opening time of the SCV reduces by 74.24% (from 29.5 ms to 7.60 ms), and the total closing time is drastically squeezed by 92.06% (from 136 ms to 10.8 ms). This provides a technical reference for improving the dynamic response speed of SCVs and popularizing digital hydraulic technology.
Study on Dynamic Lubrication Characteristics of the External Return Spherical Bearing Pair under Full Working Conditions
Authors: Deng Haishun , Zhu Pengkun , Hu Cong , He Tao
Published: January 2022

In order to study the frictional lubrication characteristics of a piston pump under varying loads and speeds in actual work, mathematical models, such as a cylinder dynamics model, cylinder micro-motion model, and external return spherical bearing pair lubrication model, were established under full working conditions. The influence of different parameters on the lubrication characteristics of the external return mechanism under full working conditions was analyzed. The results show that in a working cycle, when the pump was at low working pressure, the maximum value of the maximum oil film pressure increased with an increase in the cylinder block speed, which is basically consistent with the ideal conditions. With an increase in the working pressure, the maximum value first decreased and then increased with an increase in the cylinder block speed. When the cylinder block speed was constant, the total friction power increased with an increase in the working pressure and the internal as well as external swash plates’ inclination; considering the contact surface roughness of a friction pair under full working conditions, the total friction power increased by 46.8% compared with the ideal working conditions. The axial leakage flow increased with an increase in the external swash plate inclination and remained unchanged with an increase in the internal swash plate inclination. This research is beneficial for improving the lubrication theory of the external return mechanism and lays a foundation for improving its working performance.
Effect of Reciprocating Gait Orthosis with Hip Actuation on Upper Extremity Loading during Ambulation in Patient with Spinal Cord Injury: A Single Case Study
Authors: Lee Jong-Won , Bae Juhwan , Choi Hyuk-Jae , Kwon Chilyong , Heo Yoon , Cho Hyeonseok , Kim Gyoosuk
Published: January 2022

Reciprocating gait orthosis (RGO) is a traditional passive orthosis that provides postural stability and allows for independent upright ambulation with the assistance of walking aids, such as crutches, canes, and walkers. Previous follow-up studies of patients with RGOs have indicated a high frequency of nonusage. One of the main reasons for avoiding the use of RGOs is the excessive upper extremity loading induced by walking aids. The purpose of this study was to investigate the effect of hip actuation on the upper extremity loading induced by crutches when ambulating with an RGO. One female individual with a chronic complete spinal cord injury classified as ASIA A participated in this study. We compared the upper extremity loading during ambulation when individualized hip assistive forces were applied on the RGO (POWERED condition) and when wearing the RGO without actuation (RGO condition). Upper extremity loading was assessed by measuring the forces acting on the crutches. Compared with the RGO condition, the average upper extremity loading per unit distance and per unit time were lower for the POWERED condition by 15.21% (RGO: 0.307 ± 0.056 and POWERED: 0.260 ± 0.034 %bw·m−1) and by 21.19% (RGO: 0.120 ± 0.020 and POWERED: 0.094 ± 0.011 %bw·s−1), respectively. We believe that a substantial reduction in upper extremity loading during ambulation provided by hip actuation holds promise to promote long-term RGO use and enable patients with paraplegia to perform frequent and intensive rehabilitation training. As this is a single case study, subsequent studies should aim to verify this effect through a higher number of patients and to different injury levels.
Deep Multi-Semantic Fusion-Based Cross-Modal Hashing
Authors: Zhu Xinghui , Cai Liewu , Zou Zhuoyang , Zhu Lei
Published: January 2022

Due to the low costs of its storage and search, the cross-modal retrieval hashing method has received much research interest in the big data era. Due to the application of deep learning, the cross-modal representation capabilities have risen markedly. However, the existing deep hashing methods cannot consider multi-label semantic learning and cross-modal similarity learning simultaneously. That means potential semantic correlations among multimedia data are not fully excavated from multi-category labels, which also affects the original similarity preserving of cross-modal hash codes. To this end, this paper proposes deep multi-semantic fusion-based cross-modal hashing (DMSFH), which uses two deep neural networks to extract cross-modal features, and uses a multi-label semantic fusion method to improve cross-modal consistent semantic discrimination learning. Moreover, a graph regularization method is combined with inter-modal and intra-modal pairwise loss to preserve the nearest neighbor relationship between data in Hamming subspace. Thus, DMSFH not only retains semantic similarity between multi-modal data, but integrates multi-label information into modal learning as well. Extensive experimental results on two commonly used benchmark datasets show that our DMSFH is competitive with the state-of-the-art methods.
Controller Design for Unstable Time-Delay Systems with Unknown Transfer Functions
Authors: Tsai Hsun-Heng , Fuh Chyun-Chau , Ho Jeng-Rong , Lin Chih-Kuang , Tung Pi-Cheng
Published: January 2022

This study developed a method for designing parallel two-degree-of-freedom proportional-integral-derivative controllers for unstable time-delay processes with unknown dynamic equations. First, a performance index accounting for both transient response performance and disturbance rejection was developed. To obtain useful data even if the output of the system exceeds the allowable range, an effective penalty function was included in the performance index. The N–M simplex method was used to iteratively determine the optimal controller parameters. The proposed approach has the following advantages: (1) it can be used regardless of the stability of the open-loop system; (2) the mathematical model and parameters of the process need not be known in advance; (3) it can be used for processes that include measurement noise; (4) it has good transient response performance and is also robust against external disturbances; and (5) it enables more efficient controller design and reduces costs.
Transfer Learning Analysis of Multi-Class Classification for Landscape-Aware Algorithm Selection
Authors: Škvorc Urban , Eftimov Tome , Korošec Peter
Published: January 2022

In optimization, algorithm selection, which is the selection of the most suitable algorithm for a specific problem, is of great importance, as algorithm performance is heavily dependent on the problem being solved. However, when using machine learning for algorithm selection, the performance of the algorithm selection model depends on the data used to train and test the model, and existing optimization benchmarks only provide a limited amount of data. To help with this problem, artificial problem generation has been shown to be a useful tool for augmenting existing benchmark problems. In this paper, we are interested in the problem of knowledge transfer between the artificially generated and existing handmade benchmark problems in the domain of continuous numerical optimization. That is, can an algorithm selection model trained purely on artificially generated problems correctly provide algorithm recommendations for existing handmade problems. We show that such a model produces low-quality results, and we also provide explanations about how the algorithm selection model works and show the differences between the problem data sets in order to explain the model’s performance.
Common Fixed Points of Operators with Property (E) in CAT(0) Spaces
Authors: Bejenaru Andreea , Ciobanescu Cristian
Published: January 2022

This paper features the search for common fixed points of two operators in the nonlinear metric setting provided by CAT(0) spaces. The analysis is performed for the generalized nonexpansivity condition known as condition (E), Garcia-Falset et al., and relies on the three step iteration procedure Sn by Sintunavarat and Pitea. The convergence analysis reveals the approximate solutions as limit points for an iteration sequence, where both the nonexpansive mappings to be analyzed and the specific curved structure of the framework interfere. To point out properly the meaning of this approach, we provide also examples accompanied by numerical simulations. The Poincaré half-plane is one of the non-positively curved setting to be used.
An Inventory Model for Non-Instantaneously Deteriorating Items with Nonlinear Stock-Dependent Demand, Hybrid Payment Scheme and Partially Backlogged Shortages
Authors: Khan Md Al-Amin , Shaikh Ali Akbar , Cárdenas-Barrón Leopoldo Eduardo , Mashud Abu Hashan Md , Treviño-Garza Gerardo , Céspedes-Mota Armando
Published: January 2022

This research work presents an inventory model that involves non-instantaneous deterioration, nonlinear stock-dependent demand, and partially backlogged shortages by considering the length of the waiting time under a hybrid prepayment and cash-on-delivery scheme. The corresponding inventory problem is formulated as a nonlinear constraint optimization problem. The theoretical results for the unique optimal solution are presented, and eight special cases are also identified. Moreover, a salient theoretical result is provided: a certain condition where the optimal inventory policy may or may not involve deterioration. Finally, two numerical examples are provided using a sensitivity analysis to show the validity range of the inventory parameters.
Bayesian Estimation Using Expected LINEX Loss Function: A Novel Approach with Applications
Authors: Nassar Mazen , Alotaibi Refah , Okasha Hassan , Wang Liang
Published: January 2022

The loss function plays an important role in Bayesian analysis and decision theory. In this paper, a new Bayesian approach is introduced for parameter estimation under the asymmetric linear-exponential (LINEX) loss function. In order to provide a robust estimation and avoid making subjective choices, the proposed method assumes that the parameter of the LINEX loss function has a probability distribution. The Bayesian estimator is then obtained by taking the expectation of the common LINEX-based Bayesian estimator over the probability distribution. This alternative proposed method is applied to estimate the exponential parameter by considering three different distributions of the LINEX parameter, and the associated Bayes risks are also obtained in consequence. Extensive simulation studies are conducted in order to compare the performance of the proposed new estimators. In addition, three real data sets are analyzed to investigate the applicability of the proposed results. The results of the simulation and real data analysis show that the proposed estimation works satisfactorily and performs better than the conventional standard Bayesian approach in terms of minimum mean square error and Bayes risk.
A Dual Incentive Value-Based Paradigm for Improving the Business Market Profitability in Blockchain Token Economy
Authors: Guo Chaopeng , Zhang Pengyi , Lin Bangyao , Song Jie
Published: January 2022

Blockchain solves the problem of mutual trust and consensus in the business market of the token economy. In the existing paradigm of blockchain token economy, there are disadvantages of lacking the incentive mechanism, business applications and virtual token value. These shortcomings reduce consumers’ willingness to consume and the profits of the merchants. In this paper, we propose a novel “Dual incentive value-based” paradigm to improve the business market profitability in blockchain token economy. To evaluate our proposed paradigm, we propose a business study case for improving merchants’ environment state. In this case, we set up two economic models and make simulations to validate the profitability. The result shows that merchants with the novel paradigm have 32% more profit compared with those without the paradigm and at most 10% more profitable than those in existing paradigms.
Partial Exchangeability for Contingency Tables
Authors: Diaconis Persi
Published: January 2022

A parameter free version of classical models for contingency tables is developed along the lines of de Finetti’s notions of partial exchangeability.
Some New Midpoint and Trapezoidal-Type Inequalities for General Convex Functions in q-Calculus
Authors: Zhao Dafang , Gulshan Ghazala , Ali Muhammad Aamir , Nonlaopon Kamsing
Published: January 2022

The main objective of this study is to establish two important right q-integral equalities involving a right-quantum derivative with parameter m∈[0,1]. Then, utilizing these equalities, we derive some new variants for midpoint- and trapezoid-type inequalities for the right-quantum integral via differentiable (α,m)-convex functions. The fundamental benefit of these inequalities is that they may be transformed into q-midpoint- and q-trapezoid-type inequalities for convex functions, classical midpoint inequalities for convex functions and classical trapezoid-type inequalities for convex functions are transformed without having to prove each one independently. In addition, we present some applications of our results to special means of positive real numbers. It is expected that the ideas and techniques may stimulate further research in this field.
Do Commodities React More to Time-Varying Rare Disaster Risk? A Comparison of Commodity and Financial Assets
Authors: Chen Peng , Huang Ting
Published: January 2022

Using a rare disaster risk database from almost the last one hundred years, we examine the differences in the reaction of asset prices to rare disaster risk between commodity and financial assets. We first employ time-varying parameter VAR (TVP-VAR) models to investigate the role of rare disaster risk in the price dynamics of major asset markets. The results indicate that disaster risk generally has a more intense and persistent impact on crude oil and stock markets when compared to gold and bond markets. However, the role of rare disaster risk differs substantially between commodity and financial assets, as well as between the short and long term. Moreover, when using a nonparametric causality-in-quantiles method to detect causal relationships, we provide evidence of the nonlinear causality effect of rare disaster risks on asset volatilities, and not their returns, except for crude oil. In addition, we demonstrate that augmenting a diversified portfolio of stock or bonds with gold can significantly increase its risk-adjusted performance. The findings have important implications for investors as well as policymakers.
(−)-Agelasidine A Induces Endoplasmic Reticulum Stress-Dependent Apoptosis in Human Hepatocellular Carcinoma
Authors: Lu I-Ta , Lin Shih-Chao , Chu Yi-Chia , Wen Ya , Lin You-Cheng , Cheng Wen-Chien , Sheu Jyh-Horng , Lin Chi-Chien
Published: January 2022

Liver cancers, such as hepatocellular carcinoma (HCC), are a highly prevalent cause of cancer-related deaths. Current treatments to combat liver cancer are limited. (−)-Agelasidine A, a compound isolated from the methanol extract of Agelasnakamurai, a sesquiterpene guanidine derived from sea sponge, has antibacterial activity. We demonstrated its anticancer capabilities by researching the associated mechanism of (−)-agelasidine A in human liver cancer cells. We found that (−)-agelasidine A significantly reduced viability in Hep3B and HepG2 cells, and we determined that apoptosis was involved in the (−)-agelasidine A-induced Hep3B cell deaths. (−)-Agelasidine A activated caspases 9, 8, and 3, as well as PARP. This effect was reversed by caspase inhibitors, suggesting caspase-mediated apoptosis in the (−)-agelasidine A-treated Hep3B cells. Moreover, the reduced mitochondrial membrane potential (MMP) and the release of cytochrome c indicated that the (−)-agelasidine A-mediated mitochondrial apoptosis was mechanistic. (−)-Agelasidine A also increased apoptosis-associated proteins (DR4, DR5, FAS), which are related to extrinsic pathways. These events were accompanied by an increase in Bim and Bax, proteins that promote apoptosis, and a decrease in the antiapoptotic protein, Bcl-2. Furthermore, our results presented that (−)-agelasidine A treatment bridged the intrinsic and extrinsic apoptotic pathways. Western blot analysis of Hep3B cells treated with (−)-agelasidine A showed that endoplasmic reticulum (ER) stress-related proteins (GRP78, phosphorylated PERK, phosphorylated eIF2α, ATF4, truncated ATF6, and CHOP) were upregulated. Moreover, 4-PBA, an ER stress inhibitor, could also abrogate (−)-agelasidine A-induced cell viability reduction, annexin V+ apoptosis, death receptor (DR4, DR5, FAS) expression, mitochondrial dysfunction, and cytochrome c release. In conclusion, by activating ER stress, (−)-agelasidine A induced the extrinsic and intrinsic apoptotic pathways of human HCC.
A Novel Peptide Derived from Arca inflata Induces Apoptosis in Colorectal Cancer Cells through Mitochondria and the p38 MAPK Pathway
Authors: Li Chunlei , Zhang Sirui , Zhu Jianhua , Huang Weijuan , Luo Yuanyuan , Shi Hui , Yu Dongbo , Chen Liguo , Song Liyan , Yu Rongmin
Published: January 2022

Colorectal carcinoma (CRC) is one of the major causes of cancer-related incidence and deaths. Here, we identified a novel antitumor peptide, P6, with a molecular weight of 2794.8 Da from a marine Chinese medicine, Arca inflata Reeve. The full amino acid sequence and secondary structure of P6 were determined by tandem mass de novo sequencing and circular dichroism spectroscopy, respectively. P6 markedly inhibited cell proliferation and colony formation, and induced apoptosis in CRC cells. Mechanistically, transcriptomics analysis and a serial functional evaluation showed that P6 induced colon cancer cell apoptosis through the activation of the p38-MAPK signaling pathway. Moreover, it was demonstrated that P6 exhibited antitumor effects in a tumor xenograft model, and induced cell cycle arrest in CRC cells in a concentration-dependent mode. These findings provide the first line of indication that P6 could be a potential therapeutic agent for CRC treatment.
Design and Evaluation of Two-Stage Membrane-Separation Processes for Propylene–Propane Mixtures
Authors: Yamaki Takehiro , Thuy Nguyen , Hara Nobuo , Taniguchi Satoshi , Kataoka Sho
Published: January 2022

Propylene is industrially produced in a mixture with propane and generally separated from the mixture via distillation. However, because distillation is an energy-consuming process, a more efficient separation process should be developed to mitigate both carbon dioxide (CO2) emissions and production costs. In this study, a two-stage membrane-separation process was designed, and its CO2 emission and production costs were evaluated. The separation processes were designed to minimize energy consumption using different membrane combinations (two recently developed membranes each). To evaluate the separation processes using various membrane combinations, two indicators, i.e., CO2 emissions and total annual costs (TACs), were estimated based on the process simulation (Pro/II, version 10.1.1) results, including energy consumptions, operation expenditure, and capital expenditure. These results were compared to the distillation processes as benchmarks, and the advantages of the membrane-separation process were discussed. In the comparison, carbon taxes were implemented for assessing these two independent indicators as a single indicator, i.e., TAC with carbon tax. Furthermore, using the same scheme, model membranes were also employed in the two-stage membrane-separation process as case studies of technological forecasts.
Membrane Distillation Hybrid Peroxydisulfate Activation toward Mitigating the Membrane Wetting by Sodium Dodecyl Sulfate
Authors: Han Minyuan , Zhao Ruixue , Shi Jianchao , Li Xiaobo , He Daoling , Liu Lang , Han Le
Published: January 2022

The fouling/wetting of hydrophobic membrane caused by organic substances with low-surface energy substantially limits the development of the membrane distillation (MD) process. The sulfate radical (SO4 ·−)-based advanced oxidation process (AOP) has been a promising technology to degrade organics in wastewater treatment, and peroxydisulfate (PDS) could be efficiently activated by heat. Thus, a hybrid process of MD-AOP via PDS activated by a hot feed was hypothesized to mitigate membrane fouling/wetting. Experiments dealing with sodium dodecyl sulfate (SDS) containing a salty solution via two commercial membranes (PVDF and PTFE) were performed, and varying membrane wetting extents in the coupling process were discussed at different PDS concentrations and feed temperatures. Our results demonstrated permeate flux decline and a rise in conductivity due to membrane wetting by SDS, which was efficiently alleviated in the hybrid process rather than the standalone MD process. Moreover, such a mitigation was enhanced by a higher PDS concentration up to 5 mM and higher feed temperature. In addition, qualitative characterization on membrane coupons wetted by SDS was successfully performed using electrochemical impedance spectroscopy (EIS). The EIS results implied both types of hydrophobic membranes were protected from losing their hydrophobicity in the presence of PDS activation, agreeing with our initial hypothesis. This work could provide insight into future fouling/wetting control strategies for hydrophobic membranes and facilitate the development of an MD process.
Sn Content Effects on Microstructure, Mechanical Properties and Tribological Behavior of Biomedical Ti-Nb-Sn Alloys Fabricated by Powder Metallurgy
Authors: Xie Fangxia , Yang Hao , Huang Jiabing , Yu Jinghu , He Xueming
Published: January 2022

A group of Ti-10Nb-xSn alloys with Sn content varying from 0 to 8 wt.% were fabricated from blended elemental powders using powder metallurgy processing. The effects of the Sn content on the microstructure, mechanical performance, and tribological behavior were investigated. The results showed that Ti-10Nb-xSn alloys with high density could be fabricated using powder metallurgy. When the Sn content increased from 0 to 8 wt.%, the density increased slightly from 96.76% to 98.35%. The alloys exhibited a typical α + β microstructure. As the Sn content increased, the dendritic β grains gradually converted into a laminar α + β structure, accompanied by intergranular α and a small number of micropores. The elastic modulus of the alloys decreased with increasing Sn content but not significantly (73–76 GPa). The addition of Sn initially reduced the Vickers hardness, compressive strength, and maximum strain. When Sn was added up to 5 wt.%, these properties tended to increase slowly in the ranges 310–390 HV, 1100–1370 MPa, and 15.44–23.72%, respectively. With increasing Sn content, the friction coefficient of the alloys increased from 0.41 to 0.50. Without Sn, Ti-10Nb was dominated by abrasive wear. The wear mechanism of Ti-10Nb-3Sn and Ti-10Nb-5Sn changed to adhesive wear together with abrasive wear with increasing Sn content, while Ti-10Nb-8Sn predominately exhibited adhesive wear. Compared with Ti-10Nb alloy, an appropriate amount of Sn could achieve a lower elastic modulus, while Vickers hardness and compressive strengths were little changed. Moreover, it had a minor influence on the friction coefficient. The good mechanical performance and wear resistance make the powder-metallurgy-fabricated Ti-10Nb-xSn alloys attractive candidates for biomedical materials.
Laser Welding of Metal-Polymer-Metal Sandwich Panels
Authors: Murzin Serguei P. , Palkowski Heinz , Melnikov Alexey A. , Blokhin Maksim V.
Published: January 2022

In the production of metal-polymer multilayer composite parts, e.g., for automotive applications, the possibilities of thermal joining are limited due to the instability of the polymer core at elevated temperatures. Accordingly, such materials require a special approach to their welding. The three-layered metal-polymer-metal samples were made of DPK 30/50+ZE dual-phase steel as cover sheets that were electrolytic galvanized, and a polypropylene-polyethylene foil as core material, with thicknesses of 0.48/0.3/0.48 mm. The samples were welded on both sides using a 1.06 µm Nd:YAG ROFIN StarWeld Manual Performance laser. Significant improvements of the welding conditions are achieved by machining the edges of materials to be welded. The parameters of laser welding were chosen in such a way that the polymer structure remained almost unchanged. The weld thickness was about 40% of the thickness of each steel layer. It was established that within the selected laser processing parameters the melting occurred uniformly, while the polymer layer practically did not change its structure. Therefore, it can be stated that two-sided joint welding of metal-polymer-metal composite sandwich panels, without significant degradation of the polymer core layer, is feasible.
Research on Microstructure Characteristics of Welded Joint by Magneto-Optical Imaging Method
Authors: Wang Congyi , Wang Chuncao , Gao Xiangdong , Tian Meng , Zhang Yanxi
Published: January 2022

This paper proposes an approach for analyzing the microstructure evolution of laser welding seam by magneto-optical imaging (MOI). The Faraday magneto-optical effect and magnetic domain theory are used to account for the MOI mechanism. The influence of laser welding on the welded joint was inspected by the analysis of color, grayscale and brightness of magneto-optical images. The relation between the brightness of magneto-optical image and grain size of microstructure is discussed as well, and the characteristics of magneto-optical images of weld microstructure were compared with those of scanning electron microscope (SEM) images. Experimental results show that three regions, including the weld zone (WZ), the heat-affected zone (HAZ), and the base metal (BM) are distributed in the magneto-optical image of the welded joint. The MOI method can investigate the microstructure evolution of welded joints and provide a theory and experimental basis for detecting weld defects.
Microstructure and Mechanical Properties at Elevated Temperature of Powder Metallurgy Al-Zn-Mg-Cu Alloy Subjected to Hot Extrusion
Authors: Han Weihao , Li Yang , Li Pei , Su Guoping , Zhang Chenzeng , Sun Chunfang , Chen Cunguang , Yang Fang , Guo Zhimeng
Published: January 2022

In this work, Al-Zn-Mg-Cu powders containing 0.15 and 0.33 wt % oxygen were utilized to prepare high-strength aluminum alloys through the process of cold isostatic pressing, sintering, hot extrusion, and heat treatment. Microstructural and mechanical properties at elevated temperatures of 250, 350, and 450 °C were investigated by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and high-temperature tensile tests. Results showed that the tensile strengths of the obtained Al-Zn-Mg-Cu alloys with 0.15 wt % oxygen were 185, 46, and 18 MPa at 250, 350, and 450 °C, respectively. When the oxygen content of Al-Zn-Mg-Cu alloy rose to 0.33 wt %, the tensile strengths at the corresponding temperature reached up to 205, 68, and 25 MPa, respectively. The excellent high-temperature performance could be attributed to double hindrance to dislocation motion and grain boundary migration by a large amount of nano γ-Al2O3 created by the in-creased oxygen, thereby resulting in fine grains even at high temperatures.
Microstructure and Texture of an Aluminum Plate Produced by Multipass Cold Rolling and Graded Annealing Process
Authors: Wang Yunlei , Yang Fangzhou , Ren Liping , Liu Qi , Cao Yu , Huang Guangjie
Published: January 2022

In order to explore the microstructure, texture, individual performance, and grain size characteristic evolution law during the process of multipass cold rolling, graded annealing process, the experimental design, research approach, and methodology were investigated using the equipment of optical microscope (OM), X-ray diffraction (XRD), electron backscattered diffraction (EBSD), and transmission electron microscope (TEM). The results show that a low interannealing temperature could strengthen the cubic texture after finished product annealing, and a high volume fraction of cubic texture components was subsequently obtained. In view of the nucleation advantage of cubic texture, the Cube-{001}<100> texture formation after annealing was promoted by the cold-rolled texture of Cu-{112}<111> and S-{123}<634>, which mainly depended on the decomposition of Cu and S textures, finally, they were consumed and transformed from Cu and S textures into a cubic texture. In addition, the dislocation configuration and corrosion pit density were clearly visible and distinctive in the observation space of aluminum foil.
Diabetes-Induced Changes in Macrophage Biology Might Lead to Reduced Risk for Abdominal Aortic Aneurysm Development
Authors: Chinetti Giulia , Carboni Joseph , Murdaca Joseph , Moratal Claudine , Sibille Brigitte , Raffort Juliette , Lareyre Fabien , Baptiste Elixène Jean , Hassen-Khodja Réda , Neels Jaap G.
Published: January 2022

Type 2 diabetes patients are less likely to develop an abdominal aortic aneurysm (AAA). Since macrophages play a crucial role in AAA development, we hypothesized that this decrease in AAA risk in diabetic patients might be due to diabetes-induced changes in macrophage biology. To test this hypothesis, we treated primary macrophages obtained from healthy human volunteers with serum from non-diabetic vs. diabetic AAA patients and observed differences in extracellular acidification and the expression of genes involved in glycolysis and lipid oxidation. These results suggest an increase in metabolism in macrophages treated with serum from diabetic AAA patients. Since serum samples used did not differ in glucose content, these changes are not likely to be caused by differences in glycemia. Macrophage functions have been shown to be linked to their metabolism. In line with this, our data suggest that this increase in macrophage metabolism is accompanied by a shift towards an anti-inflammatory state. Together, these results support a model where diabetes-induced changes in metabolism in macrophages might lead to a reduced risk for AAA development.
A Review on Graphene-Based Nano-Electromechanical Resonators: Fabrication, Performance, and Applications
Authors: Xiao Yang , Luo Fang , Zhang Yuchen , Hu Feng , Zhu Mengjian , Qin Shiqiao
Published: January 2022

The emergence of graphene and other two-dimensional materials overcomes the limitation in the characteristic size of silicon-based micro-resonators and paved the way in the realization of nano-mechanical resonators. In this paper, we review the progress to date of the research on the fabrication methods, resonant performance, and device applications of graphene-based nano-mechanical resonators, from theoretical simulation to experimental results, and summarize both the excitation and detection schemes of graphene resonators. In recent years, the applications of graphene resonators such as mass sensors, pressure sensors, and accelerometers gradually moved from theory to experiment, which are specially introduced in this review. To date, the resonance performance of graphene-based nano-mechanical resonators is widely studied by theoretical approaches, while the corresponding experiments are still in the preliminary stage. However, with the continuous progress of the device fabrication and detection technique, and with the improvement of the theoretical model, suspended graphene membranes will widen the potential for ultralow-loss and high-sensitivity mechanical resonators in the near future.
Modeling of Soft Pneumatic Actuators with Different Orientation Angles Using Echo State Networks for Irregular Time Series Data
Authors: Youssef Samuel M. , Soliman MennaAllah , Saleh Mahmood A. , Mousa Mostafa A. , Elsamanty Mahmoud , Radwan Ahmed G.
Published: January 2022

Modeling of soft robotics systems proves to be an extremely difficult task, due to the large deformation of the soft materials used to make such robots. Reliable and accurate models are necessary for the control task of these soft robots. In this paper, a data-driven approach using machine learning is presented to model the kinematics of Soft Pneumatic Actuators (SPAs). An Echo State Network (ESN) architecture is used to predict the SPA’s tip position in 3 axes. Initially, data from actual 3D printed SPAs is obtained to build a training dataset for the network. Irregular-intervals pressure inputs are used to drive the SPA in different actuation sequences. The network is then iteratively trained and optimized. The demonstrated method is shown to successfully model the complex non-linear behavior of the SPA, using only the control input without any feedback sensory data as additional input to the network. In addition, the ability of the network to estimate the kinematics of SPAs with different orientation angles θ is achieved. The ESN is compared to a Long Short-Term Memory (LSTM) network that is trained on the interpolated experimental data. Both networks are then tested on Finite Element Analysis (FEA) data for other θ angle SPAs not included in the training data. This methodology could offer a general approach to modeling SPAs with varying design parameters.
Wafer-Level Filling of MEMS Vapor Cells Based on Chemical Reaction and Evaporation
Authors: Guo Ping , Meng Hongling , Dan Lin , Zhao Jianye
Published: January 2022

Micro-electro-mechanical system (MEMS) vapor cells are key components for sensors such as chip-scale atomic clocks (CSACs) and magnetometers (CSAMs). Many approaches have been proposed to fabricate MEMS vapor cells. In this article, we propose a new method to fabricate wafer-level filling of MEMS vapor cells based on chemical reaction and evaporation. The Cs metals are firstly obtained through the chemical reaction between cesium chloride and barium azide in a reservoir baseplate. Then, the Cs metals are evaporated to the preform through the microchannel plate and condensed on the inner glass surface of the preform. Lastly, the MEMS vapor cells are filled with buffer gas, sealed by anodic bonding, and mechanically diced into three dimensions: 5 mm × 5 mm × 1.2 mm, 4 mm × 4 mm × 1.2 mm, and 3 mm × 3 mm × 1.2 mm. The full width at half maximum (FWHM) linewidth of the coherent population trapping (CPT) signal of the MEMS vapor cells is found to be 4.33 kHz. The intrinsic linewidth is about 1638 Hz. Based on the CPT signal, the frequency stability is 4.41 × 10−12@1000 s. The results demonstrate that the presented method of the wafer-level filling of MEMS vapor cells fulfills the requirements of sensors such as CSACs.