bluuebunny/crossref_metadata_2025 huggingface dataset:
The Common Values of Social Media Marketing and Luxury Brands. The Millennials and Generation Z Perspective
Authors: Dobre Costinel , Milovan Anca-Maria , Duțu Cristian , Preda Gheorghe , Agapie Amadea
Published: September 2021

As consumers spend more time on social media, brands can take advantage of this opportunity to better serve and communicate with their followers. Still, given the characteristics of luxury, luxury brands may be reluctant to use social media. To determine the extent to which Millennials and Generation Z consumers perceive compatibility between social media marketing and luxury brands, a purposive sampling technique was employed. We collected data from 303 Romanian visitors of the Facebook page entitled Do You Like Luxury? This page, with postings from luxury producers, was specially created and sponsored in order to raise interest in completing the questionnaires. For data analysis, we used statistical tests, including confirmatory factorial analysis, regression, and independent-samples t-test. Our research shows that, for Millennials and Generation Z, luxury brands are compatible with social media apps as marketing channels. Even in the case of inadequacy, managers can still use the facilities of digital technologies to depict exclusivity, emotions, and sensory experiences specific to luxury. Unlike other studies, which only focused on a few dimensions, we proposed a multidimensional approach of the perceived value of luxury and social media marketing. Moreover, this is one of the few studies to focus on Eastern European consumers.
Influence of Residents’ Perception of Tourism’s Impact on Supporting Tourism Development in a GIAHS Site: The Mediating Role of Perceived Justice and Community Identity
Authors: Wang Bojie , He Siyuan , Min Qingwen , Cui Feng , Wang Guoping
Published: September 2021

How we scientifically measure residents’ perception of tourism developments and earn their understanding and support have an important impact on the scientific management and sustainable utilization of tourist attractions. This study analyzes the mediating role of perceived justice and community identity between residents’ perceptions of tourism’s impact and their support for tourism development by integrating the theories of social exchange theory (SET) and ‘cognition–affection–conation’ (CAC) relationship theory. We surveyed 334 interviewees in the Xinghua Duotian Agrosystem (XHDA), a Globally Important Agricultural Heritage Systems (GIAHS) site in Jiangsu Province, China. The findings of our study are as follows: (1) Residents’ perceptions had both a direct and indirect influence over behavioral intentions. Specifically, benefit perception of tourism had a significant positive influence, while cost perception had a significant negative influence on residents’ support for tourism development. (2) Perceived justice and community identity played an intermediary role in the relationship between tourism impact perception and support for tourism development. (3) The mediating role of emotions had strong effects on their behavioral intentions via its psychological transmission chain of perceptions. The results suggest that community-based tourism (CBT) may be an effective tool for local residents to diversify their livelihoods in the GIAHS site, and the mediating role of perceived justice and community identity should be taken seriously for the development of CBT in GIAHS sites.
Ecosystem Services, Sustainable Rural Development and Protected Areas
Authors: de Castro-Pardo Mónica , Azevedo João C. , Fernández Pascual
Published: September 2021

Enhancing social and economic development while preserving nature is one of the most significant challenges for humankind in the current century [...]
Land-Use Change and Efficiency in Laos’ Special Economic Zones
Authors: Li Dongxue , Wang Xingping
Published: September 2021

Special economic zones (SEZs) are important in Laos due to their ability to attract foreign investment, realize industrialization, and promote economic globalization. Based on Laos’ SEZs in operation, this study explored land-use intensity, structural evolution and land-use efficiency in Laos’ SEZs via the land-use dynamic degree, information entropy, super-efficiency data envelopment analysis (DEA) and gray relational analysis (GRA). The study determined that the total land-use area in Laos’ SEZs continuously increased from 2014 to 2020. The land-use intensity changes in the SEZs can be divided into three types, i.e., high intensity, medium intensity and low intensity, and most SEZs belonged to the medium-intensity type. The proportion of land used in production systems in Laos’ SEZs increased the most, and the proportion of infrastructure land notably decreased. The overall information entropy of the land-use structure exhibited an initial downward and then an upward trend. In 2018, the land-use efficiency in the Savan-Seno SEZ, Vientiane Industrial and Trade Area, Dongphosy SEZ, and Golden Triangle SEZ was relatively optimal. The basic factors of the industrial space and the factors reflecting international cooperation attributes were highly related to the land-use efficiency in Laos’ SEZs.
COVID-19 and Antimicrobial Resistance: Data from the Greek Electronic System for the Surveillance of Antimicrobial Resistance—WHONET-Greece (January 2018–March 2021)
Authors: Polemis Michalis , Mandilara Georgia , Pappa Olga , Argyropoulou Athina , Perivolioti Efstathia , Koudoumnakis Nikolaos , Pournaras Spyros , Vasilakopoulou Alexandra , Vourli Sophia , Katsifa Helen , Karampatakis Theodoros , Papavasiliou Anastasia , Petinaki Efthymia , Xitsas Stylianos , Skoura Lemonia , Protonotariou Efthymia , Mantzana Paraskevi , Gartzonika Konstantina , Priavali Efthalia , Kallinteri Amalia , Giannopoulou Panagiota , Charalampaki Nikoletta , Memezas Meletis , Calina Oana Zervaki , Papadogianni Marina , Panopoulou Maria , Koutsidou Athanasia , Vatopoulos Alkiviadis , Tryfinopoulou Kyriaki
Published: September 2021

Changes in hospitals’ daily practice due to COVID-19 pandemic may have an impact on antimicrobial resistance (AMR). We aimed to assess this possible impact as captured by the Greek Electronic System for the Surveillance of Antimicrobial Resistance (WHONET-Greece). Routine susceptibility data of 17,837 Gram-negative and Gram-positive bacterial isolates from blood and respiratory specimens of hospitalized patients in nine COVID-19 tertiary hospitals were used in order to identify potential differences in AMR trends in the last three years, divided into two periods, January 2018–March 2020 and April 2020–March 2021. Interrupted time-series analysis was used to evaluate differences in the trends of non-susceptibility before and after the changes due to COVID-19. We found significant differences in the slope of non-susceptibility trends of Acinetobacter baumannii blood and respiratory isolates to amikacin, tigecycline and colistin; of Klebsiella pneumoniae blood and respiratory isolates to meropenem and tigecycline; and of Pseudomonas aeruginosa respiratory isolates to imipenem, meropenem and levofloxacin. Additionally, we found significant differences in the slope of non-susceptibility trends of Staphylococcus aureus isolates to oxacillin and of Enterococcus faecium isolates to glycopeptides. Assessing in this early stage, through surveillance of routine laboratory data, the way a new global threat like COVID-19 could affect an already ongoing pandemic like AMR provides useful information for prompt action.
Effect of Microgravity Environment on Gut Microbiome and Angiogenesis
Authors: Siddiqui Ruqaiyyah , Qaisar Rizwan , Goswami Nandu , Khan Naveed Ahmed , Elmoselhi Adel
Published: September 2021

Microgravity environments are known to cause a plethora of stressors to astronauts. Recently, it has become apparent that gut microbiome composition of astronauts is altered following space travel, and this is of significance given the important role of the gut microbiome in human health. Other changes observed in astronauts comprise reduced muscle strength and bone fragility, visual impairment, endothelial dysfunction, metabolic changes, behavior changes due to fatigue or stress and effects on mental well-being. However, the effects of microgravity on angiogenesis, as well as the connection with the gut microbiome are incompletely understood. Here, the potential association of angiogenesis with visual impairment, skeletal muscle and gut microbiome is proposed and explored. Furthermore, metabolites that are effectors of angiogenesis are deliberated upon along with their connection with gut bacterial metabolites. Targeting and modulating the gut microbiome may potentially have a profound influence on astronaut health, given its impact on overall human health, which is thus warranted given the likelihood of increased human activity in the solar system, and the determination to travel to Mars in future missions.
Analysis of the Structural Aspects of Tannin-Based Adhesives by 2D-NMR
Authors: Omura Sachikazu , Kawazoe Yoshinori , Uemura Daisuke
Published: September 2021

We developed non-toxic, harmless adhesives composed of all-natural and renewable resources, of which one was composed of tannin and gelatin, which unfortunately was lacking water resistance, and the other of tannin and ε-poly-l-lysine. In this study, we analyzed the chemical structures of these adhesives by two-dimensional nuclear magnetic resonance (2D-NMR) to explain the difference in water-resistance of the two glues. The results showed that only one proton was left in the benzene ring of tannin after mixing. This suggests that the amino group of the protein was directly attached to the benzene ring by a Michael addition-type reaction, and not to the hydroxyl group. In addition, the heteronuclear multiple bond correlation spectrum of the tannin-poly-l-lysine compound indicated that the hydroxyl groups of the tannin oxidized, suggesting the improvement of its water resistance.
Accurate Parameter Estimation for Master–Slave Operation of a Surgical Robot
Authors: Shi Hu , Liu Qingxin , Mei Xuesong
Published: September 2021

In this paper, a parameter estimation method is proposed to predict the simultaneous joint dynamics of a surgical robotic arm that is tracking trajectories. It mainly deals with the design, modeling, prototyping and control of a serial robotic arm for robot-assisted urological surgery. This robot is composed of many joints mounted in series with the surgical tool end performing both a translational workspace and a cone-shaped orientation workspace. The joints dynamics is obtained by trajectory planning of the tool end in the virtual prototype modeling environment. The motor drive system is parameterized for design, and its comprehensive performance in motion is predicted accurately. The heterogeneous master–slave control system was built, and the performances of the master–slave prototype were experimentally evaluated by measuring the positioning error of the virtual fixed point and the surgical tool end along the planned trajectory.
A Stackelberg Game Approach toward Migration of Enterprise Applications to the Cloud
Authors: Li Shiyong , Li Wenzhe , Liu Huan , Sun Wei
Published: September 2021

With the development of cloud computing, more and more cloud resources are rented or purchased by users. Using an economics approach to achieve cloud resource management has been thought of as a good choice for an enterprise user to complete an application’s migration and deployment into the public cloud. During an application’s migration process, it is important but very challenging to achieve the satisfaction of both the enterprise user and the public cloud provider at the same time. In this paper, we apply an economics approach to investigate the migration optimization problem during the migration process of applications from the enterprise user’s data center to the remote public cloud. We consider the application migration time of the enterprise user and the energy consumption of physical machines, and establish a single static round optimization problem for both the enterprise user and the cloud provider on the premise of satisfying the quality of experience (QoE) based on the Stackelberg game, where the public cloud provider is leader and the enterprise user is follower. Then we propose a novel algorithm to find the optimal physical machine placement for application migration. After that, we further consider that an enterprise user needs to migrate several applications, and extend the single-round static game to the multi-round dynamic game, where the energy consumption costs of the physical machines are reduced by adjusting the states of the physical machines in each round. We finally illustrate the performance of our scheme through some simulation results.
Caliber and Chain Conditions in Soft Topologies
Authors: Alcantud José Carlos R. , Al-shami Tareq M. , Azzam A. A.
Published: September 2021

In this paper, we contribute to the growing literature on soft topology. Its theoretical underpinning merges point-set or classical topology with the characteristics of soft sets (a model for the representation of uncertain knowledge initiated in 1999). We introduce two types of axioms that generalize suitable concepts of soft separability. They are respectively concerned with calibers and chain conditions. We investigate explicit procedures for the construction of non-trivial soft topological spaces that satisfy these new axioms. Then we explore the role of cardinality in their study, and the relationships among these and other properties. Our results bring to light a fruitful field for future research in soft topology.
Representing Integer Sequences Using Piecewise-Affine Loops
Authors: Rodríguez Gabriel , Pouchet Louis-Noël , Touriño Juan
Published: September 2021

A formal, high-level representation of programs is typically needed for static and dynamic analyses performed by compilers. However, the source code of target applications is not always available in an analyzable form, e.g., to protect intellectual property. To reason on such applications, it becomes necessary to build models from observations of its execution. This paper details an algebraic approach which, taking as input the trace of memory addresses accessed by a single memory reference, synthesizes an affine loop with a single perfectly nested reference that generates the original trace. This approach is extended to support the synthesis of unions of affine loops, useful for minimally modeling traces generated by automatic transformations of polyhedral programs, such as tiling. The resulting system is capable of processing hundreds of gigabytes of trace data in minutes, minimally reconstructing 100% of the static control parts in PolyBench/C applications and 99.99% in the Pluto-tiled versions of these benchmarks. As an application example of the trace modeling method, trace compression is explored. The affine representations built for the memory traces of PolyBench/C codes achieve compression factors of the order of 106 and 103 with respect to gzip for the original and tiled versions of the traces, respectively.
Analysing the Stock Market as an Economic Lever, Using a Qualitative and a Quantitative Model
Authors: Cristescu Marian-Pompiliu , Nerișanu Raluca-Andreea , Flori Maria , Stoica Florin , Stoica Florentina Laura
Published: September 2021

The article aims to provide a perspective on economic growth by relying on the influence and use of the stock market as an economic lever. Two methods will be used: a quantitative one, determined by a multiple linear regression model, and a qualitative one that encumbers a sustainable vector model for generating economic growth. The data panel covers 36 states, for a period of 21 years. The paper manages to identify the main control functions that the stock exchange has over the macroeconomic context, through the quantitative and qualitative method, and to highlight the most important positive and negative attributes of using qualitative methods, in contrast to quantitative ones. The results show a predominant probabilistic characteristic of quantitative methods, in contrast to the flexibility and complexity of the qualitative method, which has been used. Additionally, the quantitative method offers a strictly cartesian perspective for determining future scenarios, while the sustainable vector model, based on a fractalized vision of reality, manages to capture a plurality of perspectives, as well as the interrelationships between the determining parameters, thus being a complex system of simple equations, as opposed to the quantitative method which is defined as a simple system of complex equations.
Dynamical Analysis of Bio-Ethanol Production Model under Generalized Nonlocal Operator in Caputo Sense
Authors: Alqahtani Rubayyi T. , Ahmad Shabir , Akgül Ali
Published: September 2021

The nonlinear fractional-order model of bioethanol production under a generalized nonlocal operator in the Caputo sense is investigated in this work. Theoretical and computational aspects of the considered model are discussed. We prove that the model has at least one solution and a unique solution using the Leray–Schauder and Banach contraction theorems. Using functional analysis, we investigate several types of Ulam–Hyres model stability. We use the predictor–corrector (P–C) method to construct a broad numerical scheme for the model’s solution. The proposed numerical method’s stability is demonstrated. Finally, we depict the numerical findings geometrically to demonstrate the model’s dynamics.
Generalized Kalman Filter and Ensemble Optimal Interpolation, Their Comparison and Application to the Hybrid Coordinate Ocean Model
Authors: Belyaev Konstantin , Kuleshov Andrey , Smirnov Ilya , Tanajura Clemente A. S.
Published: September 2021

In this paper, we consider a recently developed data assimilation method, the Generalized Kalman Filter (GKF), which is a generalization of the widely-used Ensemble Optimal Interpolation (EnOI) method. Both methods are applied for modeling the Atlantic Ocean circulation using the known Hybrid Coordinate Ocean Model. The along-track altimetry data taken from the Archiving, Validating and Interpolating Satellite Oceanography Data (AVISO) were used for data assimilation and other data from independent archives of observations; particularly, the temperature and salinity data from the Pilot Research Array in the Tropical Atlantic were used for independent comparison. Several numerical experiments were performed with their results discussed and analyzed. It is shown that values of the ocean state variables obtained in the calculations using the GKF method are closer to the observations in terms of standard metrics in comparison with the calculations using the standard data assimilation method EnOI. Furthermore, the GKF method requires less computational effort compared to the EnOI method.
A More Accurate Estimation of Semiparametric Logistic Regression
Authors: Zheng Xia , Rong Yaohua , Liu Ling , Cheng Weihu
Published: September 2021

Growing interest in genomics research has called for new semiparametric models based on kernel machine regression for modeling health outcomes. Models containing redundant predictors often show unsatisfactory prediction performance. Thus, our task is to construct a method which can guarantee the estimation accuracy by removing redundant variables. Specifically, in this paper, based on the regularization method and an innovative class of garrotized kernel functions, we propose a novel penalized kernel machine method for a semiparametric logistic model. Our method can promise us high prediction accuracies, due to its capability of flexibly describing the complicated relationship between responses and predictors and its compatibility of the interactions among the predictors. In addition, our method can also remove the redundant variables. Our numerical experiments demonstrate that our method yields higher prediction accuracies compared to competing approaches.
Robust Stabilization and Observer-Based Stabilization for a Class of Singularly Perturbed Bilinear Systems
Authors: Chen Ding-Horng , Chao Chun-Tang , Chiou Juing-Shian
Published: September 2021

An infinite-bound stabilization of a system modeled as singularly perturbed bilinear systems is examined. First, we present a Lyapunov equation approach for the stabilization of singularly perturbed bilinear systems for all ε∈(0, ∞). The method is based on the Lyapunov stability theorem. The state feedback constant gain can be determined from the admissible region of the convex polygon. Secondly, we extend this technique to study the observer and observer-based controller of singularly perturbed bilinear systems for all ε∈(0, ∞). Concerning this problem, there are two different methods to design the observer and observer-based controller: one is that the estimator gain can be calculated with known bounded input, the other is that the input gain can be calculated with known observer gain. The main advantage of this approach is that we can preserve the characteristic of the composite controller, i.e., the whole dimensional process can be separated into two subsystems. Moreover, the presented stabilization design ensures the stability for all ε∈(0, ∞). A numeral example is given to compare the new ε-bound with that of previous literature.
Novel Design Framework for Dual-Band Frequency Selective Surfaces Using Multi-Variant Differential Evolution
Authors: Boursianis Achilles D. , Papadopoulou Maria S. , Nikolaidis Spyridon , Sarigiannidis Panagiotis , Psannis Konstantinos , Georgiadis Apostolos , Tentzeris Manos M. , Goudos Sotirios K.
Published: September 2021

Frequency Selective Surfaces (FSSs) have become increasingly popular during the last years due to their combined characteristics, which meet, in general, the requirements of the next-generation wireless communication networks. In this work, a cross-platform design framework for FSS structures is presented and evaluated by utilizing a recently introduced evolutionary optimization algorithm, namely, the Multi-Variant Differential Evolution (MVDE). To the best of the authors knowledge, this is the first time that the MVDE algorithm is applied to a design problem in Electromagnetics. The proposed design framework is described in detail and the utilized evolutionary algorithm is assessed in terms of its performance by applying several benchmark functions. In this context, the MVDE is comparatively evaluated against other popular evolutionary algorithms. Moreover, it is applied to the design and optimization of two different representative examples of FSS structures based on three use cases of unit cell geometry. Optimization results indicate the efficacy of the proposed framework by quantifying the performance of the designed FSS structures in terms of several system metrics. The optimized FSS structures exhibit dual-band operation and quite acceptable results in the ISM frequency bands of 2.45 GHz and 5.8 GHz.
Contracting and Involutive Negations of Probability Distributions
Authors: Batyrshin Ildar Z.
Published: September 2021

A dozen papers have considered the concept of negation of probability distributions (pd) introduced by Yager. Usually, such negations are generated point-by-point by functions defined on a set of probability values and called here negators. Recently the class of pd-independent linear negators has been introduced and characterized using Yager’s negator. The open problem was how to introduce involutive negators generating involutive negations of pd. To solve this problem, we extend the concepts of contracting and involutive negations studied in fuzzy logic on probability distributions. First, we prove that the sequence of multiple negations of pd generated by a linear negator converges to the uniform distribution with maximal entropy. Then, we show that any pd-independent negator is non-involutive, and any non-trivial linear negator is strictly contracting. Finally, we introduce an involutive negator in the class of pd-dependent negators. It generates an involutive negation of probability distributions.
Proposing an Intelligent Dual-Energy Radiation-Based System for Metering Scale Layer Thickness in Oil Pipelines Containing an Annular Regime of Three-Phase Flow
Authors: Taylan Osman , Abusurrah Mona , Amiri Saba , Nazemi Ehsan , Eftekhari-Zadeh Ehsan , Roshani Gholam Hossein
Published: September 2021

Deposition of scale layers inside pipelines leads to many problems, e.g., reducing the internal diameter of pipelines, damage to drilling equipment because of corrosion, increasing energy consumption because of decreased efficiency of equipment, and shortened life, etc., in the petroleum industry. Gamma attenuation could be implemented as a non-invasive approach suitable for determining the mineral scale layer. In this paper, an intelligent system for metering the scale layer thickness independently of each phase’s volume fraction in an annular three-phase flow is presented. The approach is based on the use of a combination of an RBF neural network and a dual-energy radiation detection system. Photo peaks of 241Am and 133Ba registered in the two transmitted detectors, and scale-layer thickness of the pipe were considered as the network’s input and output, respectively. The architecture of the presented network was optimized using a trial-and-error method. The regression diagrams for the testing set were plotted, which demonstrate the precision of the system as well as correction. The MAE and RMSE of the presented system were 0.07 and 0.09, respectively. This novel metering system in three-phase flows could be a promising and practical tool in the oil, chemical, and petrochemical industries.
An Academic Performance Indicator Using Flexible Multi-Criteria Methods
Authors: Blasco-Blasco Olga , Liern-García Marina , López-García Aarón , Parada-Rico Sandra E.
Published: September 2021

Composite indicators are a very useful tool for conveying summary information on the overall performance of institutions and facilitating decision-making. Increasingly, there is a demand for indicators that allow performance to be assessed after the implementation of a strategy. This has several difficulties, and in this paper, we address three of them: how to evaluate at different points in time, how to estimate the weighting of the criteria and how to normalize the data. Our proposal is based on multicriteria techniques, using a recent method, uwTOPSIS, and is applied to data collected from 2975 students enrolled in the first year of science and engineering at the Industrial University of Santander (Colombia) from the first semester of 2016 to the first semester of 2019. In the paper, we show that our proposal makes it possible to measure and evaluate the academic performance of students at two points in time, and this allows the University to know whether its student support policy has been successful and to what degree it has been effective. Due to the large amount of data handled, data management has been done using R programming language, and model implementation has been done with Python.
Robust Nonlinear Position Control with Extended State Observer for Single-Rod Electro-Hydrostatic Actuator
Authors: Son Young Seop , Kim Wonhee
Published: September 2021

In the existing literature, studies on position controller design using only position feedback, considering the disturbances for single-rod electro-hydrostatic actuators (EHAs), have not been reported. Herein, we propose a robust nonlinear position control with an extended state observer (ESO) for single-rod EHAs. A new EHA model that consists of position, velocity, and acceleration with an internal state variable is developed. Instead of the separated port pressure dynamics, the acceleration dynamics were defined. The external disturbance, model, and input function uncertainties were lumped into a disturbance. An ESO is developed to estimate the disturbance, as well as the position, velocity, and acceleration. In practice, it is difficult to accurately estimate the disturbance because it includes the external disturbance, system dynamics, and input function uncertainty. The poor estimation performance may degrade the position tracking performance, but a high gain cannot be used to suppress the estimation error because of the measurement noise amplification. To resolve this problem, a robust nonlinear position controller is developed via a backstepping procedure. In the controller, a nonlinear gain is implemented to sufficiently suppress position tracking without the use of a high gain. The stability of the closed-loop system is mathematically proven using the input-to-state stability. The proposed method is simple and suitable for real-time control.
Toward Minimalistic Model of Cellular Volume Dynamics in Neurovascular Unit
Authors: Loshkarev Robert , Postnov Dmitry
Published: September 2021

The neurovascular unit (NVU) concept denotes cells and their communication mechanisms that autoregulate blood supply in the brain parenchyma. Over the past two decades, it has become clear that besides its primary function, NVU is involved in many important processes associated with maintaining brain health and that altering the proportion of the extracellular space plays a vital role in this. While biologists have studied the process of cells swelling or shrinking, the consequences of the NVU’s operation are not well understood. In addition to direct quantitative modeling of cellular processes in the NVU, there is room for developing a minimalistic mathematical description, similar to how computational neuroscience operates with very simple models of neurons, which, however, capture the main features of dynamics. In this work, we have developed a minimalistic model of cell volumes regulation in the NVU. We based our model on the FitzHugh–Nagumo model with noise excitation and supplemented it with a variable extracellular space volume. We show that such a model acquires new dynamic properties in comparison with the traditional neuron model. To validate our approach, we adjusted the parameters of the minimalistic model so that its behavior fits the dynamics computed using the high-dimensional quantitative and biophysically relevant model. The results show that our model correctly describes the change in cell volume and intercellular space in the NVU.
Specifically Targeted Transport of Plasma Membrane Transporters: From Potential Mechanisms for Regulating Cell Health or Disease to Applications
Authors: He Yeqing , He Guandi , He Tengbing
Published: September 2021

Normal substrate transport and signal transmission are the premise to ensure the health of biological somatic cells. Therefore, a comprehensive understanding of the molecular mechanism of intercellular substrate transport is of great significance for clinical treatment. In order to better understand the membrane protein through its interaction with receptors, to help maintain a healthy cell and the molecular mechanisms of disease, in this paper, we seek to clarify, first of all, the recognition mechanism for different types of membrane protein receptors; pathogen invasion using the transport pathway involved in the membrane; and the latest specific target sites of various kinds of membrane transport carriers; to provide an explanation and summary of the system. Secondly, the downstream receptor proteins and specific substrates of different membrane transporters were classified systematically; the functional differences of different subclasses and their relationship with intracellular transport disorders were analyzed to further explore the potential relationship between cell transport disorders and diseases. Finally, the paper summarizes the use of membrane transporter-specific targets for drug design and development from the latest research results; it points out the transporter-related results in disease treatment; the application prospects and the direction for drug development and disease treatment providing a new train of thought; also for disease-specific targeted therapy, it provides a certain reference value.
On the Evaluation of Energy Dissipation at the Beginning of Fatigue
Authors: Lan Ling , Guo Shaofei , Liu Xuesong
Published: September 2021

The slope method is a popular energy dissipation estimation method, which ignores the influence of heat exchange. Within the framework of the zero-dimensional thermal diffusion model, this paper presents a calculation method for evaluating the energy dissipation of materials in the initial stage of fatigue, which can be called the optimization method. Different from the slope method, this method takes the influence of thermal boundary conditions into consideration. Numerical simulation showed that the optimization method has the ability to accurately estimate energy dissipation in different experimental environments and is not sensitive to measurement noise. Compared with the popular slope method, the newly proposed optimization method has certain advantages in adaptability to different environments and flexibility in parameter selection. A case study was also carried out to study a high-cycle fatigue life of an aluminum alloy which demonstrated that results predicted by the proposed method matched the experimental data in the range of short fatigue life.
Influence of Cold Rolling Process and Chemical Composition on the Mechanical Properties and Corrosion Behavior of Zr-Based Metallic Glasses
Authors: Akbarpour Ali , Milkova Daria , Zanaeva Erzhena , Parkhomenko Mark , Cheverikin Vladimir , Lubenchenko Alexander , Bazlov Andrey
Published: September 2021

Cold rolling (CR) with thickness reduction of 10%, 30%, and 50% was applied to Zr50Cu44Al6 and Zr49.5Cu44Al6Nb0.5 metallic glassy ribbon samples. The XRD patterns showed the amorphousness of all samples after casting and CR processes. The SEM images indicated the formation of multiple shear bands (SBs) owing to plastic deformation during CR. However, the addition of 0.5 at% Nb to the alloy changed the SBs’ density and spacing characteristics. The characterization of free volume changes caused by CR was carried out by measuring the density of Archimedes. The micro-hardness of samples was studied by investigating SBs and free volume during plastic deformation. Alloy softening occurred due to the formation of free volume during CR. X-ray photoelectron spectroscopy (XPS) confirmed the presence of oxides ZrO2, CuOx, and AlOx on the surface of the ribbons. The anodic polarization curves of the cast and R50 samples in solutions of NaCl and Na2SO4 (0.5 M) were obtained using potentiodynamic polarization measurements. Compared to CR ribbons, melt-spun ribbons after casting showed better corrosion resistance with lower anodic current densities in Na2SO4 solution.
Effect of CoCrMo Addition on Ti6Al4V/xCoCrMo Biomedical Composites Processed by Powder Metallurgy
Authors: Mihalcea Elena , Olmos Luis , Vergara-Hernández Héctor , Jimenez Omar , Chávez Jorge , Arteaga Dante
Published: September 2021

A detailed experimental and numerical investigation was performed on a Ti6Al4V/xCoCrMo biomedical composite for bone implant applications. The aim was to understand the effect generated by the addition of different volume fractions of CoCrMo particles on a Ti6Al4V matrix composite processed by powder metallurgy. Distribution of CoCrMo particles inside a matrix was observed by computed microtomography. Three-dimensional image analysis allowed for the deduction that the mechanism that permitted percolation within the powder mixture was the cluster formation at 30 vol.% of CoCrMo and at a coordination number of Co–Co contacts of 2.8, which confirms existing models. Densification during powder compaction was driven by larger indentations at the Ti–Co contacts for lower quantities of CoCrMo than for those reaching percolation. Sintering was studied by dilatometry tests at 1130 °C, and results indicated that solid-state sintering generated the formation of a rigid skeleton. This endured the stress generated by the eutectic reaction liquid, which filled the interparticle porosity, resulting in relative densities above 90%. Microstructure was analyzed by SEM and X-ray diffraction, and results showed a Ti6Al4V matrix surrounded by a Ti2Co eutectic phase. In addition, the hardness of composites increased up to three times compared to the Ti6Al4V alloy. It was concluded that the best properties were obtained from 20 vol.% of CoCrMo.
Design Implications and Opportunities of Considering Fatigue Strength, Manufacturing Variations and Predictive LCC in Welds
Authors: Hagnell Mathilda Karlsson , Khurshid Mansoor , Åkermo Malin , Barsoum Zuheir
Published: September 2021

Fatigue strength dictates life and cost of welded structures and is often a direct result of initial manufacturing variations and defects. This paper addresses this coupling through proposing and applying the methodology of predictive life-cycle costing (PLCC) to evaluate a welded structure exhibiting manufacturing-induced variations in penetration depth. It is found that if a full-width crack is a fact, a 50% thicker design can result in life-cycle cost reductions of 60% due to reduced repair costs. The paper demonstrates the importance of incorporating manufacturing variations in an early design stage to ensure an overall minimized life-cycle cost.
Effect of External Impacts on the Structure and Martensitic Transformation of Rapidly Quenched TiNiCu Alloys
Authors: Shelyakov Alexander , Sitnikov Nikolay , Zaletova Irina , Tabachkova Natalia , Andreev Nikolay
Published: September 2021

TiNi-TiCu quasibinary system alloys with a high Cu content produced by rapid quenching from liquid state in the form of thin amorphous ribbons exhibit pronounced shape memory effect after crystallization and are promising materials for miniaturized and fast operating devices. There is currently no complete clarity of the mechanisms of structure formation during crystallization from the amorphous state that determine the structure-sensitive properties of these alloys. This work deals with the effect of the initial amorphous state structure and crystallization method of the alloys on their structure and phase transformations. To this end the alloy containing 30 at.% Cu was subjected to thermal and mechanical impact in the amorphous state and crystallized using isothermal or electropulse treatment. We show that after all types of treatment in the amorphous state the structure of the alloy remains almost completely amorphous but the characteristic temperatures and enthalpy of crystallization become slightly lower. Isothermal crystallization of alloy specimens produces a submicrocrystalline structure with an average grain size in the 0.4–1.0 μm range whereas electropulse crystallization generates a bimorphic structure consisting of large 4–6 μm grains and 2–3 μm high columnar crystals in the vicinity of the surface. The grains have nanosized plate-like and subgrain structures. The largest grains are observed in thermally activated samples, meanwhile, mechanical impact in the amorphous state leads to the formation of equiaxed finer grains with a less defective subgrain structure and to the shift of the temperature range of the martensitic transformation toward lower temperatures.
Bias Polarity Dependent Threshold Switching and Bipolar Resistive Switching of TiN/TaOx/ITO Device
Authors: Ryu Hojeong , Park Beomjun , Kim Sungjun
Published: September 2021

In this work, we demonstrate the threshold switching and bipolar resistive switching with non-volatile property of TiN/TaOx/indium tin oxide (ITO) memristor device. The intrinsic switching of TaOx is preferred when a positive bias is applied to the TiN electrode in which the threshold switching with volatile property is observed. On the other hand, indium diffusion could cause resistive switching by formation and rupture of metallic conducting filament when a positive bias and a negative bias are applied to the ITO electrode for set and reset processes. The bipolar resistive switching occurs both with the compliance current and without the compliance current. The conduction mechanism of low-resistance state (LRS) and high-resistance state (HRS) are dominated by Ohmic conduction and Schottky emission, respectively. Finally, threshold switching and bipolar resistive switching are verified by pulse operation.
Effect of the Surface Roughness of Tungsten on the Sputtering Yield under Helium Irradiation: A Molecular Dynamics Study
Authors: Kim Hyeonho , Kwon Joongseok , Chang Kunok
Published: September 2021

Sputtering in a divertor is one of the key phenomena that affects plasma purity and temperature. In previous experimental studies, the term sputtering yield has been used to refer to net sputtering yield, which is defined as the difference between primary sputtering yield and re-deposition. Our simulations using molecular dynamics have confirmed that both primary sputtering yield and re-deposition are affected by particle curvature. In this study, the effect of particle curvature on the net sputtering yield was quantitatively evaluated, the results were compared to existing experimental studies, and the discrepancies with experimental results were discussed.
A Buckling Instability Prediction Model for the Reliable Design of Sheet Metal Panels Based on an Artificial Intelligent Self-Learning Algorithm
Authors: Lee Seungro , Quagliato Luca , Park Donghwi , Berti Guido A. , Kim Naksoo
Published: September 2021

Sheets’ buckling instability, also known as oil canning, is an issue that characterizes the resistance to denting in thin metal panels. The oil canning phenomenon is characterized by a depression in the metal sheet, caused by a local buckling, which is a critical design issue for aesthetic parts, such as automotive outer panels. Predicting the buckling instability during the design stage is not straightforward since the shape of the component might change several times before the part is sent to production and can actually be tested. To overcome this issue, this research presents a robust prediction model based on the convolutional neural network (CNN) to estimate the buckling instability of automotive sheet metal panels, based on the major, minor, and Gaussian surface curvatures. The training dataset for the CNN model was generated by implementing finite element analysis (FEA) of the outer panels of various commercial vehicles, for a total of twenty panels, and by considering different indentation locations on each panel. From the implemented simulation models the load-stroke curves were exported and utilized to determine the presence, or absence, of buckling instability and to determine its magnitude. Moreover, from the computer aided design (CAD) files of the relevant panels, the three considered curvatures on the tested indentation points were acquired as well. All the positions considered in the FEA analyses were backed up by industrial experiments on the relevant panels in their assembled position, allowing to validate their reliability. The combined correlation of curvatures and load-displacement curves allowed correlating the geometrical features that create the conditions for buckling instability to arise and was utilized to train the CNN algorithm, defined considering 13 convolution layers and 5 pooling layers. The trained CNN model was applied to another automotive frame, not used in the training process, and the prediction results were compared with experimental indentation tests. The overall accuracy of the CNN model was calculated to be 90.1%, representing the reliability of the proposed algorithm of predicting the severity of the buckling instability for automotive sheet metal panels.
Vacuum Gasification-Directional Condensation for Separation of Tellurium from Lead Anode Slime
Authors: Gao Zhe , Kong Xiangfeng , Yi Jiafei , Yang Bin , Xu Baoqiang , Liu Dachun , Wu Jian , Xiong Heng
Published: September 2021

Tellurium is the indispensable base material of semiconductors in solar panels. Traditional tellurium recycling, a highly complicated separation process, has exhausted reagents and energy sources whilst producing waste residue and water containing multitudinous heavy metal that is hugely harmful to the ecological environment. A clean and eco-friendly vacuum distillation-directional condensation treatment was investigated for its potential to recycle tellurium from tellurium-rich lead anode slime (TLAS). The optimal distillation temperature and response time conditions of 1173 K and 50 min were obtained based on a large number of experiments. Gasification results indicated that under the optimal conditions of distillation temperature 1173 K, constant temperature time 50 min, and system pressure 5–15 Pa, 92% of tellurium was volatilized and enriched into the condenser from TLAS. Condensate results revealed that 88% of elemental tellurium was directly recovered in the volatile matter. The appropriate gasification-condensation processes realized a clean utilization to extract tellurium and separate multi valuable metals effectively.
Molten Steel Flow, Heat Transfer and Inclusion Distribution in a Single-Strand Continuous Casting Tundish with Induction Heating
Authors: Dou Weixue , Yang Zexi , Wang Ziming , Yue Qiang
Published: September 2021

The electrical magnetic field plays an important role in controlling the molten steel flow, heat transfer and migration of inclusions. However, industrial tests for inclusion distribution in a single-strand tundish under the electromagnetic field have never been reported before. The distribution of non-metallic inclusions in steel is still uncertain in an induction-heating (IH) tundish. In the present study, therefore, using numerical simulation methods, we simulate the flow and heat transfer characteristics of molten steel in the channel-type IH tundish, especially in the channel. At the same time, industrial trials were carried out on the channel-type IH tundish, and the temperature distribution of the tundish with or without IH under different pouring ladle furnace was analyzed. The method of scanning electron microscopy was employed to obtain the distribution of inclusions on different channel sections. The flow characteristics of molten steel in the channel change with flow time, and the single vortex and double vortex alternately occur under the electromagnetic field. The heat loss of molten steel can be compensated in a tundish with IH. As heating for 145 s, the temperature of the molten steel in the channel increases by 31.8 K. It demonstrates that the temperature of the molten steel in the tundish can be kept at the target value of around 1813 K, fluctuating up and down 3 K after using electromagnetic IH. In the IH channel, the large inclusions with diameters greater than 9 μm are more concentrated at the edge of the channel, and the effect of IH on the inclusion with diameters less than 9 μm has little effect.
Sensory-Based Identification of Aroma-Active Compounds in Hotpot Seasoning before and after Boiling
Authors: Yu Mingguang , Wan Suyan , Song Huanlu , Zhang Yu , Wang Chuanming , Wang Hongqiang , Wang Haowen
Published: September 2021

Boiling, the most frequent edible way to hotpot seasoning (HS), exerts a significant impact on the aroma of HS. The present study employed, for the first time, a novel switchable system between GC-O-MS and GC×GC-O-MS (SGC/GC×GC-O-MS) to study the aroma compounds of HS and hotpot seasoning boiling liquid (HSBL). A total of 79 aroma compounds and 56 aroma-active compounds were identified. The aroma extract dilution analysis (AEDA) was used to analyze the differences between the key aroma-active components in the HS and HSBL. The results showed that 13 aroma-active components were significantly affected by boiling, such as D-limonene, methional, and linalool. Moreover, a total of 22 key aroma-active components were identified through the odor activity values (OAVs) calculation. Of them, (E)-2-octenal (fatty) and linalool showed a significant difference, suggesting them to be the most critical aroma-active compounds in the HSBL, and HS, respectively. Finally, the correlation between key aroma-active compounds and the sensory properties of HS and HSBL was studied. These results demonstrated that the OAVs of key aroma-active compounds could characterize the real information of samples through bidirectional orthogonal partial least squares (O2PLS). The analysis results were consistent with the sensory evaluation results.