bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Investigation of the Characteristics of Erosion in a Centrifugal Pump for Transporting Dilute Particle-Laden Flows
Authors: Zhao Rui-Jie , Zhao You-Long , Zhang De-Sheng , Li Yan , Geng Lin-Lin
Published: September 2021

Erosion in centrifugal pumps for transporting flows with dilute particles is a main pump failure problem in many engineering processes. A numerical model combining the computational fluid dynamics (CFD) and Discrete Element Method (DEM) is applied to simulate erosion in a centrifugal pump. Different models of the liquid-solid inter-phase forces are implemented, and the particle-turbulence interaction is also defined. The inertial particles considered in this work are monodisperse and have finite size. The numerical results are validated by comparing the results with a series of experimental data. Then, the effects of particle volume fraction, size, and shape on the pump erosion are estimated in the simulations. The results demonstrate that severe erosive areas are located near the inlet and outlet of the pressure side of the impeller blade, the middle region of the blade, the corners of the shroud and hub of the impeller adjoining to the pressure side of the blade, and the volute near the pump tongue. Among these locations, the maximum erosion occurs near the inlet of the pressure side of the blade. Erosion mitigation occurs under the situation where more particles accumulate in the near-wall region of the eroded surface, forming a buffering layer. The relationship between the particle size and the erosion is nonlinear, and the 1 mm particle causes the maximum pump erosion. The sharp particles cause more severe erosion in the pump because both the frequency of particle-wall collisions and the impact angle increase with the increasing sharpness of the particle.
Association between ABCA1 Gene Polymorphisms and Plasma Lipid Concentration: A Systematic Review and Meta-Analysis
Authors: Shim Sun-Young , Yoon Ha-Young , Yee Jeong , Han Ji-Min , Gwak Hye-Sun
Published: September 2021

Background: Although ABCA1 gene polymorphisms may be associated with the plasma lipid concentration, the literature has not shown a consistent pattern. In this study, we attempted to elucidate the association between the ABCA1 69C>T, 825V>I, and 230R>C polymorphisms and the plasma lipid concentration through a systematic review and meta-analysis. Methods: We selected studies published up to October 2020 in the PubMed, Web of Science, and Embase databases according to inclusion and exclusion criteria. The mean difference (MD) and 95% confidence interval (CI) were used to assess the relationship between the presence of ABCA1 69C>T, 825V>I, and 230R>C and plasma lipid levels. Meta-analysis was performed using Review Manager (version 5.3). Both Begg’s test and Egger’s regression test of the funnel plot were performed using R Studio software (version 3.6.0) to identify publication bias. Results: We analyzed the data on the ABCA1 69C>T polymorphism involving 14,843 subjects in 11 studies, 825V>I polymorphism involving 2580 subjects in 5 studies, and 230R>C polymorphism involving 4834 subjects in 4 studies. The T allele carriers in 69C>T, II carriers in 825V>I, and C carriers in 230R>C had lower high-density lipoprotein cholesterol levels; the MD (95% CI) was −0.05 mmol/L (95% CI: −0.09 to −0.01, p = 0.02), −0.05 mmol/L (95% CI: −0.09 to −0.00, p = 0.03), and −0.1 mmol/mL (95% CI: −0.12 to −0.07 mmol/L, p < 0.00001), respectively. In the case of 230R>C, the serum total cholesterol concentration of C carriers was significantly lower than that of RR carriers (−0.2 mmol/L, 95% CI: −0.3 to −0.11, p < 0.0001). Conclusion: This meta-analysis demonstrates that the ABCA1 69C>T, 825V>I, and 230R>C polymorphisms could affect the plasma lipid concentration. As the plasma lipid concentration may be related to various diseases, ABCA1 genotyping could be useful for the management of lipid levels.
Economic Performance and Composition of Nordic Bioeconomy Sectors (NBES)
Authors: Lestan Filip , George Babu , Kabiraj Sajal
Published: September 2021

The past decade has seen rapid development of the bioeconomy in the Nordic region. Consequently, the composition of sectors that intervene in the concept of bioeconomy serves as a powerful, progressive, and pure engine, which creates and drives market opportunities across various industries, particularly in the Nordic region. While the existing literature focuses explicitly on the bioeconomy and its holistic potential and results in the Nordic region, there are no studies that focus on the distribution of economic performance across Nordic Bioeconomy Sectors. In fact, previous research highlights the lack of empirical studies in bioeconomy from the social science perspective. This research methodology was designed in four different stages with the integration of so-called hybrid research methods. The qualitative research approach was conducted in order to define the criteria and indicators for Nordic Bioeconomy Sectors (NBES) and their economic performance. The quantitative research approach was conducted to statistically test Hypothesis H1 of this study and to conduct central tendency measures of economic performance within Nordic countries and Nordic Bioeconomy Sectors (NBES). The findings contribute in several ways to understand how sectors in the Nordic region performed economically. Firstly, the economic performance among the Nordic Bioeconomy Sectors (NBES) proves that individual sectors have diverse relationships with each other; therefore, each economic activity performs independently rather than correlative.
The Economic Sustainability of Culture in Hawai’i: Tourists’ Willingness to Pay for Hawaiian Cultural Experiences
Authors: Andrade Gabriella , Itoga Holly , Linnes Cathrine , Agrusa Jerome , Lema Joseph
Published: September 2021

Given the current travel restrictions with the COVID-19 pandemic, there is an unprecedented opportunity for Hawai’i to reexamine its current tourism offerings and establish a new approach to support a more authentic, cultural, and sustainable tourism for the U.S. domestic tourist market. As tourists from the continental U.S. are the largest source market for visitors to Hawai’i, the purpose of this study is to examine the trend towards an “authentic cultural” tourism experience and evaluate whether U.S. visitors will be willing to pay for a deeper integration and representation of Hawaiian culture in tourism offerings. The contingent valuation method (CVM) was adopted to quantify the willingness to pay (WTP) more by the tourists to Hawaii in order to experience a more “authentic Hawaiian cultural experience” as well as “sustainable experiences”. Differences between returning and first-time visitors were considered. This study focused on continental U.S. visitors’ perceptions of Hawaiian culture and the sustainability of Hawaiian tourism products, as well as the assessment of locally grown food and tourists’ willingness to pay extra for these tourism products and experiences. The contingent valuation survey demonstrated that continental U.S. travelers were supportive of an additional fee in order to experience authentic Hawaiian cultural and tourism experiences designed and/or facilitated by Native Hawaiians. In addition, U.S. visitors were also supportive of paying additional fees for activities or experiences to support sustainable tourism in Hawai’i, including paying more for locally grown food, indicating that they would be willing to increase their restaurant/hotel food bill in order to support the Hawaii’s local farming industry. The results of this study demonstrate that there are economic opportunities to further integrate Hawaiian culture and sustainability into the experience of visitors, and that U.S. visitors are willing to support these cultural activities financially.
Anchoring and Asymmetric Information in the Real Estate Market: A Machine Learning Approach
Authors: Cheung Ka Shing , Chan Julian TszKin , Li Sijie , Yiu Chung Yim
Published: September 2021

Conventional wisdom suggests that non-local buyers usually pay a premium for home purchases. While the standard contract theory predicts that non-local buyers may pay such a price premium because of the higher cost of gathering information, behavioral economists argue that the premium is due to buyer anchoring biases in relation to the information. Both theories support such a price premium proposition, but the empirical evidence is mixed. In this study, we revisit this conundrum and put forward a critical test of these two alternative hypotheses using a large-scale housing transaction dataset from Hong Kong. A novel machine-learning algorithm with the latest technique in natural language processing where applicable to multi-languages is developed for identifying non-local Mainland Chinese buyers and sellers. Using the repeat-sales method that avoids omitted variable biases, non-local buyers (sellers) are found to buy (sell) at a higher (lower) price than their local counterparts. Taking advantage of a policy change in transaction tax specific to non-local buyers as a quasi-experiment and utilizing the local buyers as counterfactuals, we found that the non-local price premium switches to a discount after the policy intervention. The result implies that the hypothesis of anchoring biases is dominant.
Why the Operating Performance of Post-IPO Firms Decreases: Evidence from China
Authors: Long Hai , Lin Xiaochen , Chen Yu
Published: September 2021

Based on a database of 200 listed firms from the Growth Enterprise Market of China, this paper employs regression models to investigate the significance of IPO capital expenditure to firms’ operating performance. It suggests that a vast majority of pre-IPO money is spent on business development to promote operating performance in order to meet IPO requirements. After the IPO, most of the money is transferred to equity investments in order to increase the firms’ market value quickly, which leads to operating performance decline and deterioration.
Agricultural-Heritage-Oriented Rural Revitalization: Experiences from the Ancient Tea Town of Xiping
Authors: Shen Jing , Huang Feng-Tzu , Chou Rung-Jiun
Published: September 2021

The Anxi Tieguanyin Tea Culture System, as the proposed location of a globally important agricultural heritage system (GIAHS), has demonstrated the great significance of a network of heritage settlements and landscapes and supported rural revitalization and the participation and empowerment of women, based on agricultural heritage. Through fieldwork, participant observation, and in-depth interviews, this study attempts to analyze the experience of rural revitalization in Xiping. Firstly, the unique cultural heritage found within the agricultural landscape, formed by the multi-party linkage and dynamic adaptation of the surrounding natural environment by local residents, has shaped the Anxi Tieguanyin tea culture system of Xiping. Secondly, local residents actively participate in tea competitions and tea associations, so that the implementation process of agricultural cultural heritage preservation and development can be from the perspective of a shared experience. Thirdly, intangible cultural heritage features, such as the Female Tea Master Training Institute, have played a vital role in the development of tea towns and have proved conducive to women’s participation and empowerment. The results show that the agricultural heritage of the area, based on the Tea Manor and its multi-functional resources, has helped Xiping to move toward a more sustainable future, while eventually supporting a local society with a more distinctive rural landscape of which people can be proud. This system meets the need for local socio-economic and cultural development, and the promotion of the sustainable development of the entire region.
Assessing Heavy Metal Contamination Risk in Soil and Water in the Core Water Source Area of the Middle Route of the South-to-North Water Diversion Project, China
Authors: Tan Li , Yang Bin , Xue Zhibin , Wang Zhanqi
Published: September 2021

The Middle Route Project of China’s South-to-North Water Diversion Project (SNWDP) is a national-level water source protection zone and the ecological safety of its water quality and surrounding soil is of great significance. In this study, heavy metals in the surface water and topsoil in the core water source area were quantitatively analyzed using a geographic information system (GIS) and geostatistical techniques combined with environmental pollution and ecological risk assessment models to determine their environmental contamination levels, ecological risk levels, and spatial distribution patterns. Cd was identified as an essential factor responsible for the overall slight heavy metal pollution in the topsoil layer. Heavy metal contamination in surface water was primarily driven by alert-level concentrations of Hg and was consistently distributed in areas with high concentrations of Hg in the topsoil. Applying the potential ecological risk index (RI) revealed two key results. First, surface water showed no ecological risk. The concentrations of heavy metals in surface water met the goals set by relevant authorities in China. Second, overall, the topsoil was at low ecological risk, with a spatial pattern primarily influenced by Cd and Hg. Some heavy metals might have similar pollution sources and originate from human activities such as industrial activities, mining and smelting, and pesticide and chemical fertilizer applications. The study is important for improving the soil and water ecology in the reservoir area and ensuring the northward diversion of high-quality water. In addition, it provides a sound basis for making decisions about local heavy-metal remediation and treatment projects.
The Behavior of Supersonic Jets Generated by Combination Gas in the Steelmaking Process
Authors: Zhang Binglong , Liu Fuhai , Zhu Rong
Published: September 2021

In the duplex steelmaking process, the oxygen flow rate is suppressed to reduce the increasing rate of the temperature in the molten bath, resulting in severe dynamic conditions. To improve the mixing effect of the molten bath, a Laval nozzle structure designed for combination gas has been proposed. In this research, five types of Laval nozzle structure have been built based on the combination gas content, and both numerical simulations and experiments are performed to analyze the flow field of the supersonic jet. The axial velocity and oxygen concentration were measured in the experiment, which agreed well with the numerically simulated data. The results show that both initial axial velocity and potential core length increase with the flow rate of combination gas. Further, applying a higher N2 flow rate could improve the oxygen utilization rate at different ambient temperatures, but this issue increases the oxygen utilization rate; however, the latter can be reduced at higher ambient temperatures.
Effect of Sonic Activation on Push-Out Bond Strength of Fiber Post: An In Vitro Study
Authors: Jouhar Rizwan
Published: September 2021

This study aimed to evaluate the effectiveness of conventional and sonic activation techniques on push-out bond strength of fiber post cemented with two different monomers containing self-adhesive resin cement (SARC). Four groups (n = 19 each) were made based on the type of SARC (Rely X U200 and Panavia SA) and technique (conventional and sonic activation). After placing the fiber post, each root was sectioned into 2 mm coronal, middle, and apical portions, and a push-out bond strength test was performed using a universal testing machine. The least push-out bond strength (13.0 ± 0.9 MPa) was found in Rely X U200 conventional technique and highest with Panavia SA sonic activation technique (15.4 ± 0.9 MPa). A significant difference was found in push-out bond strength at coronal (p = 0.002), middle (p = 0.002), and apical (p = 0.001) root sections using Rely X U200 cement with sonic activation as compared to the conventional technique. However, no difference (p > 0.05) was noticed between conventional and sonic activation techniques in Panavia SA cement at any root level. Sonic activation can be used as an adjunct with a manual technique to increase bond strength. However, it was noted that 10-MDP monomer containing SARC performed well regardless of techniques.
On Wrinkling in Sandwich Panels with an Orthotropic Core
Authors: Pozorski Zbigniew , Pozorska Jolanta , Kreja Ireneusz , Smakosz Łukasz
Published: September 2021

This paper deals with the local loss of stability (wrinkling) problem of a thin facing of a sandwich panel. Classical solutions to the problem of a facing instability resting on a homogeneous and isotropic substructure (a core) are compared. The relations between strain energy components associated with different forms of core deformations are discussed. Next, a new solution for the orthotropic core is presented in detail, which is consistent with the classic solution for the isotropic core. Selected numerical examples confirm the correctness of the analytical formulas. In the last part, parametric analyses are carried out to illustrate the sensitivity of wrinkling stress to a change in the material parameters of the core. These analyses illustrate the possibility of using the equations derived in the article for the variability of Poisson’s ratio from −1 to 1 and for material parameters strongly deviating from isotropy.
A Three-Phase Transport Model for High-Temperature Concrete Simulations Validated with X-ray CT Data
Authors: Pohl Christoph , Šmilauer Vít , Unger Jörg F.
Published: September 2021

Concrete exposure to high temperatures induces thermo-hygral phenomena, causing water phase changes, buildup of pore pressure and vulnerability to spalling. In order to predict these phenomena under various conditions, a three-phase transport model is proposed. The model is validated on X-ray CT data up to 320 °C, showing good agreement of the temperature profiles and moisture changes. A dehydration description, traditionally derived from thermogravimetric analysis, was replaced by a formulation based on data from neutron radiography. In addition, treating porosity and dehydration evolution as independent processes, previous approaches do not fulfil the solid mass balance. As a consequence, a new formulation is proposed that introduces the porosity as an independent variable, ensuring the latter condition.
Gamma-Ray Attenuation and Exposure Buildup Factor of Novel Polymers in Shielding Using Geant4 Simulation
Authors: Alabsy Mahmoud T. , Alzahrani Jamila S. , Sayyed M. I. , Abbas Mahmoud I. , Tishkevich Daria I. , El-Khatib Ahmed M. , Elsafi Mohamed
Published: September 2021

Polymers are often used in medical applications, therefore, some novel polymers and their interactions with photons have been studied. The gamma-ray shielding parameters for Polymethylpentene (PMP), Polybutylene terephthalate (PBT), Polyoxymethylene (POM), Polyvinylidenefluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE) polymers were determined using the Geant4 simulation and discussed in the current work. The mass attenuation coefficients (μ/ρ) were simulated at low and high energies between 0.059 and 1.408 MeV using different radionuclides. The accuracy of the Geant4 simulated results were checked with the XCOM software. The two different methods had good agreement with each other. Exposure buildup factor (EBF) was calculated and discussed in terms of polymers under study and photon energy. Effective atomic number (Zeff) and electron density (Neff) were calculated and analyzed at different energies. Additionally, the half-value layer (HVL) of the polymers was evaluated, and the results of this parameter showed that PCTFE had the highest probability of interaction with gamma photons compared to those of the other tested polymers.
Surface Modification of Nanoporous Anodic Alumina during Self-Catalytic Atomic Layer Deposition of Silicon Dioxide from (3-Aminopropyl)Triethoxysilane
Authors: González Ana Silvia , Vega Víctor , Cuevas Ana Laura , Yuso María del Valle Martínez de , Prida Víctor M. , Benavente Juana
Published: September 2021

Changes associated to atomic layer deposition (ALD) of SiO2 from 3-aminopropyl triethoxysilane (APTES) and O3, on a nanoporous alumina structure, obtained by two-step electrochemical anodization in oxalic acid electrolyte (Ox sample) are analysed. A reduction of 16% in pore size for the Ox sample, used as support, was determined by SEM analysis after its coverage by a SiO2 layer (Ox+SiO2 sample), independently of APTES or O3 modification (Ox+SiO2/APTES and Ox+SiO2/APTES/O3 samples). Chemical surface modification was determined by X-ray photoelectron spectroscopy (XPS) technique during the different stages of the ALD process, and differences induced at the surface level on the Ox nanoporous alumina substrate seem to affect interfacial effects of both samples when they are in contact with an electrolyte solution according to electrochemical impedance spectroscopy (EIS) measurements, or their refraction index as determined by spectroscopic ellipsometry (SE) technique. However, no substantial differences in properties related to the nanoporous structure of anodic alumina (photoluminescent (PL) character or geometrical parameters) were observed between Ox+SiO2/APTES and Ox+SiO2/APTES/O3 samples.
Global Sensitivity Analysis of Chosen Harmonic Drive Parameters Affecting Its Lost Motion
Authors: Hrcek Slavomir , Brumercik Frantisek , Smetanka Lukas , Lukac Michal , Patin Branislav , Glowacz Adam
Published: September 2021

The aim of the presented study was to perform a global sensitivity analysis of various design parameters affecting the lost motion of the harmonic drive. A detailed virtual model of a harmonic drive was developed, including the wave generator, the flexible ball bearing, the flexible spline and the circular spline. Finite element analyses were performed to observe which parameter from the harmonic drive geometry parameter group affects the lost motion value most. The analyses were carried out using 4% of the rated harmonic drive output torque by the locked wave generator and fixed circular spline according the requirements for the high accuracy harmonic drive units. The described approach was applied to two harmonic drive units with the same ratio, but various dimensions and rated power were used to generalize and interpret the global sensitivity analysis results properly. The most important variable was for both harmonic drives the offset from the nominal tooth shape.
Longevity of Polymer-Infiltrated Ceramic Network and Zirconia-Reinforced Lithium Silicate Restorations: A Systematic Review and Meta-Analysis
Authors: Banh William , Hughes Jared , Sia Aaron , Chien David C. H. , Tadakamadla Santosh K. , Figueredo Carlos M. , Ahmed Khaled E.
Published: September 2021

The purpose of this study was to systematically review the existing literature to assess the clinical survival and success of PICN and ZLS indirect restorations as the clinical evidence for them remains lacking. PubMed, SCOPUS, Embase, Cochrane Library, Web of Science, LILACs, and SciElo databases were searched from 1 January 2000 to 1 February 2021. Clinical trials and cohort studies published in English were included while case studies, case series, and in vitro studies were excluded. Results were analyzed qualitatively and a meta-analysis using a random effects model was performed. A strength of recommendation taxonomy (SORT) analysis was conducted and risk of bias (RoB) was assessed using the Newcastle–Ottawa scale and Cochrane RoB tools. An electronic search through the databases yielded 2454 articles, of which 825 remained after duplicate removal. Five studies investigating PICN and four investigating ZLS indirect restorations remained after assessing for eligibility. The overall survival rate of PICN over 1 year was 99.6% and 99.2% over 2 years. The overall survival rate of ZLS over 1 year was 99%. The main mode of failure for both materials was catastrophic fracture. One study had a high RoB, four had a moderate RoB, and four had a low RoB. Both materials demonstrated moderate strength of recommendation at a level 2 evidence for all studies based on SORT analysis. PICN and ZLS show promising short-term clinical performance as full and partial coverage indirect restorations, but longer follow-up studies are required to confirm their long-term performance.
Fabrication of PCDTBT Conductive Network via Phase Separation
Authors: Xu Jianwei , Liu Zhiming , Jing Lei , Chen Jingbo
Published: September 2021

Poly[N-9′-hepta-decanyl-2,7-carbazole-alt-5-5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) is a stable semiconducting polymer with high rigidity in its molecular chains, which makes it difficult to organize into an ordered structure and affects the device performance. Here, a PCDTBT network consisting of aggregates and nanofibers in thin films was fabricated through the phase separation of mixed PCDTBT and polyethylene glycol (PEG). Using atomic force microscopy (AFM), the effect of the blending conditions (weight ratio, solution concentration, and molecular weight) and processing conditions (substrate temperature and solvent) on the resulting phase-separated morphologies of the blend films after a selective washing procedure was studied. It was found that the phase-separated structure’s transition from an island to a continuous structure occurred when the weight ratio of PCDTBT/PEG changed from 2:8 to 7:3. Increasing the solution concentration from 0.1 to 3.0 wt% led to an increase in both the height of the PCDTBT aggregate and the width of the nanofiber. When the molecular weight of the PEG was increased, the film exhibited a larger PCDTBT aggregate size. Meanwhile, denser nanofibers were found in films prepared using PCDTBT with higher molecular weight. Furthermore, the electrical characteristics of the PCDTBT network were measured using conductive AFM. Our findings suggest that phase separation plays an important role in improving the molecular chain diffusion rate and fabricating the PCDTBT network.
Reducing Waste in 3D Printing Using a Neural Network Based on an Own Elbow Exoskeleton
Authors: Rojek Izabela , Mikołajewski Dariusz , Kopowski Jakub , Kotlarz Piotr , Piechowiak Maciej , Dostatni Ewa
Published: September 2021

Traditional rehabilitation systems are evolving into advanced systems that enhance and improve rehabilitation techniques and physical exercise. The reliable assessment and robotic support of the upper limb joints provided by the presented elbow exoskeleton are important clinical goals in early rehabilitation after stroke and other neurological disorders. This allows for not only the support of activities of daily living, but also prevention of the progression neuromuscular pathology through proactive physiotherapy toward functional recovery. The prices of plastics are rising very quickly, as is their consumption, so it makes sense to optimize three dimensional (3D) printing procedures through, for example, improved artificial intelligence-based (AI-based) design or injection simulation, which reduces the use of filament, saves material, reduces waste, and reduces environmental impact. The time and cost savings will not reduce the high quality of the products and can provide a competitive advantage, especially in the case of thinly designed mass products. AI-based optimization allows for one free print after every 6.67 prints (i.e., from materials that were previously wasted).
Features of Filler Wire Melting and Transferring in Wire-Arc Additive Manufacturing of Metal Workpieces
Authors: Voropaev Artem , Korsmik Rudolf , Tsibulskiy Igor
Published: September 2021

In this paper, we present the results of a study on droplet transferring with arc space short circuits during wire-arc additive manufacturing (WAAM GMAW). Experiments were conducted on cladding of single beads with variable welding current and voltage parameters. The obtained oscillograms and video recordings were analyzed in order to compare the time parameters of short circuit and arc burning, the average process peak current, as well as the droplets size. Following the experiments conducted, 2.5D objects were built-up to determine the influence of electrode stickout and welding torch travel speed to identify the droplet transferring and formation features. Moreover, the current–voltage characteristics of the arc were investigated with varying WAAM parameters. Process parameters have been determined that make it possible to increase the stability of the formation of the built-up walls, without the use of specialized equipment for forced droplet transfer. In the course of the research, the following conclusions were established: the most stable drop transfer occurs at an arc length of 1.1–1.2 mm, reverse polarity provides the best drop formation result, the stickout of the electrode wire affects the drop transfer process and the quality of the deposited layers. The dependence of the formation of beads on the number of short circuits per unit length is noted.
Effect of Grain Size on the Corrosion Behavior of Fe-3wt.%Si-1wt.%Al Electrical Steels in Pure Water Saturated with CO2
Authors: Palumbo Gaetano , Dunikowski Dawid , Wirecka Roma , Mazur Tomasz , Lelek-Borkowska Urszula , Wawer Kinga , Banaś Jacek
Published: September 2021

The corrosion behavior of two silicon steels with the same chemical composition but different grains sizes (i.e., average grain area of 115.6 and 4265.9 µm2) was investigated by metallographic microscope, gravimetric, electrochemical and surface analysis techniques. The gravimetric and electrochemical results showed that the corrosion rate increased with decreasing the grain size. The scanning electron microscopy/energy dispersive x-ray spectroscopy and X-ray photoelectron spectroscopyanalyses revealed formation of a more homogeneous and compact corrosion product layer on the coarse-grained steel compared to fine-grained material. The Volta potential analysis, carried out on both steels, revealed formation of micro-galvanic sites at the grain boundaries and triple junctions. The results indicated that the decrease in corrosion resistance in the fine-grained steel could be attributed to the higher density of grain boundaries (e.g., a higher number of active sites and defects) brought by the refinement. The higher density of active sites at grain boundaries promote the metal dissolution of the and decreased the stability of the corrosion product layerformed on the metal surface.
Highly Stretchable and Kirigami-Structured Strain Sensors with Long Silver Nanowires of High Aspect Ratio
Authors: Huang Huiyan , Cai Catherine Jiayi , Yeow Bok Seng , Ouyang Jianyong , Ren Hongliang
Published: September 2021

Stretchable, skin-interfaced, and wearable strain sensors have risen in recent years due to their wide-ranging potential applications in health-monitoring devices, human motion detection, and soft robots. High aspect ratio (AR) silver nanowires (AgNWs) have shown great potential in the flexible and stretchable strain sensors due to the high conductivity and flexibility of AgNW conductive networks. Hence, this work aims to fabricate highly stretchable, sensitive, and linear kirigami strain sensors with high AR AgNWs. The AgNW synthesis parameters and process windows have been identified by Taguchi’s design of experiment and analysis. Long AgNWs with a high AR of 1556 have been grown at optimized synthesis parameters using the one-pot modified polyol method. Kirigami sensors were fabricated via full encapsulation of AgNWs with Ecoflex silicon rubber. Kirigami-patterned strain sensors with long AgNWs show high stretchability, moderate sensitivity, excellent linearity (R2 = 0.99) up to 70% strain and can promptly detect finger movement without obvious hysteresis.
Proximity Sensor for Thin Wire Recognition and Manipulation
Authors: Cirillo Andrea , Laudante Gianluca , Pirozzi Salvatore
Published: September 2021

In robotic grasping and manipulation, the knowledge of a precise object pose represents a key issue. The point acquires even more importance when the objects and, then, the grasping areas become smaller. This is the case of Deformable Linear Object manipulation application where the robot shall autonomously work with thin wires which pose and shape estimation could become difficult given the limited object size and possible occlusion conditions. In such applications, a vision-based system could not be enough to obtain accurate pose and shape estimation. In this work the authors propose a Time-of-Flight pre-touch sensor, integrated with a previously designed tactile sensor, for an accurate estimation of thin wire pose and shape. The paper presents the design and the characterization of the proposed sensor. Moreover, a specific object scanning and shape detection algorithm is presented. Experimental results support the proposed methodology, showing good performance. Hardware design and software applications are freely accessible to the reader.
On a One-Dimensional Hydrodynamic Model for Semiconductors with Field-Dependent Mobility
Authors: Alì Giuseppe , Lamonaca Francesco , Scuro Carmelo , Torcicollo Isabella
Published: September 2021

We consider a one-dimensional, isentropic, hydrodynamical model for a unipolar semiconductor, with the mobility depending on the electric field. The mobility is related to the momentum relaxation time, and field-dependent mobility models are commonly used to describe the occurrence of saturation velocity, that is, a limit value for the electron mean velocity as the electric field increases. For the steady state system, we prove the existence of smooth solutions in the subsonic case, with a suitable assumption on the mobility function. Furthermore, we prove uniqueness of subsonic solutions for sufficiently small currents.
A Hybrid Genetic Algorithm for the Simple Assembly Line Balancing Problem with a Fixed Number of Workstations
Authors: Álvarez-Miranda Eduardo , Pereira Jordi , Torrez-Meruvia Harold , Vilà Mariona
Published: September 2021

The assembly line balancing problem is a classical optimisation problem whose objective is to assign each production task to one of the stations on the assembly line so that the total efficiency of the line is maximized. This study proposes a novel hybrid method to solve the simple version of the problem in which the number of stations is fixed, a problem known as SALBP-2. The hybrid differs from previous approaches by encoding individuals of a genetic algorithm as instances of a modified problem that contains only a subset of the solutions to the original formulation. These individuals are decoded to feasible solutions of the original problem during fitness evaluation in which the resolution of the modified problem is conducted using a dynamic programming based approach that uses new bounds to reduce its state space. Computational experiments show the efficiency of the method as it is able to obtain several new best-known solutions for some of the benchmark instances used in the literature for comparison purposes.
High-Capacity Reversible Data Hiding in Encrypted Images Based on Adaptive Predictor and Compression of Prediction Errors
Authors: Huang Bin , Wan Chun , Chen Kaimeng
Published: September 2021

Reversible data hiding in encrypted images (RDHEI) is a technology which embeds secret data into encrypted images in a reversible way. In this paper, we proposed a novel high-capacity RDHEI method which is based on the compression of prediction errors. Before image encryption, an adaptive linear regression predictor is trained from the original image. Then, the predictor is used to obtain the prediction errors of the pixels in the original image, and the prediction errors are compressed by Huffman coding. The compressed prediction errors are used to vacate additional room with no loss. After image encryption, the vacated room is reserved for data embedding. The receiver can extract the secret data and recover the image with no errors. Compared with existing approaches, the proposed method efficiently improves the embedding capacity.
Mitochondria and Mitochondrial DNA: Key Elements in the Pathogenesis and Exacerbation of the Inflammatory State Caused by COVID-19
Authors: Valdés-Aguayo José J. , Garza-Veloz Idalia , Badillo-Almaráz José I. , Bernal-Silva Sofia , Martínez-Vázquez Maria C. , Juárez-Alcalá Vladimir , Vargas-Rodríguez José R. , Gaeta-Velasco María L. , González-Fuentes Carolina , Ávila-Carrasco Lorena , Martinez-Fierro Margarita L.
Published: September 2021

Background and Objectives. The importance of mitochondria in inflammatory pathologies, besides providing energy, is associated with the release of mitochondrial damage products, such as mitochondrial DNA (mt-DNA), which may perpetuate inflammation. In this review, we aimed to show the importance of mitochondria, as organelles that produce energy and intervene in multiple pathologies, focusing mainly in COVID-19 and using multiple molecular mechanisms that allow for the replication and maintenance of the viral genome, leading to the exacerbation and spread of the inflammatory response. The evidence suggests that mitochondria are implicated in the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which forms double-membrane vesicles and evades detection by the cell defense system. These mitochondrion-hijacking vesicles damage the integrity of the mitochondrion’s membrane, releasing mt-DNA into circulation and triggering the activation of innate immunity, which may contribute to an exacerbation of the pro-inflammatory state. Conclusions. While mitochondrial dysfunction in COVID-19 continues to be studied, the use of mt-DNA as an indicator of prognosis and severity is a potential area yet to be explored.
Effectiveness and Safety of EGFR-TKI Rechallenge Treatment in Elderly Patients with Advanced Non-Small-Cell Lung Cancer Harboring Drug-Sensitive EGFR Mutations
Authors: Yamada Yutaka , Imai Hisao , Sugiyama Tomohide , Minemura Hiroyuki , Kanazawa Kenya , Kasai Takashi , Minato Koichi , Kaira Kyoichi , Kaburagi Takayuki
Published: September 2021

Background and Objectives: Epidermal growth factor receptor–tyrosine kinase inhibitors (EGFR-TKIs) are effective first-line chemotherapeutic agents for patients with advanced non-small-cell lung cancer (NSCLC) harboring drug-sensitive EGFR mutations. However, the effectiveness of EGFR-TKI rechallenge after first-line EGFR-TKI treatment is not sufficient in elderly patients (over 75 years of age) harboring drug-sensitive EGFR mutations. Therefore, we investigated the effectiveness and safety of EGFR-TKI rechallenge after first-line EGFR-TKI treatment in elderly patients with advanced NSCLC harboring drug-sensitive EGFR mutations. Materials and Methods: Between April 2008 and December 2015, we analyzed 78 elderly patients with advanced NSCLC harboring drug-sensitive EGFR mutations with first-line EGFR-TKI treatment at four Japanese institutions. We retrospectively evaluated the clinical effectiveness and safety profiles of EGFR-TKI rechallenge after first-line EGFR-TKI treatment in elderly patients with advanced NSCLC harboring drug-sensitive EGFR mutations (exon 19 deletion/exon 21 L858R mutation). Results: Twenty-two patients in the cohort were rechallenged with EGFR-TKI. The median age was 79.5 years (range 75–87 years). Despite the fact that it was a retrospective analysis, even with EGFR-TKI rechallenge treatment the response rate was 23%, progression-free survival was 5.3 months, and overall survival was 14.4 months. Common adverse events included rash acneiform, paronychia, diarrhea, and anorexia. There were no treatment-related deaths. Due to the occurrence of adverse events of grade 2 or more, dose reduction was performed in 15 (68.2%) of 22 cases. Conclusions: EGFR-TKI rechallenge treatment after first-line EGFR-TKI treatment in elderly patients with advanced NSCLC harboring drug-sensitive EGFR mutations was one of the limited, safe and effective treatment options for elderly EGFR-positive lung cancer patients.
End-of-Life Decision-Making in Intensive Care Ten Years after a Law on Advance Directives in Germany
Authors: Graw Jan A. , Marsch Fanny , Spies Claudia D. , Francis Roland C. E.
Published: September 2021

Background and Objectives: Mortality on Intensive Care Units (ICUs) is high and death frequently occurs after decisions to limit life-sustaining therapies. An advance directive is a tool meant to preserve patient autonomy by guiding anticipated future treatment decisions once decision-making capacity is lost. Since September 2009, advance directives are legally binding for the caregiver team and the patients’ surrogate decision-maker in Germany. The change in frequencies of end-of-life decisions (EOLDs) and completed advance directives among deceased ICU patients ten years after the enactment of a law on advance directives in Germany is unknown. Materials and Methods: Retrospective analysis on all deceased patients of surgical ICUs of a German university medical center from 08/2008 to 09/2009 and from 01/2019 to 09/2019. Frequency of EOLDs and advance directives and the process of EOLDs were compared between patients admitted before and after the change in legislation. (No. of ethical approval EA2/308/20) Results: Significantly more EOLDs occurred in the 2019 cohort compared to the 2009 cohort (85.8% vs. 70.7% of deceased patients, p = 0.006). The number of patients possessing an advance directive to express a living or therapeutic will was higher in the 2019 cohort compared to the 2009 cohort (26.4% vs. 8.9%; difference: 17.5%, p < 0.001). Participation of the patients’ family in the EOLD process (74.7% vs. 60.9%; difference: 13.8%, p = 0.048) and the frequency of documentation of EOLD-relevant information (50.0% vs. 18.7%; difference: 31.3%, p < 0.001) increased from 2009 to 2019. Discussion: During a ten-year period from 2009 to 2019, the frequency of EOLDs and the completion rate of advance directives have increased considerably. In addition, EOLD-associated communication and documentation have further improved.
Aspirin Is Related to Worse Clinical Outcomes of COVID-19
Authors: Kim Isaac , Yoon Siyeong , Kim Minsup , Lee Hyunil , Park Sinhyung , Kim Wonsang , Lee Soonchul
Published: September 2021

Backgroundand Objectives: Aspirin is used globally to reduce pain and inflammation; however, its effect in patients with coronavirus disease (COVID-19) is not fully investigated and remains controversial. We evaluated the association between aspirin and COVID-19 outcomes using nationwide data from the Korean National Health Insurance System. Materials and Methods: This was a retrospective observational cohort study that included 22,660 eligible patients who underwent COVID-19 testing in South Korea between 1 January–31 July 2020. We identified all aspirin users prescribed aspirin within two weeks before or after the index date. The primary outcome was positivity for the COVID-19 test, and secondary outcomes included conventional oxygen therapy, intensive care unit, mechanical ventilation, or death. We applied the propensity score matching method to reduce the possible bias originating from the differences in patients’ baseline characteristics. Results: Of those eligible, 662 patients were prescribed aspirin. Among them, 136 patients were on aspirin within two weeks before diagnosis and 526 patients were on aspirin after diagnosis. The COVID-19 test positivity rate was not significantly different according to aspirin use. Aspirin use before COVID-19 was related to an increased death rate and aspirin use after COVID-19 was related to a higher risk of the conventional oxygen therapy. Conclusion: Aspirin use was associated with adverse effects in COVID-19 patients. Further studies for mechanisms are needed.
Cancer Biology Analysis—Tackled from Different Points of View
Authors: Ouro Alberto
Published: September 2021

In the last few decades, great advances have been made in the detection and treatment of cancer, thus increasing the survival rate [...]
Active Edible Films Fortified with Natural Extracts: Case Study with Fresh-Cut Apple Pieces
Authors: Jancikova Simona , Dordevic Dani , Tesikova Karolina , Antonic Bojan , Tremlova Bohuslava
Published: September 2021

The main aim of the study was to prepare the edible films based on carrageenan/chitosan and incorporate them into the following matrices: the natural extracts of Clitoria ternatea, Brassica oleracea, and Ipomea batatas. The films were characterized by TPC (total polyphenols content), antioxidant activity, and textural properties. Experimentally produced films were added in the packaging of freshly cut apple pieces, and the apple pieces were dipped into the films produced from carrageenan and chitosan. The appearance of the samples was monitored, as were antioxidant activity and total polyphenol content. The intelligent properties of films were evaluated too. The polymer type used for the preparation had the highest impact on the prepared films, and CHLCZ (red cabbage extract—Brassica oleracea) featured the best antioxidant activity. The intelligent properties were slightly confirmed in samples with the addition of red cabbage. The main finding was that the coating of fresh-cut apples emphasized the possibility to use a carrageenan matrix with the addition of extracts. The samples immersed in this coating type showed higher antioxidant activity as well as a superior color when compared to that of chitosan coated apple samples.
Influence of Adhesion Properties on the Crash Behavior of Steel/Polymer/Steel Sandwich Crashboxes: An Experimental Study
Authors: Harhash Mohamed , Kuhtz Moritz , Richter Jonas , Hornig Andreas , Gude Maik , Palkowski Heinz
Published: September 2021

The energy absorption behavior of crashboxes made of steel/polymer/steel (SPS) sandwich sheets can be influenced by numerous parameters, such as the materials used, their thicknesses and stacking, and the adhesion properties between their layers. Therefore, in the present study, the impact of steel/polymer adhesion quality on the occurring failure modes of the crashboxes and the resulting energy absorptions are experimentally analyzed. For this purpose, axial crushing and three-point bending tests on double-hat and top-hat crash boxes were performed, respectively. Three levels of adhesion quality are investigated: none, weak, and strong adhesion strengths. Additionally, the structural crash properties, such as energy absorption and maximal intrusion, are determined and analyzed at both of the quasi-static and highly dynamic loading rates. The results of these investigations show that the adhesion strengths chosen here significantly influence both the failure modes and the energy absorption values. In particular, the structural parameters, in the case of no adhesion, are at most half of those in the case of strong adhesion. However, it is also shown that, in the case of weak adhesion, the structural characteristics are slightly reduced. Based on these results, the possibility to adjust the adhesion strength—globally and/or locally—could be used in future activities to purposefully tailor the failure behavior of hybrid crashboxes.