bluuebunny/crossref_metadata_2025 huggingface dataset:
Selecting Genetic Variants and Interactions Associated with Amyotrophic Lateral Sclerosis: A Group LASSO Approach
Authors: Feronato Sofia Galvão , Silva Maria Luiza Matos , Izbicki Rafael , Farias Ticiana D. J. , Shigunov Patrícia , Dallagiovanna Bruno , Passetti Fabio , dos Santos Hellen Geremias
Published: August 2022

Amyotrophic lateral sclerosis (ALS) is a multi-system neurodegenerative disease that affects both upper and lower motor neurons, resulting from a combination of genetic, environmental, and lifestyle factors. Usually, the association between single-nucleotide polymorphisms (SNPs) and this disease is tested individually, which leads to the testing of multiple hypotheses. In addition, this classical approach does not support the detection of interaction-dependent SNPs. We applied a two-step procedure to select SNPs and pairwise interactions associated with ALS. SNP data from 276 ALS patients and 268 controls were analyzed by a two-step group LASSO in 2000 iterations. In the first step, we fitted a group LASSO model to a bootstrap sample and a random subset of predictors (25%) from the original data set aiming to screen for important SNPs and, in the second step, we fitted a hierarchical group LASSO model to evaluate pairwise interactions. An in silico analysis was performed on a set of variables, which were prioritized according to their bootstrap selection frequency. We identified seven SNPs (rs16984239, rs10459680, rs1436918, rs1037666, rs4552942, rs10773543, and rs2241493) and two pairwise interactions (rs16984239:rs2118657 and rs16984239:rs3172469) potentially involved in nervous system conservation and function. These results may contribute to the understanding of ALS pathogenesis, its diagnosis, and therapeutic strategy improvement.
Quality of Information and Marketing of Rural Tourism Experience
Authors: Walkowski Marinês da Conceição , Perinotto André Riani Costa , Vieira Vinicius Boneli , Santos Anna Isabelle Gomes Pereira
Published: August 2022

Investing in quality information contributes to the relationship between demand and suply. In this sense, this paper’s objective is to analyze the quality of the information generated by the social media (Instagram) of the Acolhida na Colônia association. To identify the relevance of each attribute in the consumers’ perception, categories and dimensions for quality information were analyzed based on the user’s vision and semantic criteria. The main results revealed the difference in the quality of Instagram from the families who participated in the training. The quality of images and content of property’s posts has also fed the Association’s institutional Instagram. However, there is a need to expand the amount of information and constant updating.
Momoge Internationally Important Wetland: Ecosystem Integrity Remote Assessment and Spatial Pattern Optimization Study
Authors: Han Jiaqi , Wang Dongyan , Zhang Shuwen
Published: August 2022

Along the migration route between East Asia and Australia, numerous migratory birds use the Momoge Internationally Important Wetland as a habitat. Human activities and climate variability cause salinization and meadowization. We developed the “Quality-Pressure-Pattern-Service” remote assessment framework for ecosystem integrity, using a three level approach (TLA). The model was used to assess ecosystem integrity, identify improper wetland development, and provide spatial optimization strategies. The research region was dominated by wetlands, followed by dry fields. Wetlands continued to decrease between 1965 and 2019, as arable land and construction land continued to increase. Over the course of 54 years, ecosystem integrity declined. In 2019, around half of the areas had poor or extremely poor ecosystem integrity. Because the eastern study area contained many pristine inland beaches, the eastern study area displayed greater ecosystem integrity than the central and western areas. Priority should therefore be given to wetland restoration in the HJ core area (one of the three core areas of the reserve), where most of the herb marsh has been converted to arable land. This study revealed the integrity and authenticity of wetland ecosystems. Our results can aid in the protection of wetland habitats, encourage sustainable development, and help in the building of a national park in northeastern China.
Pasture Management to Reduce the Risk of Acer pseudoplatanus Poisoning While Preserving Ecological Sustainability
Authors: Ghislain Barbara , Farinelle Arnaud , Renaud Benoît , François Anne-Christine , Wouters Clovis P. , Votion Dominique-Marie
Published: August 2022

In spring, grazing equids may suffer from a severe rhabdomyolysis syndrome named atypical myopathy. This environmental intoxication results from ingestion of toxins contained in Acer pseudoplatanus seedlings. The aim of this study was to investigate the effectiveness of herbicide spraying and mowing to reduce the toxic pressure of sycamore seedlings. In a first experiment, the efficacy of three herbicides to eradicate seedlings was compared to mowing. In a second experiment, the influence of the mowing timing on pasture productivity was determined. In both experiments, sycamore seedling counting, grass height and botanical composition were determined. In experiment 2, the final harvest biomass and its nutritional value were also determined. Herbicides and mowing both reduced the number of seedlings, which nevertheless disappear naturally over time without intervention (i.e., in control areas). As opposed to mowing, herbicide spraying altered the composition of the pasture flora. Both sprayed and mowed seedlings remain toxic until full decomposition. Early mowing (i.e., early April) did not affect the harvest yield. Late mowing (i.e., end of April) reduced the harvest yield but its nutritional value fitted the horses’ need. In conclusion, mowing is the best strategy to reduce the risk of Acer pseudoplatanus poisoning in grazing equids while preserving ecological sustainability and nutritional value of pastures.
Analysis Long-Term and Spatial Changes of Forest Cover in Typical Karst Areas of China
Authors: Chen Fei , Bai Xiaoyong , Liu Fang , Luo Guangjie , Tian Yichao , Qin Luoyi , Li Yue , Xu Yan , Wang Jinfeng , Wu Luhua , Li Chaojun , Zhang Sirui , Ran Chen
Published: August 2022

In recent decades, China has exhibited the fastest and most remarkable social-economic development in the world. As a result of such development, the forest cover of the country has undergone radical changes. This paper aims to develop a method for analyzing long-term and spatial changes in forest cover based on historical maps and remote sensing images. Moreover, we will focus on the reduction or restoration of forests distributed at different altitudes, slopes, soils, and lithologic types in different periods, to reveal the problems that should be paid attention to in forest restoration in karst areas. A typical county of China was selected as the study area. A historical military operation map was considered the principal source of basic data. These data were then combined with Landsat satellite images to conduct quantitative analysis on changes in the spatial area and location of forest cover with a long time series. The findings are as follows: in terms of time series, the forest area in the study area showed a trend of decreasing at first and then increasing, with the year 1986 as the turning point. In terms of spatial patterns, a considerable difference is observed in regions with changes in forest cover under different historical periods. Changes are obvious in limestone areas, rock soil areas, and areas with an elevation of 2000–2500 m and a slope gradient of 6°–15°. Spatial–temporal changes in forest cover reflect the effects of the war, national policy, and economic development to some extent. All these results indicate that, despite its limitations, a historical map is a valuable document for studying an ecological environment.
And She Be like ‘Tenemos Frijoles en la Casa’: Code-Switching and Identity Construction on YouTube
Authors: Wentker Michael , Schneider Carolin
Published: August 2022

This empirical case study explores the (co-)construction and negotiation of identities through code-switching (CS) as found on the video-sharing platform YouTube, disentangling the complexities of social practice anchored in a discursive online environment. Drawing on a YouTube comment corpus and paying special attention to the socio-technical affordances of the platform, the study examines users’ positioning practices and metapragmatic replies in response to a culturally themed video priming discussion about LatinX family stereotypes. More specifically, it analyses how users discursively position themselves vis-à-vis the video and which linguistic strategies they exploit to (co-)construct and negotiate their cultural identity. Focusing on interrelated positioning devices such as code-choice, identity labels and quoting, this contribution proposes a multi-level model of analysis to account for the dynamic interplay between CS practices and identity construction in a heterogeneous online space. Following a social-constructivist approach to identity, CS is shown to reinforce in-group solidarity rooted in the shared experience and discussion of LatinX culture and provides evidence of a sense of togetherness in an emerging community of practice.
The Impact of Water on the Tribological Behavior of Lubricating Grease Based on Calcium Carbonate Polymorphs
Authors: Sun Longqi , Ma Rui , Zhao Qin , Zhao Gaiqing , Wang Xiaobo
Published: August 2022

In this article, calcium sulfonate complex grease with different polymorphs was acquired. With reference to the improved rolling stability test method, 5% and 10% water were added to the calcium sulfonate composite grease respectively. The influence of water on the flow and deformation characteristics of grease under external force was characterized by rheological analysis. Moreover, the influence of water on the tribological behaviors of grease was evaluated at 30 and 80 °C. The results indicate that water could affect the flow and deformation characteristics of calcium sulfonate complex grease in vaterite polymorph (CSCG-V) more than calcium sulfonate complex grease in calcite polymorph (CSCG-C), and CSCG-V could combine with water to form a more stable grease under external force. Tribological results also clearly show that CSCG-C with water shows better tribological properties than CSCG-V with water under harsh conditions. There was no significant difference in the components of the films that consisted of CaCO3 and CaO regardless of grease within or without water. The improvement of tribological properties of CSCG-C with 5% and 10% water benefited from the influence of water on the film forming capacity of calcium carbonate on the steel surface.
Lubrication Mechanisms of a Nanocutting Fluid with Carbon Nanotubes and Sulfurized Isobutylene (CNTs@T321) Composites as Additives
Authors: Guan Jiju , Gao Chao , Xu Zhengya , Yang Lanyu , Huang Shuiquan
Published: August 2022

Developing high-efficiency lubricant additives and high-performance green cutting fluids has universal significance for maximizing processing efficiency, lowering manufacturing cost, and more importantly reducing environmental concerns caused by the use of conventional mineral oil-based cutting fluids. In this study, a nanocomposite is synthesized by filling sulfurized isobutylene (T321) into acid-treated carbon nanotubes (CNTs) with a liquid-phase wet chemical method. The milling performance of a nanocutting fluid containing CNTs@T321 composites is assessed using a micro-lubrication technology in terms of cutting temperature, cutting force, tool wear, and surface roughness. The composite nanofluid performs better than an individual CNT nanofluid regarding milling performance, with 12%, 20%, and 15% reductions in the cutting force, machining temperature, and surface roughness, respectively. The addition of CNTs@T321 nanocomposites improves the thermal conductivity and wetting performance of the nanofluid, as well as produces a complex lubricating film by releasing T321 during machining. The synergistic effect improves the cutting state at the tool–chip interface, thereby resulting in improved machining performance.
Modified Graphene/Muscovite Nanocomposite as a Lubricant Additive: Tribological Performance and Mechanism
Authors: Zhao Zhinan , Li Yujunwen , Lei Wu , Hao Qingli
Published: August 2022

Modified graphene/muscovite (MGMu) nanocomposite was synthesized with muscovite (Mu) and silane coupling agent modified graphene oxide through a simple hydrothermal method that exhibited excellent dispersion stability in oil. Compared with the base oil sample, the average friction coefficient and wear scar diameter of the MGMu oil sample decreased by 64.4 and 20.0%, respectively, and the microhardness of its wear scar was increased by 16.1%. The MGMu showed better tribological performance than its individual component due to the synergetic effect between the two components. The lubrication mechanism was proposed according to the morphology, chemical composition, and microhardness of the surface of wear scars. MGMu as an oil additive could fill between the friction pairs, cling to some asperities, and occur relative sliding between unit layers, thus playing a role in lubrication. It was found that MGMu would react with the surface of the friction pair during the friction process to generate Fe2O3, SiO2, SiC, and new aluminosilicate, which formed a self-repairing layer with high hardness. This chemically reactive film exhibited a lower shear strength, which made the oil sample containing MGMu have a lower coefficient of friction.
1-(4-Fluorobenzoyl)-9H-carbazole
Authors: Laube Markus , König Jonas , Köckerling Martin , Kniess Torsten
Published: August 2022

1-(4-Fluorobenzoyl)-9H-carbazole (1) was synthesized, starting from 9H-carbazole and 4-fluorobenzonitrile, by Friedel–Crafts acylation, using boron trichloride to direct the substitution in 1-position. Single-crystal X-ray diffraction analysis unambiguously revealed the molecular structure of 1.
Magnesium for Implants: A Review on the Effect of Alloying Elements on Biocompatibility and Properties
Authors: Hassan S. Fida , Islam M. T. , Saheb N. , Baig M. M. A.
Published: August 2022

An attempt is made to cover the whole of the topic of biodegradable magnesium (Mg) alloys with a focus on the biocompatibility of the individual alloying elements, as well as shed light on the degradation characteristics, microstructure, and mechanical properties of most binary alloys. Some of the various work processes carried out by researchers to achieve the alloys and their surface modifications have been highlighted. Additionally, a brief look into the literature on magnesium composites as also been included towards the end, to provide a more complete picture of the topic. In most cases, the chronological order of events has not been particularly followed, and instead, this work is concentrated on compiling and presenting an update of the work carried out on the topic of biodegradable magnesium alloys from the recent literature available to us.
Symmetric Engineered High Polarization-Insensitive Double Negative Metamaterial Reflector for Gain and Directivity Enhancement of Sub-6 GHz 5G Antenna
Authors: Hasan Md. Mhedi , Islam Mohammad Tariqul , Moniruzzaman Md. , Soliman Mohamed S. , Alshammari Ahmed S. , Sulayman Iman I. M. Abu , Samsuzzaman Md. , Islam Md. Shabiul
Published: August 2022

A symmetric engineered high polarization-insensitive double negative (DNG) metamaterial (MM) reflector with frequency tunable features for fifth-generation (5G) antenna gain and directivity enhancement is proposed in this paper. Four identical unique quartiles connected by a metal strip are introduced in this symmetric resonator that substantially tunes the resonance frequency. The proposed design is distinguished by its unique symmetric architecture, high polarization insensitivity, DNG, and frequency tunable features while retaining a high effective medium ratio (EMR). Moreover, the suggested patch offers excellent reflectance in the antenna system for enhancing the antenna gain and directivity. The MM is designed on a Rogers RO3010 low loss substrate, covering the 5G sub-6GHz band with near-zero permeability and refractive index. The performance of the proposed MM is investigated using Computer Simulation Technology (CST), Advanced Design Software (ADS), and measurements. Furthermore, polarization insensitivity is investigated up to 180° angles of incidence, confirming the identical response. The 4 × 4 array of the MM has been utilized on the backside of the 5G antenna as a reflector, generating additional resonances that enhance the antenna gain and directivity by 1.5 and 1.84 dBi, respectively. Thus, the proposed prototype outperforms recent relevant studies, demonstrating its suitability for enhancing antenna gain and directivity in the 5G network.
Synthesis and Characterization of Calcium Carbonate Obtained from Green Mussel and Crab Shells as a Biomaterials Candidate
Authors: Ismail Rifky , Cionita Tezara , Shing Wong Ling , Fitriyana Deni Fajar , Siregar Januar Parlaungan , Bayuseno Athanasius Priharyoto , Nugraha Fariz Wisda , Muhamadin Rilo Chandra , Junid Ramli , Endot Nor Azam
Published: August 2022

Green mussel and crab shells are natural sources of CaCO3, which is widely used as a bioceramic for biomedical applications, although they are commonly disposed of in landfills. The improper disposal of green mussel and crab shells can cause environmental pollution, reducing the quality of life in the community. Many studies have reported the preparation of CaCO3 from green mussels and crab shells. However, there are limited studies comparing the characteristics, including the crystal phase obtained, weight percentage (%) of crystal, crystal size, crystal system, and elemental composition of CaCO3 from green mussel shells, crab shells, and commercial CaCO3. The objective of this research was to compare the calcium carbonate properties formed from green mussel (PMS) and crab (PCS) shells to commercial CaCO3. Green mussel and crab shells were crushed to powder and were calcined at 900 °C for 5 h. Precipitated Calcium Carbonate (PCC) was synthesized from calcined green mussel and crab shells using a solution of 2M HNO3, NH4OH, and CO2 gas. The effect of setting parameters on the synthesized product was analyzed using XRD and SEM-EDX methods. This study shows that the chemical composition of PMS is nearly identical to that of commercial CaCO3, where no contaminants were identified. In contrast, PCS has N components other than Ca, C, and O. Furthermore, the predominance of the vaterite crystal phases in PMS and PCS, with respective weight percentages of 91.2% and 98.9%, provides a benefit for biomaterial applications. The crystallite sizes of vaterite in PMS, PCS, and calcite in commercial CaCO3 are 34 nm, 21 nm, and 15 nm, respectively.
Influence of Silicone Additives on the Properties of Pressure-Sensitive Adhesives
Authors: Mozelewska Karolina , Antosik Adrian Krzysztof
Published: August 2022

Research was carried out on the influence of various silicone compounds on the properties of pressure-sensitive adhesives. Silicone-based pressure-sensitive adhesives have good self-adhesive properties and are used in many different industries. However, their thermal resistance is relatively low. In order to improve this property, modifications were made to these adhesives. Compositions were tested, such as viscosity or thermogravimetric analysis, as well as tests of finished products in the form of self-adhesive tapes, i.e., peel adhesion, tack, cohesion at room and elevated temperature, SAFT test (Shear Adhesive Failure Temperature), pot-live (viscosity) and shrinkage. During the tests, an increase in thermal resistance (225 °C), lower shrinkage (0.08%), and lower viscosity was achieved (16.5 Pas), which is a positive phenomenon in the technology of pressure-sensitive adhesives. Thanks to this research, the properties of silicone self-adhesive adhesives have been significantly improved.
Validation of a Textile Material’s Electrostatic Characterization Device for Different Parameters and Their Effect on the Electrostatic Charge Generation
Authors: Tahir Hasan Riaz , Malengier Benny , Van Daele Didier , Van Langenhove Lieva
Published: August 2022

This research aims to validate an electrostatics characterization device to better understand the process of static charge generation in textile materials and to see how different factors affect it. This electrostatic device offers a variety of settings for controlling sample electrostatic activation and has a sample size range of up to one square meter. It can move in both horizontal and vertical directions in a controlled manner, providing a variety of possibilities for testing the effect of various movement features on electrostatic charge formation. Not only the textile polymer but also the motion characterizations influence the generation of electrostatic charges in textiles. The influence of frequency, pressure, dwell time between moves, test duration, effect of different sample sizes, and amplitude of movement on electrostatic charge generation was studied in greater detail. Two different parameters of the electrostatic waveform (peak voltage and peak-to-peak voltage) were investigated. The generation of electrostatic charges is proportional to the peak voltage and peak-to-peak voltage of the electrostatic waveform. Overall electrostatic charge generation increases with increasing frequency, stepping height, applied pressure at the same frequency, and sample size, but decreases with increasing dwell time between moves at the same frequency. The charge also increases with test duration until a saturation point is reached.
Experimental and Analytical Studies of Prefabricated Composite Steel Shear Walls under Low Reversed Cyclic Loads
Authors: Chen Shenggang , Peng Xiaotong , Lin Chen , Zhang Yingying , Hu Hexiang , He Zhengjian
Published: August 2022

Prefabricated composite shear walls (PCSW) consisting of steel plate clapped by single-sided or double-sided prefabricated reinforced concrete (RC) panels have enormous advantages for application as lateral-resisting structures in prefabricated high-rising residential buildings. In this paper, three 1/3-scaled PCSW were manufactured and tested to investigate the seismic performance of PCSW with single-sided or double-sided prefabricated RC panels. The experimental results, including hysteretic and skeleton curves, stiffness and strength degradation, ductility, energy dissipation capability and steel frame effects, were interpreted, compared and summarized. In spite of the RC panels being the same thickness, PCSW with double-sided RC panels had the most outstanding lateral-resisting properties: the highest yield strength and bearing capacity, adequate ductility, plumper and stable hysteresis loop and excellent energy absorption capacity. Finally, a simple predicting equation with a modification coefficient to calculate the effects of boundary steel frame was summarized and proposed to calculate the lateral yield load of the PCSW. All efforts were made to give reliable technical references for the design and construction of the PCSW.
Resourceful Utilization of Cow Hair in the Preparation of Iron Tailing-Based Foam Concrete
Authors: Liu Leipeng , Yang Junjie , She Yinfei , Lv Shenghua , Yang Zheng , Zhang Jia
Published: August 2022

Cow hair, a by-product of tannery waste, is usually stockpiled on a large scale as waste, which leads to serious environmental impacts. In this paper, cow hair was used as a reinforcement fiber to improve the mechanical strength of iron tailing-based foam concrete. The effects of the amount of cow hair fiber on the apparent density, compressive strength, and flexural strength of foam concrete were investigated by a series of characterization methods. Meanwhile, Image-Pro Plus software was used to analyze the porosity, average pore size, roundness, and other parameters of the specimens with different amounts of cow hair fiber. Results revealed that a proper amount of cow hair fiber can form a stable three-dimensional network structure inside the foam concrete and promote a uniform distribution and size of the pore structure inside the test piece. This could effectively improve the compressive strength, flexural strength, and crack resistance of the foam concrete, and when the fiber content was 0.2 wt%, the foam concrete exhibited the best mechanical properties, with a compressive strength of 11.19 MPa and a flexural strength of 3.58 MPa. The present work was in agreement with the strategic objective of resource recycling and solid waste utilization, which was conducive to the development of the circular and green economy.
Theoretical and Structural Study of Axial Symmetry Ce3+ Centers in the BaWO4 Single Crystal Doped with Cerium and Codoped with Sodium Ions
Authors: Bodziony Tomasz
Published: August 2022

The spin–Hamiltonian parameters g–factors (g|| and g⊥) of the Ce3+ paramagnetic centers in BaWO4: Ce and BaWO4: Ce, Na single crystals with axial symmetry are investigated using the superposition model (SPM) via complete diagonalization procedure of energy matrix (CDM method). The calculated g–factors are in reasonable agreement with the experimental values. The fitted intrinsic parameters are comparable with data from other publications for rare-earth paramagnetic centers in a similar environment. The angular distortions of the cerium dodecahedron [CeO8] are also studied. Structural analysis of paramagnetic centers with axial symmetry through the postulated cerium barium tetrahedron [CeBa4] connected via oxygens bridges was carried out. The mechanism of the charge compensation and the role of the second dopant (Na+) is also discussed.
Analysis of the Significance of Changes in the Number and Energy Parameters of Acoustic Emission Signals on the Assessment of the Strength of Fibre–Cement Boards
Authors: Adamczak-Bugno Anna , Świt Grzegorz , Krampikowska Aleksandra , Proverbio Edoardo
Published: August 2022

The article presents the results of three-point bending tests carried out for samples cut from full-size fibre–cement boards subjected to typical and exceptional conditions. The tests were carried out with the simultaneous acquisition of acoustic emission signals. It has been noted that some factors significantly deteriorate the strength parameters of the samples as well as cause the occurrence of differences in the number of acoustic emission signals of various classes and their energy parameters. A statistical analysis was carried out in order to repeat the relationship between the strength parameters of the samples and the acoustic emission parameters. Based on the research, it was found that the MOR bending strength for specimens exposed to fire and high temperature is more than 50% lower than for air-dried specimens and specimens exposed to water. The increased number of freeze–thaw cycles also has an impact on the strength of the specimens. Components exposed to more than 10 freeze–thaw cycles had a strength more than 30% smaller than the reference specimens soaked in water and exposed to bath-drying cycles. A similar dependency was indicated by the number of signals of the individual classes, their energy parameters and their frequencies. The number, strength, duration and frequency also decreased along with the increase in the test case number. On this basis, conclusions were drawn concerning the suitability of acoustic emission for the evaluation of the strength of fibre–cement elements.
Lattice Distortion, Amorphization and Wear Resistance of Carbon-Doped SUS304 by Laser Ablation
Authors: Kim Seonghoon , Kim Taewoo , Hong Eunpyo , Lee Heesoo
Published: August 2022

Lattice distortion and amorphization of carbon-doped SUS304 by variation of the laser output were investigated in terms of phase formation and the bonding state. The laser output was changed by 10% in the range of 60% to 100% after covering the SUS304 with carbon paste. A graphite peak and expanded austenite (S-phase) peak were observed in the carbon-doped SUS304, and Rietveld refinement was performed to identify the lattice distortion. The lattice constant of SUS304 was initially 3.612 Å, but expansion lattice distortion occurred in the carbon-doped SUS304 as a result of the S phase formation and carbon doping, and the lattice constant increased to 3.964 Å (100% laser output). X-ray photoelectron spectroscopy analysis for the bonding state of the carbon-doped SUS304 showed that the sp2/sp3 ratio decreased from 3.21 (70% laser output) to 2.52 (100% laser output). The residual stress in the lattice was accumulated due to carbon doping by high thermal energy, which resulted in the formation of amorphous carbon. The bonding environment was represented by the ID/IG ratio using Raman analysis, and it increased from 0.55 (70% laser output) to 1.68 (100% laser output). During microstructure analysis of the carbon-doped SUS304, disordered structures by amorphization were observed in the carbon-doped SUS304 by the greater than 90% laser output. The amorphous carbon filled the lattice grains or voids to lubricate the surface, which improved the friction coefficient and wear rate from 0.23 and 7.63 mm3(Nm)−110−6 to 0.09 and 1.43 mm3(Nm)−110−6, respectively.
Investigation on the In Situ Ti2AlC/TiAl Composite with a Homogenous Architecture by Adding Graphene Nanosheets
Authors: Hou Bo , Wang Aiqin , Liu Pei , Xie Jingpei
Published: August 2022

The Ti2AlC/TiAl composite with a homogenous architecture was fabricated via spark plasma sintering (SPS) using Ti/Al/GNSs composite powders, after ultrasonic mechanical stirring, as raw materials. The phases, microstructure, compressive properties and Vickers hardness of the composite were methodically characterized. We observed the transformation of graphene nanosheets from multi-layer to few-layer by the ultrasonic dispersion and the uniform distribution of few-layer graphene nanosheets in composite powders by ultrasonic mechanical stirring. The composite is mainly composed of rod-shaped Ti2AlC particles and a TiAl matrix, and the formation of rod-shaped morphology with the long axis along the (0001) plane is due to the fact that the growth rate of Ti2AlC parallel to the (0001) plane is much higher than the growth rate along the [0001] direction. The compressive stress and strain of the as-prepared Ti2AlC/TiAl composite reach 1451.2 MPa and 19.7%, respectively, which are better than some Ti2AlC/TiAl composites using graphite as the carbon source, and the Vickers hardness remains between 400~500 HV. The fracture morphologies show the deformation and fracture features of Ti2AlC particles, i.e., lamellae kinking and laminated tearing, which could increase the toughness of TiAl alloys.
Green Synthesis and Investigation of Surface Effects of α-Fe2O3@TiO2 Nanocomposites by Impedance Spectroscopy
Authors: Sultan Hira , Sultan Aeysha , Orfali Raha , Perveen Shagufta , Ali Tahir , Ullah Sana , Anas Haji Muhammad , Ghaffar Safina , Al-Taweel Areej , Waqas Muhammad , Shahzad Waseem , Kareem Aftaab , Liaqat Aqsa , Ashraf Zaman , Shahid Ayesha , Rauf Abdul
Published: August 2022

Nanocomposites based on iron oxide/titanium oxide nanoparticles were prepared by employing green synthesis, which involved phytochemical-mediated reduction using ginger extract. XRD confirmed the composite formation, while scanning electron microscopy (SEM), dynamic light scattering (DLS), and energy-dispersive X-ray spectroscopy (EDX) was employed to investigate the particle size, particle morphology, and elemental analysis. SEM indicated the formation of particles with non-uniform shape and size distribution, while EDX confirmed the presence of Fe, Ti and oxygen in their elemental state. The surface effects were investigated by Fourier transform infrared radiation (FTIR) and impedance spectroscopy (IS) at room temperature. IS confirmed the co-existence of grains and grain boundaries. Thus, FTIR and IS analysis helped establish a correlation between enhanced surface activity and the synthesis route adopted. It was established that the surface activity was sensitive to the synthesis route adopted. The sample density, variation in grain size, and electrical resistivity were linked with surface defects, and these defects were related to temperature. The disorder and defects created trap centers at the sample’s surface, leading to adsorption of CO2 from the environment.
Studies of Monoamine Neurotransmitters at Nanomolar Levels Using Carbon Material Electrodes: A Review
Authors: Kumar Pankaj , Soni Isha , Jayaprakash Gururaj Kudur , Flores-Moreno Roberto
Published: August 2022

Neurotransmitters (NTs) with hydroxyl groups can now be identified electrochemically, utilizing a variety of electrodes and voltammetric techniques. In particular, in monoamine, the position of the hydroxyl groups might alter the sensing properties of a certain neurotransmitter. Numerous research studies using electrodes modified on their surfaces to better detect specific neurotransmitters when other interfering factors are present are reviewed to improve the precision of these measures. An investigation of the monoamine neurotransmitters at nanoscale using electrochemical methods is the primary goal of this review article. It will be used to determine which sort of electrode is ideal for this purpose. The use of carbon materials, such as graphite carbon fiber, carbon fiber micro-electrodes, glassy carbon, and 3D printed electrodes are only some of the electrodes with surface modifications that can be utilized for this purpose. Electrochemical methods for real-time detection and quantification of monoamine neurotransmitters in real samples at the nanomolar level are summarized in this paper.
Research on Path Planning and Trajectory Tracking of an Unmanned Electric Shovel Based on Improved APF and Preview Deviation Fuzzy Control
Authors: Fang Yi , Wang Shuai , Bi Qiushi , Wu Guohua , Guan Wei , Wang Yongpeng , Yan Chuliang
Published: August 2022

With the development and upgrading of intelligent mines, research on the unmanned walking of intelligent electric shovels (ES) has been carried out to improve the moving efficiency of extra-large excavators. This paper first introduces an electric shovel’s primary moving condition in an open-pit mine. According to the moving characteristics of the heavy-duty crawler, the artificial potential field (APF) algorithm is improved to plan the moving trajectory of the electric shovel and carry out simulation verification. A dynamic model of an electric shovel is established. A fuzzy control tracking method is proposed based on preview displacement and centroid displacement deviation. The robustness of the tracking algorithm is verified by multi-condition simulation. Finally, the electric shovel prototype is tested through path planning and tracking experiments. The experimental results show that the improved artificial potential field algorithm can plan an obstacle-free path that satisfies the movement of an electric shovel, and the electric shovel can quickly track the preset trajectory. The maximum deviation of the track tracking center of mass is no more than 10 cm, and the deviation of the heading angle when the shovel reaches the endpoint is within 2°.
Yōkobo: A Robot to Strengthen Links Amongst Users with Non-Verbal Behaviours
Authors: Capy Siméon , Osorio Pablo , Hagane Shohei , Aznar Corentin , Garcin Dora , Coronado Enrique , Deuff Dominique , Ocnarescu Ioana , Milleville Isabelle , Venture Gentiane
Published: August 2022

Yōkobo is a robject; it was designed using the principle of slow technology and it aims to strengthen the bond between members (e.g., a couple). It greets people at the entrance and mirrors their interactions and the environment around them. It was constructed by applying the notions of a human–robot–human interaction. Created by joint work between designers and engineers, the form factor (semi-abstract) and the behaviours (nonverbal) were iteratively formed from the early stage of the design process. Integrated into the smart home, Yōkobo uses expressive motion as a communication medium. Yōkobo was tested in our office to evaluate its technical robustness and motion perception ahead of future long-term experiments with the target population. The results show that Yōkobo can sustain long-term interaction and serve as a welcoming partner.
Suppressing Quadrature Error and Harmonics in Resolver Signals via Disturbance-Compensated PLL
Authors: Wang Rui , Wu Zhong
Published: August 2022

The aim of this study was to obtain accurate angular positions and velocities from resolver signals; resolver-to-digital conversion (RDC) often adopts a phase-locked loop (PLL) as a demodulation algorithm. However, resolver signals often come with quadrature errors and harmonics, which lead to a severe reduction in PLL accuracy. The conventional PLL does not consider the impact of the quadrature error, and the bandwidth of the PLL is much larger than the fundamental frequency of resolver signals for pursuing a low dynamic error. These reasons render the retention of resolver harmonics in the demodulation results. In this paper, a disturbance-compensated PLL (DC-PLL) is proposed, which consists of a phase detector for suppressing quadrature error and harmonics (SQEH-PD) and a second-order observer. Firstly, since the quadrature error does not change with the angle velocity, the pre-estimated quadrature error is used in the SQEH-PD to compensate for the quadrature error in resolver signals. Secondly, although the frequency of the harmonics changes with the velocity, the amplitudes of the harmonics do not change. Therefore, the pre-estimated amplitudes of harmonics and estimated angular position are used in the SQEH-PD to compensate for the harmonics in resolver signals. Thirdly, a second-order observer is designed to estimate the angular position and velocity by regulating the phase detector error. Compared with the conventional PLL, the proposed DC-PLL has a stronger anti-disturbance ability against the quadrature error and harmonics by configurating the phase detector error and the estimated position error, which have a linear relation. Simulation and experimental results prove the effectiveness of the proposed method.
A Study on the Vibration Characteristics and Damage Mechanism of Pantograph Strips in a Railway Electrification System
Authors: Wu Qirui , Gu Xiaohan Phrain , Ma Ziyan , Wang Anbin
Published: August 2022

This paper presents the vibration characteristics of a pantograph–catenary interaction in a rigid catenary system. Both computational simulation and laboratory tests are carried out to evaluate the frequency contents of pantograph strips. Based on the observation that irregular wear is characterized by the consistency between the pantograph strips’ wear pattern and the mode shape of their dominant modal frequencies, it is deducted that resonance occurs at the pantograph strip and the contact wire interface in the high frequency range. By applying damping treatment to the pantograph strip, and hence improving its damping property, a reduction of 7 dB in the total vibration level at the sliding contact can be achieved, as verified through field tests. It is also found that the worse the initial condition of the pantograph–catenary system, the more prominent the damping effects on the control of high-frequency vibration for irregular wear problems.
An Extended Thermodynamics Model for Blood Flow
Authors: Barbera Elvira , Pollino Annamaria
Published: August 2022

A model for blood flow is introduced in the context of the Rational Extended Thermodynamics (RET). The balance equations are applied to the two-hierarchy structure recently introduced by Ruggeri and Sugiyama. The constitutive relations are derived with universal physical principles and the remaining constitutive functions are evaluated by use of the kinetic theory. The model herein obtained is a hyperbolic generalization of a classical blood flow model. Our equations by construction have the same physical proprieties of the classical system; in addition, owing to its hyperbolic structure, our model avoids the unphysical feature of instantaneous diffusive effects which is typical of parabolic systems. Furthermore we expect that our model, as all RET systems, can describe the physical phenomena better than the classical ones when the fields change rapidly or one has steep gradients.
Two Regularization Methods for the Variational Inequality Problem over the Set of Solutions of the Generalized Mixed Equilibrium Problem
Authors: Song Yanlai , Bazighifan Omar
Published: August 2022

In this work, we consider bilevel problems: variational inequality problems over the set of solutions of the generalized mixed equilibrium problems. Two new inertial extragradient methods are proposed for solving these problems. Under appropriate conditions, we prove strong convergence theorems for the proposed methods by the regularization technique. Finally, some numerical examples are provided to show the efficiency of the proposed algorithms.
Management of Transfer Prices in Professional Football as a Function of Fan Numbers
Authors: Užík Martin , Warias Roman , Glova Jozef
Published: August 2022

The intention of this paper is to provide new academic insights regarding an economically explainable valuation of transfer prices for European football players based on mathematical modeling. Football is the most popular sport in the world followed by approximately 3.5 billion people. The increasing commercialization and professionalization of the industry implies that every area of a football club is constantly put to the test for improvements. Especially after suffering financially under the consequences of the worldwide pandemic, clubs focus not only on sporting success but also on financial survival. Only financially stable clubs have the resources to be more successful. An expensive team does not have to be successful in terms of sports performance. However, a successful team in sports is expensive in the long run. Increasing digitalization offers new revenue potentials for football clubs that focus on selling merchandise in addition to gameday revenues and its media exploitation rights. However, player transfers have become increasingly important because these costs and revenues increased substantially in the relevance of a club’s financial situation. Regarding transfer costs, the question arises as to how transfer fees are determined and which factors have a major influence here. Clubs try to find new ways of evaluating the potential profit of player transfers to lower the risk of failed player investments. The aim of this article is to quantify the popularity of a football player in terms of his merchandising potential to amortize his transfer price. The mathematically formulated relationship calculates a reference value for a player, taking performance, age, number of customers purchasing merchandise, and player position into account. The information gained can be used by managers of European football clubs as a guide in transfer negotiations. For 6907 players of the European top leagues, we analyzed data in the period from 2003 to 2019. For 409 players in the season of 2018/2019 complete data sets were available, so that a model for calculating a theoretical transfer fee for a player during that season could be determined. The results of the study and the developed model suggest that, based on the available data, a football club should offer either one-year or three-year contracts to a transferred player, depending on the anticipated profit margin of merchandise sales and the quota of potential buyers of the products representing a percentage of the number of customers purchasing merchandise. This information gives football club’s management the chance to make better transfer decisions for the individual situation of the player and the club itself. Due to the increased importance of transfers on a football club’s financial performance, better transfer decision making leads to an improved financial stability of the respective clubs and eventually to sporting success.
Interpolative Meir–Keeler Mappings in Modular Metric Spaces
Authors: Karapınar Erdal , Fulga Andreea , Yeşilkaya Seher Sultan
Published: August 2022

Modular metric space is one of the most interesting spaces in the framework of the metric fixed point theory. The main goal of the paper is to provide some certain fixed point results in the context of modular metric spaces and non-Archimedean modular metric spaces. In particular, we examine the existence of interpolative Meir–Keeler contraction types via admissible mappings for fixed point theory. Our results bring together several results available in the current corresponding literature.
The Role of Broadband Infrastructure in Building Economic Resiliency in the United States during the COVID-19 Pandemic
Authors: Katz Raúl , Jung Juan
Published: August 2022

The purpose of this paper is to study the role of broadband in mitigating the economic losses resulting from COVID-19 in the United States by providing a necessary infrastructure to keep economic systems operating, albeit partially. The study is based on an empirical framework underlined by a Cobb–Douglas production function and estimated within a structural multi-equation model through the three-stage least squares approach. To consider the impact of COVID-19 on the economy, we rely on two main variables: an indicator of the quantity of deaths attributed to the disease for every 100,000 inhabitants; and the Stringency Index, a metric linked to the intensity of social restrictions imposed by national and local governments. The main contribution of this article is to provide robust evidence for how the heterogeneous effects of the pandemic across states are in part explained by differences in broadband adoption. Our results indicate that those states with higher broadband adoption were able to mitigate a larger portion of their economic losses derived from the pandemic-induced lockdowns. Addressing the digital divide and ensuring universal access to broadband represent critical goals for building economic resilience to face future emergencies.
Degradation Modeling for Lithium-Ion Batteries with an Exponential Jump-Diffusion Model
Authors: Liu Weijie , Shen Yan , Shen Lijuan
Published: August 2022

The degradation of Lithium-ion batteries is usually measured by capacity loss. When batteries deteriorate with usage, the capacities would generally have a declining trend. However, occasionally, considerable capacity regeneration may occur during the degradation process. To better capture the coexistence of capacity loss and regeneration, this paper considers a jump-diffusion model with jumps subject to the exponential distribution. For estimation of model parameters, a jump detection test is first adopted to identify jump arrival times and separate observation data into two series, jump series and diffusion series; then, with the help of probabilistic programming, the Markov chain Monte Carlo sampling algorithm is used to estimate the parameters for the jump and diffusion parts of the degradation model, respectively. The distribution functions of failure time and residual useful life are also approximated by the Monte Carlo simulation approach. Simulation results show the feasibility and good performance of the combined estimation method. Finally, real data analysis indicates that the jump-diffusion process model with the combined estimation method could give a more accurate estimation when predicting the failure time of the battery.