bluuebunny/crossref_metadata_2025 huggingface dataset:
The Evaluation of Videos about Branched-Chain Amino Acids Supplements on YouTube™: A Multi-Approach Study
Authors: Günalan Elif , Turhan Saadet , Çavak Betül Yıldırım , Cebioğlu İrem Kaya , Çonak Özge
Published: December 2022

Branched-chain amino acids (BCAAs) are one of the most controversial ergogenic aids in terms of effectiveness and safety. This study aimed to evaluate the quality and reliability of BCAA supplements related to English videos on YouTube™ and to synthesize with the sentiment–emotion analysis of comments on videos. The content analysis of the information on videos was evaluated with the use of DISCERN, Journal of American Medical Association (JAMA) benchmark criteria, and Global Quality Score (GQS). In addition, word cloud and sentiment and emotional analysis of comments in videos were performed with the R package. As a result, the mean ± standard error values of DISCERN, JAMA, and GQS scores of all videos were 29.27 ± 1.97, 1.95 ± 0.12, and 2.13 ± 0.17, respectively. It was found that advertisement-free videos have a significantly higher DISCERN and GQS score than advertisement-included videos (p < 0.05). A moderately significant positive correlation was determined between DISCERN score of video content and the positive sentiment of video comments (rs: 0.400, p = 0.002). In conclusion, it was determined that BCAA-related YouTube™ videos have mostly very poor quality in terms of content and that videos with higher quality may receive positive comments from viewers according to the DISCERN instrument.
Modeling and Simulation of Crowd Pre-Evacuation Decision-Making in Complex Traffic Environments
Authors: Li Zhihong , Qiu Shiyao , Wang Xiaoyu , Zhao Li
Published: December 2022

Human movements in complex traffic environments have been successfully simulated by various models. It is crucial to improve crowd safety and urban resilience. However, few studies focus on reproducing human behavior and predicting escape reaction time in the initial judgement stage in complex traffic environments. In this paper, a pedestrian pre-evacuation decision-making model considering pedestrian heterogeneity is proposed for complex environments. Firstly, the model takes different obvious factors into account, including cognition, information, experience, habits, stress, and decision-making ability. Then, according to the preference of the escapees, the personnel decision-making in each stage is divided into two types: stay and escape. Finally, multiple influencing factors are selected to construct the regression equation for prediction of the escape opportunity. The results show that: (1) Choices of escape opportunity are divided into several stages, which are affected by the pedestrian individual risk tolerance, risk categories strength, distance from danger, and reaction of the neighborhood crowd. (2) There are many important factors indicating the pedestrian individual risk tolerance, in which Gen, Group, Time and Mode are a positive correlation, while Age and Zone are a negative correlation. (3) The analysis of the natural response rate of different evacuation strategies shows that 19.81% of people evacuate immediately. The research in this paper can better protect public safety and promote the normal activities of the population.
Dissemination in Extension: Health Specialists’ Information Sources and Channels for Health Promotion Programming
Authors: Strayer Thomas E. , Balis Laura E. , Ramalingam NithyaPriya S. , Harden Samantha M.
Published: December 2022

In the National Cooperative Extension System (herein: Extension), state-level specialists serve as key intermediaries between research, educators, and the community members they serve. There is a need to understand information seeking and sharing practices (i.e., dissemination) among specialists to increase the adoption of evidence-based health promotion programs. Specialists (N = 94) across 47 states were identified and invited to participate in this mixed methods study. A one-way ANOVA with Bonferroni corrections was used to analyze survey data. Data collected through semi-structured interviews were analyzed using an immersion crystallization approach. Forty-seven health specialists completed the survey representing 31 eligible states (65%) and were predominately female (89%), Caucasian (70%), had a doctorate (62%), and were employed within Extension for 10.2 + 9.7 years. The information sources used most frequently were academic journals and other specialists, and most used email and online meetings to communicate. Qualitative findings support the use of other specialists as a primary source of information and indicate specialists’ desire for an on-demand, bi-directional, online national repository of Extension programs. This repository would facilitate the dissemination of evidence-based programming across the system and reduce program duplication as well as information burden on county-based educators.
Impact of Internet Development on Carbon Emissions in Jiangsu, China
Authors: Wang Shijin , Tong Fan
Published: December 2022

Based on STIRPAT and panel threshold models, this study empirically tested the impact of Internet development on carbon emissions using panel data of Jiangsu Province from 2007 to 2020. The results showed that the carbon emissions intensity of the Internet development level had a significant promotion effect, while the carbon emissions intensity of technological progress showed a significant inhibition effect, but this inhibition effect is less than the promotion effect brought about by internet development. Considering the threshold effect, the development of the Internet had a double-threshold effect on carbon emissions in northern and central Jiangsu. Jiangsu Province should further accelerate the pace of Internet development and cross the threshold value as soon as possible. Finally, this study constructed a prediction model of emissions reduction to predict the future emissions reduction potential of Jiangsu Province and found that there was still much room for improvement regarding carbon emissions reduction in Jiangsu Province.
Genome-Wide Identification of AMT2-Type Ammonium Transporters Reveal That CsAMT2.2 and CsAMT2.3 Potentially Regulate NH4+ Absorption among Three Different Cultivars of Camellia sinensis
Authors: Zhang Wenjing , Lin Lin , Wang Tao , Chen Mingjie , Song Bo , Sun Weijiang
Published: December 2022

Ammonium (NH4+), as a major inorganic source of nitrogen (N) for tea plant growth, is transported and distributed across membranes by the proteins of ammonium transporters (AMTs). However, the AMT2-type AMTs from tea plants remain poorly understood. In this study, five CsAMT2 subfamily genes were identified in tea plant genomes, and their full-length coding sequences (CDS) were isolated from roots. Then, a NH4+ uptake kinetic comparison of Fudingdabaicha (FD), Huangdan (HD), and Maoxie (MX) showed that FD was a high N efficiency (HNE) cultivar that had a wide range of adaptability to NH4+, HD was a high N efficiency under high N conditions (HNEH) cultivar, in which it was easy to obtain higher yield in a high N environment, and MX was a high N efficiency under low N conditions (HNEL) cultivar, which had a higher affinity for NH4+ than the other two. Tissue-specific expression analysis suggested that CsAMT2.2 and CsAMT2.3 were highly expressed in the roots, indicating that these two members may be unique in the CsAMT2 subfamily. This is further supported by our findings from the temporal expression profiles in the roots among these three different N adaptation cultivars. Expression levels of CsAMT2.2 and CsAMT2.3 in FD and HD were upregulated by a short time (2 h) under high NH4+ treatment, while under low NH4+ treatment, CsAMT2.2 and CsAMT2.3 were highly expressed at 0 h and 2 h in the HNEL-type cultivar—MX. Furthermore, the functional analysis illustrated that CsAMT2.2 and CsAMT2.3 could make a functional complementation of NH4+-defective mutant yeast cells at low NH4+ levels, and the transport efficiency of CsAMT2.3 was higher than that of CsAMT2.2. Thus, we concluded that CsAMT2.2 and CsAMT2.3 might play roles in controlling the NH4+ uptake from the soil to the roots. These results will further the understanding of the NH4+ signal networks of AMT2-type proteins in tea plants.
Molybdenum as a Potential Biocompatible and Resorbable Material for Osteosynthesis in Craniomaxillofacial Surgery—An In Vitro Study
Authors: Toschka André , Pöhle Georg , Quadbeck Peter , Suschek Christoph V. , Strauß Alexander , Redlich Christian , Rana Majeed
Published: December 2022

Titanium and stainless steel are commonly known as osteosynthesis materials with high strength and good biocompatibility. However, they have the big disadvantage that a second operation for hardware removal is necessary. Although resorbable systems made of polymers or magnesium are increasingly used, they show some severe adverse foreign body reactions or unsatisfying degradation behavior. Therefore, we started to investigate molybdenum as a potential new biodegradable material for osteosynthesis in craniomaxillofacial surgery. To characterize molybdenum as a biocompatible material, we performed in vitro assays in accordance with ISO Norm 10993-5. In four different experimental setups, we showed that pure molybdenum and molybdenum rhenium alloys do not lead to cytotoxicity in human and mouse fibroblasts. We also examined the degradation behavior of molybdenum by carrying out long-term immersion tests (up to 6 months) with molybdenum sheet metal. We showed that molybdenum has sufficient mechanical stability over at least 6 months for implants on the one hand and is subject to very uniform degradation on the other. The results of our experiments are very promising for the development of new resorbable osteosynthesis materials for craniomaxillofacial surgery based on molybdenum.
An Escherichia coli Expressed Multi-Disulfide Bonded SARS-CoV-2 RBD Shows Native-like Biophysical Properties and Elicits Neutralizing Antisera in a Mouse Model
Authors: Brindha Subbaian , Yoshizue Takahiro , Wongnak Rawiwan , Takemae Hitoshi , Oba Mami , Mizutani Tetsuya , Kuroda Yutaka
Published: December 2022

A large-scale Escherichia coli (E. coli) production of the receptor-binding domain (RBD) of the SARS-CoV-2 could yield a versatile and low-cost antigen for a subunit vaccine. Appropriately folded antigens can potentially elicit the production of neutralizing antisera providing immune protection against the virus. However, E. coli expression using a standard protocol produces RBDs with aberrant disulfide bonds among the RBD’s eight cysteines resulting in the expression of insoluble and non-native RBDs. Here, we evaluate whether E. coli expressing RBD can be used as an antigen candidate for a subunit vaccine. The expressed RBD exhibited native-like structural and biophysical properties as demonstrated by analytical RP-HPLC, circular dichroism, fluorescence, and light scattering. In addition, our E. coli expressed RBD binds to hACE2, the host cell’s receptor, with a binding constant of 7.9 × 10−9 M, as indicated by biolayer interferometry analysis. Our E. coli-produced RBD elicited a high IgG titer in Jcl:ICR mice, and the RBD antisera inhibited viral growth, as demonstrated by a pseudovirus-based neutralization assay. Moreover, the increased antibody level was sustained for over 15 weeks after immunization, and a high percentage of effector and central memory T cells were generated. Overall, these results show that E. coli-expressed RBDs can elicit the production of neutralizing antisera and could potentially serve as an antigen for developing an anti-SARS-CoV-2 subunit vaccine.
Fast Training Set Size Reduction Using Simple Space Partitioning Algorithms
Authors: Ougiaroglou Stefanos , Mastromanolis Theodoros , Evangelidis Georgios , Margaris Dionisis
Published: December 2022

The Reduction by Space Partitioning (RSP3) algorithm is a well-known data reduction technique. It summarizes the training data and generates representative prototypes. Its goal is to reduce the computational cost of an instance-based classifier without penalty in accuracy. The algorithm keeps on dividing the initial training data into subsets until all of them become homogeneous, i.e., they contain instances of the same class. To divide a non-homogeneous subset, the algorithm computes its two furthest instances and assigns all instances to their closest furthest instance. This is a very expensive computational task, since all distances among the instances of a non-homogeneous subset must be calculated. Moreover, noise in the training data leads to a large number of small homogeneous subsets, many of which have only one instance. These instances are probably noise, but the algorithm mistakenly generates prototypes for these subsets. This paper proposes simple and fast variations of RSP3 that avoid the computationally costly partitioning tasks and remove the noisy training instances. The experimental study conducted on sixteen datasets and the corresponding statistical tests show that the proposed variations of the algorithm are much faster and achieve higher reduction rates than the conventional RSP3 without negatively affecting the accuracy.
The Influence of Body Weight on Semen Parameters in Apis mellifera Drones
Authors: Bratu Ioan Cristian , Igna Violeta , Simiz Eliza , Dunea Ioan Bănățean , Pătruică Silvia
Published: December 2022

The quantity and quality of the honey bee drone semen have a significant determination on the performance of bee colonies. The existence of a smaller number of mature drones to participate in the mating of queens, as well as a sufficient number of drones but with poor quality semen can have serious implications for the productivity of bee colonies. Our study aimed to investigate the correlation between two body weight ranges of drones and semen parameters in the Buckfast honey bee, data that could be integrated into the optimization of instrumental insemination in been queens. Semen was collected from two groups of drones with different body weights (200–240 mg and 240–280 mg). Semen volume, semen concentration, motility, morphology and membrane integrity of spermatozoa were analyzed. The phenotype indicator related to body weight in correlation with the main semen parameters studied gives a weak influence or causality ratio. In drones with 240–280 mg body weight, a higher percentage of spermatozoa with abnormal morphology (>9.60%) was recorded, compared to drones with 200–240 mg body weight. The study reveals that a higher weight of honey bee drones is correlated with higher sperm concentration and total number of spermatozoa/ejaculate, with an increase in the percentage of spermatozoa with abnormal morphology.
Genetic Polymorphism and Phylogenetics of Aedes aegypti from Sudan Based on ND4 Mitochondrial Gene Variations
Authors: Abuelmaali Sara Abdelrahman , Jamaluddin Jamsari Amirul Firdaus , Allam Mushal , Abushama Hind Mohamed , Elnaiem Dia Eldin , Noaman Kheder , Avicor Silas Wintuma , Ishak Intan Haslina , Wajidi Mustafa Fadzil Farid , Jaal Zairi , Abu Kassim Nur Faeza
Published: December 2022

This study investigated the genetic differences between Aedes aegypti subspecies (Aedes aegypti aegypti (Aaa) and Aedes aegypti formosus (Aaf)) from Sudan using the NADH dehydrogenase subunit 4 (ND4) mitochondrial gene marker. Nineteen distinct haplotypes of the ND4 were identified in female Aedes aegypti mosquitoes from the study sites. The phylogenetic relationship of the 19 ND4 haplotypes was demonstrated in a median-joining haplotype network tree with Aaa and Aaf populations found to share three haplotypes. The genetic variance (Pairwise FST values) was estimated and found to range from 0.000 to 0.811. Isolation by distance test revealed that geographical distance was correlated to genetic variation (coefficient value (r) = 0.43). The Polar maximum likelihood tree showed the phylogenetic relationship of 91 female Aaa and Aaf from the study sites, with most of the Aaf haplotypes clustered in one group while most of the Aaa haplotypes gathered in another group, but there was an admixture of the subspecies in both clusters, especially the Aaa cluster. The Spatial Analysis of Molecular Variance (SAMOVA) test revealed that the eight populations clustered into two phylogeographic groups/clusters of the two subspecies populations. The 2 Aedes aegypti subspecies seemed not to be totally separated geographically with gene flow among the populations.
Effect of Alumina and Silicon Carbide Nanoparticle-Infused Polymer Matrix on Mechanical Properties of Unidirectional Carbon Fiber-Reinforced Polymer
Authors: Shahabaz S. M. , Shetty Pradeep Kumar , Shetty Nagaraja , Sharma Sathyashankara , Divakara Shetty S. , Naik Nithesh
Published: December 2022

Unidirectional carbon fiber-reinforced polymer nanocomposites were developed by adding alumina (Al2O3) and silicon carbide (SiC) nanoparticles using ultrasonication and magnetic stirring. The uniform nanoparticle dispersions were examined with a field-emission scanning electron microscope. The nano-phase matrix was then utilized to fabricate the hybrid carbon fiber-reinforced polymer nanocomposites by hand lay-up and compression molding. The weight fractions selected for Al2O3 and SiC nanoparticles were determined based on improvements in mechanical properties. Accordingly, the hybrid nanocomposites were fabricated at weight fractions of 1, 1.5, 1.75, and 2 wt.% for Al2O3. Likewise, the weight fractions selected for SiC were 1, 1.25, 1.5, and 2 wt.%. At 1.75 wt.% Al2O3 nanoparticle loading, the flexural strength modulus improved by 31.76% and 37.08%, respectively. Additionally, the interlaminar shear and impact strength enhanced by 40.95% and 47.51%, respectively. For SiC nanocomposites, improvements in flexural strength (12.79%) and flexural modulus (9.59%) were accomplished at 1.25 wt.% nanoparticle loading. Interlaminar shear strength was enhanced by 34.27%, and maximum impact strength was improved by 30.45%. Effective particle interactions with polymeric chains of epoxy, crack deflection, and crack arresting were the micromechanics accountable for enhancing the mechanical properties of nanocomposites.
Experimental Study of the Propagation Process of Dissection Using an Aortic Silicone Phantom
Authors: Chi Qing-Zhuo , Ge Yang-Yang , Cao Zhen , Long Li-Li , Mu Li-Zhong , He Ying , Luan Yong
Published: December 2022

Background: The mortality of acute aortic dissection (AD) can reach 65~70%. However, it is challenging to follow the progress of AD formation. The purpose of this work was to observe the process of dissection development using a novel tear-embedded silicone phantom. Methods: Silicone phantoms were fabricated by embedding a torn area and primary tear feature on the inner layer. CT scanning and laser lightening were conducted to observe the variations in thickness and volume of the true lumen (TL) and false lumen (FL) during development. Results: The model with a larger interlayer adhesion damage required a lower pressure to trigger the development of dissection. At the initiation stage of dissection, the volume of TL increased by 25.5%, accompanied by a 19.5% enlargement of tear size. The force analysis based on the change of tear size verified the deduction of the process of interlaminar separation from the earlier studies. Conclusions: The primary tear and the weakening adhesion of the vessel layers are key factors in AD development, suggesting that some forms of primary damage to the arterial wall, in particular, the lumen morphology of vessels with straight inner lumen, should be considered as early risk predictors of AD.
Accuracy and Technical Predictability of Computer Guided Bone Harvesting from the Mandible: A Cone-Beam CT Analysis in 22 Consecutive Patients
Authors: De Stavola Luca , Cristoforetti Alessandro , Fincato Andrea , Nollo Giandomenico , Ghensi Paolo , Cantarutti Anna , Tessarolo Francesco
Published: December 2022

This study assesses the accuracy and technical predictability of a computer-guided procedure for harvesting bone from the external oblique ridge using a patient-specific cutting guide. Twenty-two patients needing bone augmentation for implant placement were subjected to mandibular osteotomy employing a case-specific stereolithographic surgical guide generated through computer aided design. Differences between planned and real cut planes were measured comparing pre- and post-operative Cone Beam Computed Tomography images of the donor site according to six validated angular and displacement indexes. Accuracy and technical predictability were assessed for 119 osteotomy planes over the study population. Three different guide fitting approaches were compared. An average root-mean-square discrepancy of 0.52 (0.30–0.97) mm was detected. The accuracy of apical and medial planes was higher than the mesial and distal planes due to occasional antero-posterior guide shift. Fitting the guide with an extra reference point on the closest tooth performed better than using only the bone surface, with two indexes significantly lower and less disperse. The study showed that the surgical plan was actualized with a 1 mm safety margin, allowing effective nerve preservation and reducing technical variability. When possible, surgical guide design should allow fitting on the closest tooth based on both radiological and/or intra-oral scan data.
Optimization of Processing Steps for Superior Functional Properties of (Ba, Ca)(Zr, Ti)O3 Ceramics
Authors: Ciomaga Cristina Elena , Curecheriu Lavinia P. , Lukacs Vlad Alexandru , Horchidan Nadejda , Doroftei Florica , Valois Renaud , Lheureux Megane , Chambrier Marie Hélène , Mitoseriu Liliana
Published: December 2022

Lead-free piezoelectric ceramics with nominal composition at morphotropic phase boundary Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCTZ) prepared by different processing routes and sintered either by conventional solid-state reaction or by spark plasma sintering (SPS) techniques were comparatively investigated to observe the role of structural modifications and of microstructures on the dielectric, ferroelectric, piezoelectric and electrocaloric responses. The ceramics presented relative densities from 75% to 97% and showed variations in their phase composition as a result of variable mixing and different synthesis and sintering parameters providing local compositional heterogeneity. As result, all of the ceramics showed diffuse phase transition and ferroelectric switching responses, with parameters affected mostly by density (Pr between 3.6 to 10.1 μC/cm2). High values for the electrocaloric response in the Curie range were found for the ceramics with predominantly orthorhombic character. Field-induced structural modifications were probed by tunability anomalies and by XRD experiments in remanence conditions. Piezoelectric effects with notably high figure of merit values were assigned to the better densification and poling efficiency of BCTZ ceramics.
An Experimental Study on the Healing Performance of Complex Capsules Using Multiphase Inorganic Materials for Crack Self-Healing of Cement Mortars
Authors: Choi Yun-Wang , Kim Cheol-Gyu , Nam Eun-Joon , Oh Sung-Rok
Published: December 2022

Recently, a self-healing technique capable of repairing cracks in structures has emerged. Among various self-healing technologies, self-healing capsules can be largely classified into two types, depending on the phase of the core material: solid capsules, in which the core material is a powder; and microcapsules, in which the core material is a liquid. Solid capsules and microcapsules have different mechanisms, and their capsule sizes are also distinctly different. This suggests that each has advantages and disadvantages. Most of the studies known to date have utilized single capsules. However, if one uses a mixture of the two types of capsules, it is possible to highlight the strengths of each capsule and compensate for the weaknesses. Therefore, in this study, the first research on complex capsules that mixed solid capsules and microcapsules was attempted. As a result of the experiment, the complex capsule slightly reduced the fluidity of the mortar, but the effect was not significant. Moreover, the complex capsule tended to reduce the compressive strength of the mortar. In particular, it was found that the effect of solid capsules on the reduction in compressive strength among complex capsules was greater than that of microcapsules. Conversely, the healing performance increased when the ratio of solid capsules in the complex capsules was large.
Electrospun Conducting Polymers: Approaches and Applications
Authors: Acosta Mariana , Santiago Marvin D. , Irvin Jennifer A.
Published: December 2022

Inherently conductive polymers (CPs) can generally be switched between two or more stable oxidation states, giving rise to changes in properties including conductivity, color, and volume. The ability to prepare CP nanofibers could lead to applications including water purification, sensors, separations, nerve regeneration, wound healing, wearable electronic devices, and flexible energy storage. Electrospinning is a relatively inexpensive, simple process that is used to produce polymer nanofibers from solution. The nanofibers have many desirable qualities including high surface area per unit mass, high porosity, and low weight. Unfortunately, the low molecular weight and rigid rod nature of most CPs cannot yield enough chain entanglement for electrospinning, instead yielding polymer nanoparticles via an electrospraying process. Common workarounds include co-extruding with an insulating carrier polymer, coaxial electrospinning, and coating insulating electrospun polymer nanofibers with CPs. This review explores the benefits and drawbacks of these methods, as well as the use of these materials in sensing, biomedical, electronic, separation, purification, and energy conversion and storage applications.
Factors Influencing the Thermo-Hydro-Mechanical Behavior of Unstabilized Rammed Earth Walls
Authors: Zhang Xiang , Nowamooz Hossein
Published: December 2022

Waterproof capacity, thermal isolation, and pushover strength are the main characteristics when an unstabilized rammed earth (URE) wall is constructed. In this paper, a comprehensive numerical simulation model is built to evaluate the effect of 15 different factors on those three aforementioned properties of URE walls. The simulation results show that the hydraulic, thermal, and mechanical properties of the wall are interconnected. It is found that the waterproof capacity of the wall can be mainly improved by increasing the dry density, decreasing the rising damp effect, and reducing the fine content value of the wall. The thermal insulation characteristic of the wall can be ameliorated by increasing the wall thickness and reducing the rising damp effect, fine content, and dry density. In addition, the pushover capacity of the wall can be strengthened by increasing the wall width, fine content, wall thickness, and vertical load and decreasing the rising dampness and wall height. In addition, time has a positive effect on the waterproof capacity, thermal insulation, and mechanical strength of URE walls. These properties change significantly in the first 100 days and then stabilize after 180 days for a typical URE wall. Eventually, a new theoretical approach is proposed to predict the long-term THM behavior of URE walls by considering the 15 factors in its framework.
Mechanical Strength and Thermal Properties of Cement Concrete Containing Waste Materials as Substitutes for Fine Aggregate
Authors: Łukowski Paweł , Horszczaruk Elżbieta , Seul Cyprian , Strzałkowski Jarosław
Published: December 2022

The increasing volume of waste and the requirements of sustainable development are the reasons for the research on new waste management concepts. The research results presented in this paper show the effect of recycled aggregate on the selected properties of cement concrete. The aggregates obtained from three types of wastes are tested: recycled concrete paving, crushed ceramic bricks, and burnt sewage sludges. The recycled aggregates replaced 25% and 50% of the volume of the fine aggregate. The tested aggregates worsen the concrete mixes’ consistency and decrease, to some extent, the compressive strength of the concrete. However, the tensile splitting strength of the concrete with recycled aggregates is similar to that of the reference concrete. Using recycled aggregates worsens the tightness of the concrete, which manifests itself by increasing water penetration depth. The thermal properties of concrete are slightly affected by the type and content of the recycled aggregate. Considering the expected improvement in recycled aggregate processing, they can be an alternative to natural aggregates. Using recycled aggregates in cement concrete requires extensive studies to search for ways to increase their possible content without worsening concrete performance.
Microwave Electrodynamic Study on Antiferroelectric Materials in a Wide Temperature Range
Authors: Astafev Pavel , Pavelko Aleksey , Andryushin Konstantin , Lerer Alexander , Reizenkind Jakov , Reznichenko Larisa
Published: December 2022

The electrodynamic properties of lead zirconate titanate ceramic solid solutions, exhibiting ferro-antiferroelectric phase transition, are investigated at microwave frequencies in a wide temperature range. Significant changes in the electrodynamic response are found, presumably associated with structural rearrangements accompanying the sequence of phase transitions between para-, ferro-, and antiferroelectric states. The phenomena observed in the experiments are considered under conditions of changing temperature and concentrations of the components; several independent measurement techniques were used for their unambiguous identification.
The Effect of Shot Peening on Residual Stress and Surface Roughness of AMS 5504 Stainless Steel Joints Welded Using the TIG Method
Authors: Bucior Magdalena , Kluz Rafał , Trzepieciński Tomasz , Jurczak Kamil , Kubit Andrzej , Ochał Kamil
Published: December 2022

This article presents the influence of the Shot Peening (SP) process on residual stress and surface roughness of AMS 5504 joints welded using the Tungsten Inert Gas (TIG) method. Thin-walled steel structures are widely used in the aviation and automotive industries, among others. Unfortunately, the fatigue properties become worse during the welding process. Samples of 1 mm-thick AMS 5504 steel plates were first prepared using TIG welding and then strengthened by the Shot Peening (SP) process. The technological parameters of the SP process were changed in the range of time t from 2 min to 4 min and of pressure p from 0.4 MPa to 0.6 Mpa. The residual stresses were measured by X-ray diffraction in three zones: fusion zone (FZ), heat-affected zone (HAZ) and base metal (BM). The results showed that SP introduced compressive residual stresses in all of the zones measured, especially in the FZ. The greatest value of compressive residual stresses σ = −609 MPa in the FZ was observed for the maximum parameters of SP (p = 0.6 MPa, t = 4 min). The increase in value of residual stress is about 580% when compared to welding specimens without treatment. As a result of shot peening in the FZ, the mean roughness value Ra decreased in range 63.07% to 77.67% in the FZ, while in the BM increased in range 236.87% to 352.78% in comparison to specimen without treatment. Selected surface roughness parameters in FZ and BM were analyzed using neural networks. In FZ, it was demonstrated that the most correlated parameters with residual stresses are Rt and Rsk. On the other hand, in the BM zone, the most correlated parameters were Rv, Rt and Rq. This enables the estimation of stresses in the welded joint after SP on the basis of selected roughness parameters.
Effect of Granite Powder Grain Size and Grinding Time of the Properties of Cementitious Composites
Authors: Stempkowska Agata , Gawenda Tomasz , Chajec Adrian , Sadowski Łukasz
Published: December 2022

The purpose of this article is to determine the effect of granite powder grain size and grinding time on the properties of cement paste. A series of cement pastes modified by the addition of granite powder were made and the properties of the fresh mixtures and the mechanical properties of hardened pastes were studied. Based on the study, the best results, from the point of view of the application of granite powder in cementitious composites, were obtained for a sample with granite powder ground for 3 h, in which 50% of the particles were smaller than 4 μm, and 90% were below 20 μm. Compressive strength of 55 MPa and flexural strength of 6.8 MPa were obtained on this sample after aging for 28 days. To confirm the validity of using granite powder as substitute materials, additional tests such as scanning microscopy with elemental analysis (SEM, EDS) and infrared (FTIR) studies were performed.
The Effect of Different Moderate Thermal Modification Durations on the Wood Properties of American Alder
Authors: Liu Honghai , Li Zhilan , Zhang Xiaokai , Tang Bin , Wan Chuan , Wang Kemin
Published: December 2022

To investigate the effect of moderate thermal modification (TM) on wood properties, American alder (Alnus rubra) wood was treated at 140 °C for 4 h, 8 h and 13 h, the physical and mechanical properties, dimensional stability and color changes of wood were compared and studied. The results showed that the absolute dry density of moderate-TM wood decreased significantly with time except for the 4 h treatment. Moderate TM can significantly reduce the residual stress of wood up to 90.3%. There were no significant differences in MOR and MOE between most moderate TM wood and the control group; moderate TM decreased the moisture absorption and water up-taking of wood significantly; compared to the control group, the swelling of TM wood for 13 h decreased by 24.2% and 16.0% in the tangential and radial direction, respectively, showing a significant improvement in dimensional stability. There were almost no color changes even when wood endured 140 °C and 13 h TM. The moderate TM at 140 °C for 13 h can efficiently improve wood dimensional stability and retains the natural color of wood while causing almost no damage to the wood’s mechanical strength.
Theoretical and Practical Evaluation of the Feasibility of Zinc Evaporation from the Bottom Zinc Dross as a Valuable Secondary Material
Authors: Katarína Pauerová , Jarmila Trpčevská , Jaroslav Briančin , Beatrice Plešingerová
Published: December 2022

This study presents a theoretical and practical evaluation of zinc evaporation from bottom zinc dross (hard zinc) as a secondary zinc source (zinc content approximately 94–97%), which originates in the batch hot-dip galvanizing process. The thermodynamics of the zinc evaporation process were studied under the normal pressure (100 kPa) in the inert atmosphere, using argon with flow rate 90 mL/min. Samples were subjected to the evaporation process for 5, 10 and 20 min under the temperature of 700 °C and 800 °C, respectively. For the theoretical thermodynamic study, HSC Chemistry 6.1 software was used and final products, as well as residuals after the evaporation process, were analyzed by SEM (Scanning Electron Microscopy) and EDX (Energy Dispersive X-ray). Calculated and experimental argon consumption in the process of zinc evaporation has been compared. A high purity zinc with efficiency over 99% was reached. Due to a dynamic regime, argon consumption at the temperature of 700 °C and 800 °C were 7 times and 3 times, respectively, less than calculated.
A Hierarchical SnO2@Ni6MnO8 Composite for High-Capacity Lithium-Ion Batteries
Authors: Li Jiying , Long Jiawei , Han Tianli , Lin Xirong , Sun Bai , Zhu Shuguang , Li Jinjin , Liu Jinyun
Published: December 2022

Semiconductor-based composites are potential anodes for Li-ion batteries, owing to their high theoretical capacity and low cost. However, low stability induced by large volumetric change in cycling restricts the applications of such composites. Here, a hierarchical SnO2@Ni6MnO8 composite comprising Ni6MnO8 nanoflakes growing on the surface of a three-dimensional (3D) SnO2 is developed by a hydrothermal synthesis method, achieving good electrochemical performance as a Li-ion battery anode. The composite provides spaces to buffer volume expansion, its hierarchical profile benefits the fast transport of Li+ ions and electrons, and the Ni6MnO8 coating on SnO2 improves conductivity. Compared to SnO2, the Ni6MnO8 coating significantly enhances the discharge capacity and stability. The SnO2@Ni6MnO8 anode displays 1030 mAh g−1 at 0.1 A g−1 and exhibits 800 mAh g−1 under 0.5 A g−1, along with high Coulombic efficiency of 95%. Furthermore, stable rate performance can be achieved, indicating promising applications.
The Effect of Mineral Admixtures and Fine Aggregates on the Characteristics of High-Strength Fiber-Reinforced Concrete
Authors: Aleksandrova Olga , Quang Nguyen , Bulgakov Boris , Fedosov Sergey , Lukyanova Nadezhda , Petropavlovskaya Victoria
Published: December 2022

Introduction: the article discusses the effect of the complex of active mineral additives consisting of silica and fly ash, and a fine aggregate, including finely ground natural-white quartz sand for partial replacement of river sand, on the mechanical properties of high-strength concrete containing steel fiber. Materials and methods: high-strength concrete containing Dramix®3D 65/35 steel fiber in the amount of 100 kg per 1 m3 of concrete mixture was suggested where 22% to 100% of river sand was replaced by finely ground white natural sand of the particle size of 5 to 1800 μm and containing the complex of active mineral additives for partial replacement of cement as part of a multicomponent binder, consisting of low-calcium fly ash of thermal power plants and silica and containing, respectively, 20, 30, 40% fly ash and from 5 to 15% silica by weight of the binder. Results: research results have shown that 100% replacement of river sand with finely ground natural white sand, in concrete containing 20% of the mass as part of a multicomponent binder, fly ash and from 5 to 15% by weight of silica, contributes to the increase of its strength properties: the values of concrete compressive strength after 28 days were in the range from 118.5 to 128 MPa, tensile strength during bending and splitting, respectively, from 18.8 to 25.4 MPa and from 10.2 to 11.9 MPa, which is higher than the strength of concrete samples containing river sand. Conclusions: the achieved results have demonstrated the efficiency of using finely ground natural white sand as an alternative to river sand for producing high-strength concrete, thus helping to save the river sand resources in Vietnam. The use of fly ash and micro silicon, which are power and metallurgy wastes, as part of a multicomponent binder in order to partially replace cement reduces the carbon footprint in the production of binders and will also have a beneficial effect on environmental protection against industrial waste pollution.
Triboelectric Energy-Harvesting Floor Tile
Authors: Thainiramit Panu , Jayasvasti Subhawat , Yingyong Phonexai , Nandrakwang Songmoung , Isarakorn Don
Published: December 2022

The aim of this study was to investigate the real-world electrical parameters that strongly affected the performance of a triboelectric energy-harvesting floor tile design: triboelectric material thickness, cover plate displacement distance or gap width, and cover plate pressing frequency, so that real-world specifications of the harvesting floor tile can be accurately specified. The structure of the designed triboelectric energy harvester, with readily available polytetrafluoroethylene (PTFE) film and aluminum foil, was simple and hence easy to fabricate, and the material cost was low. A square wave was used to simulate the pressing frequency on the test bench’s cover plate. The results showed that the voltage and current were proportional to the gap width, and the thinner the triboelectric layer thickness, the higher the output voltage and current. A test bench with a 0.2 mm thick PTFE triboelectric layer generated the highest energy output. In a later experiment, a triboelectric energy-harvesting floor tile (TEHFT) prototype was constructed with 0.1 and 0.2 mm thick PTFE layers. We found that at 2 Hz stepping frequency and 0.1 mm PTFE thickness, the optimal load and cumulative energy of the TEHFT were 0.8 MΩ and 3.81 mJ, respectively, while with 0.2 mm PTFE thickness, these two parameters were 1.1 MΩ and 7.69 mJ, respectively. The TEHFT with 0.2 mm thick PTFE layer was able to illuminate a series of 100 to 150 LEDs, sufficient power to drive small electronics and sensor nodes. This discovery provides important data on the structure, material, and contact surface area of a TEHFT that can be adjusted to suit specific requirements of a special function triboelectric energy harvester.
The Effect of Pyrolysis Temperature and the Source Biomass on the Properties of Biochar Produced for the Agronomical Applications as the Soil Conditioner
Authors: Kalina Michal , Sovova Sarka , Svec Jiri , Trudicova Monika , Hajzler Jan , Kubikova Leona , Enev Vojtech
Published: December 2022

Biochar is a versatile carbon-rich organic material originating from pyrolyzed biomass residues that possess the potential to stabilize organic carbon in the soil, improve soil fertility and water retention, and enhance plant growth. For the utilization of biochar as a soil conditioner, the mutual interconnection of the physicochemical properties of biochar with the production conditions used during the pyrolysis (temperature, heating rate, residence time) and the role of the origin of used biomass seem to be crucial. The aim of the research was focused on a comparison of the properties of biochar samples (originated from oat brans, mixed woodcut, corn residues and commercial compost) produced at different temperatures (400–700 °C) and different residence times (10 and 60 min). The results indicated similar structural features of produced biochar samples; nevertheless, the original biomass showed differences in physicochemical properties. The morphological and structural analysis showed well-developed aromatic porous structures for biochar samples originated from oat brans, mixed woodcut and corn residues. The higher pyrolysis temperature resulted in lower yields; however, it provided products with higher content of organic carbon and a more developed surface area. The lignocellulose biomass with higher contents of lignin is an attractive feedstock material for the production of biochar with potential agricultural applications.
Water Kefir Grains—Microbial Biomass Source for Carbonaceous Materials Used as Sulfur-Host Cathode in Li-S Batteries
Authors: Páez Jerez Ana L. , Mori M. Fernanda , Flexer Victoria , Tesio Alvaro Y.
Published: December 2022

Nowadays, the use of biomass to produce cathode materials for lithium–sulfur (Li-S) batteries is an excellent alternative due to its numerous advantages. Generally, biomass-derived materials are abundant, and their production processes are environmentally friendly, inexpensive, safe, and easily scalable. Herein, a novel biomass-derived material was used as the cathode material in Li-S batteries. The synthesis of the new carbonaceous materials by simple carbonization and washing of water kefir grains, i.e., a mixed culture of micro-organisms, is reported. The carbonaceous materials were characterized morphologically, texturally and chemically by using scanning electron microscopy, N2 adsorption–desorption, thermogravimetric analysis, X-ray diffraction, and both Raman and X-ray photoelectron spectroscopy. After sulfur infiltration using the melt diffusion method, a high sulfur content of ~70% was achieved. Results demonstrated that the cell fitted with a cathode prepared following a washing step with distilled water after carbonization of the water kefir grains only, i.e., not subjected to any chemical activation, achieved good electrochemical performance at 0.1 C. The cell reached capacity values of 1019 and 500 mAh g−1 sulfur for the first cycle and after 200 cycles, respectively, at a high mass loading of 2.5 mgS cm−2. Finally, a mass loading study was carried out.
Forming-Free Tunable Analog Switching in WOx/TaOx Heterojunction for Emulating Electronic Synapses
Authors: Mahata Chandreswar , Pyo Juyeong , Jeon Beomki , Ismail Muhammad , Kang Myounggon , Kim Sungjun
Published: December 2022

In this work, the sputtered deposited WOx/TaOx switching layer has been studied for resistive random-access memory (RRAM) devices. Gradual SET and RESET behaviors with reliable device-to-device variability were obtained with DC voltage sweep cycling without an electroforming process. The memristor shows uniform switching characteristics, low switching voltages, and a high RON/ROFF ratio (~102). The transition from short-term plasticity (STP) to long-term potentiation (LTP) can be observed by increasing the pulse amplitude and number. Spike-rate-dependent plasticity (SRDP) and paired-pulse facilitation (PPF) learning processes were successfully emulated by sequential pulse trains. By reducing the pulse interval, the synaptic weight change increases due to the residual oxygen vacancy near the conductive filaments (CFs). This work explores mimicking the biological synaptic behavior and further development for next-generation neuromorphic applications.
Thermo-Mechanical Processing as Method Decreasing Delta-Ferrite and Improving the Impact Toughness of the Novel 12% Cr Steels with Low N and High B Contents
Authors: Fedoseeva Alexandra , Dolzhenko Anastasiia , Kaibyshev Rustam
Published: December 2022

The universal thermo-mechanical processing including the interim long-term annealing together with forging for three 12% Cr martensitic steels with different alloying. This thermo-mechanical processing remarkably increases the impact toughness of these steels in wide temperature ranges and reduces the ductile-brittle transition temperature by 10–20 K. There is a 25 °C impact toughness of all 12% Cr steels subjected to the thermo-mechanical processing exceeds 60 J cm−2. Such an increment in impact toughness is accompanied with the significant changes in the structures of all 12% Cr steels with different alloying. The common feature for all 12% Cr steels subjected to the thermo-mechanical processing is found to be a noticeable decrease in delta-ferrite amount. In the steels containing Ta, the decrease in the mean size of prior austenite grains by 20–26% was revealed. For the 12% Cr steels with ultra-low N content, the thermo-mechanical processing provides the changes in the dispersion of M23C6 carbides and MX carbonitrides.
Enhanced Electromagnetic Wave Absorption of SiOC/Porous Carbon Composites
Authors: Yang Wen , Li Li , Hou Yongzhao , Liu Yun , Xiao Xinwei
Published: December 2022

Carbon-based materials have been widely explored as electromagnetic (EM) wave absorbing materials with specific surface areas and low density. Herein, novel porous carbon/SiOC ceramic composites materials (porous C/sp-SiOC) were prepared from the binary mixture, which used the low cost pitch as carbon resource and the polysilylacetylene (PSA) as SiOC ceramic precursor. With the melt-blending-phase separation route, the PSA resin formed micro-spheres in the pitch. Then, numerous SiOC ceramic micro-spheres were generated in porous carbon matrices during the pyrolysis process. By changing the percent of SiOC, the microstructure and wave absorption of porous C/sp-SiOC composites could be adjusted. The synergistic effect of the unique structure, the strong interfacial polarization, and the optimized impedance matching properties contributed to the excellent absorption performance of porous C/sp-SiOC composites. The minimum reflection loss for porous C/sp-SiOC absorber reached −56.85 dB, and the widest effective bandwidth was more than 4 GHz with a thickness of only 1.39 mm. This presented research provides an innovative and practical approach to developing high-performance porous carbon-based microwave absorption materials from green chemistry.