bluuebunny/crossref_metadata_2025 huggingface dataset:
Sharks Do Not Always Grow Slowly: Tagging Data Reveal a Different Pattern of Growth, Longevity and Maturity for Threatened Smooth-Hounds in the Central Mediterranean Sea
Authors: Boscolo Palo Gabriele , Di Lorenzo Manfredi , Gancitano Salvatore , Ragonese Sergio , Mazzoldi Carlotta , Colloca Francesco
Published: November 2022

Elasmobranchs are among the marine species more threatened by overfishing. Their conservation is often impaired by the lack of knowledge of species’ life history traits. We filled knowledge gaps on age and growth of two threatened smooth-hound sharks (Mustelus mustelus, Mm; Mustelus punctulatus, Mp) in the central Mediterranean Sea, combining standard vertebrae analysis with growth increment data from a tagging survey. Our data revealed that the two species grow at a faster rate than previously estimated using vertebrae reading only. The maximum age/size found was higher for Mm (16 years, 170 cm TL) than Mp (8 years, 120 cm TL), the first species attaining larger size-at-age than the second one. Mp reaches maturity at earlier ages (A50 3 years for both females and males) than Mm (A50 females: 4 years; males: 3 years). The use of the tag-recapture method to validate the growth rate, firstly derived by sectioned vertebrae readings, highlighted the presence of false check marks. The new estimates of growth and longevity have important implications for the assessment of natural mortality, productivity, and stock resilience to fishing pressure which, combined with the high site fidelity highlighted by tagging data, may have crucial implications for the conservation of these two threatened sharks in the Mediterranean Sea.
Coastal Defences on Low-Lying Reef Flats: A Laboratory Study of Seawall Shape and Position
Authors: Rossignol Goélanne , Sous Damien
Published: November 2022

The present study reports on a series of laboratory experiments aiming to understand and to optimize the deployment of seawall defences over low-lying coral reef flats. The study is performed in a purely cross-shore configuration, with varying wave forcing, water depth, and seawall shapes and positions along the reef flat. The observations reveal the individual and combined effects of the external parameters. A higher seawall efficiency is reached for low waves, shallow water depth, seaward position, and a stepped seawall shape. A dimensionless formulation is proposed to predict the short wave transmission coefficient dependency on the seawall freeboard, incoming wave height, berm width, and seawall shape.
Correction: Fazal et al. Geochemical Analysis of Cretaceous Shales from the Hazara Basin, Pakistan: Provenance Signatures and Paleo-Weathering Conditions. J. Mar. Sci. Eng. 2022, 10, 800
Authors: Fazal Abdul Ghaffar , Umar Muhammad , Shah Faisal , Miraj Muhammad Armaghan Faisal , Janjuhah Hammad Tariq , Kontakiotis George , Jan Abdul Khaliq
Published: November 2022

In the original publication [...]
Molecular, Morphological and Chemical Diversity of Two New Species of Antarctic Diatoms, Craspedostauros ineffabilis sp. nov. and Craspedostauros zucchellii sp. nov.
Authors: Trentin Riccardo , Moschin Emanuela , Duarte Lopes André , Schiaparelli Stefano , Custódio Luísa , Moro Isabella
Published: November 2022

The current study focuses on the biological diversity of two strains of Antarctic diatoms (strains IMA082A and IMA088A) collected and isolated from the Ross Sea (Antarctica) during the XXXIV Italian Antarctic Expedition. Both species presented the typical morphological characters of the genus Craspedostauros: cribrate areolae, two “fore-and-aft” chloroplasts and a narrow “stauros”. This classification is congruent with the molecular phylogeny based on the concatenated 18S rDNA-rbcL-psbC alignment, which showed that these algae formed a monophyletic lineage including six taxonomically accepted species of Craspedostauros. Since the study of the evolution of this genus and of others raphe-bearing diatoms with a “stauros” is particularly challenging and their phylogeny is still debated, we tested alternative tree topologies to evaluate the relationships among these taxa. The metabolic fingerprinting approach was implemented for the assessment of the chemical diversity of IMA082A and IMA088A. In conclusion, combining (1) traditional morphological features used in diatoms identification, (2) phylogenetic analyses of the small subunit rDNA (18S rDNA), rbcL and psbC genes, and (3) metabolic fingerprint, we described the strains IMA082A and IMA088A as Craspedostauros ineffabilis sp. nov. and Craspedostauros zucchellii sp. nov. as new species, respectively.
Lethal Concentration and Sporulation by Contact and Direct Spray of the Entomopathogenic Fungus Beauveria bassiana on Different Stages of Nezara viridula (Heteroptera: Pentatomidae)
Authors: Portilla Maribel , Zhang Minling , Glover James Paul , Reddy Gadi V. P. , Johnson Chris
Published: November 2022

The southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) is the most significant pest of soybean worldwide. The present study was conducted to compare the effectiveness of a Delta native strain NI8 of Beauveria bassiana by contact and direct spray on nymphs (2nd to 5th instar) and adults of N. viridula. Water control and four concentrations of B. bassiana were used to evaluate the survival, mortality, and molting percentage and to estimate median lethal concentration (LC50), median lethal sporulation (LS50), and resistance ratio (RR50). Direct spray at all concentrations observed the greatest reduction in survival on all life stages. Mortality and sporulation were positively correlated by concentration, while molting was highly variable with a significantly lower negative correlation on insects that were directly sprayed. Pathogenicity exhibited reduction as young stages developed and emerged to adult. The LC50 (Contact: 612 spores/mm2; Direct spray: 179 spores/mm2) and LS50 (Contact: 1960 spores/mm2 Spray: 3.3 × 106) values showed that adults of N. viridula were highly resistant than any other life stage when exposed to either contact or direct spray. Fourth instar was the most susceptible (LC50: Contact: 18 spores/mm2; Direct spray: 23 spores/mm2) (LS50: Contact: 53 spores/mm2; Direct spray: 26 spores/mm2) followed by second, third, and fifth instars.
Knowledge of Chronic Kidney Disease among the General Population: A Questionnaire Survey in Hokkaido Prefecture, Japan
Authors: Nakagawa Naoki , Nishio Saori
Published: November 2022

Public education programs about chronic kidney disease (CKD) are important activities worldwide. The present study investigated the knowledge of CKD in the general population of 58 out of 179 cities or towns in Hokkaido between 1 April and 30 September 2019. A total of 15,012 respondents who underwent specific health checkups at these centers answered the questionnaire. In response to a questionnaire item asking about the respondent’s familiarity with the term “CKD”, only 6% of the respondents answered “know it well” and 13% answered “heard of it”. In contrast, in response to a questionnaire item asking about the respondent’s familiarity with “chronic kidney disease”, 31% answered “know it well” and 33% answered “heard of it”. The leading avenue by which the respondents learned about CKD was television, followed by newspapers, magazines, and a family doctor or nurse. The leading component that the respondents considered essential for the diagnosis of CKD was proteinuria. These results indicated that the knowledge of CKD in Hokkaido prefecture is still inadequate. Many people did not appear to realize that the term “CKD” represents “chronic kidney disease”. Further continuous public education efforts are required to enlighten people about CKD.
Institutional Investors’ Willingness to Pay for Green Bonds: A Case for Shanghai
Authors: Zenno Yoshihiro , Aruga Kentaka
Published: November 2022

The issuance of green bonds has been increasing since 2016 in China, and the number of papers covering the topic is growing. In previous studies on greenium, not much has been investigated from the institutional investors’ perspective. The study estimates the institutional investors’ level of greenium by surveying the institutional investors in Shanghai, China, from October 23 to 1 November 2021, using the double-bound dichotomous choice (DBDC) contingent valuation method (CVM). The study also analyzes the effects of variables that are known to be important for the green bond based on previous studies. The study identifies that there is a greenium level of 0.47%. Among the seven variables tested with logit regression models, the credit and currency of the bond had a positive effect on the greenium. The study provides helpful insights for issuers’ strategic planning and could be a stepping stone to increasing issuance not only for the Chinese green bond market but also for the global green bond market.
The Different Dividend Signaling Effect under Tax Deduction around Ex-Right Day: Evidence from Taiwan Stock Exchange
Authors: Hsiung Hsing-Hua , Wang Juo-Lien , Huang Hong-Wei
Published: November 2022

Dividend tax policy is one of the important tools of government taxation. Observing the dividend tax policy and the behavior of stock prices around ex-rights will not only shed light on investment strategies, but also give us a clearer understanding of the microstructure of the capital market. Taiwan went through dividend tax policy and National Health Insurance (NHI) supplementary premium changes from 2014 to 2016. Therefore, this paper adopts the event study method to conduct empirical research on this major event period. The research conclusion points out: (1) During the research period, the company studied had a positive cumulative abnormal return before and on the ex-right day, and there was a negative cumulative abnormal return after the ex-right day. (2) When the tax reduction effect is more favorable to investors, there will be only a positive relationship with positive abnormal returns. (3) There is no statistical significance between the dividend tax reform policy and the negative abnormal return after ex-rights. The empirical results of this paper can help to better understand the pricing process of stocks by market microstructure systems such as dividend tax policies and help build a more stable stock market transaction structure. On the other hand, investors and companies can also gain their own investment or dividend policy inspiration from this research.
A Positive-Unlabeled Learning Algorithm for Urban Flood Susceptibility Modeling
Authors: Li Wenkai , Liu Yuanchi , Liu Ziyue , Gao Zhen , Huang Huabing , Huang Weijun
Published: November 2022

Flood susceptibility modeling helps understand the relationship between influencing factors and occurrence of urban flooding and further provides spatial distribution of flood risk, which is critical for flood-risk reduction. Machine learning methods have been widely applied in flood susceptibility modeling, but traditional supervised learning requires both positive (flood) and negative (non-flood) samples in model training. Historical flood inventory data usually contain positive-only data, whereas negative data selected from areas without flood records are prone to be contaminated by positive data, which is referred to as case-control sampling with contaminated controls. In order to address this problem, we propose to apply a novel positive-unlabeled learning algorithm, namely positive and background learning with constraints (PBLC), in flood susceptibility modeling. PBLC trains a binary classifier from case-control positive and unlabeled samples without requiring truly labeled negative data. With historical records of flood locations and environmental covariates, including elevation, slope, aspect, plan curvature, profile curvature, slope length factor, stream power index, topographic position index, topographic wetness index, distance to rivers, distance to roads, land use, normalized difference vegetation index, and precipitation, we compared the performances of the traditional artificial neural network (ANN) and the novel PBLC in flood susceptibility modeling in the city of Guangzhou, China. Experimental results show that PBLC can produce more calibrated probabilistic prediction, more accurate binary prediction, and more reliable susceptibility mapping of urban flooding than traditional ANN, indicating that PBLC is effective in addressing the problem of case-control sampling with contaminated controls and it can be successfully applied in urban flood susceptibility mapping.
Realizing Emergent Ecologies: Nature-Based Solutions from Design to Implementation
Authors: Roggema Rob , Tillie Nico
Published: November 2022

The current state of nature is concerning. The levels of biodiversity are rapidly decreasing; existing policies sketch ambitious objectives, but their effectiveness is relatively low. This is caused by a combination of three main elements: physical elements, planning processes, and psychological reasons. In dealing with these deeply rooted problems, following qualities are missing: attention to planning and design in nature-based solution policies, the gap between plan and execution of plans, and the transformation to eco-leadership of young people. In four consecutive years, research design studios have been executed, in which students collaboratively design eco-solutions for complex and urgent problems. The core subjects of each of these studios were four interlinked aspects of eco-design: (1) designing in parallel at master plan and concrete project level, (2) planning, designing and building within a short period, (3) the emergence and succession of ecosystems on site, and (4) ecological leadership practice. By investigating these aspects year after year, designing integrated and coherent solutions, and realizing these solutions in built form, an ecological spatial framework emerged within which smaller projects were and will be embedded. This way, the ecosystem on campus grows, matures, and develops as a self-regulating system. Moreover, new leadership emerged amongst the young participants in the research design studios.
Heat Shock Proteins (Hsps) in Cellular Homeostasis: A Promising Tool for Health Management in Crustacean Aquaculture
Authors: Kumar Vikash , Roy Suvra , Behera Bijay , Das Basanta
Published: November 2022

Heat shock proteins (Hsps) are a family of ubiquitously expressed stress proteins and extrinsic chaperones that are required for viability and cell growth in all living organisms. These proteins are highly conserved and produced in all cellular organisms when exposed to stress. Hsps play a significant role in protein synthesis and homeostasis, as well as in the maintenance of overall health in crustaceans against various internal and external environmental stresses. Recent reports have suggested that enhancing in vivo Hsp levels via non-lethal heat shock, exogenous Hsps, or plant-based compounds, could be a promising strategy used to develop protective immunity in crustaceans against both abiotic and biotic stresses. Hence, Hsps as the agent of being an immune booster and increasing disease resistance will present a significant advancement in reducing stressful conditions in the aquaculture system.
Progesterone Promotes In Vitro Maturation of Domestic Dog Oocytes Leading to Successful Live Births
Authors: Qin Yumin , Feng Shenjiong , Zheng Min , Liu Xiaojuan , Zhao Jianping , Zhao Qintao , Ye Junhua , Mi Jidong , Zhong Yougang
Published: November 2022

Gene-edited dogs are promising models for biomedical research because they have hundreds of genetic diseases that are similar to humans. A common method for producing gene-edited dogs is assisted reproductive technology (ART) using in vivo oocytes or embryos, but it is much more inefficient and has a higher cost. ART for dogs has lagged mostly because of the lack of an efficient in vitro maturation system. Because early maturation of canine oocytes occurs in follicles with extremely high concentrations of progesterone (P4), we hypothesize that P4 has an important role during maturation. In this study, we obtained ovaries of female dogs and collected cumulus–oocyte complexes, which were cultured in vitro in microdrops containing different P4 concentrations (0, 10, 40, 100 or 200 µg/mL). We found that 40 µg/mL P4 produced the highest oocyte maturation rate (29.7% ± 7.1%, p < 0.05). We also evaluated the quality of in vitro matured oocytes by in vitro fertilization and single-cell RNA sequencing, and both indicated an improvement in oocyte developmental potential. In conclusion, we successfully obtained the first live dogs using in vitro matured oocytes by adding P4 to optimize the in vitro maturation system of canine oocytes, and established a new and low-cost method to produce dogs via in vitro maturation and in vitro fertilization.
Thymoquinone Alleviates Cadmium Induced Stress in Germinated Lens culinaris Seeds by Reducing Oxidative Stress and Increasing Antioxidative Activities
Authors: Ben Mrid Reda , Ennoury Abdelhamid , Roussi Zoulfa , Naboulsi Imane , Benmrid Bouchra , Kchikich Anass , Omari Redouane El , Nhiri Mohamed , Yasri Abdelaziz
Published: November 2022

This study investigated the effect of thymoquinone on seeds germination and young seedlings of lentils under cadmium (Cd) stress (300 µM). Three different concentrations (10 µM, 1 µM, and 0.1 µM) of thymoquinone were applied. Our results indicated that thymoquinone has a positive effect on several physiological and biochemical parameters on seeds germination and young seedlings of lentils under Cd stress, which led to enhancing their growth. A significant increase in shoot and root length, fresh and dry weight, and chlorophyll content was observed in the treated plants compared to the control plants. However, the thymoquinone treatment significantly reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents compared to untreated roots and seedlings under Cd-stress. Nevertheless, our results show that the thymoquinone significantly improved the activities of enzymes involved in antioxidant response, including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), thioredoxin reductase (TrxR), and ascorbate peroxidase (APX). We have also studied the activities of isocitrate dehydrogenase (ICDH) and malate dehydrogenase (MDH); ICDH was increased significantly in roots and seedlings in the presence of different doses of thymoquinone. However, the activity MDH was increased only in roots. Our results suggest that the application of thymoquinone could mitigate cadmium induced oxidative stress.
Gravi-Sensitivity of Mosses and Their Gravity-Dependent Ontogenetic Adaptations
Authors: Lobachevska Oksana , Kyyak Natalia , Kordyum Elizabeth , Khorkavtsiv Yaroslava , Kern Volker
Published: November 2022

Gravi-morphoses affect the variability of plants and are the morphogenetic adaptation to different environmental conditions. Gravity-dependent phenotypic plasticity of gametophytes as well as gravi-sensitivity of moss protonemata in microgravity and simulated microgravity conditions are discussed. The moss protonema, a filamentous multicellular system, representing a juvenile stage of moss development, develops as a result of the elongation and division of the apical cell. This apical cell of the protonema is a unique object for research on moss gravi-sensitivity, as graviperception and gravitropic growth occur within the same single cell. Attention is focused on the influence of gravity on bryophyte ontogenesis, including the gravitropic reactivity of moss protonemata, gravi-sensitivity at the stage of leafy shoot development and sporogonium formation, gravity-influenced morphogenesis of apical cell budding, and gravity-dependent spiral growth patterns. The role of gravireceptors in the growth processes of mosses at the cellular level under microgravity conditions are being discussed, as well as the involvement of auxin transport, Ca2+-induced gravitropism and the cytoskeleton in gravitropic reactions.
In Vitro Antioxidant, Antimicrobial, Anticoccidial, and Anti-Inflammatory Study of Essential Oils of Oregano, Thyme, and Sage from Epirus, Greece
Authors: Sidiropoulou Erasmia , Marugán-Hernández Virginia , Skoufos Ioannis , Giannenas Ilias , Bonos Eleftherios , Aguiar-Martins Kensilandia , Lazari Diamanto , Papagrigoriou Theodora , Fotou Konstantina , Grigoriadou Katerina , Blake Damer P. , Tzora Athina
Published: November 2022

Origanum vulgare subsp. hirtum, Thymus vulgaris, and Salvia fructicosa are aromatic plants commonly found in Mediterranean countries and are traditionally used in Greece as a remedy for humans, since they are well known as potent antibacterial, antioxidant, and anti-inflammatory agents. Essential oils (EOs) derived from plants cultivated in the mountainous region of Epirus, Greece, were investigated for their inhibitory activity against key microorganisms with relevance to avian health, while also assessing their antioxidant and anti-inflammatory activity. The total phenolic content (TPC) of the EOs was estimated according to the Folin–Ciocalteu method, while the antioxidant capacity was tested through the EOs’ ability to scavenge free radicals by means of the DPPH, ABTS, and FRAP assays. Antibacterial and anti-inflammatory effects were examined by the agar disc diffusion method and the lipoxygenase (LOX) inhibition test, respectively. Furthermore, the EOs’ ability to inhibit the invasion of sporozoites of Eimeria tenella (Wisconsin strain) along with any toxic effects were assayed in Madin–Darby bovine kidney (MDBK) cells. The antioxidant activity of the EOs was observed in descending order: oregano > thyme > sage. The antimicrobial effects of thyme and oregano were equivalent and higher than that of sage, while the anti-inflammatory effect of thyme was higher compared to both sage and oregano. The intracellular invasion of sporozoites was evaluated by the detection of E. tenella DNA by qPCR from cell monolayers harvested at 2 and 24 h post-infection. Parasite invasion was inhibited by the addition of oregano essential oil at the concentration of 100 μg/mL by 83% or 93% after 2 or 24 h, respectively, and was higher compared to the addition of thyme and sage, which had similar effects, but at a less intensive level. The cytotoxic assessment of all three essential oils revealed that they had no effect on MDBK cells compared to dimethyl sulfoxide (DMSO), used as the control substance. The supplementation of oregano, thyme, and sage essential oils had a potent antioxidant, anti-inflammatory, antimicrobial, and anticoccidial in vitro effect that is comparable to synthetic substances or approved drugs, justifying the need for further evaluation by in vivo studies in broilers reared in the absence of antimicrobial and anticoccidial drugs or synthetic antioxidant and/or anti-inflammatory compounds.
RNA-Sequencing Analysis of Gene-Expression Profiles in the Dorsal Gland of Alligator sinensis at Different Time Points of Embryonic and Neonatal Development
Authors: Nie Haitao , Zhang Yuqian , Duan Shulong , Zhang Ying , Xu Yunlu , Zhan Jixiang , Wen Yue , Wu Xiaobing
Published: November 2022

Significant advances have been made in the morphological observations of the dorsal gland (DG), an oval organ/tissue which lies on both sides of the dorsal midline of the crocodilian. In the current study, RNA sequencing (RNA-seq) was used to identify the changing patterns of Alligator sinesis DGs at different timepoints from the 31st embryonic day (E31) to the newly hatched 1st day (NH1). A comprehensive transcriptional changes of differentially expression gene (DEGs) involved in the melanogenesis, cholesterol metabolism, and cell apoptosis pathways suggested that the DG might serves as a functional secretory gland in formation, transport and deposition of pigment, and lipids secretion via lysosomal exocytosis. Furthermore, the remarkable immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (Bcl-2)-positive signals in the basilar cells, in parallel with the immuno-reactive TdT-mediated dUTP nick-End labeling(TUNEL) within suprabasal cells, provided direct molecular evidence supporting for the speculation that DG serves as a holocrine secretion mode. Finally, subsequent phylogenetic and immunohistochemical analysis for the PITX2, the identified DEGs in the RNA-seq, was helpful to further elucidate the transcriptional regulatory mechanism of candidate genes. In conclusion, the current results are of considerable importance in enriching our understanding of the intrinsic relationship between the skin derivatives and lifestyles of newborn Alligator sinesis.
The Fluid-Structure-Thermal Performance Analysis of Gas Foil Thrust Bearing by Using Computational Fluid Dynamics
Authors: Liu Xiaomin , Li Changlin , Du Jianjun
Published: November 2022

This paper presents a detailed three-dimensional (3D) thermo-elastic-hydrodynamic (TEHD) multi-physics model of the bump-type gas foil thrust bearing based on computational fluid dynamics (CFD). In this model, the moving mesh technology is applied in the fluid flow domain, and the new boundary condition of fully developed flow is applied at the inlet and outlet boundaries, which is consistent with the continuous property of fluid flow and has better convergence performance in CFD. The groove between pads is set as the symmetry boundary. The contact pairs with Coulomb friction and contact/separation behaviors are considered in the structure deformation and heat transfer. The simulation results indicated that the boundary pressure has a significant influence on the foil deformation. It also revealed the heat flux transfer path and temperature distribution in the gas foil thrust-bearing (GFTB) system.
Optimization Design of Aerostatic Bearings with Square Micro-Hole Arrayed Restrictor for the Improvement of Stability: Theoretical Predictions and Experimental Measurements
Authors: Yu Puliang , Lu Jiong , Luo Qiang , Li Guanghui , Yin Xianxiong
Published: November 2022

Aerostatic bearings are widely used in ultra-precision manufacturing equipment as a crucial support component. However, turbulent vortices in the recess can induce micro-vibration of the aerostatic bearing, which can severely affect stability. To further suppress the formation of turbulent vortices and reduce the micro-vibration, an aerostatic bearing with a square micro-hole arrayed restrictor (SMAR) was designed and the influences of structural parameters of the SMAR on its static and dynamic performance were investigated using numerical simulations and experiments. The transient flow characteristics of aerostatic bearings with different numbers and spacing of micro-holes were studied using 3D large eddy simulation (LES), and the formation mechanism of turbulent vortices and the law of turbulent interaction between adjacent micro-holes were analyzed. The static performance and micro-vibration of the aerostatic bearing were measured experimentally to verify the effectiveness of the SMAR. The results show that the formation of turbulent vortices and micro-vibrations can be effectively reduced by the optimized design of the SMAR, while the static performance of the bearing is basically unchanged. The micro-vibration decreases rapidly with the number of micro-holes ranging from 1 to 36 and remains steady with the number of micro-holes ranging from 36 to 100. The micro-vibration decreases rapidly with the spacing of micro-holes ranging from 2 dn to 8 dn and remains steady with the spacing of micro-holes ranging from 8 dn to 10 dn. This study contributes to further understanding the mechanism of turbulent vortex formation in aerostatic bearings with a SMAR.
Effect of Groove Texture on Deformation and Sealing Performance of Engine Piston Ring
Authors: Chen Tingkun , Wang Lin , Xu Jin , Gao Tianyu , Qin Xiuzhang , Yang Xiaobin , Cong Qian , Jin Jingfu , Liu Chaozong
Published: November 2022

During the present study, a double groove texture was designed on the surface of a piston ring to improve the sealing performance between the piston ring and cylinder liner. The experimental design method was used to fabricate the test plan according to the groove width, depth, and spacing. By using the thermal–structural coupling analysis method, the finite element analysis of the standard piston ring and the textured piston ring was carried out to simulate the deformation state of the cylinder liner system of the piston ring group during the working stroke. The piston rings with different parameters designed by the test scheme were manufactured by wire electrical discharge machining, and the self-made experiment device carried out the sealing test. The results showed that the groove texture could improve the sealing performance of the piston ring, and the analyzed results demonstrated that the groove texture had little effect on the maximum deformation of the piston ring. Still, it could significantly reduce the minimum deformation of the piston ring group. A piston ring with groove texture would improve the sealing performance and reduce the deformation during the work stroke. During the test, the average deformation of the No.7 piston ring group, with a groove depth of 1 mm, a groove width of 0.5 mm, and a groove spacing of 0.1 mm, was the smallest, about 29.6% lower than that of the standard piston ring group. The sealing performance of the No.7 piston ring group was the best, and the reduction rate of the top gas leakage rate was 52.18%. During the present study, the sealing performance of the piston ring was improved by designing the grooved structure on the piston ring surface, thereby improving the fuel economy and power performance of the engine. The present study could provide a reference for the engineering field to design a piston ring with high sealing performance.
Magnetic Field-Induced Deformation of Isotropic Magnetorheological Elastomers
Authors: Balogh Diána , Guba Sándor , Horváth Barnabás , Szalai István
Published: November 2022

In our research, the magnetic field-induced deformation of isotropic magnetorheological elastomer (MRE) discs loaded with two types of magnetite and an iron powder were examined. A measurement system using a microscope camera was assembled, and the magnitude of the deformation was determined from the optical contour obtained with digital image processing. We found that the MRE discs with a height-to-width aspect ratio of 1:2 underwent expansion in the direction of the external field in all cases. The magnitude of the dilatation increased with the magnetic field strength in cases of all filler materials, but the exact trend depended on the type and concentration of the filler. An inhibition of the polymerization of the matrix was observed in the case of one of the magnetite fillers, which resulted in a decreased zero-field elastic modulus at higher particle loadings. A correlation was found between the reduced elastic modulus and the increased magnitude of the deformation.
Improved Estimation of the Inverted Kumaraswamy Distribution Parameters Based on Ranked Set Sampling with an Application to Real Data
Authors: Nagy Heba F. , Al-Omari Amer Ibrahim , Hassan Amal S. , Alomani Ghadah A.
Published: November 2022

The ranked set sampling (RSS) methodology is an effective technique of acquiring data when measuring the units in a population is costly, while ranking them is easy according to the variable of interest. In this article, we deal with an RSS-based estimation of the inverted Kumaraswamy distribution parameters, which is extensively applied in life testing and reliability studies. Some estimation techniques are regarded, including the maximum likelihood, the maximum product of spacing’s, ordinary least squares, weighted least squares, Cramer–von Mises, and Anderson–Darling. We demonstrate a simulation investigation to assess the performance of the suggested RSS-based estimators via accuracy measures relative to simple random sampling. On the basis of actual data regarding the waiting times between 65 consecutive eruptions of Kiama Blowhole, additional conclusions have been drawn. The outcomes of simulation and real data application demonstrated that RSS-based estimators outperformed their simple random sampling counterparts significantly based on the same number of measured units.
Numerical Simulation Research of Bubble Characteristics and Bubble Departure Diameter in Subcooled Flow Boiling
Authors: Wang Jinfeng , Wang Bingjun , Xie Jing , Lei Ke , Yu Bo , Sun Yuhang
Published: November 2022

Three-dimensional subcooled flow boiling of R134a in a horizontal tube was simulated by a VOF (volume of fluid) model combined with the level set method. Bubble characteristics were explored at heat flux of 0.3 MW/m2, inlet subcooling of 3 K, and inlet velocity of 0.4 m/s. It was observed that five representative bubbles occurred in subcooled flow boiling, including sliding bubble, coalescing bubble, non-departed bubble, bouncing bubble, and continuous-boiling bubble. The results showed that the bubble radial velocity was an important factor of bubble departure after a sliding process. Moreover, the effect of heat flux, inlet velocity, and inlet subcooling on bubble departure diameter were investigated. The departure diameter increased with increasing inlet velocity from 0.2 to 0.4 m/s and heat flux from 0.2 to 0.4 MW/m2, while diameter decreased with inlet subcooling from 3 to 10 K. Finally, based on the influence of heat flux, inlet velocity, and inlet subcooling on average departure diameter of the bubble except the coalescing bubble, a model was proposed to predict the average departure diameter. The deviation of the model was within 5%.
Fractional Systems’ Identification Based on Implicit Modulating Functions
Authors: Stark Oliver , Eckert Marius , Malan Albertus Johannes , Hohmann Sören
Published: November 2022

This paper presents a new method for parameter identification based on the modulating function method for commensurable fractional-order models. The novelty of the method lies in the automatic determination of a specific modulating function by controlling a model-based auxiliary system, instead of applying and parameterizing a generic modulating function. The input signal of the model-based auxiliary system used to determine the modulating function is designed such that a separate identification of each individual parameter of the fractional-order model is enabled. This eliminates the shortcomings of the common modulating function method in which a modulating function must be adapted to the investigated system heuristically.
Robust Flatness-Based Tracking Control for a “Full-Bridge Buck Inverter–DC Motor” System
Authors: Silva-Ortigoza Ramón , Marciano-Melchor Magdalena , García-Chávez Rogelio Ernesto , Roldán-Caballero Alfredo , Hernández-Guzmán Victor Manuel , Hernández-Márquez Eduardo , García-Sánchez José Rafael , García-Cortés Rocío , Silva-Ortigoza Gilberto
Published: November 2022

By developing a robust control strategy based on the differential flatness concept, this paper presents a solution for the bidirectional trajectory tracking task in the “full-bridge Buck inverter–DC motor” system. The robustness of the proposed control is achieved by taking advantage of the differential flatness property related to the mathematical model of the system. The performance of the control, designed via the flatness concept, is verified in two ways. The first is by implementing experimentally the flatness control and proposing different shapes for the desired angular velocity profiles. For this aim, a built prototype of the “full-bridge Buck inverter–DC motor” system, along with Matlab–Simulink and a DS1104 board from dSPACE are used. The second is via simulation results, i.e., by programming the system in closed-loop with the proposed control algorithm through Matlab–Simulink. The experimental and the simulation results are similar, thus demonstrating the effectiveness of the designed robust control even when abrupt electrical variations are considered in the system.
Gamification for Maths and Physics in University Degrees through a Transportation Challenge
Authors: Hilario Lucía , Mora Marta Covadonga , Montés Nicolás , Romero Pantaleón David , Barquero Sara
Published: November 2022

Our society is immersed in the Fourth Industrial Revolution due to the fast evolution of the new technologies that are modifying the labor market. In the near future, technologies related to Industry 4.0 will produce totally new goods and services. Therefore, the educational systems should adapt their programs to the future needs of an uncertain labor market. In particular, mathematics will play a key role in future jobs and there is a strong need to connect its teaching methodologies to the new technological scene. This work uses the STEAM approach (science, technology, engineering, arts and mathematics) along with active methodologies and educational robotics with the aim of developing a new strategy for the application of mathematics and physics in an engineering degree. In particular, a transportation challenge is posed to tackle the teaching–learning process of the Bézier curves and their applications in physics. A pilot project is developed using a LEGO EV3 robot and an active methodology, where students become the center of the learning process. The experimental results of the pilot study indicate an increase in the motivation due to the use of robots and the realistic context of the challenge.
The Relationship between Neuropsychiatric Symptoms and Cognitive Performance in Older Adults with Normal Cognition
Authors: Liampas Ioannis , Siokas Vasileios , Lyketsos Constantine George , Dardiotis Efthimios
Published: November 2022

Background and Objectives: To explore whether specific Neuropsychiatric Symptoms (NPS) are related to worse performance in particular cognitive domains. Materials and Methods: A cross-sectional analysis of the baseline evaluations of older (≥60 years), cognitively unimpaired (CU) participants from the National Alzheimer’s Coordinating Center (NACC) Uniform Data Set was performed. Data were derived from 43 Alzheimer’s Disease Research Centers. Cognitively impaired individuals, participants with psychiatric disorders and/or under treatment with antipsychotic, anxiolytic, sedative, or hypnotic agents were excluded. NPS were assessed using the Neuropsychiatric Inventory Questionnaire. The association of NPS with participants’ performance on episodic memory, semantic memory, language, attention, processing speed and executive function was analysed using an adjusted (considering important demographic and medical factors) multivariate general linear model. Results: A total of 7179 CU, older, predominantly female, Caucasian, and well-educated participants were included in the present analysis. Among them, 1856 individuals had one or more NPS. Our analysis revealed that moderate/severe anxiety was related to worse performance on semantic memory, attention and executive function, the presence of hallucinations was linked to worse processing speed and executive function scores, while the presence of elation/euphoria and aberrant motor behaviour were associated with poorer attention and language performance, respectively. In the context of a secondary, exploratory analysis, the presence of moderate/severe delusions was related to worse processing speed and executive function performance. Conclusions: The relationship between specific NPS and worse performance in particular cognitive domains could inform the formulation of individualized preventive strategies directed to the ‘‘fortification’’ of specific cognitive functions in CU individuals with NPS.
The Influence of a Modified 3rd Generation Cementation Technique and Vaccum Mixing of Bone Cement on the Bone Cement Implantation Syndrome (BCIS) in Geriatric Patients with Cemented Hemiarthroplasty for Femoral Neck Fractures
Authors: Bökeler Ulf , Bühler Alissa , Eschbach Daphne , Ilies Christoph , Liener Ulrich , Knauf Tom
Published: November 2022

Background and Objectives: Cemented hemi arthroplasty is a common and effective procedure performed to treat femoral neck fractures in elderly patients. The bone cement implantation syndrome (BCIS) is a severe and potentially fatal complication which can be associated with the implantation of a hip prosthesis. The aim of this study was to investigate the influence of a modified cementing technique on the incidence of BCIS. Material and Methods: The clinical data of patients which were treated with a cemented hip arthroplasty after the introduction of the modified 3rd generation cementing technique were compared with a matched group of patients who were treated with a 2nd generation cementing technique. The anesthesia charts for all patients were reviewed for the relevant parameters before, during and after cementation. Each patient was classified as having no BCIS (grade 0) or BCIS grade 1,2, or 3 depending on the severity of hypotension, hypoxia loss of consciousness. Results: A total of 92 patients with complete data sets could be included in the study. The mean age was 83 years. 43 patients (Group A) were treated with a 2nd and 49 patients (Group B) with a 3rd generation cementing technique. The incidence of BCIS grade 1,2, and 3 was significantly higher (p = 0,036) in group A (n = 25; 58%) compared to group B (n = 17; 35%). Early mortality was higher in group A (n = 4) compared to group B (n = 0). Conclusions: BCIS is a potentially severe complication with a significant impact on early mortality following cemented hemiarthroplasty of the hip for the treatment of proximal femur fracture. Using a modified 3rd generation cementing technique, it is possible to significantly reduce the incidence of BCIS and its associated mortality.
Diaphragmatic Injuries among Severely Injured Patients (ISS ≥ 16)—An Indicator of Injury Pattern and Severity of Abdominal Trauma
Authors: Schurr Leonhard Andreas , Thiedemann Claudius , Alt Volker , Schlitt Hans Jürgen , Götz Markus , Riedl Moritz , Brunner Stefan Martin , Popp Daniel
Published: November 2022

Background and Objectives: Abdominal trauma among severely injured patients with an injury severity score (ISS) of 16 and above can lead to potentially life-threatening injuries that might need immediate surgical intervention. Traumatic injuries to the diaphragm (TID) are a challenging condition often accompanied by other injuries in the thoracoabdominal region. Materials and Methods: We retrospectively analyzed the occurrence and clinical course of TID among severely injured patients treated at our center between 2008 and 2019 and compared them to other groups of severely injured patients without TID. Results: Thirty-five patients with TID and a median ISS of 41 were treated in the period mentioned above. They were predominantly middle-aged men and mostly victims of blunt trauma as a consequence of motor vehicle accidents. A total of 70.6% had left-sided TID, and in 69.6%, the size of defect was larger than 10 cm. The diagnosis was made with computed tomography (CT) in 68.6% of the cases, while in 25.8%, it was made intraoperatively or delayed by a false-negative initial CT scan, and in 5.7%, an intraoperative diagnosis was made without preoperative CT imaging. Surgical repair was mostly conducted via laparotomy, performing a direct closure with continuous suture. A comparison to 191 patients that required laparotomy for abdominal injuries other than TID revealed significantly higher rates of concomitant injuries to several abdominal organs among patients suffering from TID. Compared to all other severely injured patients treated in the same period (n = 1377), patients suffering from TID had a significantly higher median ISS and a longer mean duration of hospital stay. Conclusions: Our findings show that TID can be seen as an indicator of particularly severe thoracoabdominal trauma that requires increased attention from the treatment team so as not to miss relevant concomitant injuries that require immediate intervention.
Critical Assessment of Two-Dimensional Methods for the Microstructural Characterization of Cemented Carbides
Authors: Fang Shiqi , Salán Núria , Pauly Christoph , Llanes Luis , Mücklich Frank
Published: November 2022

Cemented carbides, or hard metals, are ceramic–metal composites usually consisting of tungsten carbide particles bound by a cobalt-based alloy. They are the backbone materials for the tooling industry, as a direct consequence of the outstanding range of property combinations, depending on their effective microstructural assemblage, i.e., the physical dimensions and relative content of their constitutive phases. Hence, reliable microstructural characterization becomes key for hard metal grade selection and quality control. This work aimed to assess the practical two-dimensional characterization methods for the most important one- and two-phase properties of cemented carbides, i.e., the carbide grain size, phase fraction, carbide contiguity, and binder mean free path. Three different methods—point, line, and area analysis—were implemented to characterize four microstructurally distinct grades. The images were acquired by optical and scanning electron microscopy, with the latter through both secondary and backscattered electrons. Results were critically discussed by comparing the obtained values of properties and the different characterization methodology. Inspection technique combinations were finally ranked based on accuracy, accessibility, and operability considerations. The line method was used to analyze all the properties, the area method, for the one-phase properties, and the point method, for only the phase fraction. It was found that the combination of optical microscopy and the line analysis method was suitable for a direct inspection and rapid estimation for carbides above fine grain size. The most precise results were achieved using line analysis of the images obtained by the backscattered electrons of the scanning electron microscope.
Microstructure-Based Modeling and Mechanical Characteristics of Accumulative Roll Bonded Al Nanocomposites with SiC Nanoparticles
Authors: Alsoruji Ghazi S. , Sadoun Ayman M. , Elmahdy Marwa
Published: November 2022

This research work aims to fabricate the Al-4 wt.% SiC nanocomposite using the accumulative roll bonding (ARB) technique. Moreover, a finite element model based on real microstructure representative volume element representation and cohesive zone modeling was developed to predict the mechanical response of the produced composites. The results demonstrated that SiC particles were homogenously distributed inside the Al matrix after five passes. The tensile strength and hardness were improved by increasing the number of ARB passes. The microhardness of an Al-4%SiC composite subjected to five ARB passes was increased to 67 HV compared to 53 HV for Al sheets subjected to the same rolling process. Moreover, owing to greater bonding and grain refinement, tensile strength was increased by a factor of three compared to pure Al. The result of the proposed micro-model successfully predicts the experimentally obtained results of the Al–SiC macro composite. The numerically obtained stress–strain curve was comparable with the experimental one. The results also showed that the size of the used RVE was significantly influential in the prediction of the stress–strain behavior.