bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow field reconstruction and shock train leading edge position detection of scramjet isolation section based on a small amount of CFD data
Authors: CHEN HAO , Tian Ye , Guo Mingming , Le Jialing , Ji Yuan , Zhang Yi , Zhang Hua , Zhang Chenlin 
Published: July 2022

Abstract
In scramjet, the position of shock train is affected by the change of back pressure. When the leading edge of the shock train is pushed out from the inlet of the isolation section, the engine will not start. Therefore, it is very important to detect the flow field structure in the isolation section and the leading edge position of the shock train. The traditional shock train detection method has low detection accuracy and slow detection speed. This paper describes a method based on deep learning to reconstruct the flow field in the isolation section and detect the leading edge of the shock train. Under various back pressure conditions, the flow field images of computational fluid dynamics (CFD) data and the corresponding upper and lower wall pressure data were obtained, and a data set corresponding to pressure and flow field was constructed. By constructing and training convolution neural network, a mapping model with pressure information as input and flow field image as output is obtained, and then the leading edge position of shock train is detected on the output flow field image. The experimental results show that the average structure similarity (SSIM) between the reconstructed flow field image and the CFD flow field image is 0.902, the average peak signal-to-noise ratio (PSNR) is 25.289, the average correlation coefficient (CORR) is 0.956, and the root mean square error of shock train leading edge detection is 3.28mm. Finally, in order to improve the detection accuracy of the leading edge position, we fine tuned the model and obtained another detection method, which reduced the root mean square error of the detection results to 1.87mm.
Research on Abrasive Pool Machining Method Based on Gas-solid Two-phase Flow
Authors: Yuan Wei , Wang Wenhua , Guo Qianjian , Lv xuehu , Wang Xingcan , Chi Baotao 
Published: July 2022

Abstract
For complex curved difficult to machine parts, a new method based on pneumatic suspension abrasive pool bright finishing processing is proposed, using the mixing of pneumatic suspension abrasive, the workpiece surface and fluidized abrasive to produce relative motion velocity, so that the solid particles and workpiece surface microscopic two-body abrasive wear to achieve the effect of precision machining. The experimental test material is the widely used Q235 steel plate. The experimental parameters include workpiece shape (round tube, square tube, cylindrical), abrasive particle size (24, 80, 120 mesh count), gas-solid two-phase flow pattern (dispersion fluidization state, turbulent fluidization state, spurting fluidization state), abrasive particle shape (sphere, irregularity) and spindle speed (600, 900, 1200 rpm). An orthogonal test was designed according to the experimental parameters, and the degree of influence of each parameter on the processing of the abrasive cell was evaluated by the roughness of the workpiece surface together with the scanning electron microscope (SEM) micrograph of the workpiece surface, and the optimal combination of parameters was judged using the extreme difference method as well as the factor trend diagram. The results show that under the present experimental conditions, the workpiece surface roughness (Ra) can reach a minimum value of 0.4 µm. The feasibility of gas-solid two-phase flow processing is demonstrated from an experimental point of view, and the advantages of abrasive cell processing are explored.
New Oral Anticoagulants Versus Vitamin K Antagonists in Patients with Left-Sided Bioprosthetic Heart Valves and Atrial Fibrillation: A Systematic Review and Meta-Analysis
Authors: Li Dong , Chang Peng , Zhang Hongliang , Wu Qiang , Bai Feng 
Published: July 2022

Abstract
Purposes: The aim of the present meta-analysis is to evaluate the efficacy and safety of NOACs versus VKAs in patients with AF and left-sided BHV.Methods: We review literatures for data from Pubmed, Cochrane, ISI Web of Sciences and Embase comparing NOACs with VKAs among patients with left-sided BHV and AF. The efficacy outcomes of this meta-analysis are stroke and all-causes mortality, while major bleeding and any bleeding, as the safety outcomes, are also analyzed.Results: The analysis includes 13 studies enrolling 28,099 patients with AF and left-sided BHV. There are no differences in the incidence of stroke [Risk Ratio (RR) 0.53; 95% confidence interval (CI) 0.21-1.31], all-cause mortality [RR 0.92; 95% CI 0.71-1.18] and any bleeding [RR 0.82; 95% CI 0.60-1.10], when NOACs significantly reduce the rate of major bleeding by 30% compared with VKAs [RR 0.70; 95% CI 0.56-0.87]. For patients younger than 80 years, NOACs may be more valuable in preventing brain embolism than VKAs [RR 0.55; 95% CI 0.35-0.87]. And NOACs may result in fewer bleeding events in patients without heart failure [RR 0.72; 95% CI 0.67-0.78].Conclusion: In patients with AF and left-sided BHV, NOACs correlate with a similar incidence of stroke, all-cause mortality and any bleeding as compared to VKAs, while may reduce the rate of major bleeding. Overall, there is at least comparable safety and efficacy between the using of NOACs and VKAs in this meta-analysis.
Underformed chip thickness and machined surface roughness in radial ultrasonic vibration-assisted grinding process
Authors: Yue Yansong , Zhao Biao , Wu Bangfu , Ding Wenfeng 
Published: July 2022

Abstract
Particle reinforced titanium matrix composites have attracted increasing attention to fabricate key components in the aerospace field. Grinding process, as a precision machining method, has been widely adopted to guarantee the desired machining quality. However, poor machining quality and severe tool wear are inevitable for the conventional grinding (CG) process, resulting from the presence of reinforced particles and fibers. In addition, the material removal characteristics and ground surface quality are significantly affected by the undeformed chip thickness (UCT). In this case, a radial ultrasonic vibration-assisted grinding (UVAG) device was fabricated, and the associated UCT model was established in views of the actual exposure height of grains, the number of dynamic grains, and the intermittent grinding of abrasive grains. The UCT model was then modified on the basis of ground surface roughness. Results showed that the maximum error of the UCT was 9.5% compared with the developed model and experimental value, and the UCT in UVAG reached 15–20 times compared with that in the CG process. Moreover, the influence of grinding depth on the UCT was not monotonous, and the UCT was the smallest when the grinding depth was approximately 60 µm.
Frost resistance investigation of fiber reinforced recycled brick aggregate cementitious materials
Authors: Ji Yongcheng , Zhang Hongrui 
Published: July 2022

Abstract
In order to solve the problem of environmental pollution caused by construction waste, one typical waste of red bricks was selected as raw materials in recycled concrete. This study presented recycled concrete by substitution some natural aggregates with treated red brick aggregates to study and analyze the mechanism degradation law of recycled brick aggregates concrete in the cold region. Total fifteen categories specimens and three experimental parameters were considered, which included numbers of freeze-thaw cycles (0, 50, and 100), steel fiber admixtures (0%, 1%, and 2%), and brick aggregate substitution rates (0%, 25%, 50%, 75%, and 100%), respectively. The quick freeze-thaw test method was selected to investigate the degradation law of mass loss rate and relative dynamic elastic modulus of recycled concrete under various freeze-thaw cycles. The digital microscope and SEM were used to observe the internal microstructural changes of the specimens under different freeze-thaw times. In addition, the microscopic damage morphology and damage mechanism of the specimens were analyzed. Finally, the flexural strength of the frost-damaged specimens was tested to analyze the mechanical deterioration of the recycled concrete, and the numerical model corresponding to steel fiber dosing and recycled aggregate replacement rate was presented. The gray correlation analysis was used to quantify the influence of each experimental variable on the corresponding experimental indexes under various freeze-thaw cycles. Results showed that the specimen's mass decreased after freeze-thaw cycles, and the mass loss exerted the most serious for the specimens at 50% and 75% brick substitution rates. In addition, the specimens showed the best relative dynamic modulus and the maximum flexural strength when the steel fiber doping was 1%. The numerical model agreed with experimental data and effectively predicted the specimens' mass loss rate, relative dynamic modulus, and flexural strength after freeze-thaw cycles. The gray correlation analysis showed that the steel fiber contents had a maximum correlation with the flexural strength, the brick substitution rates for the relative dynamic modulus, and mass loss controls the freeze-thaw cycles.
Grassland versus forest dwelling rodents as indicators of environmental contamination with the zoonotic nematode Toxocara canis
Authors: Krupińska Martyna , Antonová Daniela , Tołkacz Katarzyna , Strachecka Aneta , Goll Aleksander , Nowicka Joanna , Baranowicz Karolina , Bajer Anna , Behnke Jerzy M. , Grzybek Maciej 
Published: July 2022

Abstract
Small mammals are suspected of contributing to the dissemination of Toxocara canis and helping with the parasite's survival during periods when there is a temporary absence of suitable definitive hosts. While the primary aim of the current study was the assessment of seroprevalence of Toxocara spp. infections in wild rodents in Poland, we also explored the role of intrinsic (sex, age) and extrinsic factors (study site, year of study) influencing dynamics of this infection to ascertain whether grassland versus forest rodents play a greater role as indicators of environmental contamination with T. canis. We trapped 577 rodents belonging to four species (Myodes glareolus, Microtus arvalis, Microtus agrestis, Alexandromys oeconomus) in north-eastern Poland. Blood was collected during the parasitological examination, and serum was frozen at -80°C until further analyses. A bespoke enzyme-linked immunosorbent assay was used to detect antibodies against T. canis. We found T. canis antibodies in the sera of all four rodent species with an overall seroprevalence of 2.8% [1.9-4.1]. There was a significant difference in seroprevalence between vole species, with the grassland species (M. arvalis, M. agrestis, and A. oeconomus) showing a 16-fold higher seroprevalence (15.7% [8.7-25.9]) than the forest-dwelling, M. glareolus (0.98% [0.5-1.8]). We hypothesise that the seroprevalence of T. canis differs between forest and grassland rodents because of the higher contamination of grasslands by domestic dogs and wild canids. Our results underline the need for wide biomonitoring of both types of ecosystems to assess the role of rodents as indicators of environmental contamination with zoonotic pathogens.
Inclination controls CO2 and N2O fluxes, but not CH4 uptake, from a temperate upland forest soil
Authors: Triches Nathalie Ylenia , Gillespie Lauren Michelle , Abalos Diego , Finke Peter , Zechmeister-Boltenstern Sophie , Glatzel Stephan , Díaz-Pinés Eugenio 
Published: July 2022

Abstract
Inclination and spatial variability in soil and litter properties influence soil greenhouse gas (GHG) fluxes, but their relationship in forest ecosystems is poorly understood. To elucidate this, we explored the effect of inclination, distance to a stream, soil moisture, soil temperature, and other soil and litter properties on soil-atmosphere fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) with automated static chambers in a temperate upland forest in Eastern Austria. We hypothesised that soil CO2 emissions and CH4 uptake are higher in sloped locations with lower soil moisture content, whereas soil N2O emissions are higher in flat, wetter locations. During the measurement period, soil CO2 emissions were significantly higher on flat locations (p < 0.05), and increased with increasing soil temperature (p < 0.001) and decreasing soil moisture (p < 0.001). The soil acted as a CH4 sink, and CH4 uptake was not significantly related to inclination. However, CH4 uptake was significantly higher at locations furthest away from the stream compared to at the stream (p < 0.001), and positively related to litter weight and soil C content (p < 0.01). N2O fluxes were significantly higher on flat locations and further away from the stream (p < 0.05), and increased with increasing soil moisture (p < 0.001), soil temperature (p < 0.001) and litter depth (p < 0.05). Overall, this study underlines the importance of inclination and the resulting soil and litter properties in predicting GHG fluxes from forest soils.
Post COVID-19 condition diagnosis: A population-based cohort study of occurrence, associated factors, and healthcare use by severity of acute infection
Authors: Hedberg Pontus , Granath Fredrik , Bruchfeld Judith , Askling Johan , Sjöholm Daniel , Fored Michael , Färnert Anna , Naucler Pontus 
Published: July 2022

Abstract
Background
The occurrence and healthcare use trajectory of post COVID-19 is poorly understood. Our aim was to investigate these aspects in SARS-CoV-2 positive individuals with and without a post COVID-19 condition diagnosis.
Methods
We conducted a population-based cohort study of adults in the entire Stockholm Region, Sweden, with a positive SARS-CoV-2 test from 1 March 2020 to 31 July 2021, stratified by severity of the acute infection. The study outcome was a post COVID-19 condition diagnosis registered any time 90 to 360 days after positive test. We performed Cox regression models to assess baseline characteristics associated with post COVID-19. Individuals with post COVID-19 were then propensity-score matched to individuals without post COVID-19 to assess healthcare use beyond the acute infection.
Findings:
Among 204 805 SARS-CoV-2-positive individuals, the proportion receiving a post COVID-19 diagnosis was 1% among individuals not hospitalized for their COVID-19 infection, 6% among hospitalized, and 32% among ICU-treated individuals. Female sex was associated with post COVID-19 among non-hospitalized and hospitalized individuals, with interactions between age and sex. Previous mental health disorders and asthma were associated with post COVID-19 among non-hospitalized [aHR 2·18 (95% CI 1·98 − 2·39), aHR 2·09 (95% CI 1·82 − 2·40)] and hospitalized [aHR 1·38 (95% CI 1·17 − 1·64), aHR 1·64 (95% CI 1·34 − 2·00)] individuals. Among individuals with post COVID-19, the monthly proportion with outpatient care visits after the infection compared to before the infection was substantially elevated up to one year after the acute infection, with substantial proportions of this care attributed to care related to post COVID-19.
Interpretation:
The differential association of age, sex, comorbidities, and healthcare use with severity of the acute infection indicates different trajectories and phenotypes of post COVID-19 condition, with incomplete resolution one year after infection.
Symbiont-driven niche expansion shapes the adaptive radiation of insects
Authors: Cornwallis Charlie , Padje Anouk van’t , Ellers Jacintha , Klein Malin , Jackson Raphaella , Kiers Toby , West Stuart , Henry Lee 
Published: July 2022

Abstract
For over 300 million years, insects have relied on symbiotic microbes for nutrition and defence1,2. However, it is unclear whether specific ecological conditions have repeatedly favoured the evolution of symbioses, and how this has influenced insect diversification1,3,4. Using data on 1849 microbe-insect symbioses across 402 insect families, we found that symbionts have allowed insects to specialize on a range of nutrient-imbalanced diets, including phloem, blood and wood. Across diets, the only limiting nutrient consistently associated with the evolution of obligate symbiosis was B vitamins. The shift to new diets, facilitated by symbionts, had mixed consequences for insect diversification. In some cases, such as herbivory, it resulted in spectacular species proliferation. In other niches, such as strict blood feeding, diversification has been severely constrained. Symbioses therefore appear to solve widespread nutrient deficiencies for insects, but the consequences for insect diversification depend on the feeding niche invaded.
Iron oxide/hydroxide – nitrogen doped graphene-like visible-light active photocatalytic layers for antibiotics removal from wastewater
Authors: Ivan R. , Popescu C. , Antohe V. A. , Antohe S. , Logofatu C. , Pino A. Pérez , György E. 
Published: July 2022

Abstract
Hybrid layers consisting of Fe oxide, Fe hydroxide, and nitrogen doped graphene-like platelets have been synthesized by an eco-friendly laser-based method for photocatalytic applications. The complex composite layers show high photodecomposition efficiency towards degradation of antibiotic molecules under visible light irradiation. The photodecomposition efficiency was investigated as a function of relative concentrations of base materials, Fe oxide nanoparticles and graphene oxide platelets used for the preparation of target dispersions submitted to laser irradiation. Although reference pure Fe oxide / Fe hydroxide layers have high absorption in the visible spectral region, their photodecomposition efficiency is negligible under the same irradiation conditions. The high photocatalytic decomposition efficiency of the nanohybrid layer, up to 80% of the initial antibiotic molecules was assigned to synergistic effects between the constituent materials, efficient separation of the electron-hole pairs generated by visible light irradiation on the surface of Fe oxide and Fe hydroxide nanoparticles, in the presence of conducting graphene-like platelets. Nitrogen doped graphene-like platelets contribute also to the generation of electron-hole pairs under visible light irradiation, as demonstrated by the photocatalytic activity of pure, reference nitrogen doped graphene-like layers. The results also showed that adsorption processes do not contribute significantly to the removal of antibiotic molecules from the test solutions. The decrease of the antibiotic concentration under visible light irradiation was assigned primarily to photocatalytic decomposition mechanisms.
Recapitulation of folliculogenesis to ovulation in a biomimetic micro-cavity ovary
Authors: Ye Min , Shan Yiran , Lu Bingchuan , Luo Hao , Wang Zixuan , Guo Yuzhi , Ouyang Liliang , Gu Jin , Xiong Zhuo , Zhang Ting 
Published: July 2022

Abstract
Ovary disease is a major cause of female infertility and could disrupt the hormone balance, which may cause multi-organ disorders in the long-term effect. However, conventional artificial ovary techniques usually encapsulate follicles in 3D hydrogels and block the ovulation ability. In this study, we fabricated a biomimetic micro-cavity ovary by a microsphere-templated technique to recapitulate the ovulation process, where sacrificial gelatin microspheres were mixed with photo-crosslinkable gelatin methacryloyl (GelMA) to engineer an open cavity niche for follicle growth. The microcavity’s parameters were optimized to be suitable for follicle growth. With that, we showed that the micro-cavity ovary could support the follicle growth to antral stage and the ovulation of meiosis-matured oocytes out of the micro-cavity ovary without extra manipulation. The ovulated oocyte was characterized in a great quality. This technique would be of great advantage to be further applied in clinics that recover natural conception after in vivo transplantation of the biomimetic ovary.
The Effect of Different Surface Treatments on the Repair of 3D Permanent Resin Restorations by Composite Resin Different surface treatments and repair of 3D permanent resin
Authors: Sonkaya Ezgi , Kürklü Z. Gonca Bek 
Published: July 2022

Abstract
Purpose: The repairability of ceramic containing 3D printed materials has not yet been investigated. This study aimed to compare the repair bond strength of permanent resin blocks with composite by applying different intraoral surface treatments after aging in water.Methods: The study material comprised thirty-five 3D printing cubes, which were aged in 10,000 thermocycles. Surface treatments were applied to the seven groups as A. Negative control (untreated) B. Positive control C. Phosphoric acid D. Er,Cr;YSGG laser E. Sandblasting F. Hydrofluoric acid, and G. Burr abrasion followed by multi-primer and universal bond. The best 1×1×12 mm sticks were tested on a universal testing machine. Data were analyzed using one-way ANOVA and the Duncan test.Results: The negative control group reached a significantly lower micro tensile bond strength than the laser and sandblasting groups (p≤ 0.05). The repair bond strength of the positive control group didn’t differ significantly from that of the other experimental groups (p=0.374).Conclusion: The bonding strength of composite resin hasn’t shown a statistically significant difference when different surface treatments were applied to 3D-printed resin. It can be concluded that it is possible to make small repairs of 3D printed permanent restorations with the application of primer and bond.
The Electrochemical Corrosion Behaviour of compacted (Bi, Pb)-2223 superconductors in Aqueous Solutions
Authors: Abdel-Gaber Ashraf M. , Najem Ahmad , Awad Ramadan 
Published: July 2022

Abstract
The corrosion behaviour of (Bi, Pb)-2223 samples compacted at 0.3–1.9 GPa in 0.5 M of HCl, NaCl, and NaOH solutions at 30°C was investigated using potentiodynamic polarization curves measurements and electrochemical impedance spectroscopy (EIS) technique as well as scanning electron microscopy (SEM) and energy dispersive X-ray emission spectroscopy (EDX). Polarization results showed that the increase in compaction decreases both cathodic hydrogen evolution or oxygen reduction and anodic (BiPb)-2223 superconductor dissolution in 0.5 M HCl, and 0.5 M NaOH. On the other hand, compaction mainly affects the anodic part of the polarization curves of (Bi, Pb)-2223 in 0.5 M NaCl solution. EIS measurements revealed that the highest protection of the superconductors was achieved in 0.5 M NaCl, while the lowest degree of protection was observed in 0.5 M HCl. SEM images show a random plate-like morphology fitted with the marker of (Bi, Pb)-2223 material. The compacted sample at 1.9 GPa indicates deformation of the grains and the formation of a micro-crack. The corrosion mechanism of the superconductor at different pH values was also discussed.
Multi-port DC-DC converter modelling
Authors: Arizaga-Ayala Francisco J. , Ramirez Juan M. 
Published: July 2022

Abstract
This paper is focused on bidirectional DC-DC converters in renewable energy systems. It discusses a triple active bridge (TAB) converter, including how to model, control, and simulate it. First, Kirchhoff's principles are used to identify the equations governing the converter's behaviour and then construct the system model. Next, the control system was developed using the plant's state-space representation. The closed-loop model Laplace transform and some simulator data provide the control technique. Finally, the simulator tools evaluate the system's stability and behaviour before and after management. The results show that the active converter may be used with renewable energy.