bluuebunny/crossref_metadata_2025 huggingface dataset:
Encephalartos villosus Lem. Displays a Strong In Vivo and In Vitro Antifungal Potential against Candida glabrata Clinical Isolates
Authors: Alqahtani Moneerah J. , Elekhnawy Engy , Negm Walaa A. , Mahgoub Sebaey , Hussein Ismail A.
Published: May 2022

Recently, Candida glabrata has been recognized as one of the most common fungal species that is highly associated with invasive candidiasis. Its spread could be attributed to its increasing resistance to antifungal drugs. Thus, there is a high need for safer and more efficient therapeutic alternatives such as plant extracts. Here, we investigated the antifungal potential of Encephalartos villosus leaves methanol extract (EVME) against C. glabrata clinical isolates. Tentative phytochemical identification of 51 metabolites was conducted in EVME using LC–MS/MS. EVME demonstrated antifungal activity with minimum inhibitory concentrations that ranged from 32 to 256 µg/mL. The mechanism of the antifungal action was studied by investigating the impact of EVME on nucleotide leakage. Additionally, a sorbitol bioassay was performed, and we found that EVME affected the fungal cell wall. In addition, the effect of EVME was elucidated on the efflux activity of C. glabrata isolates using acridine orange assay and quantitative real-time PCR. EVME resulted in downregulation of the expression of the efflux pump genes CDR1, CDR2, and ERG11 in the tested isolates with percentages of 33.33%, 41.67%, and 33.33%, respectively. Moreover, we investigated the in vivo antifungal activity of EVME using a murine model with systemic infection. The fungal burden was determined in the kidney tissues. Histological and immunohistochemical studies were carried out to investigate the effect of EVME. We noticed that EVME reduced the congestion of the glomeruli and tubules of the kidney tissues of the rats infected with C. glabrata. Furthermore, it decreased both the proinflammatory cytokine tumor necrosis factor-alpha and the abnormal collagen fibers. Our results reveal, for the first time, the potential in vitro (by inhibition of the efflux activity) and in vivo (by decreasing the congestion and inflammation of the kidney tissues) antifungal activity of EVME against C. glabrata isolates.
Heme Oxygenase-1 (HMX1) Loss of Function Increases the In-Host Fitness of the Saccharomyces ‘boulardii’ Probiotic Yeast in a Mouse Fungemia Model
Authors: Imre Alexandra , Kovács Renátó , Tóth Zoltán , Majoros László , Benkő Zsigmond , Pfliegler Walter P. , Pócsi István
Published: May 2022

The use of yeast-containing probiotics is on the rise; however, these products occasionally cause fungal infections and possibly even fungemia among susceptible probiotic-treated patients. The incidence of such cases is probably underestimated, which is why it is important to delve deeper into the pathomechanism and the adaptive features of S. ‘boulardii’. Here in this study, the potential role of the gene heme oxygenase-1 (HMX1) in probiotic yeast bloodstream-derived infections was studied by generating marker-free HMX1 deletion mutants with CRISPR/Cas9 technology from both commercial and clinical S. ‘boulardii’ isolates. The six commercial and clinical yeasts used here represented closely related but different genetic backgrounds as revealed by comparative genomic analysis. We compared the wild-type isolates against deletion mutants for their tolerance of iron starvation, hemolytic activity, as well as kidney burden in immunosuppressed BALB/c mice after lateral tail vein injection. Our results reveal that the lack of HMX1 in S. ‘boulardii’ significantly (p < 0.0001) increases the kidney burden of the mice in most genetic backgrounds, while at the same time causes decreased growth in iron-deprived media in vitro. These findings indicate that even a single-gene loss-of-function mutation can, surprisingly, cause elevated fitness in the host during an opportunistic systemic infection. Our findings indicate that the safety assessment of S. ‘boulardii’ strains should not only take strain-to-strain variation into account, but also avoid extrapolating in vitro results to in vivo virulence factor determination.
Issues in Islamic Derivatives and Proposals for Reforms in the OTC Market in Indonesia
Authors: Setiawan Romi Adetio
Published: May 2022

This paper aims to propose reforms to develop the Islamic derivatives transactions in Indonesia’s over-the-counter (OTC) market. It is argued that the use of derivatives instruments is considered non-sharia compliant by the National Sharia Board (NSB) of the Indonesian Council of Ulama. However, other Ulamas had adopted a different approach in discussing the issues of derivatives contracts. Standard doctrinal and comparative approaches are employed in this discursive qualitative analysis using an extensive review of the literature from primary and secondary sources to collect the data on Islamic derivatives in the OTC market. This research concludes with two proposals for Islamic derivatives in the OTC market in Indonesia; first, the use of musawamah (sale without revealing the cost) in the swap, al-khiyar (the right to make choice) in option, ju’alah (commission) in future contracts, and wa’ad (a promise) in option can further boost the investors in the OTC market. Second, the Islamic scholars should be softening towards the decision of using derivatives instruments in Indonesia. Such as in the case of the forward agreements, which should be exempted from non-sharia compliance, provided they are used solely for reducing risk due to necessity in al-tahawuth lil hajah al-massah (sharia-compliant genuine hedging needs).
Spatio-Temporal Pattern and Conflict Identification of Production–Living–Ecological Space in the Yellow River Basin
Authors: Xi Furui , Wang Runping , Shi Jusong , Zhang Jinde , Yu Yang , Wang Na , Wang Zhiyi
Published: May 2022

Production–living–ecological space (PLES) is the main body of the optimization of the development and protection pattern of territorial space, and the spatial conflict in PLES reflects a struggle for ecological protection and socio-economic development in the process of spatial development and utilization. The Yellow River Basin is one of the most concentrated and prominent areas of spatial conflict of PLES in China. Therefore, clarifying the spatio-temporal pattern of PLES of the region and scientifically identifying the characteristics of its spatial conflict will significantly improve the efficiency of comprehensive utilization of spatial resources, promote the integrated and orderly development of resource elements in the basin, and eventually achieve the strategic goals of ecological protection and high-quality development of the Yellow River Basin. In this research, the CA–Markov model was applied to simulate the spatio-temporal pattern of PLES in the Yellow River Basin from 2010 to 2025, and the landscape ecology method was adopted to construct the spatial conflict of the PLES measurement model for identifying the spatio-temporal trends of conflicts and their intensity. The results reveal that, from 2010 to 2025, ecological–production space (EPS) dominates the PLES in the Yellow River Basin, as its total area remains stable amid fluctuations; living–production space (LPS) shows the most notable change, as it grows yearly along with urbanization and industrialization process of the region; the transition between ecological–production space (EPS) and production–ecological space (PES) is the most frequent, and the two also account for the largest area. Spatial conflict of PLES in the Yellow River Basin is mainly reflected in the encroachment of LPS on other PLES, concentrated in the regions from Hekou Town to the left bank of Longmen, Fen River, Shizuishan to the southern bank of Hekou Town, and Daxia River and Tao River in the Yellow River Basin. From 2010 to 2025, the space conflict composite index of PLES (SCCI) of most regions in the basin lies within 0.7, which is a stable or basically controllable level. Among the 29 tertiary water resource divisions in the Yellow River Basin, the SCCI of 15 indicate a major, decreasing trend.
Impact of Relationship Governance and Third-Party Intervention on Farmland Transfer Rents—Empirical Evidence from Rural China
Authors: Chen Jia , Xu Jingwen , Zhang Hongxiao
Published: May 2022

The marketization of transfer rent is an important symbol of the development of the farmland factor market. At present, the price formation mechanism of rent in China’s farmland market is not perfect. Based on the theoretical analysis starting with the post transaction cost of leasers, this paper uses 1648 farmland transfer samples collected by the China Land Economic Survey (CLES) in 2020, and employs OLS, 2SLS and CMP methods to empirically test the impact of relationship governance on transfer rent and the role of third-party (including county and township governments and village committees) intervention on the change in relationship governance pattern and rent decisions. The results show that the close relationship between the two sides of transfer represents the strong relationship governance functioned by the constraints of the trust and reputation mechanism, which can reduce the post transaction cost. Additionally, the two sides play a game on this part of the transaction cost, making the transfer rent lower than the market price. Furthermore, the involvement of third parties such as county and township governments and village committees in the transfer has replaced the role of relationship governance in reducing transaction cost, and changed the relationship governance pattern of acquaintance society, which makes the transfer rent close to the market price.
Effects of Forest Harvesting Operations on the Recovery of Earthworms and Nematodes in the Hyrcanain Old-Growth Forest: Assessment, Mitigation, and Best Management Practice
Authors: Sohrabi Hadi , Jourgholami Meghdad , Lo Monaco Angela , Picchio Rodolfo
Published: May 2022

The quality and performance of forest soil is closely related to the characteristics of the faunal community in the soil. Focusing on soil organisms can provide good indicators to choose the best soil restoration methods to improve the properties of degraded forest soils. Therefore, the present study aimed to evaluate the effects of the tree litter of different species on the recovery of soil organisms (earthworms and nematodes) from skid trails over a 20-year period after harvest operations. For this purpose, three skid trails with different ages after harvest operations (6, 10, and 20 years), considering three tree litter treatments (beech, beech–hornbeam, and mixed beech) and three traffic intensity classes (low, medium, and high), were identified. The combination of treatments was carried out in the forest with three replications, and a total of 18 sample plots of 0.5 m2 were harvested to measure earthworms and nematodes. The results showed that 20 years after harvest operations, the highest values of earthworm density (5.72 n m−2), earthworm biomass (97.18 mg m−2), and total nematodes (313.65 in 100 g of soil) were obtained in the mixed beech litter treatment compared to other litter treatments. With decreasing traffic intensity from high to low, the activity of soil organisms increased, and the highest values of earthworm density (5.46 n m−2), earthworm biomass (87.21 mg m−2), and soil nematodes (216.33 in 100 g soil) were associated with low traffic intensity. Additionally, in all three litter treatments and traffic intensities, the epigeic ecological species were more abundant than the anecic and endogeic species. Key soil variables including water content, porosity, available nutrients, pH, total organic C, and total N were significantly correlated with earthworm density and biomass and soil nematode population. Litter management and addition to compacted soil can support the functional dynamics and processes of the soil and maintenance of the abundances and activities of the soil fauna.
Inference of Local Climate Zones from GIS Data, and Comparison to WUDAPT Classification and Custom-Fit Clusters
Authors: Muhammad Fadel , Xie Changkun , Vogel Julian , Afshari Afshin
Published: May 2022

A GIS-based approach is used in this study to obtain a better LCZ map of Berlin in comparison to the remote-sensing-based WUDAPT L0 approach. The LCZ classification of land use/cover can be used, among other applications, to characterize the urban heat island. An improved fuzzy logic method is employed for the purpose of classification of the zone properties to yield the GIS-LCZ map over 100 m × 100 m grid tiles covering the Berlin region. The zone properties are calculated from raster and vector datasets with the aids of the urban multi-scale environmental predictor (UMEP), QGIS and Python scripts. The standard framework is modified by reducing the threshold for the zone property impervious fraction for LCZ E to better detect paved surfaces in urban areas. Another modification is the reduction in the window size in the majority filter during post-processing, compared to the WUDAPT L0 method, to retain more details in the GIS-LCZ map. Moreover, new training areas are generated considering building height information. The result of the GIS-LCZ approach is compared to the new training areas for accuracy assessment, which shows better overall accuracy compared to that of the WUDAPT L0 method. The new training areas are also submitted to the LCZ generator and the resulting LCZ-map gives a better overall accuracy value compared to the previous (WUDAPT) submission. This study shows one shortcoming of the WUDAPT L0 method: it does not explicitly use building height information and that leads to misclassification of LCZs in several cases. The GIS-LCZ method addresses this shortcoming effectively. Finally, an unsupervised machine learning method, k-means clustering, is applied to cluster the grid tiles according to their zone properties into custom classes. The custom clusters are compared to the GIS-LCZ classes and the results indicate that k-means clustering can identify more complex city-specific classes or LCZ transition types, while the GIS-LCZ method always divides regions into the standard LCZ classes.
Structured, Harmonized, and Interoperable Integration of Clinical Routine Data to Compute Heart Failure Risk Scores
Authors: Sommer Kim K. , Amr Ali , Bavendiek Udo , Beierle Felix , Brunecker Peter , Dathe Henning , Eils Jürgen , Ertl Maximilian , Fette Georg , Gietzelt Matthias , Heidecker Bettina , Hellenkamp Kristian , Heuschmann Peter , Hoos Jennifer D. E. , Kesztyüs Tibor , Kerwagen Fabian , Kindermann Aljoscha , Krefting Dagmar , Landmesser Ulf , Marschollek Michael , Meder Benjamin , Merzweiler Angela , Prasser Fabian , Pryss Rüdiger , Richter Jendrik , Schneider Philipp , Störk Stefan , Dieterich Christoph
Published: May 2022

Risk prediction in patients with heart failure (HF) is essential to improve the tailoring of preventive, diagnostic, and therapeutic strategies for the individual patient, and effectively use health care resources. Risk scores derived from controlled clinical studies can be used to calculate the risk of mortality and HF hospitalizations. However, these scores are poorly implemented into routine care, predominantly because their calculation requires considerable efforts in practice and necessary data often are not available in an interoperable format. In this work, we demonstrate the feasibility of a multi-site solution to derive and calculate two exemplary HF scores from clinical routine data (MAGGIC score with six continuous and eight categorical variables; Barcelona Bio-HF score with five continuous and six categorical variables). Within HiGHmed, a German Medical Informatics Initiative consortium, we implemented an interoperable solution, collecting a harmonized HF-phenotypic core data set (CDS) within the openEHR framework. Our approach minimizes the need for manual data entry by automatically retrieving data from primary systems. We show, across five participating medical centers, that the implemented structures to execute dedicated data queries, followed by harmonized data processing and score calculation, work well in practice. In summary, we demonstrated the feasibility of clinical routine data usage across multiple partner sites to compute HF risk scores. This solution can be extended to a large spectrum of applications in clinical care.
Digitalization for Fast, Fair, and Safe Humanitarian Logistics
Authors: Khan Muhammad , Khan Marwan , Ali Abbas , Khan Muhammad Imran , Ullah Ihsan , Iqbal Muhammad
Published: May 2022

Background: Mismanagement in disaster relief operations (DROs) has created a requirement for fast, fair, and safe humanitarian logistics (HL). The deployment of digital solutions in DROs is supported by humanitarian organizations (HOs) as well as recent research; therefore, the key purpose of this article is to investigate the impact of digitalization for fast, fair, and safe HL in DROs. Methods: Primary empirical data were acquired from 449 disaster relief workers (DRWs) via questionnaires and by employing the snowball sampling methodology and partial least squares structural equation modeling (PLS-SEM) in SmartPLS 3. Results: The result of this study indicates that fast, fair, and safe HL is crucial because it can save people’s lives and reduce suffering, and it achieves long-term sustainable development. The findings of the study could be beneficial to all catastrophe risk-management stakeholders as they look for ways to help victims. In addition, the ultimate beneficiaries of digitalized and effective HL will be all of society, notably disaster victims. Conclusions: By implementing proper technologies in DROs, the afflicted may receive needed resources on time, which can save many lives. The utility of the proposed variables is promoting awareness about HL in a fast, fair, and safe manner, and we discuss implications, limitations, and future research. The research adds to the literature by presenting the first quantitative evidence assessing the independent role of digitalization in generating fast, fair, and safe HL from one of the world’s most disaster-prone countries.
2,4-Diamino-5-(nitromethyl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile
Authors: Ryzhkova Yuliya E. , Ryzhkov Fedor V. , Maslov Oleg I. , Elinson Michail N.
Published: May 2022

Dimethyl sulfoxide (DMSO) is a cheap polar aprotic solvent used in organic synthesis and in pharmacology because of its low cost, high stability, and non-toxicity. Multicomponent reactions (MCRs) are highly convergent processes and have good atom, step, and pot economies. In this communication, the multicomponent transformation of salicylaldehyde, malononitrile dimer, and nitromethane in DMSO at room temperature was investigated to give 2,4-diamino-5-(nitromethyl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile in good yield. The structure of the earlier unknown compound was confirmed by means of elemental analysis, mass-, nuclear magnetic resonance, and infrared spectroscopy.
Influence of Low Sintering Temperature on BaCe0.2Zr0.6Y0.2O3−δ IT-SOFC Perovskite Electrolyte Synthesized by Co-Precipitation Method
Authors: Rafique Muhammad , Safdar Neelam , Irshad Muneeb , Usman Muhammad , Akhtar Maaz , Saleem Muhammad Wajid , Abbas Muhammad Mujtaba , Ashour Ahmed , Soudagar Manzoore Elahi
Published: May 2022

BaCe0.2Zr0.6Y0.2O3−δ (BCZY) perovskite electrolytes were synthesized for intermediate-temperature solid oxide fuel cell with a cost-effective and versatile co-precipitation method. The synthesized BCZY electrolytes were sintered at 900, 1000, and 1100 °C to observe the effects of low sintering temperature on the structural, morphological, thermal, and electrical properties of BCZY. All BCZY electrolytes materials exhibited a crystalline perovskite structure and were found to be thermally stable. The crystallinity and conductivity of BCZY electrolyte enhanced with increased sintering temperature, due to the grain growth. At the same time, secondary phases of carbonates were also observed for samples sintered at a temperature lower than 1100 °C. The BCZY sintered at 1100 °C exhibited a density >95%, and a power density of 350 mWcm−2 with open-circuit voltage 1.02 V at 650 °C was observed due its dense and airtight structure. Based on the current investigation, we suggest that the BaCe0.2Zr0.6Y0.2O3−δ perovskite electrolyte sintered at a temperature of 1100 °C is a suitable electrolyte for IT-SOFC.
Investigation of the Shrinkage and Air Permeability of Woolen Blankets and Blankets Made with Regenerated Wool
Authors: Kumpikaitė Eglė , Laureckienė Ginta , Milašienė Daiva , Petraitienė Stasė
Published: May 2022

The aim of this article was to compare the shrinkage and air permeability properties of woolen fabrics and fabrics with regenerated wool woven with different weaves for establishing the suitability of regenerated wool for blankets. Two series of products with yarns of different raw materials were woven. One group of fabrics was woven with regenerated woolen yarn in the weft and woolen yarn in the warp. The other group of fabrics was woven only from 100% woolen yarns. The shrinkage in the directions of the warp and the weft and the air permeability of the fabrics with regenerated wool and 100% woolen fabrics with different weaves were investigated. The shrinkage in the directions of the warp and the weft in the fabrics with regenerated wool in the weft and 100% woolen fabrics depended on the float length in the weave. When the length of the weave increased, the shrinkage also increased. The air permeability value changed depending on the number of intersections and the float length. The fabrics with regenerated wool in the direction of the weft had higher air permeability. The Two-way analysis of variance (ANOVA) results showed that the weave influenced the shrinkage in the directions of the weft and warp, but the raw material had no influence on the shrinkage. The weave did not influence the air permeability, in contrast to the raw material. The shrinkage in the directions of the warp and weft and the air permeability did not depend on the interrelationships of the weave group and the raw material of the fabric.
Preparation and Characterization of Electromagnetic-Induced Rupture Microcapsules for Self-Repairing Mortars
Authors: Li Erwang , Du Wei , Zhuang Ronghua , Ba Mingfang , Yuan Lianwang , Zhang Qian , Zhang Yuepin
Published: May 2022

Cement-based materials are susceptible to internal cracks during service, leading to a reduction in their durability. Microcapsules can effectively self-repair cracks in cement-based materials. In this study, novel electromagnetic-induced rupture microcapsules (DWMs) were prepared by using the melt dispersion method with Fe3O4 nano-particles/polyethylene wax as the shell and epoxy resin as the repairing agent. The core fraction, compactness, particle size distribution, morphology, and chemical structure of DWMs were characterized. DWMs were subsequently incorporated into the mortar to measure the pore size distribution, compressive strength recovery, and maximum amplitudes of the pre-damaged mortar after self-repairing. DWMs were also evaluated for their ability to self-repair cracks on mortar surfaces. The results showed that the core fraction, remaining weight (30 days), and mean size of DWMs were 72.5%, 97.6 g, and 220 μm, respectively. SEM showed that the DWMs were regular spherical with a rough surface and could form a good bond with cement matrix. FTIR indicated that the epoxy resin was successfully encapsulated in the Fe3O4 nano-particles/polyethylene wax. After 15 days of self-repairing, the harmful pore ratio, compressive strength recovery, and maximum amplitude of the pre-damaged mortars were 48.97%, 91.9%, and 24.03 mV, respectively. The mortar with an initial crack width of 0.4–0.5 mm was self-repaired within 7 days. This indicated that the incorporation of DWMs can improve the self-repair ability of the mortar. This work is expected to provide new insights to address the mechanism of microcapsule rupture in self-repairing cement-based materials.
Evaluation of the Fatigue Behaviour and Failure Mechanisms of 52100 Steel Coated with WIP-C1 (Ni/CrC) by Cold Spray
Authors: Goanta Viorel , Munteanu Corneliu , Müftü Sinan , Istrate Bogdan , Schwartz Patricia , Boese Samuel , Ferguson Gehn , Morăraș Ciprian Ionut
Published: May 2022

Cold spray technique has been major improved in the last decades, for studying new properties for metals and alloys of aluminum, copper, nickel, and titanium, as well as steels, stainless steel and other types of alloys. Cold sprayed Ni/CrC coatings have the potential to provide a barrier as well as improved protection to steels. Fatigue characteristics of 52100 steel coated with Ni/Chrome-Carbide (Ni/CrC) powder mixture by using cold gas dynamic spray are investigated. Fatigue samples were subjected to symmetrically alternating, axially applied cyclic fatigue loading until failure. The test was stopped if a sample survived more than 5 × 106 cycles at the applied stress. Fracture surfaces for each sample were examined to investigate the behaviour of the coating both at high stress levels and at a high number of stress cycles. Scanning electron microscopy was used to assess the damage in the interface of the two materials. Good fatigue behaviour of the coating material was observed, especially at low stresses and a high number of cycles. Details of the crack initiation region, the stable crack propagation region and the sudden crack expansion region are identified for each sample. In most of the samples, the initiation of the crack occurred on the surface of the base material and propagated into the coating material. The possible effects of coatings on the initial deterioration of the base material and the reduction of the lifespan of the coated system were also investigated. The aim of the paper was to study the interface between the base material and the coating material at the fatigue analysis for different stresses, highlighting the appearance of cracks and the number of breaking cycles required for each sample.
Multi-Step Forming Simulation and Quality Control of Aluminum Alloy Automobile Rear Upper Control Arm
Authors: Chen Xiaogu , Shu Xuedao , Wang Donggang , Xu Sheng , Xiang Wei
Published: May 2022

Aluminum alloy is widely used in automobile parts because of its light weight and good process performance. In view of the complex structure of aluminum alloy automobile rear upper control arms, multiple forming processes and the difficulty in quality control, in this paper, we propose a rolling-forging composite process to produce a rear upper control arm. Based on the reasonable volume distribution of the blank by cross-wedge rolling, multi-step forging was carried out. Finite element simulation of thermomechanically coupled multi-step forming was carried out using DEFORM software. Based on a comparison of the traditional process and the proposed rolling-forging composite forming process, we concluded that the rolling-forging composite process can greatly reduce the material cost and the forming force, resulting in superior product performance. The coarse-grain structure of products at different process temperatures was analyzed by a crystal-phase experiment. The results show that the process temperature of the multi-step process, as well as the heat treatment temperature and time have an important influence on the coarse-grain structure of the product. The optimal preheating temperatures for preforging and final forging dies were determined to be 335 °C and 350 °C, respectively; a preheating temperature of 530 °C and a solution time of 45 min resulted in the least coarse-grain surface structure. The research results provide a theoretical basis for improving the multi-step forming quality of automobile rear upper control arms.
Facile Synthesis with TiO2 Xerogel and Urea Enhanced Aniline Aerofloat Degradation Performance of Direct Z-Scheme Heterojunction TiO2/g-C3N4 Composite
Authors: Zhu Sipin , Chen Zhiyong , Wang Chunying , Pan Jiahao , Luo Xianping
Published: May 2022

Different TiO2/g-C3N4 (TCN) composites were synthesized by a simple pyrolysis method with TiO2 xerogel and urea. The structure and physicochemical properties of TCN were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, ultraviolet-visible diffuse reflectance spectrum, X-ray photoelectron spectroscopy, N2-adsorption isotherms and electrochemical impedance spectroscopy. Aniline Aerofloat was chosen as a typical degradation-resistant contaminant to investigate the photodegradation activity of TCN under UV irradiation. The results indicated that TCN had higher light absorption intensity, larger specific surface area and smaller particle size compared to pure TiO2. Furthermore, TCN had great recycling photocatalytic stability for the photodegradation of Aniline Aerofloat. The photocatalytic activity depends on the synergistic reaction between holes (h+) and hydroxyl radicals (·OH). Meanwhile, the direct Z-scheme heterojunction structure of TiO2 and g-C3N4 postpones the recombination of h+ and electrons to enhance UV-light photocatalytic activity.
Role of Polyoxometalate Contents in Polypyrrole: Linear Actuation and Energy Storage
Authors: Le Quoc Bao , Zondaka Zane , Harjo Madis , Nguyen Ngoc Tuan , Kiefer Rudolf
Published: May 2022

A combination of polyoxometalates with polypyrrole is introduced in this work. Our goal was to include phosphotungstic acid (PTA) in different molar concentrations (0.005, 0.01, and 0.05 M) in the electropolymerization of pyrrole doped with dodecylbenzene sulfonate (DBS) and phosphotungstinates (PT), forming PPy/DBS-PT films. Scanning electron microscopy (SEM) revealed that the PPy/DBS-PT films became denser and more compact with increasing PTA concentrations. The incorporation of PT in PPy/DBS was analyzed using Fourier-transform infrared (FTIR) and energy dispersive X-ray (EDX) spectroscopy. The linear actuation in cyclic voltammetry and potential square wave steps in an organic electrolyte revealed increasing mixed actuation, with major expansion upon oxidation found for PPy/DBS-PT films with a PTA concentration of 0.005 M. Best results of a strain of 12.8% and stress at 0.68 MPa were obtained for PPy/DBS-PT (0.01 M). The PPy/DBS-PT films polymerized in the presence of 0.05 M of PTA and showed main expansion upon reduction, changing the actuation direction. Chronopotentiometric measurements of PPy/DBS-PT samples were conducted to determine the specific capacitance optimal for a 0.01 M PTA concentration in the range of 80 F g−1 (±0.22 A g−1).
Analysis of the Influence of Component Type and Operating Condition on the Selection of Preventive Maintenance Strategy in Multistage Industrial Machines: A Case Study
Authors: García Francisco Javier Álvarez , Salgado David Rodríguez
Published: May 2022

The study of industrial multistage component’s reliability, availability and efficiency poses a constant challenge for the manufacturing industry. Components that suffer wear and tear must be replaced according to the times recommended by the manufacturers and users of the machines. This paper studies the influence of the individual maintenance values of Main Time To Repair (MTTR), Time To Provisioning (TTPR) and Time Lost Production (TLP) of each component, including the type of component and operation conditions as variables that can influence deciding on the best preventive maintenance strategy for each component. The comparison between different preventive maintenance strategies, Preventive Programming Maintenance (PPM) and Improve Preventive Programming Maintenance (IPPM) provide very interesting efficiency and availability results in the components. A case study is evaluated using PPM and IPPM strategies checking the improvement in availability and efficiency of the components. However, the improvement of stock cost of components by adopting IPPM strategy supposes the search of another more optimal solution. This paper concludes with the creation of a multidimensional matrix, for that purpose, to select the best preventive maintenance strategy (PPM, IPPM or interval between PPM and IPPM) for each component of the multistage machine based on its operating conditions, type of component and individual maintenance times. The authors consider this matrix can be used by other industrial manufacturing multistage machines to decide on the best maintenance strategy for their components.
Prediction Method of Aeroengine Rotor Assembly Errors Based on a Novel Multi-Axis Measuring and Connecting Mechanism
Authors: Zhou Tianyi , Gao Hang , Wang Xuanping , Li Lun , Chen Jianfeng , Peng Can
Published: May 2022

The aeroengine industry has set strict upper limits for assembly errors in rotor-connecting processes, because assembly errors significantly affect aeroengine stability. Applications of multi-axis mechanisms have the potential to solve the low efficiency of traditional manual connection processes. However, multiple error sources are simultaneously introduced. Thus, an accurate prediction method of rotor assembly error considering multiple error sources is of vital importance, by which the applicability of the new mechanism to rotors can be tested. In this study, a new prediction method for rotor assembly errors is proposed based on the use of a novel multi-axis measuring and connecting mechanism. First, the error propagation among the rotor errors, measurement errors, mechanism errors, and mounting errors is analyzed. Second, reasonable characterization models for these error sources are established using homogeneous transformation matrices. Third, based on the abovementioned error models, a new rotor assembly error prediction algorithm is constructed. It is highly consistent with the actual connection processes. Finally, verification experiments are conducted. The experimental results show that deviation rates of the average values of six types of assembly errors relative to the predictions are all lower than 14%. The proposed prediction method has acceptable accuracy and practical significance.
Digital-Twins-Driven Semi-Physical Simulation for Testing and Evaluation of Industrial Software in a Smart Manufacturing System
Authors: Cheng Keqiang , Wang Qiang , Yang Dongyu , Dai Qingyun , Wang Meilin
Published: May 2022

To satisfy the needs of the individualized manufacturing of products, the smart manufacturing system (SMS) is frequently reconfigured. To quickly verify the reliability and adaptability of industrial software in reconfiguring the SMS for new or upgraded product orders, a semi-physical simulation method for testing and evaluation of industrial software is proposed based on digital-twins-driven technology. By establishing a semi-physical simulation model of SMS, the reliability and robustness of the software system are quickly verified by running industrial software in various manufacturing scenarios. In this paper, the key technologies to carry out semi-physical simulation testing and evaluation of industrial software for SMSs are expounded in detail, including how to synchronize cyber and physical systems, how to conduct semi-physical accelerated simulation testing, and how to identify defects quickly in industrial software used in actual production environments. By establishing a semi-physical simulation production line model for stepper motors, the effectiveness and practicality of the proposed approach are verified, and the testing verification time of industrial software is significantly reduced. Finally, the robustness of the industrial software for SMS is further verified by conducting fault injection testing, so as to provide implications for fault prognostics or fault-prevention research.
Windage Loss Characteristics of Aviation Spiral Bevel Gear and Windage Reduction Mechanism of Shroud
Authors: Li Linlin , Wang Sanmin , Zou Haoran , Cao Peitao
Published: May 2022

With the increasing speed of aviation gear, windage loss has been the main component of power loss. Reducing windage is of great significance to improving the transmission efficiency of aviation spiral bevel gear. Firstly, the calculation model of enclosed spiral bevel gear was established, and the basic physical mechanism of windage power loss was illustrated by numerical simulation, so as to obtain the mechanical and energy characteristics of windage loss. Then, the influence of the geometry and clearance parameters of the shroud on the windage loss was studied by orthogonal test, variance analysis and optimization design. The mechanism of the shroud to reduce the windage loss under the multi-factors was also studied, and their interaction was obtained. The results show that the tooth surface clearance, heel clearance and meshing opening are significant factors, and the most significant factor is the heel clearance. The non-significant factor is the interaction of each factor. The least significant factor is the toe clearance. In other words, the windage power loss can be reduced to the greatest extent by simultaneously reducing the meshing opening of the shroud and the clearance value between shroud and the surface of the gear. Finally, based on the mechanism of reducing windage loss of shroud, the optimization design principle affecting the structural performance of shroud is put forward, which provides theoretical guidance for the practical application of shroud in windage reduction engineering.
Maximal Regularity Estimates and the Solvability of Nonlinear Differential Equations
Authors: Ospanov Myrzagali , Ospanov Kordan
Published: May 2022

We study a type of third-order linear differential equations with variable and unbounded coefficients, which are defined in an infinite interval. We also consider a non-linear generalization with coefficients that depends on an unknown function. We establish sufficient conditions for the correctness of this linear equation and the maximal regularity estimate for their solution. Using these results, we prove the solvability of a nonlinear differential equation and estimate the norms of its terms.
Using Augmented Reality to Enhance Students’ Representational Fluency: The Case of Linear Functions
Authors: Li Shuhui , Shen Yihua , Jiao Xinyue , Cai Su
Published: May 2022

Using multiple representations is advocated and emphasized in mathematics and science education. However, many students have difficulty connecting multiple representations of linear functions. Augmented Reality (AR) may affect these teaching and learning difficulties by offering dynamically linked representations. Inspired by this, our study aims to develop, implement, and evaluate an AR-based multi-representational learning environment (MRLE) with three representations of linear functions. The data were collected from 82 seventh graders from two high-performing classes in an urban area in China, through a pre-test, a post-questionnaire, and follow-up interviews. The results reveal that students were satisfied with the AR-based MRLE, which assisted in enhancing their understanding of the real-life, symbolic, and graphical representations and connections among them. Regarding students’ interactions with multiple representations, apparent differences in learning sequences and preferences existed among students in terms of their representational learning profile. In sum, learning in the AR-based MRLE is a complex interaction process between the mathematics content, forms of representations, digital features, and students’ representational learning profile.
New Properties and Identities for Fibonacci Finite Operator Quaternions
Authors: Terzioğlu Nazlıhan , Kızılateş Can , Du Wei-Shih
Published: May 2022

In this paper, with the help of the finite operators and Fibonacci numbers, we define a new family of quaternions whose components are the Fibonacci finite operator numbers. We also provide some properties of these types of quaternions. Moreover, we derive many identities related to Fibonacci finite operator quaternions by using the matrix representations.
A Correlational Predictive Study of Teacher Well-Being and Professional Success in Foreign Language Student Teachers
Authors: Cardoso-Pulido Manuel Jesús , Guijarro-Ojeda Juan Ramón , Pérez-Valverde Cristina
Published: May 2022

The teaching profession has an important emotional burden that, together with the erosion of different elements that compose it from continuous educational reform to the bad behavior and demotivation of students has led to many teachers experiencing physical and psychological illness or leaving the profession. Nevertheless, studies and interventions in this regard are still insufficient in the Spanish context. This situation also exponentially affects pre-service teachers, which according to numerous studies is the stage during which the diminishing of teacher well-being begins and consolidates. Within this panorama, with this study the authors pursue to determine which dimensions of teacher well-being are capable of predicting the professional success of 88 pre-service primary education teachers who specialize in a foreign language so that they can be addressed in the training process. To this end, an ex post facto study was carried out correlating the following instruments: the Teacher Distress Questionnaire, the Trait Emotional Intelligence Questionnaire and the Maslach Burnout Inventory-Educators Survey with an adaptation of the Rueda de la vida escolar sobre el éxito y la satisfacción laboral del docente (Wheel of school life on teacher success and job satisfaction). Multiple linear regression revealed that of all the variables studied for teacher well-being (intrinsic motivation, expectations about good professional performance, professional distress, professional exhaustion, irrational beliefs, emotional intelligence and burnout) only emotional intelligence and intrinsic motivation have the ability to predict the success of teachers in training in their future professional performance. This result is of paramount importance for reconsidering the training that teachers receive during their university stage, which currently and substantially prioritizes the cognitive component over psychosocial and emotional components.
Preface to the Special Issue on “Advances in Artificial Intelligence: Models, Optimization, and Machine Learning”
Authors: Leon Florin , Hulea Mircea , Gavrilescu Marius
Published: May 2022

Recent advancements in artificial intelligence and machine learning have led to the development of powerful tools for use in problem solving in a wide array of scientific and technical fields [...]
Supply Chain Pricing Models Considering Risk Attitudes under Free-Riding Behavior
Authors: Gao Taiguang , Wang Kui , Mei Yali , He Shan , Wang Yanfang
Published: May 2022

The free-riding behavior of companies that do not act will bring losses to companies that provide services. A market consists of two secondary supply chains: manufacturers and retailers. Each supply chain can choose to adopt promotional strategies to expand its market demand. This paper constructs the centralized decision-making in the supply chain and the Nash game competition model between supply chains and primarily studies the impact of risk aversion and the free-riding coefficient on supply chain pricing, promotion strategy selection, and expected utility. We show that the supply chain with high-risk aversion has relatively low pricing, but the demand and a total expected utility are high. We also identify that, on the premise of the same risk aversion degree of the two supply chains, when the free-riding coefficient between the chains is small and equal, the supply chain tends to implement the promotion strategy. When consumers have the same preference for the products of two retailers, the pricing of the free-riding supply chain increases with the increase in the free-riding coefficient, while the supply chain with a promotion strategy is the opposite. Based on the numerical results, we further give the optimal one-way free-riding coefficient when the two supply chains have the same degree of risk aversion; when there is a bidirectional free-riding behavior in the market, competition among supply chains gradually tends to the first two scenarios.
State Estimation for Complex-Valued Inertial Neural Networks with Multiple Time Delays
Authors: Yu Yaning , Zhang Ziye
Published: May 2022

In this paper, the problem of state estimation for complex-valued inertial neural networks with leakage, additive and distributed delays is considered. By means of the Lyapunov–Krasovskii functional method, the Jensen inequality, and the reciprocally convex approach, a delay-dependent criterion based on linear matrix inequalities (LMIs) is derived. At the same time, the network state is estimated by observing the output measurements to ensure the global asymptotic stability of the error system. Finally, two examples are given to verify the effectiveness of the proposed method.
Identification and Classification of Aggregation Operators Using Bipolar Complex Fuzzy Settings and Their Application in Decision Support Systems
Authors: Mahmood Tahir , Rehman Ubaid ur , Ali Zeeshan , Aslam Muhammad , Chinram Ronnason
Published: May 2022

The idea of bipolar complex fuzzy (BCF) sets, as a genuine modification of both bipolar fuzzy sets and complex fuzzy sets, gives a massive valuable framework for representing and evaluating ambiguous information. In intelligence decision making based on BCF sets, it is a critical dilemma to compare or rank positive and negative membership grades. In this framework, we deliberated various techniques for aggregating the collection of information into a singleton set, called BCF weighted arithmetic averaging (BCFWAA), BCF ordered weighted arithmetic averaging (BCFOWAA), BCF weighted geometric averaging (BCFWGA), and BCF ordered weighted geometric averaging (BCFOWGA) operators for BCF numbers (BCFNs). To illustrate the feasibility and original worth of the diagnosed approaches, we demonstrated various properties of the diagnosed operators, in addition to their capability that the evaluated value of a set of BCF numbers is a unique BCF number. Further, multiattribute decision making (“MADM”) refers to a technique employed to compute a brief and dominant assessment of opinions with multiattributes. The main influence of this theory is implementing the diagnosed theory in the field of the MADM tool using BCF settings. Finally, a benchmark dilemma is used for comparison with various prevailing techniques to justify the cogency and dominancy of the evaluated operators.
A Note on Generalized Quasi-Einstein and (λ, n + m)-Einstein Manifolds with Harmonic Conformal Tensor
Authors: Shenawy Sameh , Mantica Carlo Alberto , Molinari Luca Guido , Bin Turki Nasser
Published: May 2022

Sufficient conditions for a Lorentzian generalized quasi-Einstein manifold M,g,f,μ to be a generalized Robertson–Walker spacetime with Einstein fibers are derived. The Ricci tensor in this case gains the perfect fluid form. Likewise, it is proven that a λ,n+m-Einstein manifold M,g,w having harmonic Weyl tensor, ∇jw∇mwCjklm=0 and ∇lw∇lw<0 reduces to a perfect fluid generalized Robertson–Walker spacetime with Einstein fibers. Finally, M,g,w reduces to a perfect fluid manifold if φ=−m∇lnw is a φRic-vector field on M and to an Einstein manifold if ψ=∇w is a ψRic-vector field on M. Some consequences of these results are considered.