bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Printing of PLLA/Biomineral Composite Bone Tissue Engineering Scaffolds
Authors: Gang Fangli , Ye Weilong , Ma Chunyang , Wang Wenting , Xiao Yi , Liu Chang , Sun Xiaodan
Published: June 2022

Tissue engineering is one of the most effective ways to treat bone defects in recent years. However, current highly active bone tissue engineering (BTE) scaffolds are mainly based on the addition of active biological components (such as growth factors) to promote bone repair. High cost, easy inactivation and complex regulatory requirements greatly limit their practical applications. In addition, conventional fabrication methods make it difficult to meet the needs of personalized customization for the macroscopic and internal structure of tissue engineering scaffolds. Herein, this paper proposes to select five natural biominerals (eggshell, pearl, turtle shell, degelatinated deer antler and cuttlebone) with widely available sources, low price and potential osteo-inductive activity as functional particles. Subsequently compounding them into L-polylactic acid (PLLA) biomaterial ink to further explore 3D printing processes of the composite scaffold, and reveal their potential as biomimetic 3D scaffolds for bone tissue repair. The research results of this project provide a new idea for the construction of a 3D scaffold with growth-factor-free biomimetic structure, personalized customization ability and osteo-inductive activity.
Pressure-Dependent Structure of BaZrO3 Crystals as Determined by Raman Spectroscopy
Authors: Gim Dong-Hyeon , Sur Yeahan , Lee Yoon Han , Lee Jeong Hyuk , Moon Soonjae , Oh Yoon Seok , Kim Kee Hoon
Published: June 2022

The structure of dielectric perovskite BaZrO3, long known to be cubic at room temperature without any structural phase transition with variation in temperature, has been recently disputed to have different ground state structures with lower symmetries involving octahedra rotation. Pressure-dependent Raman scattering measurements can identify the hierarchy of energetically-adjacent polymorphs, helping in turn to understand its ground state structure at atmospheric pressure. Here, the Raman scattering spectra of high-quality BaZrO3 single crystals grown by the optical floating zone method are investigated in a pressure range from 1 atm to 42 GPa. First, based on the analyses of the infrared and Raman spectra measured at atmospheric pressure, it was found that all the observed vibrational modes could be assigned according to the cubic Pm3¯m structure. In addition, by applying pressure, two structural phase transitions were found at 8.4 and 19.2 GPa, one from the cubic to the rhombohedral R3¯c phase and the other from the rhombohedral to the tetragonal I4/mcm phase. Based on the two pressure-induced structural phase transitions, the true ground state structure of BaZrO3 at room temperature and ambient pressure was corroborated to be cubic while the rhombohedral phase was the closest second.
Influence of Magnetic Water on Concrete Properties with Different Magnetic Field Exposure Times
Authors: Ramalingam Malathy , Narayanan Karuppasamy , Masilamani Arivoli , Kathirvel Parthiban , Murali Gunasekaran , Vatin Nikolai Ivanovich
Published: June 2022

The characteristics of a concrete mix are purely dependent on the hydration of cement that is carried forward by using the water quality used in the mix. Several researchers have focused on incorporating pozzolanic or nanomaterials to improve the hydration mechanisms and impart high strength to concrete. A new technology has been introduced to improve the properties of concrete by magnetic-field-treated water (MFTW). Due to magnetization, water particles become charged and the molecules inside the water cluster decrease from 13 to 5 or 6, which eventually decreases the hardness of water, thus improving the strength of concrete when compared to the use of normal water (NW). In advanced construction techniques and practices, the application of Magnetic Water (MW) plays an important role in boosting physicochemical properties. This research work focused on evaluating the standards of water quality through physiochemical analysis, such as Electrical Conductivity (EC), Viscosity, pH, and Total Dissolved Solids (TDS) with the MW at different exposure periods (60 min (MW60), 45 min (MW45), 30 min (MW30), 15 min (MW15), and instant exposure (MWI)). Experiments were carried out to evaluate the fresh, hardened, and microstructural behavior of concrete made with magnetic water (MW) using a permanent magnet of PERMAG (N407) under a field intensity of 0.9 Tesla. In addition, optical properties such as X-ray Diffraction (XRD) and Ultraviolet (UV) absorption were considered for the MW60 mix to ensure water magnetization. Characterization methods such as Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) were employed for NWC and MWC to quantify the hydrated products. From the results, it was observed that the magnetic effect on water characteristics showed significant improvement in the concrete properties with the increase in exposure duration. There were increments of 25.6% and 24.1% in workability and compressive strength, respectively, for the MW60 mix compared to normal water concrete (NWC).
Evaluation of Shear Bond Strength between Resin Composites and Conventional Glass Ionomer Cement in Class II Restorative Technique—An In Vitro Study
Authors: Bilgrami Afreen , Maqsood Afsheen , Alam Mohammad Khursheed , Ahmed Naseer , Mustafa Mohammed , Alqahtani Ali Robaian , Alshehri Abdullah , Alqahtani Abdullah Ali , Alghannam Shahad
Published: June 2022

The success of dental restorations depends mainly on the ability to bond to other filling materials and tooth substances, in order to resist the multitude of forces acting on the bond within the oral cavity. Although the shortcomings of composite resins have been significantly reduced over the past three decades, microleakage due to shrinkage under masticatory loads is unavoidable. In order to overcome such problems, two materials laminated with matched properties can be used to achieve optimum results. The sandwich technique is an approach in which dentine is replaced by glass ionomer cement (GIC), and enamel is replaced by composite resin. In the past, numerous materials have been proposed with adequate properties to be used in this manner, but the results are conflicting in terms of bonding to the various forms of GIC, and the appearance of microcracks or gap formation during functional loading. This study aimed to evaluate the shear bond strength (SBS) and mode of failure between the following core materials: composite resins (CR) (Methacrylate Z350™, Ceram X™, and Spectrum™) with a base material of glass ionomer cement (GIC, Ketac Molar™). Eight samples were made with the help of polytetrafluoroethylene sheets (TEFLON, Wilmington, DE, USA). Each sheet consisted of holes which were 4 mm in diameter and 2 mm in thickness. The combination of materials was sandwiched. The samples were stored in distilled water and then placed in an incubator for 24 h in order to ensure complete polymerization. The samples were thermocycled for 500 cycles between 5–55 °C/ 30 s. Following thermocycling, SBS testing was performed using a universal testing machine. Additionally, scanning electron microscopy (SEM) was performed on representative samples for the bond failure analysis between GIC and the composite resins. The Ceram-X™ nanocomposite showed significantly higher bond strength than Methacrylate Z350™ or Spectrum™ (p = 0.002). The Methacrylate Z350™ and the Spectrum™ composite specimens demonstrated a similar SBS (p = 0.281). The SBS of the Ceram X™ to GIC was the highest compared to Methacrylate Z350™ and Spectrum™. Therefore Ceram X™ may produce a better bond with GIC, and may protect teeth against recurrent caries and failure of the restoration. Methacrylate Z350™ is comparable to Spectrum™ CR and can be used as an alternative. A combination of adhesive and mixed failure was observed in Methacrylate Z350™ CR and GIC, while adhesive failure was predominantly found in both Ceram X™ and Spectrum™ with GIC restorations.
Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
Authors: Lotkov Aleksandr , Grishkov Victor , Laptev Roman , Mironov Yuri , Zhapova Dorzhima , Girsova Natalia , Gusarenko Angelina , Barmina Elena , Kashina Olga
Published: June 2022

The experimental results regarding the effect of warm (573 K) abc pressing with an increase in the specified true strain, e, up to 9.55, on the microstructure and crystal structure defects (dislocations, vacancies) of the Ti49.8Ni50.2 (at %) alloy are presented. It is shown that all samples (regardless of e) have a two-level microstructure. The grains–subgrains of the submicrocrystalline scale level are in the volumes of large grains. The average sizes of both large grains and subgrain grains decrease with increasing e to 9.55 (from 27 to 12 µm and from 0.36 to 0.13 µm, respectively). All samples had a two-phase state (rhombohedral R and monoclinic B19′ martensitic phases) at 295 K. The full-profile analysis of X-ray reflections of the B2 phase obtained at 393 K shows that the dislocation density increases from 1014 m−2 to 1015 m−2 after pressing with e = 1.84 and reaches 2·1015 m−2 when e increases to 9.55. It has been established by positron annihilation lifetime spectroscopy that dislocations are the main type of defects in initial samples and the only type of defects in samples after abc pressing. The lifetime of positrons trapped by dislocations is 166 ps, and the intensity of this component increases from 83% in the initial samples to 99.4% after pressing with e = 9.55. The initial samples contain a component with a positron lifetime of 192 ps (intensity 16.4%), which corresponds to the presence of monovacancies in the nickel sublattice of the B2 phase (concentration ≈10−5). This component is absent in the positron lifetime spectra in the samples after pressing. The results of the analysis of the Doppler broadening spectroscopy correlate with the data obtained by the positron annihilation lifetime spectroscopy.
New Heterotrinuclear CuIILnIIICuII (Ln = Ho, Er) Compounds with the Schiff Base: Syntheses, Structural Characterization, Thermal and Magnetic Properties
Authors: Cristóvão Beata , Osypiuk Dariusz , Bartyzel Agata
Published: June 2022

New heterotrinuclear complexes with the general formula [Cu2Ln(H2L)(HL)(NO3)2]·MeOH (Ln = Ho (1), Er (2), H4L = N,N′-bis(2,3-dihydroxybenzylidene)-1,3-diaminopropane) were synthesized using compartmental Schiff base ligand in conjugation with auxiliary ligands. The compounds were characterized by elemental analysis, ATR-FTIR spectroscopy, X-ray diffraction, TG, DSC, TG-FTIR and XRD analysis. The N2O4 salen-type ligand coordinates 3d and 4f metal centers via azomethine nitrogen and phenoxo oxygen atoms, respectively, to form heteropolynuclear complexes having CuO2Ln cores. In the crystals 1 and 2, two terminal Cu(II) ions are penta-coordinated with a distorted square-pyramidal geometry and a LnIII ion with trigonal dodecahedral geometry is coordinated by eight oxygen atoms from [CuII(H2L)(NO3)]− and [CuII(HL)(NO3)]2− units. Compounds 1 and 2 are stable at room temperature. During heating, they decompose in a similar way. In the first decomposition step, they lose solvent molecules. The exothermic decomposition of ligands is connected with emission large amounts of gaseous products e.g., water, nitric oxides, carbon dioxide, carbon monoxide. The final solid products of decomposition 1 and 2 in air are mixtures of CuO and Ho2O3/Er2O3. The measurements of magnetic susceptibilities and field dependent magnetization indicate the ferromagnetic interaction between CuII and HoIII ions 1.
Photoelectric Properties of Planar and Mesoporous Structured Perovskite Solar Cells
Authors: Ašmontas Steponas , Čerškus Aurimas , Gradauskas Jonas , Grigucevičienė Asta , Juškėnas Remigijus , Leinartas Konstantinas , Lučun Andžej , Petrauskas Kazimieras , Selskis Algirdas , Staišiūnas Laurynas , Sužiedėlis Algirdas , Šilėnas Aldis , Širmulis Edmundas
Published: June 2022

The high efficiency of perovskite solar cells strongly depends on the quality of perovskite films and carrier extraction layers. Here, we present the results of an investigation of the photoelectric properties of solar cells based on perovskite films grown on compact and mesoporous titanium dioxide layers. Kinetics of charge carrier transport and their extraction in triple-cation perovskite solar cells were studied by using transient photovoltage and time-resolved photoluminescence decay measurements. X-ray diffraction analysis revealed that the crystallinity of the perovskite films grown on mesoporous titanium dioxide is better compared to the films grown on compact TiO2. Mesoporous structured perovskite solar cells are found to have higher power conversion efficiency mainly due to enlarged perovskite/mesoporous -TiO2 interfacial area and better crystallinity of their perovskite films.
Evaluation of Sediments from the River Drava and Their Potential for Further Use in the Building Sector
Authors: Ducman Vilma , Bizjak Karmen Fifer , Likar Barbara , Kolar Mitja , Robba Ana , Imperl Jernej , Božič Mojca , Gregorc Boštjan
Published: June 2022

Sedimentation is a naturally occurring process of allowing particles in water bodies to settle out of the suspension under a gravity effect. In this study, the sediments of the Drava River were fully investigated to determine the heavy metal concentrations along the river and their potential reuse in the construction sector. Naturally dehydrated sediments from the Drava River were tested as an additive for the production of fired bricks. The dredged sediments were used as a substitute for natural brick clay in amounts up to 50% by weight, and it was confirmed that up to 20% by weight of the added sediment could be used directly in the process without critically affecting performance. Finally, the naturally dehydrated sediments were also evaluated for their use as a filling material in the construction of levees. The natural moisture content of the dehydrated sediment was too high for it to be used without additives, so quicklime was added as an inorganic binder. The test results showed an improvement in the geotechnical properties of the material to such an extent that it is suitable as a filling material for levees.
Stability Analysis of the Horseshoe Tunnel Face in Rock Masses
Authors: Liu Jun , Zhang Qingsong , Liu An , Chen Guanghui
Published: June 2022

Accurately estimating the stability of horseshoe tunnel faces remains a challenge, especially when excavating in rock masses. This study aims to propose an analytical model to analyze the stability of the horseshoe tunnel face in rock masses. Based on discretization and “point-by-point” techniques, a rotational failure model for horseshoe tunnel faces is first proposed. Based on the proposed failure model, the upper-bound limit analysis method is then adopted to determine the limit support pressure of the tunnel face under the nonlinear Hoek–Brown failure criterion, and the calculated results are validated by comparisons with the numerical results. Finally, the effects of the rock properties on the limit support pressure and the 3D failure surface are discussed. The results show that (1) compared with the numerical simulation method, the proposed method is an efficient and accurate approach to evaluating the face stability of the horseshoe tunnel; (2) from the parametric analysis, it can be seen that the normalized limit support pressure of the tunnel face decreases with the increasing of geological strength index, GSI, Hoek–Brown coefficient, mi, and uniaxial compressive strength, σci, and with the decreasing of the disturbance coefficient of rock, Di; and (3) a larger 3D failure surface is associated with a high value of the normalized limit support pressure.
DMnet: A New Few-Shot Framework for Wind Turbine Surface Defect Detection
Authors: Yu Jinyun , Liu Kaipei , Qin Liang , Li Qiang , Zhao Feng , Wang Qiulin , Liu Haofeng , Li Boqiang , Wang Jing , Li Kexin
Published: June 2022

In the field of wind turbine surface defect detection, most existing defect detection algorithms have a single solution with poor generalization to the dilemma of insufficient defect samples and have unsatisfactory precision for small and concealed defects. Inspired by meta-learning ideology, we devised a cross-task training strategy. By exploring the common properties between tasks, the hypothesis space shrinks so that the needed sample size that satisfies a reliable empirical risk minimizer is reduced. To improve the training efficiency, a depth metric-based classification method is specially designed to find a sample-matching feature space with a good similarity measure by cosine distance. Additionally, a real-time feedback session is innovatively added to the model training loop, which performs information enhancement and filtering according to the task relevance. With dynamic activation mapping, it alleviates the information loss during traditional pooling operations, thus helping to avoid the missed detection of small-scale targets. Experimental results show that the proposed method has significantly improved the defect recognition ability under few-shot training conditions.
Application of ROC Curve Analysis for Predicting Students’ Passing Grade in a Course Based on Prerequisite Grades
Authors: Orynbassar Alibek , Sapazhanov Yershat , Kadyrov Shirali , Lyublinskaya Irina
Published: June 2022

Determining prerequisite requirements is vital for successful curriculum development and student on-schedule completion of the course of study. This study adapts the Receiver Operating Characteristic (ROC) curve analysis to determine a threshold grade in a prerequisite course necessary for passing the next course in a sequence. This method was tested on a dataset of Calculus 1 and Calculus 2 grades of 164 undergraduate students majoring in mathematics at a private university in Kazakhstan. The results showed that while the currently used practice of setting prerequisite grade requirements is accurately identifying successful completions of Calculus 2, the ROC method is more accurate in identifying possible failures in Calculus 2. The findings also indicate that prior completion of Calculus 1 is positively associated with success in a Calculus 2 course. Thus, this study contributes to the field of mathematics education by providing a new data-driven methodology for determining the optimal threshold grade for mathematics prerequisite courses.
Reduced Calibration Strategy Using a Basketball for RGB-D Cameras
Authors: Roman-Rivera Luis-Rogelio , Sotelo-Rodríguez Israel , Pedraza-Ortega Jesus Carlos , Aceves-Fernandez Marco Antonio , Ramos-Arreguín Juan Manuel , Gorrostieta-Hurtado Efrén
Published: June 2022

RGB-D cameras produce depth and color information commonly used in the 3D reconstruction and vision computer areas. Different cameras with the same model usually produce images with different calibration errors. The color and depth layer usually requires calibration to minimize alignment errors, adjust precision, and improve data quality in general. Standard calibration protocols for RGB-D cameras require a controlled environment to allow operators to take many RGB and depth pair images as an input for calibration frameworks making the calibration protocol challenging to implement without ideal conditions and the operator experience. In this work, we proposed a novel strategy that simplifies the calibration protocol by requiring fewer images than other methods. Our strategy uses an ordinary object, a know-size basketball, as a ground truth sphere geometry during the calibration. Our experiments show comparable results requiring fewer images and non-ideal scene conditions than a reference method to align color and depth image layers.
Harris Hawk Optimization-Based Deep Neural Networks Architecture for Optimal Bidding in the Electricity Market
Authors: Jain Kavita , Jasser Muhammed Basheer , Hamzah Muzaffar , Saxena Akash , Mohamed Ali Wagdy
Published: June 2022

In the power sector, competitive strategic bidding optimization has become a major challenge. Digital plate-form provides a superior technical base as well as backing for the optimization’s execution. The state-of-the-art frameworks used for simulating strategic bidding decisions in deregulated electricity markets (EM’s) in this article are bi-level optimization and neural networks. In this research, we provide HHO-NN (Harris Hawk Optimization-Neural network), a novel algorithm based on Harris Hawk Optimization (HHO) that is capable of fast convergence when compared to previous evolutionary algorithms for automatically searching for meaningful multilayered perceptron neural networks (MPNNs) topologies for optimal bidding. This technique usually demands a considerable amount of time and computer resources. This method sets up the problem in multi-dimensional continuous state-action spaces, allowing market players to get precise information on the effect of their bidding judgments on the market clearing results, as well as implement more valuable bidding decisions by utilizing a whole action domain and accounting for non-convex operating principles. Due to the use of the MPNN, case studies show that the suggested methodology delivers a much larger profit than other state-of-the-art methods and has a better computational performance than the benchmark HHO technique.
Modified Iterative Schemes for a Fixed Point Problem and a Split Variational Inclusion Problem
Authors: Akram Mohammad , Dilshad Mohammad , Rajpoot Arvind Kumar , Babu Feeroz , Ahmad Rais , Yao Jen-Chih
Published: June 2022

In this paper, we alter Wang’s new iterative method as well as apply it to find the common solution of fixed point problem (FPP) and split variational inclusion problem (SpVIP) in Hilbert space. We discuss the weak convergence for (SpVIP) and strong convergence for the common solution of (SpVIP) and (FPP) using appropriate assumptions. Some consequences of the proposed methods are studied. We compare our iterative schemes with other existing related schemes.
Modified Erlang Loss System for Cognitive Wireless Networks
Authors: Morozov Evsey , Rogozin Stepan , Nguyen Hung Q. , Phung-Duc Tuan
Published: June 2022

This paper considers a modified Erlang loss system for cognitive wireless networks and related applications. A primary user has pre-emptive priority over secondary users, and the primary customer is lost if upon arrival all the channels are used by other primary users. Secondary users cognitively use idle channels, and they can stay (either in an infinite buffer or in an orbit) in cases where idle channels are not available upon arrival or they are interrupted by primary users. While the infinite buffer model represents the case with zero sensing time, the infinite orbit model represents the case with positive sensing time. We obtain an explicit stability condition for the cases where arrival processes of primary users and secondary users follow Poisson processes, and their service times follow two distinct arbitrary distributions. The stability condition is insensitive to the service time distributions and implies the maximal throughout of secondary users. Moreover, we extend the stability analysis to the system with outgoing calls. For a special case of exponential service time distributions, we analyze the buffered system in depth to show the effect of parameters on the delay performance and the mean number of interruptions of secondary users. Our simulations for distributions rather than exponential reveal that the mean number of terminations for secondary users is less sensitive to the service time distribution of primary users.
Exact Solutions of the Bloch Equations of a Two-Level Atom Driven by the Generalized Double Exponential Quotient Pulses with Dephasing
Authors: Grira Sofiane , Boutabba Nadia , Eleuch Hichem
Published: June 2022

We theoretically investigate a two-level atom driven by a time-dependent external field with a generalized double exponential temporal shape, in the presence of dephasing. Therefore, we provide exact analytical solutions for the population inversion, the real and the imaginary parts of the coherence for a family of chirped and time-dependent laser waveforms. We demonstrate that the remaining atomic population inversion can be controlled by the manipulation of the pulse’s shape structure.
Using Fuzzy Comprehensive Evaluation to Assess the Competency of Full-Time Water Conservancy Emergency Rescue Teams
Authors: Fan Chuanhao , Chen Yan , Zhu Yan , Zhang Long , Wu Wenjuan , Ling Bin , Tang Sijie
Published: June 2022

Drought and flood disasters are common events threatening the safety of human lives, and full-time water conservancy emergency rescue teams play an important role in fighting against these disasters. In this paper, a competency assessment indicator system full-time water conservancy emergency rescue teams was first constructed by the Delphi Method. Four first-level, seventeen second-level and sixty third-level competency assessment indicators are proposed. Secondly, the weights of assessment indicators for a full-time water conservancy emergency rescue team at all levels were obtained by an analytic hierarchy process. Thirdly, based on that established assessment indicator system, the competency of the water conservancy emergency rescue team in Province A was assessed using a fuzzy comprehensive evaluation. Finally, the assessment results for the full-time water conservancy emergency rescue team in Province A were obtained. This study concludes by noting some practical implications of the results.
Exploring the Driving Forces of Stock-Cryptocurrency Comovements during COVID-19 Pandemic: An Analysis Using Wavelet Coherence and Seemingly Unrelated Regression
Authors: Abdul-Rahim Ruzita , Khalid Airil , Karim Zulkefly Abdul , Rashid Mamunur
Published: June 2022

This paper estimates the comovement between two leading cryptocurrencies and the G7 stock markets. It then attempts to explain the comovement with the rational investment theory by examining whether it is driven by market uncertainty measures, public attention to COVID-19, and the government’s containment and health responses to COVID-19. Wavelet Coherence heatmaps show that the stock-cryptocurrency comovements increase significantly and positively during the pandemic, indicating that cryptocurrencies lose their safe haven properties against stocks during the heightened market uncertainties. Over the longer investment horizons, Bitcoin reemerges as a safe haven or strong hedger while Ethereum’s properties weaken. Seemingly Unrelated Regression results reveal that the stock-cryptocurrency comovements are rationally explained by market uncertainties, government responses to COVID-19, and market fundamentals. However, the comovements are also driven by the fear of COVID-19 to a certain extent. Our findings offer valuable insights for investors considering cryptocurrencies to rebalance their equity portfolios during market distress. For policymakers, the Economic Policy Uncertainty (EPU) results suggest that government policies and regulatory frameworks can be used to regulate speculation and investment activities in the cryptocurrency market.
Information Disclosure Decision for Tourism O2O Supply Chain Based on Blockchain Technology
Authors: Zhou Li , Tan Chunqiao , Zhao Huimin
Published: June 2022

(1) Background: With the development of blockchain technology and fierce competition between tourism platforms, tourism platforms can adopt blockchain technology to disclose product information to enhance their core competitiveness. As for a tourism O2O, i.e., online to offline, supply chain, the tourism platform sells the product online, and the tour operator provides services offline. (2) Methods: We establish a game theory model and study the optimal strategies of supply chain members in two scenarios (decentralized and centralized) when the online platform does not adopt or adopts blockchain technology. Then, we introduce a two-part tariff contract for coordination. Furthermore, we discuss the impact of the cost of adopting blockchain technology, disclosing information and the proportion of information-sensitive consumers on the optimal strategies. (3) Conclusions: When the costs of adopting blockchain technology and information disclosure are low, if the proportion of information-sensitive consumers is large, adopting blockchain technology is beneficial to supply chain members. Compared with a wholesale price contract, a two-part tariff contract can encourage the platform to improve information disclosure quality, so the tour operator can adjust their cooperation contract to achieve Pareto improvements. Under a two-part tariff contract, the tourism platforms are more likely to disclose information and can effectively regulate the operational performance of the tourism O2O supply chain.
SEPSI: A Secure and Efficient Privacy-Preserving Set Intersection with Identity Authentication in IoT
Authors: Liu Bai , Zhang Xiangyi , Shi Runhua , Zhang Mingwu , Zhang Guoxing
Published: June 2022

The rapid development of the Internet of Things (IoT), big data and artificial intelligence (AI) technology has brought extensive IoT services to entities. However, most IoT services carry the risk of leaking privacy. Privacy-preserving set intersection in IoT is used for a wide range of basic services, and its privacy protection issues have received widespread attention. The traditional candidate protocols to solve the privacy-preserving set intersection are classical encryption protocols based on computational difficulty. With the emergence of quantum computing, some advanced quantum algorithms may undermine the security and reliability of traditional protocols. Therefore, it is important to design more secure privacy-preserving set intersection protocols. In addition, identity information is also very important compared to data security. To this end, we propose a quantum privacy-preserving set intersection protocol for IoT scenarios, which has higher security and linear communication efficiency. This protocol can protect identity anonymity while protecting private data.
Value of the Neutrophil to Lymphocyte Ratio and Platelet to Lymphocyte Ratio in Predicting CPET Performance in Patients with Stable CAD and Recent Elective PCI
Authors: Drugescu Andrei , Roca Mihai , Zota Ioana Mădălina , Costache Alexandru-Dan , Gavril Oana Irina , Gavril Radu Sebastian , Vasilcu Teodor Flaviu , Mitu Ovidiu , Esanu Irina Mihaela , Roca Iulia-Cristina , Ghiciuc Cristina Mihaela , Mitu Florin
Published: June 2022

Background and Objectives: Functional capacity (FC) assessed via cardiopulmonary exercise testing (CPET) is a novel, independent prognostic marker for patients with coronary artery disease (CAD). Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are two readily available predictors of systemic inflammation and cardiovascular event risk, which could be used as cost-effective predictors of poor FC. The purpose of this study was to evaluate the utility of NLR and PLR in predicting poor FC in patients with CAD and recent elective percutaneous coronary intervention (PCI). Materials and Methods: Our cross-sectional retrospective analysis included 80 patients with stable CAD and recent elective PCI (mean age 55.51 ± 11.83 years, 71.3% male) who were referred to a cardiovascular rehabilitation center from January 2020 to June 2021. All patients underwent clinical examination, cardiopulmonary exercise testing on a cycle ergometer, transthoracic echocardiography and standard blood analysis. Results: Patients were classified according to percent predicted oxygen uptake (% VO2 max) in two groups—poor FC (≤70%, n = 35) and preserved FC (>70%, n = 45). There was no significant difference between groups regarding age, gender ratio, presence of associated comorbidities, left ventricular ejection fraction and NLR. PLR was higher in patients with poor FC (169.8 ± 59.3 vs. 137.4 ± 35.9, p = 0.003). A PLR cut-off point of 139 had 74% sensitivity and 60% specificity in predicting poor FC. After multivariate analysis, PLR remained a significant predictor of poor functional status. Conclusions: Although CPET is the gold standard test for assessing FC prior to cardiovascular rehabilitation, its availability remains limited. PLR, a cheap and simple test, could predict poor FC in patients with stable CAD and recent elective PCI and help prioritize referral for cardiovascular rehabilitation in high-risk patients.
Senescence: Pathogenic Driver in Chronic Obstructive Pulmonary Disease
Authors: Rivas Melissa , Gupta Gayatri , Costanzo Louis , Ahmed Huma , Wyman Anne E. , Geraghty Patrick
Published: June 2022

Chronic obstructive pulmonary disease (COPD) is recognized as a disease of accelerated lung aging. Over the past two decades, mounting evidence suggests an accumulation of senescent cells within the lungs of patients with COPD that contributes to dysregulated tissue repair and the secretion of multiple inflammatory proteins, termed the senescence-associated secretory phenotype (SASP). Cellular senescence in COPD is linked to telomere dysfunction, DNA damage, and oxidative stress. This review gives an overview of the mechanistic contributions and pathologic consequences of cellular senescence in COPD and discusses potential therapeutic approaches targeting senescence-associated signaling in COPD.
Optimal Control of Direct Contact Membrane Distillation Operated under Fluctuating Energy Source
Authors: Ali Emad
Published: June 2022

An optimal control strategy was tested to regulate the flow rate of the cold stream to maximize the time-averaged water production of a laboratory-scale membrane distillation (MD) process. The MD process is operated under fluctuating inlet hot temperatures at a fixed flow rate for the hot stream. The inlet hot temperature fluctuates due to fluctuation in the supplied renewable energy source, such as solar energy. The simulation revealed the possibility of enhancing the average water production by up to 4.2%, by alternating the flow rate of the cold stream relative to a fixed flow rate of the hot stream. The enhancement was limited because, when using a long membrane, the mass flux degrades when the ratio of the cold stream to the hot stream flow rates is either very high or low. By modifying the control strategy to adapt the membrane length in addition to the flow rate of the cold stream, highly improved performance could be obtained. In fact, up to 40% enhancement in the average water production was observed.
A Tribological Study on the Effect of Reinforcing SiC and Al2O3 in Al7075: Applications for Spur Gears
Authors: Budapanahalli Shridhar H. , Mallur Shekhar B. , Patil Arun Y. , Alosaimi Abeer Mohamed , Khan Anish , Hussein Mahmoud Ali , Asiri Abdullah M.
Published: June 2022

In today’s world, efficiency and margin of safety are prime considerations for any applications. To address such parameters in aerospace or high-tech consumer products, there are still limitations in terms of capabilities from a material perspective. Aluminium 7075 is predominantly used as a combination material in these applications, but it has many drawbacks such as early wear/friction, low fatigue life cycle, high weight ratios, high deformation and stresses. To overcome these key issues, many reinforcements have been used to date. However, the results are not so convincing with respect to tribological applications, and the aforementioned issues still persist. In the current work, a novel hybrid composite comprising Aluminium 7075 as substrate and the reinforcement of silicon carbide and aluminium oxide at varying combinations of 3 to 9% in steps of 3% and a constant percentage of 5% were added, respectively. The exhaustive work focuses on extracting the mechanical, tribological and physical properties of a hybrid composite. Furthermore, a microcharacterisation study of these combinations was carried out using FE-SEM and EDX. In a continuation to this simulation, a study was performed using ANSYS Workbench to identify a suitable gear application with real-time loading conditions. The observed results show a tensile strength of 366 MPa for 6%SiC, hardness of 93 VHN and wear rate of 0.00025 mm3/Nm for the 9%SiC combination.
Processing of Low-Quality Gibbsite-Kaolinite Bauxites
Authors: Dyussenova Symbat , Abdulvaliyev Rinat , Akcil Ata , Gladyshev Sergey , Ruzakhunova Galiya
Published: June 2022

The results of studies on the processing of gibbsite-kaolinite bauxite are presented. The developed technology includes preliminary chemical activation and thermal transformation during enrichment to obtain a concentrate suitable for processing by the Bayer method. As a result of the chemical activation of gibbsite-kaolinite bauxite in a solution of sodium bicarbonate, a change in the phase composition occurs, which made it possible to improve the results of gravity enrichment with the production of a coarse-grained gibbsite fraction. The transformation of bauxite in the temperature range of 900–1000 °C is explained by the decomposition reactions of siderite, gibbsite, kaolinite, calcite, dolomite and sodium ferro-sulfide oxide, as well as the formation of sodium aluminosilicate, hematite, quartz and the chemically stable phase of corundum. The optimum firing temperature of bauxite is 950 °C, after which, as a result of alkaline treatment during chemical enrichment, the extraction of SiO2 into solution was 74.9%. A silicon modulus of enriched bauxite 10.9 units was obtained. As a result of the autoclave leaching of gibbsite-kaolinite bauxite after a two-stage enrichment, the maximum extraction of alumina into solution was 87.4%. The yield of red mud during the processing of bauxite enriched and calcined at 950 °C was 37.62%. During the autoclave leaching of bauxite without enrichment, the yield of red mud was 71%.
Fatigue Analysis of Long-Span Steel Truss Arched Bridge Part II: Fatigue Life Assessment of Suspenders Subjected to Dynamic Overloaded Moving Vehicles
Authors: Liu Peng , Lu Hongping , Chen Yixuan , Zhao Jian , An Luming , Wang Yuanqing , Liu Jianping
Published: June 2022

In a half-through steel arched bridge, the suspenders are the critical load transfer component that transmits the deck system and traffic load to the arch rib. These suspenders are subjected to traffic and environmental vibrations and are prone to fatigue failure, especially for overloaded moving vehicles. This paper aims to study the impact of moving vehicles’ overloaded rate on the fatigue performance of suspenders in a long-span three steel truss arch bridge. Based on the Mingzhu Bay steel arch bridge, a 3D finite element bridge model was first established and seven types of moving fatigue vehicle models were considered. Then the stress amplitude and dynamic response of the suspenders on the middle steel truss arch were studied under a standard, 25%, and 50% overloaded moving vehicles load. Following that, the Miner fatigue cumulative damage theory was employed to evaluate the fatigue life of the suspenders. The results show that the short suspenders in the middle steel truss arch have the shortest fatigue life but can still meet the design requirements under the standard load. However, the fatigue life of the suspenders decreases by 20% and 30% when the overloading rate reaches 25% and 50%. The fatigue life cannot meet the design requirement when the overload rate is 50%.
Hg/Se/PbSO4 Recovery by Microwave-Intensified HgSe Pyrolysis from Toxic Acid Mud
Authors: Zeng Hanlin , Liu Peng , Hong Yan , Yang Kun , Zhang Libo
Published: June 2022

The acid mud produced in the nonferrous smelting process is a hazardous waste, which mainly consists of elements Hg, Se, and Pb. Valuable metal (Hg/Se/Pb) can be recovered from acid mud by heat treatment. For safe disposal of the toxic acid mud, a new resource utilization technology by microwave roasting is proposed in this paper. The reaction mechanisms were revealed through thermodynamics and thermogravimetric analysis, which showed that the main reaction was the oxidative pyrolysis of HgSe in the process of roasting. Moreover, the mercury removal effects of acid mud by microwave heating and conventional heating were studied, the recovery rate of mercury by microwave heating for 30 min at 400 °C was 99.5%: far higher than that of conventional heating for 30 min at 500 °C (44.3%). This was due to the high dielectric constant of HgSe, as microwaves can preferentially heat HgSe and reduce the adsorption energy of HgSe on the surface of PbSO4 blocks, thus strengthening the pyrolysis process of HgSe and reducing energy consumption. The preferable prototyping technology for resource utilization of toxic acid mud should be microwave roasting. This study is of great significance for the realization of mercury pollution reduction and for green production of lead-zinc smelting.
Trends in ANPP Response to Temperature in Wetland Meadows across a Subcontinental Gradient in Patagonia
Authors: Irisarri Jorge Gonzalo N. , Cipriotti Pablo A. , Texeira Marcos , Curcio Matias H.
Published: June 2022

Due to ongoing global warming, seasonal patterns of aboveground net primary production (ANPP) may be altered by temperature trends. Of particular interest is the seasonal association between ANPP and temperature at the beginning of the growing season (the period encompassing minimum to maximum ANPP), where two contrasting mechanisms are in tension. On the one hand, the restrictions exerted by low temperatures in winter may be relaxed, increasing the slope of seasonal association between ANPP and temperature over the years. On the other hand, increases in temperature may increase water demand, reducing the slope over time. Across 543 wetland meadow areas in Patagonia, we estimated ANPP and obtained temperature records on a monthly basis from 2001 to 2019. The seasonal association between ANPP and temperature, tested through linear regression, was statistically significant in 96% of the cases (9921/10317 (543 wetland areas × 19 growing seasons)). The fitted linear models explained, on average, 84% of ANPP seasonal (June–December) variations. Through regression trees, we found out that the two tested mechanisms, the relaxation of temperature restriction and the increase in water demand, showed clear spatial patterns. The relaxation due to temperature increase took place at higher latitudes, but the water-limiting mechanism increased over mid-latitude areas.
Diversity and Functional Roles of the Gut Microbiota in Lepidopteran Insects
Authors: Zhang Xiancui , Zhang Fan , Lu Xingmeng
Published: June 2022

Lepidopteran insects are one of the most widespread and speciose lineages on Earth, with many common pests and beneficial insect species. The evolutionary success of their diversification depends on the essential functions of gut microorganisms. This diverse gut microbiota of lepidopteran insects provides benefits in nutrition and reproductive regulation and plays an important role in the defence against pathogens, enhancing host immune homeostasis. In addition, gut symbionts have shown promising applications in the development of novel tools for biological control, biodegradation of waste, and blocking the transmission of insect-borne diseases. Even though most microbial symbionts are unculturable, the rapidly expanding catalogue of microbial genomes and the application of modern genetic techniques offer a viable alternative for studying these microbes. Here, we discuss the gut structure and microbial diversity of lepidopteran insects, as well as advances in the understanding of symbiotic relationships and interactions between hosts and symbionts. Furthermore, we provide an overview of the function of the gut microbiota, including in host nutrition and metabolism, immune defence, and potential mechanisms of detoxification. Due to the relevance of lepidopteran pests in agricultural production, it can be expected that the research on the interactions between lepidopteran insects and their gut microbiota will be used for biological pest control and protection of beneficial insects in the future.
Taxonomic Re-Evaluation and Genomic Comparison of Novel Extracellular Electron Uptake-Capable Rhodovulum visakhapatnamense and Rhodovulum sulfidophilum Isolates
Authors: Davenport Emily J. , Bose Arpita
Published: June 2022

Rhodovulum spp. are anoxygenic phototrophic purple bacteria with versatile metabolisms, including the ability to obtain electrons from minerals in their environment to drive photosynthesis, a relatively novel process called phototrophic extracellular electron uptake (pEEU). A total of 15 strains of Rhodovulum sulfidophilum were isolated from a marine estuary to observe these metabolisms in marine phototrophs. One representative strain, Rhodovulum sulfidophilum strain AB26, can perform phototrophic iron oxidation (photoferrotrophy) and couples carbon dioxide fixation to pEEU. Here, we reclassify two R. sulfidophilum isolates, strainAB26 and strain AB19, as Rhodovulum visakhapatnamense using taxonomic re-evaluation based on 16S and pufM phylogenetic analyses. The strain AB26 genome consists of 4,380,746 base-pairs, including two plasmids, and encodes 4296 predicted protein-coding genes. Strain AB26 contains 22 histidine kinases, 20 response regulators, and dedicates ~16% of its genome to transport. Transcriptomic data under aerobic, photoheterotrophy, photoautotrophy, and pEEU reveals how gene expression varies between metabolisms in a novel R. visakhapatnamense strain. Genome comparison led by transcriptomic data under pEEU reveals potential pEEU-relevant genes both unique to R. visakhapatnamense strains and shared within the R. sulfidophilum genomes. With these data we identify potential pEEU-important transcripts and how speciation may affect molecular mechanisms of pEEU in Rhodovulum species from the same environment.
Distribution of Tick-Borne Pathogens in Domestic Animals and Their Ticks in the Countries of the Mediterranean Basin between 2000 and 2021: A Systematic Review
Authors: Defaye Baptiste , Moutailler Sara , Pasqualini Vanina , Quilichini Yann
Published: June 2022

Tick-borne pathogens (TBPs) include a wide range of bacteria, parasites and viruses that cause a large spectrum of animal, human and zoonotic tick-borne diseases (TBDs). The object of this review was to establish an inventory and an analysis of TBPs found in domestic animals in the countries of the Mediterranean Basin. This geographic area occupies a central position between several continents and is an area of movement for animals, humans and pathogens of interest and their vectors, which is important in terms of animal and human health. In this systematic review, we included a total of 271 publications produced between 2000–2021 concerning TBPs in domestic animals. Among this literature, we found a total of 90 pathogen species (known as TBPs) reported in the 20 countries of the area; these were detected in tick species from domestic animals and were also directly detected in domestic animals. In all, 31 tick species were recorded and 12 domestic animal species, the latter comprising nine livestock and three pet species. More than 50% of the publications were from Western Europe. Island data were extracted and assessed, as islands of the Mediterranean Basin were represented in 16% of the publications and 77.8% of the TBPs reported. Our results show the importance of islands in the monitoring of TBPs, despite the low percentage of publications.