bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic Detection of Biosignatures in Natural Ice Samples as a Proxy for Icy Moons
Authors: Calapez Francisco , Dias Rodrigo , Cesário Rute , Gonçalves Diogo , Pedras Bruno , Canário João , Martins Zita
Published: February 2023

Some of the icy moons of the solar system with a subsurface ocean, such as Europa and Enceladus, are the targets of future space missions that search for potential extraterrestrial life forms. While the ice shells that envelop these moons have been studied by several spacecrafts, the oceans beneath them remain unreachable. To better constrain the habitability conditions of these moons, we must understand the interactions between their frozen crusts, liquid layers, and silicate mantles. To that end, astrobiologists rely on planetary field analogues, for which the polar regions of Earth have proven to be great candidates. This review shows how spectroscopy is a powerful tool in space missions to detect potential biosignatures, in particular on the aforementioned moons, and how the polar regions of the Earth are being used as planetary field analogues for these extra-terrestrial environments.
The Histopathological “Placentitis Triad” Is Specific for SARS-CoV-2 Infection, and Its Acute Presentation Can Be Associated with Poor Fetal Outcome
Authors: Remoué Annabelle , Suazo Yurina , Uguen Marie , Uguen Arnaud , Marcorelles Pascale , de Moreuil Claire
Published: February 2023

(1) Background: Placental histological lesions reported in relation with SARS-CoV-2 infection are various, with potential consequences such as fetal growth retardation, prematurity or stillbirth/neonatal death. We report here on a placental pathological association which could be specific for SARS-CoV-2 infection and associated with poor fetal outcome; (2) Methods: We collected all the placental pathological examinations performed in Brest University Hospital (France) since the beginning of COVID-19 pandemic with a known maternal SARS-CoV-2 infection and a poor pregnancy outcome. In these cases, we described the pathological lesions and we searched for these lesions in a large series of placentas collected and examined in the same institution before the SARS-CoV-2 pandemic; (3) Results: Three cases with severe fetal outcome (tardive abortion, prematurity, neonatal death), from the first to the third trimesters of pregnancy, were included. The three cases showed features of massive and acute “placentitis triad” consisting in massive perivillous fibrin deposition, sub-acute intervillositis and trophoblastic necrosis. This association was not encountered in any of 8857 placentas analyzed during the period between 2002 and 2012 in our institution; (4) Conclusions: The “placentitis triad” appears to be specific for SARS-CoV-2 infection and, in case of massive and acute presentation, could result in poor fetal outcome.
From Virtual Reconstruction to Additive Manufacturing: Application of Advanced Technologies for the Integration of a 17th-Century Wooden Ciborium
Authors: Rizzo Daniela , Fico Daniela , Montagna Francesco , Casciaro Raffaele , Esposito Corcione Carola
Published: February 2023

3D modelling and 3D printing techniques have become increasingly popular in different fields, including cultural heritage. In this field, there are still many challenges to overcome, such as the difficulty of faithfully reproducing complex geometries or finding materials suitable for restoration, due to the limited scientific studies. This work proposes an example of the application of advanced technologies for the reproduction of four missing columns of a 17th century polychrome wooden ciborium. The difficulties of an automatic scan due to its reflective surface (water gilding and estofado decorations) were overcome by creating a 2D manual survey and a subsequent manual 3D redrawing. The CAD model was used to print the missing elements with fused filament fabrication (FFF) in polyethylene terephthalate glycol (PETG), using the following printing parameters: nozzle 0.4 mm, infill 20%, extrusion temperature of PLA 200 °C and of PETG 220 °C, plate temperature 50 °C, printing speed 60 mm/s, layer height 0.2 mm. The conservation and restoration of the ciborium is nearing completion. This study highlights the importance of collaboration between different professionals for the correct design of a restoration, as well as the need to promote scientific research into the development of new high-performance 3D printing materials suitable for conservation.
Assessment of Condition Diagnosis System for Axles with Ferrous Particle Sensor
Authors: Hong Sung-Ho , Jeon Hong-Gyu
Published: February 2023

This study presents a condition diagnosis system based on a ferrous particle sensor to estimate the durability of axles in construction equipment. Axles are mechanical devices that play the role of the differential gear in construction equipment that move with wheels and require high reliability. In the durability testing of new axles, failure identification and real-time diagnosis are required. One of the typical failure modes of an axle is increased ferrous-wear particles due to metal-to-metal contact. Therefore, a condition diagnostic program based on the ferrous particle sensor is developed and applied in the bench tests of axles. This program provides information on the amount of wear with respect to ferrous particles using a simple diagnostic algorithm. Additionally, it allows separation and storage of measured data that exceed the reference values; the system provides warnings using color, sound, and pop-up windows to facilitate diagnosis. In the two tests, the first case detected a failure, but in the other case, the sensor did not detect it even though a failure occurred. From the results of bench tests, it is confirmed that the sensor location is a critical factor. Therefore, a multi-physics-based analysis method is suggested for positioning the ferrous particle sensor.
Investigation of the Influence of Hot Forging Parameters on the Closing Conditions of Internal Metallurgical Defects in Zirconium Alloy Ingots
Authors: Banaszek Grzegorz , Ozhmegov Kirill , Kawalek Anna , Sawicki Sylwester , Magzhanov Medet , Arbuz Alexandr
Published: February 2023

In this article, we present research results on the closing conditions of internal metallurgical discontinuities during the hot elongation operation of a Zr-1%Nb alloy ingot using physical and numerical modeling. Research on the influence of thermal and deformation parameters of elongation operations on the rheological behavior of a Zr-1% Nb alloy was conducted using the Gleeble 3800 metallurgical process simulator. Modeling of the influence of thermal–mechanical parameters of hot elongation operations in combinations of rhombic and flat anvils on the closure of metallurgical discontinuities was performed with the help of the FORGE®NxT 2.1 program. Based on the results of the research, recommendations were made regarding forging elongation technology and the geometry of working tools in order to ensure the closure of metallurgical discontinuities during hot elongation operations of Zr-1% Nb alloy ingots.
Biological Scaffolds Assembled with Magnetic Nanoparticles for Bone Tissue Engineering: A Review
Authors: Li Zheng , Xue Le , Wang Peng , Ren Xueqian , Zhang Yunyang , Wang Chuan , Sun Jianfei
Published: February 2023

Superparamagnetic iron oxide nanoparticles (SPION) are widely used in bone tissue engineering because of their unique physical and chemical properties and their excellent biocompatibility. Under the action of a magnetic field, SPIONs loaded in a biological scaffold can effectively promote osteoblast proliferation, differentiation, angiogenesis, and so on. SPIONs have very broad application prospects in bone repair, bone reconstruction, bone regeneration, and other fields. In this paper, several methods for forming biological scaffolds via the biological assembly of SPIONs are reviewed, and the specific applications of these biological scaffolds in bone tissue engineering are discussed.
Achieving High Performance Electrode for Energy Storage with Advanced Prussian Blue-Drived Nanocomposites—A Review
Authors: Cui Dingyu , Wang Ronghao , Qian Chengfei , Shen Hao , Xia Jingjie , Sun Kaiwen , Liu He , Guo Cong , Li Jingfa , Yu Feng , Bao Weizhai
Published: February 2023

Recently, Prussian blue analogues (PBAs)-based anode materials (oxides, sulfides, selenides, phosphides, borides, and carbides) have been extensively investigated in the field of energy conversion and storage. This is due to PBAs’ unique properties, including high theoretical specific capacity, environmental friendly, and low cost. We thoroughly discussed the formation of PBAs in conjunction with other materials. The performance of composite materials improves the electrochemical performance of its energy storage materials. Furthermore, new insights are provided for the manufacture of low-cost, high-capacity, and long-life battery materials in order to solve the difficulties in different electrode materials, combined with advanced manufacturing technology and principles. Finally, PBAs and their composites’ future challenges and opportunities are discussed.
The Algorithm to Predict the Grain Boundary Diffusion in Non-Dilute Metallic Systems
Authors: Tcherdyntsev Victor , Rodin Alexey
Published: February 2023

The analysis of grain boundary (GB) diffusion in metallic systems based on Cu, Ni, Ag and Al was made to set demonstrate the common behavior. It was shown that the slow penetration for 11 systems can be connected with negative segregation or specific interatomic interaction. Two energetic parameters such as energy of interaction with GB and energy of interatomic interaction are proposed as main characteristics. The analysis of a tendency toward segregation and tendency of intermediate phase formation in these terms allows us to divide the systems on four groups and formulate a qualitative way to predict the behavior of the diffusing elements in a non-dilute solution. Mathematical formulation of GB diffusion problem and typical solutions are presented.
Multifunctional Integration of Optical Fibers and Nanomaterials for Aircraft Systems
Authors: Marques Carlos , Leal-Júnior Arnaldo , Kumar Santosh
Published: February 2023

Smart sensing for aeronautical applications is a multidisciplinary process that involves the development of various sensor elements and advancements in the nanomaterials field. The expansion of research has fueled the development of commercial and military aircrafts in the aeronautical field. Optical technology is one of the supporting pillars for this, as well as the fact that the unique high-tech qualities of aircrafts align with sustainability criteria. In this study, a multidisciplinary investigation of airplane monitoring systems employing optical technologies based on optical fiber and nanomaterials that are incorporated into essential systems is presented. This manuscript reports the multifunctional integration of optical fibers and nanomaterials for aircraft sector discussing topics, such as airframe monitoring, flight environment sensing (from temperature and humidity to pressure sensing), sensors for navigation (such as gyroscopes and displacement or position sensors), pilot vital health monitoring, and novel nanomaterials for aerospace applications. The primary objective of this review is to provide researchers with direction and motivation to design and fabricate the future of the aeronautical industry, based on the actual state of the art of such vital technology, thereby aiding their future research.
Preparation of N-Doped Layered Porous Carbon and Its Capacitive Deionization Performance
Authors: Liu Rui , Yao Shouguang , Shen Yan , Tian Yu , Zhang Qiqi
Published: February 2023

In this study, N-doped layered porous carbon prepared by the high-temperature solid-state method is used as electrode material. Nano calcium carbonate (CaCO3) (40 nm diameter) is used as the hard template, sucrose (C12H22O11) as the carbon source, and melamine (C3H6N6) as the nitrogen source. The materials prepared at 850 °C, 750 °C, and 650 °C are compared with YP-50F commercial super-activated carbon from Japan Kuraray Company. The electrode material at 850 °C pyrolysis temperature has a higher specific surface area and more pores suitable for ion adsorption. Due to these advantages, the salt adsorption capacity (SAC) of the N-doped layered porous carbon at 850 °C reached 12.56 mg/g at 1.2 V applied DC voltage, 500 mg/L initial solution concentration, and 15 mL/min inlet solution flow rate, which is better than the commercial super activated carbon as a comparison. In addition, it will be demonstrated that the N-doped layered porous carbon at 850 °C has a high salt adsorption capacity CDI performance than YP-50F by studying parameters with different applied voltages and flow rates as well as solution concentrations.
Antioxidant and Antimicrobial Properties of Hydrolysed Collagen Nanofibers Loaded with Ginger Essential Oil
Authors: Berechet Mariana Daniela , Gaidau Carmen , Nešić Aleksandra , Constantinescu Rodica Roxana , Simion Demetra , Niculescu Olga , Stelescu Maria Daniela , Sandulache Irina , Râpă Maria
Published: February 2023

Hydrolysed collagen obtained from bovine leather by-products were loaded with ginger essential oil and processed by the electrospinning technique for obtaining bioactive nanofibers. Particle size measurements of hydrolysed collagen, GC-MS analysis of ginger essential oil (EO), and structural and SEM examinations of collagen nanofibers loaded with ginger essential oil collected on waxed paper, cotton, and leather supports were performed. Antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli and antifungal activity against Candida albicans were also determined. Data show that the hydrolysed collagen nanofibers loaded with ginger EO can be used in the medical, pharmaceutical, cosmetic, or niche fields.
Superplastic Behavior and Microstructural Features of the VT6 Titanium Alloy with an Ultrafine-Grained Structure during Upsetting
Authors: Dyakonov Grigory S. , Stotskiy Andrey G. , Modina Iuliia M. , Semenova Irina P.
Published: February 2023

In this paper, the superplastic behavior of the two-phase titanium alloy VT6 with an ultrafine-grained (UFG) structure produced by equal-channel angular pressing is examined. The deformation of specimens with a UFG structure was performed by upsetting in a temperature range of 650–750 °C and strain rate range of 1 × 10−4–5 × 10−1 s−1. Under these conditions, an increased strain-rate sensitivity coefficient m was observed. The calculation of apparent activation energy showed values in a range of 160–200 kJ/mol while the superplastic flow of the VT6 alloy was occurring. When superplastic behavior (SPB) was impeded, the energy Q grew considerably, indicating a change in mechanism from grain-boundary sliding (GBS) to bulk diffusion. A change in temperature and strain rate influenced the development of superplastic flow and the balance of relaxation processes. Microstructural analysis shows that the UFG state is preserved at upsetting temperatures of 650 and 700 °C. A decrease in strain rate and/or an increase in upsetting temperature promoted a more active development of recrystallization and grain growth, as well as α2-phase formation. In a certain temperature and strain-rate range of the UFG VT6 alloy, α2-phase plates were found, the formation of which was controlled by diffusion. The effect of the α2-phase on the alloy’s mechanical behavior is discussed.
Effect of Lattice Constants and Precipitates on the Dimensional Stability of Rolled 2024Al during Isothermal Aging
Authors: Pan Rongdi , Wang Pingping , Jiang Shan , Yang Wenshu , Wu Ping , Qiao Jing , Chen Guoqin , Wu Gaohui
Published: February 2023

The change in material dimensional will lead to the decline of instrument accuracy and reliability. In this paper, the characterization and analysis of the lattice constant, precipitates, and dislocation density of the material by X-ray diffraction (XRD) and transmission electron microscopy (TEM) reveals the reason why the relative dimensional change in the rolled 2024Al is one order of magnitude lower than that of the as-cast 2024Al during isothermal aging. Compared with as-cast 2024Al, the dislocation density of rolled 2024Al is higher, the lattice constant decreases less before and after aging, and the precipitates have orientation and more content, resulting in the dimensional change in rolled 2024Al being smaller than that of as-cast 2024Al. In addition, two main reasons for decreasing the dimensional change in rolled 2024Al are discussed: the decrease in lattice constant, the formation and growth of the S phase before and after aging.
Improving the Dispersibility of TiO2 in the Colloidal System Using Trifunctional Spherosilicates
Authors: Sztorch Bogna , Nowak Krzysztof , Frydrych Miłosz , Leśniewska Julia , Krysiak Klaudia , Przekop Robert E. , Olejnik Anna
Published: February 2023

Titanium dioxide is a commonly used ingredient in cosmetics acting as a thickening agent and inorganic UV filter. However, TiO2 is difficult to disperse, which causes problems in spreading the formulations. The solution to this problem is to modify the titanium dioxide surface to change its properties by creation of the new type of hybrid inorganic–organic UV filter. Therefore, this study aimed to functionalize titanium dioxide with organosilicon compounds and determine how this modification will affect the dispersibility of TiO2 in the colloidal system and the stability of emulsions. First, the functionalized octaspherosilicates were obtained and characterized. Next, the synthesized compounds were applied as modifiers for titanium dioxide and were analyzed by FT-IR, UV-Vis, and laser diffraction. Furthermore, the hydrophilic–hydrophobic character was assessed by measuring the contact angle. The new materials were introduced into emulsions and the formulations were analyzed in terms of particle size distribution and stability by multiple light scattering. It was found that the modification of titanium dioxide with spherosilicates significantly improved both the stability of emulsion and the dispersibility of novel materials in the colloidal system compared to nonmodified TiO2. The covalent binding of the modifier with the titanium dioxide had an impact on the stability of the emulsion.
Experimental and Numerical Studies on Hot Compressive Deformation Behavior of a Cu–Ni–Sn–Mn–Zn Alloy
Authors: Zhang Yufang , Xiao Zhu , Meng Xiangpeng , Xiao Lairong , Pei Yongjun , Gan Xueping
Published: February 2023

Cu–9Ni–6Sn alloys have received widespread attention due to their good mechanical properties and resistance to stress relaxation in the electronic and electrical industries. The hot compression deformation behaviors of the Cu–9Ni–6Sn–0.3Mn–0.2Zn alloy were investigated using the Gleeble-3500 thermal simulator at a temperature range of 700–900 °C and a strain rate range of 0.001–1 s−1. The microstructural evolution of the Cu–9Ni–6Sn alloy during hot compression was studied by means of an optical microscope and a scanning electron microscope. The constitutive equation of hot compression of the alloy was constructed by peak flow stress, and the corresponding 3D hot processing maps were plotted. The results showed that the peak flow stress decreased with the increase in the compression temperature and the decrease in the strain rate. The hot deformation activation energy was calculated as 243.67 kJ/mol by the Arrhenius equation, and the optimum deformation parameters for the alloy were 740–760 °C and 840–900 °C with a strain rate of 0.001~0.01 s−1. According to Deform-3D finite element simulation results, the distribution of the equivalent strain field in the hot deformation samples was inhomogeneous. The alloy was more sensitive to the deformation rate than to the temperature. The simulation results can provide a guideline for the optimization of the microstructure and hot deformation parameters of the Cu–9Ni–6Sn–0.3Mn–0.2Zn alloy.
Adsorption of Phosphate and Ammonium on Waste Building Sludge
Authors: Bedrnová Eva , Doušová Barbora , Koloušek David , Maxová Kateřina , Angelis Milan
Published: February 2023

Two selected waste building sludges (WBS) were used in this study: (i) sludge from the production and processing of prestressed concrete pillars (B) and (ii) sludge from the production of technical stone (TS). The materials were used in their original and Fe-modified forms (BFe/TSFe) for the adsorption of NH4+ and PO43− from contaminated waters. The experiments were performed on a model solution simulating real wastewater with a concentration of 1.7 mmol·L−1 (NH4+) and 0.2 mmol·L−1 (PO43−). The adsorption of PO43− had a high efficiency (>99%) on B, BFe and TSFe, while for TS, the adsorption of PO43− was futile due to the high content of available P in the raw TS. The adsorption of NH4+ on all sorbents (B/BFe, TS/TSFe) had a lower efficiency (<60%), while TS proved to be the most effective. Leaching tests were performed according to the CSN EN 12457 standard for B/BFe and TS/TSFe before and after NH4+ and PO43− sorption when the contents of these ions in the leachates were affected by adsorption experiments in the cases of B and TS. For BFe and TSFe, the ion content in the leachates before and after the adsorption experiments was similar.
Study on the Effect of Metal Mesh on Pulsed Eddy-Current Testing of Corrosion under Insulation Using an Early-Phase Signal Feature
Authors: Chen Hanqing , Xu Zhiyuan , Zhou Zhen , Jin Junqi , Hu Zihua
Published: February 2023

Corrosion under insulation (CUI) is a major threat to the structural integrity of insulated pipes and vessels. Pulsed eddy-current testing (PECT) is well known in the industry for detecting CUI, but its readings can be easily influenced by nearby conductive objects, including the insulation supporting metal mesh. As a sequel to our previous study, this paper focuses on the surface distribution of eddy currents at the time of the turning off of the driving voltage instead of examining the overall process of eddy current diffusion. Based on the fact that CUI takes place on the outside of the insulated specimen, the probe footprint was calculated only on the specimen surface. The corrosion depth was regarded as an increment to the probe lift-off, whose information was carried in the early PECT signal. Finite element simulations were performed to facilitate the calculation of the probe footprint and predict the signal behavior. The peak value, which appeared in the early phase of the differential PECT signal, was found to be well correlated with the corrosion depth. Further studies revealed that the mild steel mesh could result in the enlargement of the probe footprint and a decrease in the change rate of the peak value in relation to the corrosion depth. Finally, experiments were conducted to verify the simulation results. The presented findings are consistent with the previously reported results and provide a potential alternative to evaluate CUI in specific scenarios where the insulation has a fixed and uniform thickness.
Comparison of CoW/SiO2 and CoB/SiO2 Interconnects from the Perspective of Electrical and Reliability Characteristics
Authors: Cheng Yi-Lung , Wang Kai-Hsieh , Lee Chih-Yen , Chen Giin-Shan , Fang Jau-Shiung
Published: February 2023

As the feature size of integrated circuits has been scaled down to 10 nm, the rapid increase in the electrical resistance of copper (Cu) metallization has become a critical issue. To alleviate the resistance increases of Cu lines, co-sputtered CoW and CoB alloying metals were investigated as conductors and barriers in this study. Annealing CoM (M = W or B)/SiO2/p-Si structures reduced the resistivity of CoM alloys, removed sputtering-deposition-induced damage, and promoted adhesion. Additionally, both annealed CoW/SiO2 or CoB/SiO2 structures displayed a negligible Vfb shift from capacitance-voltage measurements under electrical stress, revealing an effective barrier capacity, which is attributed to the formation of MOx layers at the CoM/SiO2 interface. Based on the thermodynamics, the B2O3 layer tends to form more easily than the WOx layer. Hence, the annealed CoB/SiO2/p-Si MIS capacitor had a higher capacitance and a larger breakdown strength did than the annealed CoW/SiO2/p-Si MIS capacitor.
Prevention of Root Caries Using Oxalic Acid
Authors: Oguma Hidetoshi , Matsuda Yasuhiro , Yoshihara Kumiko , Okuyama Katsushi , Sakurai Masahiko , Saito Takashi , Inoue Satoshi , Yoshida Yasuhiro
Published: February 2023

Certain dentin hypersensitivity treatment materials include oxalic acid to coat dentin surfaces with minerals, while certain organic acids possess a remineralization effect. Herein, an organic acid that inhibits the demineralization and coating of root surfaces was evaluated. Specimens were produced using five non-carious extracted bovines. Four different acids were used: oxalic acid (OA), malonic acid (MA), polyacrylic acid (PA), and succinic acid (SA). Each acid was applied to the root surface and washed using distilled water or a remineralization solution, and the surface was observed using scanning electron microscopy (SEM). All the surfaces of each specimen, barring the polished surface, were covered with wax and immersed in an automatic pH cycling system for two weeks. Dentin demineralization was analyzed using transverse microradiography (TMR) before and after pH cycling. SEM analysis demonstrated that the three acid groups demineralized the dentin surface, whereas the OA group generated crystals covering the dentin surface, even in a distilled water environment. TMR analysis revealed that the OA groups showed significantly lower integrated mineral loss compared with the other groups, even in the distilled water environment. The results suggest that OA generates insoluble calcium oxalate crystals on the dentin and suppresses demineralization even under low saliva conditions.
Bounded Positioning Control of Manipulators Subject to Base Oscillation and Payload Uncertainty
Authors: Guo Yufei , Hou Baolin , Hao Zhiqiang , Wang Zhigang , Huynh Van Thanh
Published: February 2023

Mounting base oscillation poses a significant challenge to the control of these mechanical systems called oscillatory base manipulators (OBMs). The positioning accuracy of the system is severely affected by base oscillations. Many control strategies have been investigated, but most of them require measurement or prediction of base oscillations. This paper focuses on a unique type of OBMs—the vehicle-mounted manipulator that operates completely within the non-inertial task space (base-fixed space). It is a great challenge to obtain its base oscillation in practical applications. In addition, the inherent payload uncertainty and actuator saturation make its control design more challenging. To solve above problems, this study developed a novel control strategy. A nonlinear dynamics model is constructed firstly, where the base-oscillation term is considered as the external disturbance of the system. Then, a positioning control, which can be regarded as a proportional derivative (PD) control with continuous time-varying gains, is proposed based on the implicit Lyapunov method. Finally, the simulations and hardware experiments are carried out to certify the effectiveness of the proposed control. Results demonstrate that, even though without prediction or measurement of the base oscillations, the proposed control offers superior positioning performance in terms of robustness against the base oscillation and payload uncertainty as well as assurance of boundedness of the control input.
Detection of Bird Nests on Transmission Towers in Aerial Images Based on Improved YOLOv5s
Authors: Han Gujing , Wang Ruijie , Yuan Qiwei , Li Saidian , Zhao Liu , He Min , Yang Shiqi , Qin Liang
Published: February 2023

To further improve the accuracy of bird nest model detection on transmission towers in aerial images without significantly increasing the model size and to make detection more suitable for edge-end applications, the lightweight model YOLOv5s is improved in this paper. First, the original backbone network is reconfigured using the OSA (One-Shot Aggregation) module in the VOVNet and the CBAM (Convolution Block Attention Module) is embedded into the feature extraction network, which improves the accuracy of the model for small target recognition. Then, the atrous rates and the number of atrous convolutions of the ASPP (Atrous Spatial Pyramid Pooling) module are reduced to effectively decrease the parameters of the ASPP. The ASPP is then embedded into the feature fusion network to enhance the detection of the targets in complex backgrounds, improving the model accuracy. The experiments show that the mAP (mean-Average Precision) of the fusion-improved YOLOv5s model improves from 91.84% to 95.18%, with only a 27.4% increase in model size. Finally, the improved YOLOv5s model is deployed into the Jeston Xavier NX, resulting in a model that runs well and has a substantial increase in accuracy and a speed of 10.2 FPS, which is only 0.7 FPS slower than the original YOLOv5s model.
Significance of Darcy–Forchheimer Law, Activation Energy, and Brownian Motion of Tiny Particles on the Dynamics of Rotating MHD Micropolar Nanofluid
Authors: Alanazi Meznah M. , Hendi Awatif A. , Ali Bagh , Majeed Sonia , Hussein Ahmed Kadhim , Shah Nehad Ali
Published: February 2023

The time-independent performance of a micropolar nanofluid under the influence of magneto hydrodynamics and the existence of a porous medium on a stretching sheet has been investigated. Nano-sized particles were incorporated in the base fluid because of their properties such as their extraordinary heat-enhancing ability, which plays a very important role in modern nanotechnology, cooling electronic devices, various types of heat exchangers, etc. The effects of Brownian motion and thermophoresis are accounted for in this comprehensive study. Using similarity conversion, the leading equations based on conservation principles are non-dimensionalized with various parameters yielding a set of ODEs. The numerical approach boundary value problem fourth-order method (bvp4c) was implemented as listed in the MATLAB computational tool. The purpose of this examination was to study and analyze the influence of different parameters on velocity, micro-rotation, concentration, and temperature profiles. The primary and secondary velocities reduced against the higher inputs of boundary concentration, rotation, porosity, and magnetic parameters, however, the base fluid temperature distribution grows with the increasing values of these parameters. The micro-rotation distribution increased against the rising strength of the Lorentz force and a decline is reported against the growing values of the micropolar material and rotational parameters.
Metric Dimensions of Bicyclic Graphs
Authors: Khan Asad , Haidar Ghulam , Abbas Naeem , Khan Murad Ul Islam , Niazi Azmat Ullah Khan , Khan Asad Ul Islam
Published: February 2023

The distance d(va,vb) between two vertices of a simple connected graph G is the length of the shortest path between va and vb. Vertices va,vb of G are considered to be resolved by a vertex v if d(va,v)≠d(vb,v). An ordered set W={v1,v2,v3,…,vs}⊆V(G) is said to be a resolving set for G, if for any va,vb∈V(G),∃vi∈W∋d(va,vi)≠d(vb,vi). The representation of vertex v with respect to W is denoted by r(v|W) and is an s-vector(s-tuple) (d(v,v1),d(v,v2),d(v,v3),…,d(v,vs)). Using representation r(v|W), we can say that W is a resolving set if, for any two vertices va,vb∈V(G), we have r(va|W)≠r(vb|W). A minimal resolving set is termed a metric basis for G. The cardinality of the metric basis set is called the metric dimension of G, represented by dim(G). In this article, we study the metric dimension of two types of bicyclic graphs. The obtained results prove that they have constant metric dimension.
Mathematical Modelling of Leptin-Induced Effects on Electrophysiological Properties of Rat Cardiomyocytes and Cardiac Arrhythmias
Authors: Nesterova Tatiana , Rokeakh Roman , Solovyova Olga , Panfilov Alexander
Published: February 2023

Elevated plasma leptin levels, or hyperleptinemia, have been demonstrated to correlate with metabolic syndrome markers, including obesity, and may be an independent risk factor for the development of cardiovascular disease. In this paper, we use cardiac models to study possible effects of hyperleptinemia on the electrophysiological properties of cardiomyocytes and cardiac arrhythmias. We modified the parameters of an improved Gattoni 2016 model of rat ventricular cardiomyocytes to simulate experimental data for the leptin effects on ionic currents. We used four model variants to investigate the effects of leptin-induced parameter modification at the cellular level and in 2D tissue. In all models, leptin was found to increase the duration of the action potential. In some cases, we observed a dramatic change in the shape of the action potential from triangular, characteristic of rat cardiomyocytes, to a spike-and-dome, indicating predisposition to arrhythmias. In all 2D tissue models, leptin increased the period of cardiac arrhythmia caused by a spiral wave and enhanced dynamic instability, manifesting as increased meandering, onset of hypermeandering, and even spiral wave breakup. The leptin-modified cellular models developed can be used in subsequent research in rat heart anatomy models.
A Structure-Preserving Finite Volume Scheme for a Hyperbolic Reformulation of the Navier–Stokes–Korteweg Equations
Authors: Dhaouadi Firas , Dumbser Michael
Published: February 2023

In this paper, we present a new explicit second-order accurate structure-preserving finite volume scheme for the first-order hyperbolic reformulation of the Navier–Stokes–Korteweg equations. The model combines the unified Godunov-Peshkov-Romenski model of continuum mechanics with a recently proposed hyperbolic reformulation of the Euler–Korteweg system. The considered PDE system includes an evolution equation for a gradient field that is by construction endowed with a curl-free constraint. The new numerical scheme presented here relies on the use of vertex-based staggered grids and is proven to preserve the curl constraint exactly at the discrete level, up to machine precision. Besides a theoretical proof, we also show evidence of this property via a set of numerical tests, including a stationary droplet, non-condensing bubbles as well as non-stationary Ostwald ripening test cases with several bubbles. We present quantitative and qualitative comparisons of the numerical solution, both, when the new structure-preserving discretization is applied and when it is not. In particular for under-resolved simulations on coarse grids we show that some numerical solutions tend to blow up when the curl-free constraint is not respected.
Outstanding Separation Performance of Oil-in-Water Emulsions with TiO2/CNT Nanocomposite-Modified PVDF Membranes
Authors: Fekete Laura , Fazekas Ákos Ferenc , Hodúr Cecilia , László Zsuzsanna , Ágoston Áron , Janovák László , Gyulavári Tamás , Pap Zsolt , Hernadi Klara , Veréb Gábor
Published: February 2023

Membrane filtration is an effective technique for separating micro- and nano-sized oil droplets from harmful oil-contaminated waters produced by numerous industrial activities. However, significant flux reduction discourages the extensive application of this technology; therefore, developing antifouling membranes is necessary. For this purpose, various titanium dioxide/carbon nanotube (TiO2/CNT) nanocomposites (containing 1, 2, and 5 wt.% multi-walled CNTs) were used for the modification of polyvinylidene fluoride (PVDF) ultrafilter (250 kDa) membrane surfaces. The effects of surface modifications were compared in relation to the flux, the filtration resistance, the flux recovery ratio, and the purification efficiency. TiO2/CNT2% composite modification reduced both irreversible and total filtration resistances the most during the filtration of 100 ppm oil emulsions. The fluxes were approximately 4–7 times higher compared to the unmodified PVDF membrane, depending on the used transmembrane pressure (510, 900, and 1340 L/m2h fluxes were measured at 0.1, 0.2, and 0.3 MPa pressures, respectively). Moreover, the flux recovery ratio (up to 68%) and the purification efficiency (95.1–99.8%) were also significantly higher because of the surface modification, and the beneficial effects were more dominant at higher transmembrane pressures. TiO2/CNT2% nanocomposites are promising to be applied to modify membranes used for oil–water separation and achieve outstanding flux, cleanability, and purification efficiency.
A Detailed Analysis of the Microstructural Changes in the Vicinity of a Crack-Initiating Defect in Additively Manufactured AISI 316L
Authors: Blinn Bastian , Barrirero Jenifer , Campo Schneider Lucía Paula , Pauly Christoph , Lion Philipp , Mücklich Frank , Beck Tilmann
Published: February 2023

The fatigue life of metals manufactured via laser-based powder bed fusion (L-PBF) highly depends on process-induced defects. In this context, not only the size and geometry of the defect, but also the properties and the microstructure of the surrounding material volume must be considered. In the presented work, the microstructural changes in the vicinity of a crack-initiating defect in a fatigue specimen produced via L-PBF and made of AISI 316L were analyzed in detail. Xenon plasma focused ion beam (Xe-FIB) technique, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) were used to investigate the phase distribution, local misorientations, and grain structure, including the crystallographic orientations. These analyses revealed a fine grain structure in the vicinity of the defect, which is arranged in accordance with the melt pool geometry. Besides pronounced cyclic plastic deformation, a deformation-induced transformation of the initial austenitic phase into α’-martensite was observed. The plastic deformation as well as the phase transformation were more pronounced near the border between the defect and the surrounding material volume. However, the extent of the plastic deformation and the deformation-induced phase transformation varies locally in this border region. Although a beneficial effect of certain grain orientations on the phase transformation and plastic deformability was observed, the microstructural changes found cannot solely be explained by the respective crystallographic orientation. These changes are assumed to further depend on the inhomogeneous distribution of the multiaxial stresses beneath the defect as well as the grain morphology.
Bulk Ultrasonic Treatment of Crystalline Materials
Authors: Nazarov Ayrat , Murzinova Mariya , Mukhametgalina Aygul , Shayakhmetova Elvina
Published: February 2023

Ultrasound is widely used in the treatment of materials. Its applications in melt processing, surface hardening or finishing, metal forming, welding, etc., are well known and have been reviewed in numerous review articles and books. Among ultrasound-assisted processes, the direct action of ultrasonic waves on the structure and properties of bulk materials is of special interest. Ultrasonic waves induce oscillating shear stresses in materials which exert mechanical forces on crystal lattice defects, primarily on dislocations, which can yield a number of interesting effects on the structure and properties of crystals. The present paper aims to review studies on the effects of ultrasonic treatment (UST) on crystalline materials. First, the methods for the excitation of standing ultrasonic waves in bulk samples of materials are analyzed. Then, early studies on the effect of UST on the dislocation structure and phase composition, hardness and strength of materials with different initial structures are analyzed. An emphasis is then made on the influence of UST on the structure and mechanical properties of advanced ultrafine-grained (UFG) metals and alloys processed by severe plastic deformation (SPD). The results of simulations of ultrasound’s effect on the dislocation and atomic structures of materials by dislocation and molecular dynamics methods are also reviewed.
A Review of Progress in the Study of Al-Mg-Zn(-Cu) Wrought Alloys
Authors: Shen Guwei , Chen Xiaolin , Yan Jie , Fan Longyi , Yang Zhou , Zhang Jin , Guan Renguo
Published: February 2023

Modern industrial development has put forward higher demands on the performance of metallic structural materials, especially in terms of light weight, high strength and corrosion resistance. All of these characteristics are of particular importance in transportation fields. As one of the most representative structural materials, aluminum and alloys have exhibited significant advantages in light weight. Most of the alloys are prominently featured in one specific aspect. The overall performance still needs to be improved. In recent years, researchers have developed Al-Mg-Zn(-Cu) alloy, a new wrought aluminum alloy, whose design strategy is known as “crossover alloying”. This novel alloy is an age-hardened Al-Mg alloy with a T-Mg32(Al, X)49 (X is Zn, Cu) phase as the main strengthening phase. This system of alloys exhibits excellent properties in terms of strength and corrosion resistance, which makes it promising for applications in automotive, marine, aerospace and other fields. This paper summarizes the research progress of Al-Mg-Zn(-Cu) alloy, and analyzes the basic methods of microstructural control in terms of composition design and property research. Finally, the future directions of this alloy are proposed.
Association of Sarcopenia with Cognitive Function and Dementia Risk Score: A National Prospective Cohort Study
Authors: Lin Ailing , Wang Ting , Li Chenxi , Pu Fan , Abdelrahman Zeinab , Jin Mengqi , Yang Zhenqing , Zhang Liming , Cao Xingqi , Sun Kaili , Hou Tongyao , Liu Zuyun , Chen Liying , Chen Zuobing
Published: February 2023

The relationship between skeletal muscle and cognitive disorders has drawn increasing attention. This study aims to examine the associations of sarcopenia with cognitive function and dementia risk score. Data on 1978 participants (aged 65 years and older) from the 2011 wave of the China Health and Retirement Longitudinal Study, with four follow-up waves to 2018, were used. Cognitive function was assessed by four dimensions, with a lower score indicating lower cognitive function. Dementia risk was assessed by a risk score using the Rotterdam Study Basic Dementia Risk Model (BDRM), with a higher score indicating a greater risk. Sarcopenia was defined when low muscle mass plus low muscle strength or low physical performance were met. We used generalized estimating equations to examine the associations of sarcopenia. In the fully adjusted models, sarcopenia was significantly associated with lower cognitive function (standardized, β = −0.15; 95% CIs: −0.26, −0.04) and a higher BDRM score (standardized, β = 0.42; 95% CIs: 0.29, 0.55). Our findings may provide a new avenue for alleviating the burden of cognitive disorders by preventing sarcopenia.
Two-Dimensional Octuple-Atomic-Layer M2Si2N4 (M = Al, Ga and In) with Long Carrier Lifetime
Authors: Ding Yimin , Xue Kui , Zhang Jing , Yan Luo , Li Qiaoqiao , Yao Yisen , Zhou Liujiang
Published: February 2023

Bulk III-nitride materials MN (M = Al, Ga and In) and their alloys have been widely used in high-power electronic and optoelectronic devices, but stable two-dimensional (2D) III-nitride materials, except h-BN, have not been realized yet. A new kind of 2D III-nitride material M2Si2N4 (M = Al, Ga and In) is predicted by choosing Si as the appropriate passivation element. The stability, electronic and optical properties of 2D M2Si2N4 materials are studied systematically based on first-principles calculations. The results show that Al2Si2N4 and Ga2Si2N4 are found to be indirect bandgap semiconductors, while In2Si2N4 is a direct bandgap semiconductor. Moreover, Al2Si2N4 and In2Si2N4 have good absorption ability in the visible light region, while Ga2Si2N4 is an ultraviolet-light-absorbing material. Furthermore, the carrier lifetimes of Ga2Si2N4 and In2Si2N4 are as large as 157.89 and 103.99 ns, respectively. All these desirable properties of M2Si2N4 materials make them attractive for applications in electronics and photoelectronics.
Optimization of a Screw Centrifugal Blood Pump Based on Random Forest and Multi-Objective Gray Wolf Optimization Algorithm
Authors: Jing Teng , Sun Haoran , Cheng Jianan , Zhou Ling
Published: February 2023

The centrifugal blood pump is a commonly used ventricular assist device. It can replace part of the heart function, pumping blood throughout the body in order to maintain normal function. However, the high shear stress caused by the impeller rotating at high speeds can lead to hemolysis and, as a consequence, to stroke and other syndromes. Therefore, reducing the hemolysis level while ensuring adequate pressure generation is key to the optimization of centrifugal blood pumps. In this study, a screw centrifugal blood pump was used as the research object. In addition, pressure generation and the hemolysis level were optimized simultaneously using a coupled algorithm composed of random forest (RF) and multi-objective gray wolf optimization (MOGWO). After verifying the prediction accuracy of the algorithm, three optimized models were selected and compared with the baseline model in terms of pressure cloud, 2D streamline, SSS distribution, HI distribution, and vortex distribution. Finally, via a comprehensive evaluation, the optimized model was selected as the final optimization design, in which the pressure generation increased by 24% and the hemolysis value decreased by 48%.
Label-Free Sensing of Cell Viability Using a Low-Cost Impedance Cytometry Device
Authors: Yang Bowen , Wang Chao , Liang Xinyi , Li Jinchao , Li Shanshan , Wu Jie Jayne , Su Tanbin , Li Junwei
Published: February 2023

Cell viability is an essential physiological status for drug screening. While cell staining is a conventional cell viability analysis method, dye staining is usually cytotoxic. Alternatively, impedance cytometry provides a straightforward and label-free sensing approach for the assessment of cell viability. A key element of impedance cytometry is its sensing electrodes. Most state-of-the-art electrodes are made of expensive metals, microfabricated by lithography, with a typical size of ten microns. In this work, we proposed a low-cost microfluidic impedance cytometry device with 100-micron wide indium tin oxide (ITO) electrodes to achieve a comparable performance to the 10-micron wide Au electrodes. The effectiveness was experimentally verified as 7 μm beads can be distinguished from 10 μm beads. To the best of our knowledge, this is the lowest geometry ratio of the target to the sensing unit in the impedance cytometry technology. Furthermore, a cell viability test was performed on MCF-7 cells. The proposed double differential impedance cytometry device has successfully differentiated the living and dead MCF-7 cells with a throughput of ~1000 cells/s. The label-free and low-cost, high-throughput impedance cytometry could benefit drug screening, fundamental biological research and other biomedical applications.