Four-layer Structure Research Articles

ГЕОДИНАМІКА

The purpose of the work is the analysis and geological-tectonic interpretation of the anomalous gravity field of the Ukrainian Carpathians and adjacent territories, as well as the construction of a density model of the Earth's crust and upper mantle according to the international PANCAKE seismic profile. The need to build a density model along the PANCAKE profile is due to the significant interest of a number of geologists and geophysicists in the results of seismic research along this profile. It is also caused by certain discrepancies in the seismological models of different authors. The gravity modeling technique, used in the work, includes the analysis of geological-geophysical maps and models. They are related to the geological-tectonic structure of the research region, to the creation of the initial structural part of the model and to the determination of the densities of strata and blocks of the model. The geometry and densities of the model are refined by the selection method, which is based on the interactive solution of the direct problem of gravimetric and the analysis of the reasons for the inconsistency of the calculated gravity field and Bouguer anomalies. A qualitative correspondence of the density model to the tectonic interpretation of the seismic section along the PANCAKE profile was achieved by using the methods of gravity modeling. The modelling results confirm the four-layer structure of the Earth's crust: the sedimentary cover, the upper, middle, and lower parts of the crust, which differ significantly in density. There is also evidence of the difference of the ALCAPA lithospheric plate, Flysch Carpathians and Precambrian Craton in Earth's crust and upper mantle structure. The ALCAPA plate is characterized by a small thickness (up to 29 km) and a low density of the Earth's crust. The density of the ALCAPA upper mantle is lower (3.20-3.21×103 kg/m3) compared to the upper mantle under the Ukrainian Carpathians and the East European Craton (3.28-3.30×103 kg/m3). This may be related to a change of a mantle composition and increased heat flow under ALCAPA. The Ukrainian fragment of the East European craton in the PANCAKE profile zone is characterized by a typical thickness of the crust (~41-45 km). The upper part of the crystalline crust, in contrast to the middle (2.86-2.90×103 kg/m3) and the lower part (2.98-3.10×103 kg/m3), is characterized by a lower density and greater differentiation in horizontal direction and with depth (from 2.66×103 kg/m3 to 2.86×103 kg/m3). The complex transition zone (subduction zone, Carpathian Orogen) between the ALCAPA microplate and the East European Craton causes an intense negative Bouguer anomaly – the Carpathian gravity minimum, which reaches -90×10-5 m/s2. It has a complex nature: Neogene and Paleogene-Cretaceous flysch rocks low density (≤2.50×103 kg/m3) of the Boryslav-Pokuttia cover, the main huge Precarpathian sub-vertical fault (>4 km) on the extreme southwestern slope of the platform (relatively local factors) and significant deepening of the MOHO surface under the Carpathian structure (regional factor). According to our density model, the depth of the MOHO under the front of the Carpathian thrust reaches 56 km.

Design of absorptive multilayer coatings for satellite thin-film solar cells and studying the dispersion effect on them

Using the Transfer Matrix method and Abele’s Matrix method, several types of absorptive multilayer structures have been proposed exclusively for thin-film solar cells, which can absorb the solar spectrum in the wavelength range from 300 nm to 3000 nm with the angles of incidence from 0° to 90° considerably. Furthermore, the absorption rate of these structures has been investigated and calculated at the angle of incidence 70° with considering the dispersion effect and making use of the Sellmeier Equations. For coherency sunlight, the results illustrate that the absorption rate of all structures has been increased significantly by applying the dispersion effect compared with the absence of the dispersion effect for TM waves while the absorption rate has been expanded up to 40% in all structures virtually with undergoing optimization for incoherency sunlight. As a result, the four-layer structure with the maximum absorption rate, without applying the dispersion relation has been absorbed 91% of the sunlight on average while utilizing the dispersion relation has been absorbed 99% of the sunlight on average for TM waves. In addition, the magnetic fields under dispersion effect have been reduced to keep safe the structures and also intensity of sunlight was monotone in TM waves and incoherency light to preserve them against solar intensity fluctuations at various angles.

Effect of Y on the corrosion behavior of Fe22Cr5Al3Mo alloy in 500 ℃ super-heated steam

Fe22Cr5Al3Mo-xY (x = 0, 0.15%, mass fraction) alloys were fabricated and corroded in 500 ℃/10.3 MPa super-heated steam using a static autoclave. The results show that the oxide films present a four-layer structure consisting of Fe oxide, Cr oxide, mixed oxide region, and Al oxide from outside to inside. There is α-(Fe, Cr) in Al2O3 layer near the oxide/metal interface. The addition of Y can delay the formation of the large iron oxide particles and increase the ratio of Cr2O3 film thickness to the thickness of the flat oxide film area, thus improving the corrosion resistance of the alloys.

Microampere-level piezoelectric energy generation in Pb-free inorganic halide thin-film multilayers with Cu interlayers

Although asymmetric perovskite halides are known to possess viable piezoelectricity, their performance of energy harvesting has been limitedly reported. Herein, we propose the first Pb-free inorganic halide-based thin film harvester having strong capability of power-generation, particularly with additional efforts to enhance the device performance using an unprecedented multilayer structure incorporated with metallic interlayers. Representative high-quality CsSnI3 thin films were prepared by one-step spin coating, and up to four layers were stacked with alternating Cu interlayers. Impressive piezoelectric energy harvesting characteristics of ~22.9 V and ~1233 nA were attained for the four-layered halide structure after poling, which are highest values recorded thus far for perovskite halide thin films. The origin of the enhanced energy-generation is believed to be directly associated with the increased SnI6-octahedra distortion (with off-centering of Sn atoms) by poling and the extra space-charge polarization by Cu interlayers.

Multifunctional Mitochondria-Targeting Nanosystems for Enhanced Anticancer Efficacy.

Mitochondria, a kind of subcellular organelle, play crucial roles in cancer cells as an energy source and as a generator of reactive substrates, which concern the generation, proliferation, drug resistance, and other functions of cancer. Therefore, precise delivery of anticancer agents to mitochondria can be a novel strategy for enhanced cancer treatment. Mitochondria have a four-layer structure with a high negative potential, which thereby prevents many molecules from reaching the mitochondria. Luckily, the advances in nanosystems have provided enormous hope to overcome this challenge. These nanosystems include liposomes, nanoparticles, and nanomicelles. Here, we summarize the very latest developments in mitochondria-targeting nanomedicines in cancer treatment as well as focus on designing multifunctional mitochondria-targeting nanosystems based on the latest nanotechnology.

Design and analysis of a broadband metamaterial absorber applied to visible light band

In this paper, a broadband metamaterial absorber (MA) operated in the visible light band with ultra wide-angle and polarization-insensitive characteristics which consists of a four-layer periodic structure is presented and analyzed, materials of the structure are tungsten, silicon dioxide, silicon nitride and silicon, respectively. According to numerical calculation analysis from finite-difference time-domain method, an absorptivity more than 96% and an average absorptivity of 99.1% are exhibited on this proposed MA. Furthermore, the MA shows not only preferably polarization-independent property through adjusting polarization angle from 0° to 90°, but also better wide-angle characteristics for both TE and TM modes. The MA's physical absorption mechanism which is generated by the coupling of dipole resonance and surface plasmon polaritons is analyzed by the electric and magnetic field distributions on the section plane. The influence for absorption from structure parameters is also investigated and construed. Finally, the equivalent circuit is drawn at the end of this article. The presented absorber has the potential to be applied in solar energy collection, light-to-heat conversion and other applications.

Direct sludge granulation by applying mycelial pellets in continuous-flow aerobic membrane bioreactor: Performance, granulation process and mechanism

This study provides a sustainable manner for direct cultivation of aerobic granular sludge (AGS) by addition of mycelial pellets (MPs) into continuous-flow aerobic MBR. The results showed that the granulation time in MPs-MBR was shortened by at least 65 days, accounting for enhanced mean size of granules (0.68–0.76 mm), increased mixed liquor suspended solids (MLSS) concentration (12.8 g/L) and improved settling ability (78.1 mL/g), in comparison with that of 0.23–0.28 mm, 9.8 g/L and 102.1 mL/g in control MBR. MPs-MBR demonstrated significant advantages in terms of COD reduction (97.0–99.1%), NH4+-N reduction (100%) and TN reduction (32.27–42.33%). MPs, extracellular polymeric substances (EPS) and filamentous bacteria acted as inducible nucleus, crosslinking matter and supporting skeleton, respectively, in favor of promoting the formation and stabilization of AGS with a four-layered structure. The relevant mechanism was underlined by rheological analysis, indicating that MPs addition enhanced non-Newtonian flow characteristics and network structure of sludge.

Method of integro-differential equations for interpreting the results of vertical electrical sounding of the soil

The paper is devoted to the problem of determining the geoelectric structure of the soil within the procedure of testing the grounding arrangements of existing power plants and substations to the required depth in conditions of dense development. To solve the problem, it was proposed to use the Schlumbergers method , which has a greater sounding depth compared to the Wenner electrode array. The purpose of the work is to develop a mathematical model for interpreting the results of soil sounding by the Schlumberger method in the form of a four-layer geoelectric structure. Methodology. To construct a mathematical model, it is proposed to use the solution of a particular problem about the field of a point current source, which, like the observation point, is located in the first layer of a four-layer soil. Based on this expressions, a system of linear algebraic equations of the 7-th order with respect to the unknown coefficients ai and bi was compiled. On the basis of its analytical solution, an expression for the potential of the electric field was obtained for conducting VES (the point current source and the observation point are located only on the soil surface). Results. Comparison of the results of soil sounding by the Schlumberger installation and the interpretation of its results for the same points shows a sufficient degree of approximation: the maximum relative error does not exceed 9.7 % (for the second point), and the average relative error is 3.6 %. Originality. Based on the obtained expression, a test version of the program was implemented in Visual Basic for Applications to interpret the results of VES by the Schlumberger method. To check the obtained expressions, the interpretation of the VES results was carried out on the territory of a 150 kV substation of one of the mining and processing plants in the city of Kriviy Rih. Practical significance. The developed mathematical model will make it possible to increase the sounding depth, and, consequently, the accuracy of determining the standardized parameters of the grounding arrangements of power stations and substations.

Four-Layered Structure of E-Government Systems

The structure of the e-government systems plays a vital role for provision of quality of e-services offered. These systems are quite complex deploying the most advanced technologies and developed and rich countries minimised this complexity with centralised systems. However, the less developed and countries with limited financial support are creating distributed and decentralised systems trying to keep the pace with more developed in provision of e-government services. The common identifier for both types of the systems is four-layered structure, which provides quality of service provision. This paper discusses the four-layered structure of e-government systems on cases of Estonia, Serbia and Bosnia and Herzegovina. The four-layered structure was found as the quality solution for distributed and decentralised e-government systems.

Velocity–vorticity correlations and the four-layer regime in turbulent channel flow of generalized Newtonian fluids

The data of Arosemena et al. (2021), consisting of turbulent channel flow simulations of generalized Newtonian (GN) fluids, are considered to study the effects of shear-dependent rheology on the nonzero velocity–vorticity correlations and the mean dynamics. In the near-wall region and compared to Newtonian channel flow, the velocity–vorticity products contributing to the turbulent inertia term decrease/increase with shear-thinning/thickening fluid behaviour suggesting that with e.g. shear-thinning rheology, the sublayer streaks are more stable, the near-wall vortical motions are dampened and there is a narrower range of turbulent length scales. The mean momentum balance analysis, on the other hand, revealed that the four-layer structure first recognized by Wei et al. (2005a) remains for all GN fluids and that the shear-dependent rheology only seems to influence the location of the layers. For instance, with shear-thinning behaviour, layers II and III are thicker and there is an increase in the importance of the viscous forces in these intermediate layers. The influence of shear-thinning/thickening fluid behaviour on the extent of the layers II and III is found remarkably similar to an increase/decrease of the Reynolds number for Newtonian channel flow. These findings suggest that the shear-dependent rheology should also be taken into account for proper scaling of the intermediate layers. A potential length scale factor is proposed and its suitability is tested.

Machine Learning-based Mist Computing Enabled Internet of Battlefield Things

The rapid advancement in information and communication technology has revolutionized military departments and their operations. This advancement also gave birth to the idea of the Internet of Battlefield Things (IoBT). The IoBT refers to the fusion of the Internet of Things (IoT) with military operations on the battlefield. Various IoBT-based frameworks have been developed for the military. Nonetheless, many of these frameworks fail to maintain a high Quality of Service (QoS) due to the demanding and critical nature of IoBT. This study makes the use of mist computing while leveraging machine learning. Mist computing places computational capabilities on the edge itself (mist nodes), e.g., on end devices, wearables, sensors, and micro-controllers. This way, mist computing not only decreases latency but also saves power consumption and bandwidth as well by eliminating the need to communicate all data acquired, produced, or sensed. A mist-based version of the IoTNetWar framework is also proposed in this study. The mist-based IoTNetWar framework is a four-layer structure that aims at decreasing latency while maintaining QoS. Additionally, to further minimize delays, mist nodes utilize machine learning. Specifically, they use the delay-based K nearest neighbour algorithm for device-to-device communication purposes. The primary research objective of this work is to develop a system that is not only energy, time, and bandwidth-efficient, but it also helps military organizations with time-critical and resources-critical scenarios to monitor troops. By doing so, the system improves the overall decision-making process in a military campaign or battle. The proposed work is evaluated with the help of simulations in the EdgeCloudSim. The obtained results indicate that the proposed framework can achieve decreased network latency of 0.01 s and failure rate of 0.25% on average while maintaining high QoS in comparison to existing solutions.

Tissue-engineered esophagus: recellular esophageal extracellular matrix based on perfusion-decellularized technique and mesenchymal stem cells

Perfusion-decellularization was an interesting technique to generate a natural extracellular matrix (ECM) with the complete three-dimensional anatomical structure and vascular system. In this study, the esophageal ECM (E-ECM) scaffold was successfully constructed by perfusion-decellularized technique through the vascular system for the first time. And the physicochemical and biological properties of the E-ECM scaffolds were evaluated. The bone marrow mesenchymal stem cells (BMSCs) were induced to differentiate into myocytes in vitro. E-ECM scaffolds reseeded with myocytes were implanted into the greater omenta to obtain recellular esophageal ECM (RE-ECM), a tissue-engineered esophagus. The results showed that the cells of the esophagi were completely and uniformly removed after perfusion. E-ECM scaffolds retained the original four-layer organizational structure and vascular system with excellent biocompatibility. And the E-ECM scaffolds had no significant difference in mechanical properties comparing with fresh esophagi, p > 0.05. Immunocytochemistry showed positive expression of α-sarcomeric actin, suggesting that BMSCs had successfully differentiated into myocytes. Most importantly, we found that in the RE-ECM muscularis, the myocytes regenerated linearly and continuously and migrated to the deep, and the tissue vascularization was obvious. The cell survival rates at 1 week and 2 weeks were 98.5 ± 3.0% and 96.4 ± 4.6%, respectively. It was demonstrated that myocytes maintained the ability for proliferation and differentiation for at least 2 weeks, and the cell activity was satisfactory in the RE-ECM. It follows that the tissue-engineered esophagus based on perfusion-decellularized technique and mesenchymal stem cells has great potential in esophageal repair. It is proposed as a promising alternative for reconstruction of esophageal defects in the future.

In-field cotton detection algorithm based on the dual-path feature extraction

The complex distribution, mutual occlusion, and scale difference greatly increase the difficulty of cotton detection in the wild. To reduce the omission ratio and raise the detection accuracy of cotton, a dual-path feature extraction (DPFE) cotton detection algorithm is proposed. It consists of a DPFE convolutional neural network, a multi-path feature fusion module, and a multi-scale prediction module. First, the algorithm uses the Darknet network as the main path for feature extraction. At the same time, the double downsampling feature map of the main path is enhanced by a proposed feature enhancement module—spatial pyramid convolution. Then a four-layer convolutional neural structure is designed as the auxiliary path for feature extraction. Finally, multiple feature information is incorporated to locate and recognize cotton with a higher accuracy. In addition, we collected and labeled a cotton dataset with 168 high-resolution images, including 4922 cotton instances for research. The experimental results demonstrate that the DPFE algorithm increases the average detection precision by 9.55% and the recall rate by 13.69%, compared with the traditional algorithm.

Modified solar cells with antireflection coatings

Designing a solar cell that can harvest energy with a high level of efficiency is an important research topic. For improving the performance of solar cells, this paper introduces four proposed structures for solar cells and examines their efficiencies for potential production with low cost and high efficiency. In each model, the absorbent material is Borofloat glass and the antireflection coatings used are SiNx and sol-gel -based materials. The four proposed solar cell structures are as follows: (i) a three-layer solar cell in which a sol-gel film is used to match the refractive index between the glass substrate and air cladding; (ii) a four-layer solar cell in which a sol-gel film is used to match the refractive index between SiN x laid on top of a glass substrate and air cladding; (iii) a four-layer structure in which a sol-gel film topped with air cladding is used as a match between the glass and SiN x ; and (iv) a four-layer solar cell in which two layers of SiN x are stacked between the glass and the air. A transfer-matrix method is used to solve for the total transmission and total reflection for all structures, and the effects of the film thicknesses and incidence angles are considered in each case. An analysis is carried out using Maple 17, and the results show that using a sol-gel material between glass and air gives almost zero reflection for a wide range of wavelengths, meaning that this can be used as a perfect absorbent and can therefore be recommended for high-efficiency solar cells. Using two layers of SiN x between the air and glass gives almost zero reflection at 600 nm, making this approach an outstanding candidate for solar cells with a maximum absorption of around 600 nm. The other two structures have lower values of transmission, meaning that they are good candidates for low-efficiency solar cells. However, further techno-economic studies of the proposed structures should be carried out, and that solar cell manufacturers should consider these structures.

A high gain and compact transmitarray antenna for Ku-band satellite communications

ABSTRACT This work focuses on designing a low-profile frequency selective surface transmitarray antenna at 12 GHz using a four-layer Split Ring Resonator structure. The parametric analysis shows a high transmission coefficient magnitude of −2.38 dB and 349-degrees phase range. X-band horn antenna is used as a feed source to illuminate the Frequency Selective Surface (FSS) transmitarray layers. Each FSS layer is comprised of 121 elements. The measured results show a wide impedance bandwidth of 35%, a high gain value of 21.9 dBi and 11.6% 1-dB bandwidth. The proposed design can be used in high gain array antenna applications, particularly Ku band Satellite communication systems.

Enhanced tuning efficiency and sensitivity based on mode transition of symmetric cladding modes in fibre Bragg grating overlaid with high refractive nm-thick film

In this paper, we theoretically investigate the tuning characteristics of a four-layer structure optic fibre Bragg grating (FBG) coated with high refractive index (HRI) overlay. The attention is mainly focused on the analysis of the effects of the mode transition and the mode reorganization on the tuning sensitivity to the overlay HRI of the structure. The cladding diameter of FBG is also considered as a parameter for enhancing the sensitivity of FBG to HRI. Moreover, different cladding modes show different sensitivities. For FBG with negative thermo-optical coefficient coating material, the thermal property of the structure could be effectively suppressed by selecting an optimal fibre cladding diameter. The reported results demonstrate the possibility of this structure can be used as thermal-stable tunable all-fibre photonic device, such as filter, modulator and sensing element.

Research on High Precision solution of Fractional partial differential equations under Heat conduction Model

Aiming at the heat conduction equation, the heat conduction model is a very typical example of the partial differential equation. This paper focuses on the development and preliminary knowledge of the partial differential equation, the establishment of the heat conduction model and the solution of the heat conduction model. The partial differential equation with fractional Laplace operator is a kind of typical fractional partial differential equation, which has important applications in the fields of science and engineering. Fractional Laplace operator is a kind of nonlocal quasi-differential operator, which is the infinitesimal generator of L é vy steady-state process. It is essentially different from the classical Laplace operator, which leads to the disappearance of some classical properties, which generally brings difficulties to the study of this kind of problems. It is very difficult to solve the explicit solution of partial differential equation with fractional Laplace operator. In order to improve the accuracy and speed of solving partial differential equation, a high precision method for solving partial differential equation based on deep learning network is proposed. A multilayer radial basis function neural network is constructed and its structural layers are determined. By introducing subnetworks into each layer of the multilayer radial basis function neural network, a composite multilayer radial basis function neural network is constructed to improve the real function approximation performance and operation accuracy of the multilayer radial basis function neural network. The high-precision compound multi-layer radial basis function neural network is used to solve the partial differential equation. By giving a specific example of solving the partial differential equation, the solution effect of the method is tested. The results show that the method has very high solution accuracy under the four-layer network structure, which can improve about 1.5 orders of magnitude compared with the first layer. Under different number of training samples, it has higher solution accuracy and speed, and the comprehensive performance is superior. Therefore, it is a practical but challenging work to study the existence of solutions of partial differential equations with fractional Laplace operators. This paper mainly describes the research progress and trends of the existence of solutions of several classes of partial differential equations with fractional Laplace operators, including some of the work done by the author in this field in recent years.

Survey of security supervision on blockchain from the perspective of technology

Due to decentralization, immutability, circulation, anonymity, blockchain technology has become a hot topic but also a hotbed of various cyber-crimes. Many perpetrators attack blockchain to steal cryptocurrencies or use anonymous addresses to conduct illicit financial transactions or receive ransoms while hiding their identities. Since blockchain technology has not developed for a long time, the security issues in this area cannot be well resolved through its own mechanisms, which brings great challenges to protect the security of blockchain and users. Although there are some protective measures to prevent attackers from attacking, most of them are proposed after attacks, and it is impossible to find the masterminds behind modern cyber-crimes, so it is necessary to continuously monitor suspicious nodes or users. In this paper, we first present a systematic overview of blockchain technology and security issues according to the four-layer structure, and explain the problem of security supervision of blockchain. Subsequently, we divide the key technologies for security supervision of blockchain into three aspects: node discovery technology on the network layer, data analysis technology of transaction records on the transaction layer, and network traffic analysis technology on the application layer. In terms of each aspect, we summarize the studies from various angles according to its characteristics. In the end, we discuss the relationship between blockchain and traditional law. Moreover, we present the challenges of security supervision and possible future research directions in this field.

Ultrahigh energy storage performances derived from the relaxation behaviors and inhibition of the grain growth in La doped Bi5Ti3FeO15 films

Developing environment-friendly film capacitors, which possessing a high energy storage performance, an extra wide working temperature range and a longest lifetime are desirable in applications owning to energy shortage and environmental pollution. Here, lead-free Bi5-xLaxTi3FeO15 films with four-layer Aurivillius structure were fabricated by the sol–gel method. It is revealed that the introduction of lanthanum ions into Bi5Ti3FeO15 films induces relaxation behaviors and inhibits grain growth, thus improving the energy storage performances. Bi4LaTi3FeO15 films achieved a large recoverable energy storage density of 83.2 J/cm3 and a high efficiency of 79.1% under 3460 kV/cm. Moreover, Bi4LaTi3FeO15 films exhibited excellent energy storage performances in fatigue endurance and thermal stability. This work demonstrates that the route through rare-earth doped multilayered perovskite ferroelectric films is an effective approach to enhance energy storage properties.

The superplastic forming/diffusion bonding and mechanical property of TA15 alloy for four‐layer hollow structure with squad grid

The superplastic forming/diffusion bonding (SPF/DB) process has been widely applied to manufacture the multi-layer components. In this paper, a four-layer hollow structure with squad grid was fabricated by SPF/DB process. The superplastic behavior of TA15 alloy was investigated by the uni-axial tensile tests at high temperature, and the maximum elongation of 911 % was obtained at 920 °C/0.001 s− 1. The finite element method (FEM) of the four-layer structure was conducted, and the results showed that TA15 alloy was appropriate for fabricating this complex-shaped structure. Then the four-layer hollow structure was successfully fabricated by SPF/DB process at 920 °C with the target strain rate of 0.001 s− 1. Finally, the microstructure, thickness distribution and mechanical property of the four-layer hollow structure were investigated. The grain size increased from 5 μm to 10 μm and the sound bonding interface was achieved. The thickness distribution was symmetrical in height direction. The compressive strength and the maximum bending load of the four-layer hollow structure was 50 MPa and 64.4 kN, respectively.