Cone Structure Research Articles

Will Japan Sink? ———The Explanation of the Seismo-Geothermics

Using the local earthquake catalog of Japan, based on the author’s original Seismo-Geothermics and it’s working methods, and from the study of the stereoscopic image of seismic cone structure, the independence of seismic cone tectonic activity and the inheritance of volcanic activity, this paper draws a conclusion that the Japanese home islands will not sink as long as earthquake still exists, volcano is still active and their lava cones are still there. In this paper, based on the independence of seismic cone tectonic activities, the general relationship between strong earthquakes, volcanoes and seismic cone tectonics in Japan and its adjacent areas is preliminarily clarified. Relying on the mature seismic data in Japan, Interested parties may be able to find out the prediction methods of intracrustal strong earthquakes and seismic cone type volcanism as soon as possible through the principle and working method of Seismo-Geothermics.

Modulating the corrosion performance of magnesium alloys through hydroxyapatite coating

Magnesium and its alloys have attracted attention as medical bone implant materials due to their excellent biocompatibility, bone-like mechanical properties, and degradability. However, the clinical application of magnesium is limited by the fact that it corrodes too quickly in body fluids, leading to premature mechanical failure. Surface hydroxyapatite coatings can significantly reduce the initial corrosion of magnesium alloys, but suffer from the problems of non-dense coatings, many defects and poor adhesion strength to the substrate. In this study, we propose femtosecond laser construction of microemulsion cone structures on the surface of magnesium alloys to significantly enhance the densities and thicknesses of the coatings, as well as to improve the bonding strength of the coatings to the substrate, which ultimately reduces the corrosion rate. The corrosion rate of modified hydroxyapatite coating in simulated body fluid is only 0.146 mm/y, and it has the ability to rapidly induce hydroxyapatite mineralization and promote osteoblast proliferation. Furthermore, the surface morphology, chemical composition, and wettability of the laser-modified Mg alloy were analyzed. It was demonstrated that the microstructure and thin oxide layer formed on the surface of the magnesium alloy could provide more sites for HA nucleation, which promotes the deposition and growth of HA and the existence of a mechanical interlocking effect with the substrate. The application of femtosecond laser surface modification represents a rapid and efficacious approach to enhance the quality of hydroxyapatite coatings. This method has successfully controlled the corrosion rate of magnesium alloys with excellent biocompatibility, thereby overcoming potential obstacles to the use of magnesium alloys in clinical applications.

Ultrafast gelation of multifunctional β-cyclodextrin based hydrogel electrolyte for self-healing supercapacitor

The increasing attention towards flexible supercapacitors with self-healing ability can be attributed to their capacity to endure deformation and damage. However, the development of self-healing and adhesive hydrogel electrolytes, which serve as substrate materials for supercapacitors, remains a challenge. This work reports an ultrafast gelation method for fabricating multifunctional PAA-SL-CD hydrogels with ultrahigh stretchability, fast self-healing ability, superior adhesion, and high ionic conductivity (6.15 S/m). These excellent properties can be attributed to the hydrogen bonding between β-CD, the catechol groups and PAA chains, as well as metal-catechol coordination, metal-carboxyl coordination, and the unique truncated cone structure of the β-CD molecule. A flexible supercapacitor, fabricated using PAA-SL-CD hydrogel as electrolyte, demonstrates high areal specific capacitance (950 mF/cm2) and a capacitance retention rate of 76.3 % even after five cutting and healing cycles. With the well-designed adhesion of the hydrogel electrolyte, the device exhibits impressive specific capacitance retention after cyclic bending. Notably, a series supercapacitor retains the ability to power a clock for 28 min.

Structural design and multi-objective optimization of an MR isolator based on flow valve-cone rubber structure

Due to the distinctive working environment of high precision machining and manufacturing field, it poses challenges in meeting the isolation requirements, including limited installation space, multi-dimensional vibration, and a wide range of vibration frequencies. To tackle these obstacles, this paper introduces a magnetorheological (MR) isolator that offers adjustable vertical damping characteristics while guaranteeing three-axis vibration isolation through an inclined cone structure. First, the structure of the isolator was designed by combining a flow valve damper with a conical rubber structure. Second, in pursuit of lightweight design and enhanced magnetic field strength, collaborative simulations using ANSYS and Maxwell are conducted to subject the critical components of the isolator to multi-objective optimization. The optimization results demonstrate that the mass of the isolator has been reduced by approximately 27.7%, while the magnetic field intensity has increased by around 20%. Finally, the performance of the MR isolator was verified through static testing and dynamic testing, respectively. The experimental results demonstrate that the isolator can generate a maximum damping force of approximately 778[Formula: see text]N when exposed to a current of 1.5[Formula: see text]A. Compared to the initial value of 445.06[Formula: see text]N at 0[Formula: see text]A, there has been an approximate increase of 1.74 times.

Energy optimization of parabolic dish solar concentrator coupled to organic Rankine cycle: Experimental and analytical investigation of cavity receiver design and covering effects

Concentrated solar power (CSP) systems offer a promising solution for sustainable energy, but achieving high and stable efficiency requires careful design optimization. This study evaluated the overall performance of a parabolic dish solar concentrator coupled to an Organic Rankine Cycle (ORC) system through experimental and analytical assessments. The research examined the impact of cavity receiver shape (cylindrical vs. spherical) and the use of a glass cover on thermal efficiency. Additionally, the effectiveness of a cone structure to reduce spillage losses and improve optical efficiency was explored. Testing showed a significant improvement in system performance, with an increase from 75 % for the open cavity to 90 % for the sealed cavity equipped with the cone structure (15 % increase). This highlights the importance of receiver design in reducing heat loss. To further optimize the system, a numerical model was developed and validated against experimental measurements. The simulation demonstrated that the overall system performance is significantly influenced by the water outlet temperature from the cavity receiver and the pressure drop within it. The model suggests that overall performance could be enhanced from 4.6 % to higher than 6 % by optimizing factors like water mass flow rate, cavity tube diameter, and the selection of a more suitable ORC working fluid (e.g., R245fa instead of R134a).

High Gain Defected Slots 3D Antenna Structure for Millimeter Applications

The antenna is designed as a 3D structure and is made from a conductible cylindrical antenna cone. The cone structure is realized using etching of elliptical slot array on the antenna. We use a conductible circular reflector under the proposed cone and increase the gain of the antenna. The proposed antenna provides effective bandwidth from 1GHz to 30GHz, but the gain of the proposed antenna is varying between 3dBi and 15dBi in the frequency band we are interested in. Geometrical details of the antenna are optimized numerically using parametric study using CST MWS Software Package. Once the optimal design is arrived at, the results are validated with another software package using HFSS Simulation Technology. The obtained results from both software packages agree very well.

Bi-level distributionally robust optimization model for low-carbon planning of integrated electricity and heat systems

Interdependence among diverse energy forms within integrated electricity and heat systems (IEHSs) holds the potential to harness cooperation effects. This paper proposes a bi-level optimization model for the low-carbon planning of IEHSs, which realizes the coordination between IEHSs and their upstream networks. The precise carbon emissions of IEHSs are traced through carbon emission flows of components, power distribution networks, and district heating networks. Moreover, the distributionally robust optimization approach is employed to account for the inherent uncertainty in renewable power outputs faced by IEHS planning, by incorporating the moment information into an ambiguity set. The bi-level distributionally robust planning model of IEHSs is initially reconfigured into a second-order cone structure, employing the strong duality theory, second-order cone duality theory, and linear decision rules. Subsequently, an iterative approach is introduced to attain convergence of the reformulated bi-level model. Numerical results demonstrate the effectiveness and superiority of the proposed approach for reducing carbon emissions and economic costs of IEHSs.

Ordered silicon nanocone fabrication by using pseudo-Bosch process and maskless etching

Nanocone arrays are widely employed for applications such as antireflection structures and field emission devices. Silicon nanocones are typically obtained by an etching process, but the profile is hard to attain because anisotropic dry etching generally gives vertical or only slightly tapered sidewall profiles, and isotropic dry plasma etching gives curved sidewalls. In this work, we report the fabrication of cone structures by using masked etching followed by maskless etching techniques. The silicon structure is first etched using fluorine-based plasma under the protection of a hard metal mask, with a tapered or vertical sidewall profile. The mask is then removed, and maskless etching with an optimized nonswitching pseudo-Bosch recipe is applied to achieve the cone structure with a sharp apex. The gas flow ratio of C4F8 and SF6 is significantly increased from 38:22 (which creates a vertical profile) to 56:4, creating a taper angle of approximately 80°. After subsequent maskless etching, the sidewall taper angle is decreased to 74°, and the structure is sharpened to give a pointed apex. The effect of an oxygen cleaning step is also studied. With the introduction of periodic oxygen plasma cleaning steps, both the etch rate and surface smoothness are greatly improved. Lastly, it was found that the aspect ratio-dependent etching effect becomes prominent for dense patterns of cone arrays, with a greatly reduced etch depth at a 600 nm pitch array compared to a 1200 nm pitch array.

Experimental and numerical investigation of transpiration cooling with gradient porosity layout for the thermal protection of nose cone

Transpiration cooling with liquid phase change has been widely regarded as one of the most promising thermal protection technology for aerospace vehicles. However, when applied to the nose cone with small curvature radius, cooling failure may occur due to the extreme high heat flux and pressure at the stagnation point. In order to deal with this issue, a wedged-shaped nose cone structures with a gradient porosity layout is designed in this work to optimize the coolant distribution in the porous nose cone, and the corresponding transpiration cooling performance with liquid phase change is experimentally and numerically investigated. At last, to meet the thermal protection requirements under different flight conditions as best as possible, an orthogonal experiment and fuzzy gray analysis were carried out to optimize the particle diameter, porosity layout and division interval of the porous nose cone with gradient porosity layout, taking a specific flight condition as an example. The results obtained in this work showed that gradient porosity layout can significantly improve the cooling efficiency at the stagnation point and the temperature uniformity on the outer surface. The porosity has the highest impact on the cooling performance, while the division interval has little impact. By optimizing, the cooling efficiency at the stagnation point can reach 74.5%, and the maximum temperature difference is less than 500K.

Interior point algorithm for second-order cone optimization based on a new kernel function

Second-order cone optimization (SOCO) problems are crucial in various fields such as engineering, finance, and machine learning due to their ability to model complex convex optimization tasks efficiently. In this article, we propose an interior point algorithm tailored for SOCO, leveraging a novel kernel function to enhance optimization performance. Traditional interior point methods for SOCO often encounter challenges in scalability and efficiency, particularly with large-scale problems. These methods typically rely on barrier functions that may suffer from slow convergence rates, especially when dealing with highly ill-conditioned or degenerate cones. To address these limitations, our approach introduces a new kernel function that exploits the geometric properties of second-order cones, thereby improving convergence behavior and computational efficiency. The key innovation of our algorithm lies in the construction of the kernel function, which incorporates insights from the structure of second-order cones to efficiently capture the curvature information of the optimization problem. By exploiting this curvature information, our algorithm can effectively navigate the optimization landscape, leading to faster convergence and enhanced robustness compared to traditional methods. Furthermore, our algorithm is equipped with advanced techniques for handling various challenges encountered in SOCO, such as dealing with degenerate cones and exploiting problem structure to accelerate convergence. Additionally, we incorporate strategies for warm-starting and adaptive step-size selection to further improve efficiency, particularly in iterative optimization processes. Finally, our proposed interior point algorithm for second-order cone optimization, based on a new kernel function, derives the iteration bounds O (Nlog (N/∊)) for large update methods. Here denotes N the number of second-order cones in the problem formulation and ∊ the desired accuracy. These iteration bounds are currently the best known bounds for such methods.

Parafoveal cone function in choroideremia assessed with adaptive optics optoretinography

Choroideremia (CHM) is an X-linked retinal degeneration leading to loss of the photoreceptors, retinal pigment epithelium (RPE), and choroid. Adaptive optics optoretinography is an emerging technique for noninvasive, objective assessment of photoreceptor function. Here, we investigate parafoveal cone function in CHM using adaptive optics optoretinography and compare with cone structure and clinical assessments of vision. Parafoveal cone mosaics of 10 CHM and four normal-sighted participants were imaged with an adaptive optics scanning light ophthalmoscope. While acquiring video sequences, a 2 s 550Δ10 nm, 450 nW/deg2 stimulus was presented. Videos were registered and the intensity of each cone in each frame was extracted, normalized, standardized, and aggregated to generate the population optoretinogram (ORG) over time. A gamma-pdf was fit to the ORG and the peak was extracted as ORG amplitude. CHM ORG amplitudes were compared to normal and were correlated with bound cone density, ellipsoid zone to RPE/Bruch’s membrane (EZ-to-RPE/BrM) distance, and foveal sensitivity using Pearson correlation analysis. ORG amplitude was significantly reduced in CHM compared to normal (0.22 ± 0.15 vs. 1.34 ± 0.31). In addition, CHM ORG amplitude was positively correlated with cone density, EZ-to-RPE/BrM distance, and foveal sensitivity. Our results demonstrate promise for using ORG as a biomarker of photoreceptor function.

Burn Severity and Postfire Salvage Logging Effects on Vegetation and Soil System in a Short-Term Period in Mediterranean Pine Forests

Wildfires are a natural part of the dynamics of Mediterranean forest ecosystems. The fire patterns in the Mediterranean basin have been altered mainly due to changes in land use and climate change. In 2017, a wildfire in Yeste (Spain) burned 3200 hectares of two Mediterranean pine forests. We investigated the effects of burn severity and postfire salvage logging practices on vegetation and soil properties in four experimental areas distributed within the wildfire perimeter. These areas included unburned, low, high, and high burn severity with salvage logging, all located under Pinus halepensis Mill and Pinus pinaster Aiton stands. Salvage logging was applied 18 months after the fire. We established 72 circular plots (nine per treatment and pine species). We collected soil samples to analyze physicochemical and biological soil properties, including pH, electrical conductivity (EC), soil organic matter (SOM) content, carbon from microbial biomass (CBM), basal soil respiration (BSR), metabolic quotient (qCO2), and two enzymatic activities: β-glucosidase (GLU) and phosphatase (PHP). To understand how vegetation changed after fire, we implemented three linear transects per plot to calculate α-diversity indices (richness, Shannon, and Simpson), vegetation coverage (COBV), fraction of bare soil (BSOIL), the number of postfire seedlings (NSeed) and their average height (Hm), and we grouped vegetation into different postfire adaptive strategies: facultative seeder (R+S+), obligate resprouter (R+S−), obligate seeder (R−S+), and non-fire-adapted (R−S−). We ran ANOVA and Tukey’s HSD post hoc tests to evaluate the differences between burn severity and salvage logging practices on the variables examined for each pine stand. We used PCA and correlation analysis to identify plant-soil interactions. Our results suggest that Pinus halepensis stands were more affected by the wildfire than Pinus pinaster stands due to the distinct characteristics of each species (morphology of the leaves, bark thickness, cone structure, etc.) and the significant differences observed in terms of pH, SOM, CBM, qCO2, GLU, PHP, and Nseed. The proportion of obligate resprouter species was higher in Pinus halepensis stands, and the obligate seeder species were higher in Pinus pinaster stands. The study highlighted the importance of monitoring burn severity and postfire management practices to promote forest recovery and reduce wildfire risk. Limiting the negative impact of postfire salvage logging practices can enhance the resilience of vulnerable ecosystems.

A DFT study of the proximity effect in the spin-orbit coupling in Au/graphene, Au/silicene, and Bi/silicene bilayers

The relativistic band structures of bilayers, built from graphene and silicene and monolayers of heavy atoms, Au and Bi, have been calculated within DFT. It is shown that when the orbital overlap is minor, like in the case of Au monolayer on graphene, a strong spin-orbit coupling in Au does not open a substantial gap in the Dirac cone. When, in contrast, the overlap of the wave functions is significant, like in the cases of Au and Bi adsorbed on silicene, the mixing of the bands (hybridization) destroys the cone structure and makes a separation of the bands by their origin or possession uncertain. In such cases, the spin-orbit splitting of the bands hardly could be attributed to a particular layer and corresponds to the band structure of the net layered system.

Extremal structure of cones of positive homogeneous polynomials

It was proved by Anthony Wickstead that the cone of positive linear operators between Banach lattices E and F coincides with the strongly closed convex hull of the set of lattice homomorphisms from E to F if and only if the cone of positive elements on E is the weakly closed convex hull of the union of extremal rays of the cone of positive liner functionals on E. This note aims to show that this result extends to a wider class of operators, namely, orthogonally additive homogeneous polynomials acting between vector lattices.

Collision dynamics in AUV docking with conical hood type dock: influencing factors and performance analysis

ABSTRACT To enhance docking safety, the collision dynamics during autonomous underwater vehicle (AUV) docking is investigated. Various factors such as dock structures, motion conditions, and related parameters are considered. The relationship between docking collision force and key parameters is unveiled by the mathematical model based on the restoration coefficient method and equivalent spring damping method. Multivariate nonlinear fitting functions are proposed to evaluate collision force and docking time. Furthermore, the deductions made in the research are supported by a preliminary test and the groundwork for further analysis is laid. The study demonstrates the impacts of various factors on docking, including different docking cone hood profiles, structures, velocities, accelerations, eccentricities, traction forces, angles, and force indices. By clarifying relevant mechanism, docking parameters can be achieved to meet diverse docking requirements and enhance the device's lifespan. The research offers valuable insights for achieving smoother AUV docking with conical hood type docks.

The Jordan algebraic structure of the rotated quadratic cone

In this paper, we look into the rotated quadratic cone and analyze its algebraic structure. We construct an algebra associated with this cone and show that this algebra is a Euclidean Jordan algebra (EJA) with a certain inner product. We also demonstrate some spectral and algebraic characteristics of this EJA. The rotated quadratic cone is then proven to be the cone of squares of the generated EJA. The obtained results can help optimization researchers improve specialized interior-point algorithms for rotated quadratic cone programming based on the generated EJA. Additionally, since it is known that the rotated quadratic cone is a special case of the power cone, another reason for this study may be to open the door to understanding the algebraic structure of the general power cone in the future.

Morphology analysis and process optimization of μ-SLA 3D manufactured micro-nano conic structure

PurposeThis paper is devoted to prepare micro-cone structure with variable cross-section size by Stereo Lithography Appearance (SLA)-based 3D additive manufacturing technology. It is mainly focused on analyzing the forming mechanism of equipment and factors affecting the forming quality and accuracy, investigating the influence of forming process parameters on the printing quality and optimization of the printing quality. This study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.Design/methodology/approachThe µ-SLA process is optimized based on the variable cross-section micro-cone structure printing. Multi-index analysis method was used to analyze the influence of process parameters. The process parameter influencing order is determined and validated with flawless micro array structure.FindingsAfter the optimization analysis of the top diameter size, the bottom diameter size and the overall height, the influence order of the printing process parameters on the quality of the micro-cone forming is: exposure time (B), print layer thickness (A) and number of vibrations (C). The optimal scheme is A1B3C1, that is, the layer thickness of 5 µm, the exposure time of 3000 ms and the vibration of 64x. At this time, the cone structure with the bottom diameter of 50 µm and the cone angle of 5° could obtain a better surface structure.Originality/valueThis study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.

Ethanolamine gas sensors based on NdFeO3 modified hexagonal pyramid shaped ZnO nanocrystals

It is well known that two metal oxides can form depletion layers at the interface by constructing heterojunctions due to the different Fermi energy levels of each metal oxide, which can improve the carrier mobility and provide significant advantages for gas sensing. In this work, NdFeO3 nanoparticles were grown on ZnO with hexagonal cone structure by secondary hydrothermal method to successfully construct n-ZnO/p-NdFeO3 heterojunctions, and the crystal structures, oxygen vacancies, microstructures, optical properties, and gas-sensing properties of the ZnO/NdFeO3 composites were investigated. The ZnO/NdFeO3 sensors showed good ethanolamine (EA) The response characteristics of the ZnO/NdFeO3 sensor to ethanolamine (EA) with a concentration of 100 ppm EA at 240 °C (Rg/Ra) is about 25, which improves the response by a factor of 1.6 and 1.32 compared with that of NdFeO3 and ZnO. Meanwhile, it has excellent selectivity, good cyclic reproducibility, and durable long-term stability with response/recovery times of 19 s/49 s. The improved EA sensing performance of NdFeO3-modified ZnO, in addition to its large specific surface area due to its unique rough inhomogeneous structure, is also related to the higher concentration of oxygen vacancies at the ZnO/NdFeO3 interface after the composite. In addition, the construction of ZnO/NdFeO3 heterostructure brings more efficient carrier migration, which is favorable to the surface reaction and diffusion of EA molecules, and lowers the ZnO operating temperature, thus reducing the energy consumption. The ZnO/NdFeO3 composite sensor based on n-p heterojunction provides a valuable strategy for the detection of volatile organic compounds.

A hybrid simulator with novel bicone-wire grid antenna.

The simulator is an indispensable device for the study of high-altitude electromagnetic pulse (HEMP) effects. In order to improve the quality of the electric field waveforms of the HEMP simulator, we carried out simulation and experimental studies for the biconical-wire grid antenna. A new bicone-wire grid antenna HEMP simulator was designed by using skeletonized cones instead of solid cones, which can substantially improve the mobility of the simulator. The effects of different aspect ratios and different cone structures of the simulator on the waveform and distribution characteristics of the electric field were analyzed. The accuracy of the simulation results was verified by testing the bicone-wire grid antenna simulator with the new structure. The results obtained are as follows: First, the simulator can provide a HEMP environment compliant with the International Electrotechnical Commission (IEC) standard in an area of 5 × 6 × 2m3. Second, the simulator possesses optimal waveform quality and working space among simulators with different aspect ratios. Finally, the influence of using skeletonized cones instead of solid cones on the simulator's electric field waveforms is negligible, and the mobility of the new simulator is significantly improved compared to the original simulator.

Novel insights into the effect of cone structure on the classification performance of dual-cone hydrocyclones

The classification process in hydrocyclones is affected by many factors, with the cone angle being recognized as a critical parameter determining the classification performance. In the context of recycling iron ore tailings, this paper primarily focuses on the influence of cone angles and their combination sequences on the classification performance of quartz particles within a dual-cone hydrocyclone through numerical simulations. The upper and lower cone angles were configured in 16 combinations to assess their respective impacts on classification. The results indicate that the upper cone angle primarily governs the pressure drop and tangential velocity, thereby controlling the centrifugal intensity and cut sharpness. Furthermore, the lower cone angle plays a pivotal role in determining axial velocity and particle enrichment ratio in the lower cone, thus influencing the cut size and grade efficiency. These findings should provide valuable guidance for the design and application of compound cone hydrocyclones, depending on specific requirements.