Types Of Arrays Research Articles

A Review on the Inertial Measurement Unit Array of Microelectromechanical Systems

In recent years, microelectromechanical systems (MEMS) technology has developed rapidly, and low precision inertial devices have achieved small volume, light weight, and mass production. Under this background, array technology has emerged to achieve high precision inertial measurement under the premise of low cost. This paper reviews the development of MEMS inertial measurement unit (IMU) array technology. First, the different types of common inertial measurement unit arrays are introduced and the basic principles are explained. Secondly, IMU array’s development status is summarized by analyzing the research results over the years. Then, the key technologies and corresponding development status of IMU array are described, respectively, including error analysis modeling and calibration, data fusion technology, fault detection, and isolation technology. Finally, the characteristics and shortcomings of the past research results are summarized, the future research direction is discussed, and some thoughts are put forward to further improve the accuracy of the IMU array.

Effects of Single‐Axis and Fixed‐Tilt Photovoltaic Array Construction on the Soil Seed Bank Characteristics in Semi‐Arid Grasslands

ABSTRACTWith the rapid global development of photovoltaic power generation, research on its impact on land and ecosystems has become increasingly significant. However, its impact on soil seed bank characteristics has yet to be better assessed. In this study, monitoring plots were established in a semi‐arid grassland undergoing solar energy development. This setup allowed us, for the first time, to investigate how soil seed bank characteristics respond to the construction of two typical photovoltaic array systems: single‐axis and fixed‐tilt systems. This study demonstrated that in both single‐axis and fixed‐tilt systems, the establishment of photovoltaic arrays resulted in a significant increase in soil seed density, with seed counts rising by approximately 47.5% compared with control sites without arrays. The aggregation effect of soil seed density under the photovoltaic array primarily occurred in the 0–10 cm soil layer. The soil seed density under the single‐axis arrays was higher than that under the fixed‐tilt arrays. The construction of photovoltaic arrays resets local soil and directly changes the micro‐environment—including reductions in solar radiation, decreases in average temperature by 0.1°C, and wind speed decreases by 1.5 m/s—which negatively affected the richness and diversity of the soil seed bank, resulting in a 21.1% decrease in species richness and a 10.1% reduction in seed diversity. Furthermore, this study highlights that seed germination in semi‐arid grasslands is under pressure due to environmental changes associated with photovoltaic construction areas. Specifically, soil moisture and organic matter were the key factors affecting the vegetation restoration potential of the entire construction area. We recommend selecting the single‐axis system of photovoltaic components. This selection is crucial, which considers both energy production efficiency and supports the facilitation of future vegetation ecosystem succession. Altogether, this study provides information for future land‐use planning in photovoltaic construction areas and sustainable development of photovoltaic power generation.

Faсile synthesis of vase-like CeO2 microcapsules and their ordered arrays using the technique of spraying Ce(NO3)3 solution microdroplets on the alkali solution surface

In this work, it has been demonstrated for the first time that CeO2 microcapsules with a unique vase-like morphology can be produced using a facile technique of spraying microdroplets of an aqueous Ce(NO3)3 solution onto the alkaline solution surface of Na2SO4. It has been shown that layers of these microcapsules can be transferred from the solution surface to the substrate surface in two different ways, and depending on the transfer method, they can form ordered, oriented arrays on the substrate. A peculiarity of one of these arrays is that in the layer on the substrate surface, almost all of the microcapsules are oriented with the hole in the wall toward the substrate, while in the other type of array they are oriented in the opposite direction. The structural and chemical characteristics of these microcapsules were investigated using SEM, STEM, HRTEM, EDX, XRD, UV-Vis DR, Raman and FT-IR spectroscopy. It has been established that the walls of these microcapsules are approximately 50-100 nm thick and consist of CeO2 nanocrystals with a size of 2-5 nm with fcc crystal structure of fluorite. On the surface of these nanocrystals, there are adsorbed NO3- and SO42- anions that can be removed by heating the samples to temperatures of 400°C and 600°C, respectively. The use of a solution containing a mixture of Ce(III) and Eu(III) nitrates as a reagent in the synthesis process allows for the production of microcapsules whose walls consist of CeO2 nanocrystals that were doped with Eu(III) cations. These microcapsules exhibit photoluminescent properties in the visible region of the spectrum with maximum band intensities at λex = 330 nm and 462 nm. It is proposed that this technique for synthesizing microcapsules could be used to produce microcapsules based on CeO2 nanoparticles doped with a wide range of metal cations.

Generation of partially coherent full Poincaré beam arrays and their Stokes scintillations in turbulent media

A type of vector beam arrays, called partially coherent full Poincaré (PCFP) beam arrays, is introduced and experimentally synthesized using modal-vector-decomposition method. Our experimental system involves a digital micro-mirror device, which can generate such beam arrays with controllable spatial coherence and array structure in almost real-time, enabling to test the impact of atmospheric turbulence on them. Furthermore, we experimentally examine the scintillations of four Stokes parameters (denoted as S0, S1, S2, and S3) of PCFP beam arrays propagating through lab-simulated turbulence. The results indicate that the Stokes scintillations decrease as the number of beamlets increase or spatial coherence decreases. In contrast to S0 scintillation (intensity scintillation), S1, S2, or S3 scintillation is less affected by the turbulence under the same conditions. Our experimental results show that S2 and S3 scintillations could reduce by 67.2% and 52.4% compared to the intensity scintillation in strong turbulence. Our findings have potential applications in free-space optical communication when the Stokes parameter S2 or S3 is served as an information carrier.

Short-cycle borehole thermal energy storage: Impact of thermal cycle duration on overall performance

Borehole thermal energy storage arrays are a common form of seasonal underground energy storage which relies on the thermal mass of subsurface rock or sediment to store hot or cold thermal energy. However in practice, typical seasonal operation seldom leads to cyclic energy recovery factors greater than 50%–60% due to significant thermal losses during prolonged periods between consecutive charges. In this paper, the impact of short cycle operation (down to a few days) on energy recovery and overall performance is investigated. Analytical and numerical models are used to estimate energy recovery as a function of cycle length for a typical array and for two distinct charging and discharging scenarios (constant temperature or thermal charge load), which is novel and has not been done before. The results show that shorter cycle duration yields increased recovery factors and storage capacity, which is ascribed to a greater rate of charge to rate of thermal loss ratio. In particular, short-cycle operation at the scale of days unlocks recovery factors in excess of 85 %. The results, supported by a numerical subsurface analysis of the temperature distribution, also show that the recovery efficiency increases with time as losses approach, but never fully reach, a steady-state.

Perceived Quality of Binaural Rendering from Baffled Microphone Arrays Evaluated Without an Explicit Reference

The authors present a perceptual evaluation of the binaural rendering quality of signals from several types of baffled microphone arrays. They employ the multi-stimulus category rating (MuSCR) paradigm that does not require a reference stimulus. The tested conditions also comprise a very high numerical accuracy stimulus, given the highest quality rating in approximately half of the multi-stimulus trials. A comparison with the literature on spherical microphone arrays (SMAs) shows that MuSCR allows for drawing representative conclusions regarding the dependency of the perceived quality on the array and rendering parameters as in previous experiments with an explicit high-fidelity reference. The authors applied the MuSCR paradigm to evaluate the perceived reproduction quality of equatorial microphone arrays (EMAs) with microphones only along the equator of the spherical baffle and of equatorial arrays with a nonspherical baffle (XMAs). The results endorse the observations from SMAs that an increasing spherical harmonic order leads to improved perceived quality. The authors also confirm that EMAs lead to the same perceived quality as SMAs despite the substantial difference in the number of microphones. Magnitude equalization of artifacts from spatial undersampling can be very effective for XMAs the raw solution deviates significantly from the other array types at high frequencies.

An efficient multi‐probe enabled midfield over‐the‐air test method for 5G base station antenna pattern reconstruction

AbstractWith the accelerated deployment of 5G massive multi‐input multi‐output (MIMO)‐structured base stations (BSs), accurate and efficient testing of massive MIMO arrays is essential to ensure that the 5G massive MIMO antenna array can perform as expected. The increasing trend of both antenna element and array physical size makes massive MIMO antenna pattern measurement in the direct‐far‐field OTA environment unrealistic due to the signal attenuation, long measurement time, and ultra‐high test system construction cost. Therefore, the necessity of a compact, efficient, low‐complex, yet accurate OTA test method is evident, especially for 5G massive MIMO BS arrays. This paper proposes a novel multi‐probe‐enabled midfield (MF) OTA test method for 5G massive MIMO devices in compact measurement settings where antenna pattern measurement can be efficiently performed. The detailed theoretical analysis for the 5G massive MIMO array MF antenna pattern reconstruction method is presented, and the simulated validation results based on the typical 5G BS antenna arrays are provided and analysed, which demonstrate the effectiveness of the proposed MF OTA test method and can provide insights into the radio frequency parametric measurement for 5G massive MIMO devices.

Highly energy-efficient degradation of simulated dye wastewater by array type underwater bubble discharge plasma: Key factors identification and degradation pathways

The extensive use of dyes presents a significant safety concern for the reuse of water resources, highlighting the critical need for a rapid and efficient degradation method for dye mixtures in wastewater. This study introduces a degradation system based on an array type underwater bubble discharge plasma specifically designed to treat a dye mixture wastewater containing methylene blue (MB) and methyl violet 2B (MV2B). Analysis of the optical and electrical characteristics reveals that the device experiences minimal temperature increase, with the highest intensity of the band associated with N2 in the emission spectra, and discharges occurring predominantly during the rising and falling edges of a pulse cycle. Experimental results demonstrate that the most effective degradation efficiencies (MB = 94.83%, MV2B = 93.48%) are achieved at an initial dye concentration of 50 mg/L, a power supply frequency of 6 kHz, an air flow rate of 2.5 SLM and an initial electrical conductivity of 50 μS/cm. The degradation of dyes is primarily attributed to the demethylation process of O3(aq) and other species. Toxicity analysis indicates that the plasma degradation process significantly reduces the toxicity of the intermediate products of dyes. This study not only presents a novel approach for treating high concentration mixed dye wastewater, but also provides valuable insights for future research in this area.

Microneedle Arrays: Advancements, Applications and Future Prospects in Pharmaceutical Delivery

Microneedle arrays have emerged as a cutting-edge technology revolutionizing the field of pharmaceutical delivery. These micron-sized needles offer a minimally invasive and painless approach to administer drugs, vaccines, and various therapeutic agents through the skin, bypassing traditional routes of administration. This review article comprehensively explores the advancements, applications, and future prospects of microneedle arrays in pharmaceutical delivery. This review delves into the different types of microneedle arrays, including solid, hollow, dissolving, and coated microneedles, highlighting their unique properties and fabrication techniques. The discussion encompasses recent breakthroughs in microneedle design, such as biodegradable materials, smart responsive systems, and personalized arrays tailored to specific patient needs. Furthermore, this review addresses the challenges and safety considerations associated with microneedle usage, such as skin irritation and regulatory aspects. It analyzes ongoing research efforts aimed at optimizing design, functionality, and scalability for large-scale manufacturing. The future prospects of microneedle arrays in pharmaceutical delivery qwew also discussed. Anticipated advancements in the field, including personalized medicine, combination therapy, and disease monitoring through biosensing, offer promising avenues for transformative healthcare solutions. In conclusion, microneedle arrays represent a paradigm shift in pharmaceutical delivery, offering numerous advantages over traditional methods. As research and development continue, these micro-sized devices hold the potential to revolutionize the landscape of drug administration, leading to safer, more effective, and patient-centric healthcare practices.

Impact of Display Sub-Pixel Arrays on Perceived Gloss and Transparency.

In recent years, improvements in display image quality have made it easier to perceive rich object information, such as gloss and transparency, from images, known as shitsukan. Do the different display specifications in the world affect their appearance? Clarifying the effects of differences in pixel structure on shitsukan perception is necessary to realize shitsukan management for displays with different hardware structures, which has not been fully clarified before. In this study, we experimentally investigated the effects of display pixel arrays on the perception of glossiness and transparency. In a visual evaluation experiment, we investigated the effects of three types of sub-pixel arrays (RGB, RGBW, and PenTile) on the perception of glossiness and transparency using natural images. The results confirmed that sub-pixel arrays affect the appearance of glossiness and transparency. A general relationship of RGB > PenTile > RGBW for glossiness and RGB > RGBW > PenTile for transparency was found; however, detailed analysis, such as cluster analysis, confirmed that the relative superiority of these sub-pixel arrays may vary depending on the observer and image content.

Assessing the effect of offline topography on electrical resistivity measurements: insights from flood embankments

Summary Electrical resistivity tomography (ERT), a geophysical imaging method, is commonly used on flood embankments (dykes or levees) to characterise their internal structure and look for defects. These surveys often use a single line of electrodes to enable 2D imaging through the embankment crest, an approach that enables rapid and efficient surveying compared to 3D surveys. However, offline variations in topography can introduce artefacts into these 2D images, by affecting the measured resistivity data. Such topographic effects have only been explored on a site-specific basis. If the topographic effects can be assessed for a distribution of embankment geometries (e.g. slope angle and crest width) and resistivity variations, it would allow for targeted correction procedures and improved survey design. To investigate topographic effects on ERT measurements, we forward-modelled embankments with different trapezoidal cross-sections sat atop a flat foundation layer with contrasting resistivity values. Each was compared to a corresponding flat model with the same vertical resistivity distribution. The modelling workflow was designed to minimise the effect of forward modelling errors on the calculation of topographic effect. We ran 1872 unique embankment forward models, representing 144 geometries, each with 13 different resistivity contrasts. Modelling results show that offline topography affects the tested array types (Wenner-Schlumberger, Dipole-Dipole, and Multiple-Gradient) in slightly different ways, but the magnitudes are similar, so all are equally suitable for embankment surveys. Three separate mechanisms are found to cause topographic effects. The dominant mechanism is caused by the offline topography confining the electrical current flow, increasing the measured transfer resistance from the embankment model. The two other mechanisms, previously unidentified, decrease the measured transfer resistances from the embankment model compared to a layered half-space but only affect embankments with specific geometries and resistivity distributions. Overall, we found that for typical embankment geometries and resistivity distributions, the resistivity distribution has a greater control on the magnitude of the topographic effect than the exact embankment geometry: the subsurface resistivity distribution cannot be neglected. 2D inversions are suitable when both the embankment is more resistive than the foundations and when the embankment's cross-sectional area is greater than 4 m2/m2 (area scaled to an embankment with a height of 1 m). Topographic corrections, 3D data acquisition or 3D forward models are required when these conditions are not met. These are demonstrated using field data from an embankment at Hexham, Northumberland, UK. Improving the accuracy of the resistivity values in ERT models will enable more accurate ground models, better integration of resistivity data with geotechnical datasets, and will improve the translation of resistivity values into geotechnical properties. Such developments will contribute to a better characterised and safer flood defence network.

A Novel Two-dimensional Low-redundancy Array Design for Solar Radio Imaging

The radioheliograph is an extensive array of antennas operating on the principle of aperture synthesis to produce images of the Sun. The image acquired by the telescope results from convoluting the Sun’s true brightness distribution with the antenna array’s directional pattern. The imaging quality of the radioheliograph is affected by a multitude of factors, with the performance of the “dirty beam” being simply one component. Other factors such as imaging methods, calibration techniques, clean algorithms, and more also play a significant influence on the resulting image quality. As the layout of the antenna array directly affects the performance of the dirty beam, the design of an appropriate antenna configuration is critical to improving the imaging quality of the radioheliograph. Based on the actual needs of observing the Sun, this work optimized the antenna array design and proposed a two-dimensional low-redundancy array. The proposed array was compared with common T-shaped arrays, Y-shaped arrays, uniformly spaced circular arrays, and three-arm spiral arrays. Through simulations and experiments, their performance in terms of sampling point numbers, UV coverage area, beam-half width, sidelobe level, and performance in the absence of antennas are compared and analyzed. It was found that each of these arrays has its advantages, but the two-dimensional low-redundancy array proposed in this paper performs best in overall evaluation. It has the shortest imaging calculation time among the array types and is highly robust when antennas are missing, making it the most suitable choice.

Numerical study of NOx emission reduction by MILD and air staged synergistic combustion in a new type of coke oven flue

In order to address the issue of high emissions in the coke industry, we require innovative solutions. This article designs a coke oven flue with an array type secondary air nozzle, achieving the synergistic occurrence of MILD combustion and air staged combustion, which can significantly reduce nitrogen oxide emissions. However, further research is needed on the optimal control methods for synergistic combustion effects. First, Analyzed the mixing state of air and fuel under different air mass flow ratios. Next, by taking into account the oxygen distribution law, analyze the temperature distribution in both the primary and secondary combustion zones. Finally, analyze the distribution of NOx concentration. Study the impact of temperature differences caused by air mass flow ratio in synergistic effects on NOx emissions. The results indicate that by adjusting the air flow ratio, the air vortex intensity in the collaborative combustion process can be enhanced. This method can reduces flame temperature, achieving the objective of reducing NOx concentration. In the new type of coke oven flue, when the air mass flow ratio is 0.4, the combustion state in the primary and secondary combustion zones is optimal, and the NOx emission concentration is 312.88 mg/m3, representing a reduction of 38 %.

Detection of Beaded Karst Caves in Subway Works by Mixed-Source Surface Wave Survey: A Case Study

Abstract Karst cave causes geological disasters in tunneling engineering, which brings great risks to subway construction. The microtremor survey has become one of the main methods for karst cave detection in urban areas due to its convenience and great detection depth. However, the microtremor survey lacks high-frequency signals, resulting in poor detection accuracy on the shallow layer. An advanced method called mixed-source surface wave (MSW) method is proposed by imposing active sources during the continuous passive surface wave survey. MSW is applied to the detection of beaded karst caves (i.e. two or three karst caves at different depths in the same location) in Ji'nan, China. The influences of ambient noise, array type, and other factors on the detection accuracy were studied. Experimental results show that the detection depth and accuracy of MSW are much better than those of passive surface wave method. The inversion accuracy of linear array perpendicular to road is better than the triangle array and L-shaped array. The accuracy of the linear array along the road is worst. The detection accuracy of MSW is similar to that of combined active–passive surface wave methods. However, the basic principle of MSW is easier to understand, and its operation is more convenient. The two-dimensional measurement results show that the MSW method can well reflect the size and location of the beaded karst cave and provide important references for the practical engineering.

(Nanocarbons Division Poster Award, 2nd Place) Rare-Earth Families of Metallofullertubes or Metallofullerenes?

In our quest to isolate larger carbon cage fullertubes (e.g., C90-C130), we have explored the effect of adding metal atoms to the plasma of an electric-arc reactor. In the extracted metal-containing soot, we observe the typical array of Gd@C2n, Gd2@C2n, and Gd3N@C2n endohedral metallofullerenes that have been characterized for decades. However, upon addition of aminopropanol to the extracted endohedral soot, we are able to observe interesting metallo-carbon clusters which have not yet experimentally isolated or characterized (i.e. unknown structures). In this presentation, I will discuss our recent findings from 4 rare-earth families of endohedral species (e.g., Er, Gd, Lu, Ho).

4H-SiC 64 pixels CMOS image sensors with 3T/4T-APS arrays

For radiation-hardened CMOS image sensors (CIS), 4H-SiC 64 pixel array CIS were developed, and real time imaging with an operation frequency of 30 Hz was demonstrated. Two types of pixel arrays with a 3-transistor active pixel sensor (3T-APS) and a 4-transistor active pixel sensor (4T-APS) were fabricated with SiC MOSFETs, UV photodiodes and 3-layered Al interconnections. The SiC pixel arrays were combined with peripheral circuits and an optical lens, and SiC 64 pixel CIS with 3T-/4T-APS arrays were developed.

Dispersion Influence of Electroacoustic Transducer Parameters in the Design Process of Miniature Loudspeaker Arrays and Omnidirectional Sound Sources.

Electroacoustic transducers represent one of the crucial materials used in the construction of loudspeaker arrays. The dispersion in their parameters may influence the performance of a speaker set. Parametric loudspeaker arrays and omnidirectional sound sources have been used for years. However, the possible influence of transducer manufacturing tolerances on the arrays' performance has not been investigated. In previous research, the sources of possible dispersion in acoustic measurements carried out with omnidirectional sources were studied, pointing out that the problems with sound sources may be a significant reason behind the small measurement repeatability in standards. This paper investigated the measurement of several common types of miniature speakers, using 10 pieces of each type and investigating the influence of their parameter dispersion in electric and acoustic ways. Numerical simulations of omnidirectional sound sources were performed to investigate the drivers' dispersion influence sensitivity. The results provided proof of the small-signal parameter dispersion reaching 20% of the variation. The acoustic measurements show that the loudspeakers may differ in sensitivity parameters by up to 4 dB in 10 transducer tests. The analysis of an example multitransducer array indicated that a dispersion of a sensitivity higher than 1 dB might lead to significant misperformance in constructed arrays and measurement deviations with this type of array.

Insight into antibacterial effect of titanium nanotubular surfaces with focus on Staphylococcus aureus and Pseudomonas aeruginosa

Materials used for orthopedic implants should not only have physical properties close to those of bones, durability and biocompatibility, but should also exhibit a sufficient degree of antibacterial functionality. Due to its excellent properties, titanium is still a widely used material for production of orthopedic implants, but the unmodified material exhibits poor antibacterial activity. In this work, the physicochemical characteristics, such as chemical composition, crystallinity, wettability, roughness, and release of Ti ions of the titanium surface modified with nanotubular layers were analyzed and its antibacterial activity against two biofilm-forming bacterial strains responsible for prosthetic joint infection (Staphylococcus aureus and Pseudomonas aeruginosa) was investigated. Electrochemical anodization (anodic oxidation) was used to prepare two types of nanotubular arrays with nanotubes differing in dimensions (with diameters of 73 and 118 nm and lengths of 572 and 343 nm, respectively). These two surface types showed similar chemistry, crystallinity, and surface energy. The surface with smaller nanotube diameter (TNT-73) but larger values of roughness parameters was more effective against S. aureus. For P. aeruginosa the sample with a larger nanotube diameter (TNT-118) had better antibacterial effect with proven cell lysis. Antibacterial properties of titanium nanotubular surfaces with potential in implantology, which in our previous work demonstrated a positive effect on the behavior of human gingival fibroblasts, were investigated in terms of surface parameters. The interplay between nanotube diameter and roughness appeared critical for the bacterial fate on nanotubular surfaces. The relationship of nanotube diameter, values of roughness parameters, and other surface properties to bacterial behavior is discussed in detail. The study is believed to shed more light on how nanotubular surface parameters and their interplay affect antibacterial activity.

Experimental study of micro-prismatic electrode array wear during EDM and application to the preparation of microcylindrical electrode array

The focus of this study is to compare the wear characteristics of different types of micro-prismatic electrode array during EDM, and to propose a method for preparing microcylindrical electrode array based on micro-prismatic electrode array. Firstly, the characteristic of the micro-prismatic electrode that the front cross-section becomes circular after wear during EDM is clarified, and the wear form of the micro-prismatic electrode is analyzed. Then, the laws of the influence of electrode shape (triangle, square, hexagon), electrode material (pure copper, copper-tungsten alloy, pure tungsten), electrode size (200 μm, 300 μm, 400 μm) on the wear characteristics of the micro-prismatic electrode array, including the length of the wear of each part of the electrodes, the length of the area of the front cross-section that becomes rounded, the consistency of the wear of the electrode array, the machining efficiency, and electrode wear rate are summarized. After that, the process of changing the electrode array from square columns to cylinders using the new method is given, which confirms the feasibility of the method. Finally, the effects of peak current and pulse width on the size, machining efficiency, surface roughness, and surface micro-morphology of micro-cylindrical electrode array prepared by the new method are summarized. This study is of great significance for achieving mass production of microcylindrical electrode array.

Optimization of spherically arranged lens arrays based on class II and III geodesic polyhedra

Spherical arrangement is a common way to pack lens arrays. Due to the restriction of original structures, the previous optimization methods based on icosahedral subdivision are only applicable to a few types of lens arrays adopting different numbers of sub-lenses. In order to design more types of lens arrays, an optimization packing method is proposed with the vertices of class II and class III geodesic polyhedra as the arrangement positions of sub-lenses. The vertices of the geodesic polyhedron are generated by projecting grid nodes on each face of the ortho-icosahedron to a sphere. The vertex translation function is established in a barycentric coordinate system, and then the chord ratio and packing density are used as evaluation functions to optimize the vertices’ positions. The universality of the optimization method is tested, and its robustness is certified by analyzing the optimization results of different original structures with the same number of vertices. Finally, the effectiveness and feasibility of the optimization method in engineering applications are demonstrated in a monocentric multi-scale imaging system. The optimization method proposed in this paper can significantly increase the types of lens arrays from 9 to 37 types, adopting different numbers of sub-lenses within 1000 and effectively improved the distribution uniformity of lens arrays.