Uniform Characteristics Research Articles

Fabrication and characterization of flexible microelectrode arrays for the long-term recording of mammalian brain slices

Abstract A profound understanding of brain disorders is essential for developing more effective treatments, targeted therapies, and reliable diagnoses. Electrical in vitro long-term and repetitive measurements give insight to neural activity of more complex neural circuits and, thus, into malfunctioning caused by illness. Flexible microelectrode arrays (flexMEAs) enable the recording of neural activity with promising spatial and temporal resolution over longer durations. The present study aims to combine the long-term recording by flexMEAs with the cultivation of brain slices inside an incubator. An 8 μm-thin flexMEA with up to 256 electrodes with 30 μm in diameter and interelectrode spacing of 200 μm was fabricated. Characterization showed uniform and reproducible electronic characteristics. Coating with PEDOT:PSS by electropolymerization formed stable low-impedance spectra. The platform is ready for future experiments with brain slices inside an incubator.

Study of the image characteristics of school uniforms in the educational environment

The article is devoted to the study of the school uniform image characteristics. The relevance of the work is related to the discussion that has resumed in Russian society in connection with the possibility of introducing a standard for school uniforms by 2024. This study analyzes the attitude towards the problem of students, parents and employees of educational institutions. The sociological method (survey in the form of a questionnaire) was used in the work. The respondents were residents of the Primorsky Territory, 452 people took part in the survey. It has been established that students deny the need for uniform, while parents and teachers support the idea of a school uniform in education institutions. Positive and negative image characteristics of a school suit are revealed. Respondents consider the absence of a problem in the everyday choice of clothes and the maintenance of school discipline as positive characteristics of wearing a uniform. The negative characteristics of the school suit, according to students, are the lack of opportunities for self-expression and individuality, while most parents and teachers believe that there are no negative image characteristics of the school uniform. In terms of visual image characteristics, students would prefer to wear a preppy school uniform, parents and teachers would like to see a business style school uniform (classic with casual elements). When choosing a color solution for school uniforms, students would like to wear black clothes, arguing that black is a versatile and elegant color. Parents and teachers would prefer to see school uniforms predominantly blue.

Seed purity assessment of two local upland rice cultivars of Southeast Sulawesi based on agronomic characteristics

This research intended to purify upland rice seeds that have presumably been unintentionally mixed with various types of rice seeds, causing decreased quality or nature of the superior upland rice cultivars. Seed purification effort is needed to restore the purity of the seeds of promising local upland rice cultivars. The second long term goal of this research was to produce basic pure seeds, that are required for further breeding programs, and/or for the purpose of releasing new varieties. This study was the second generation of purification effort, aimed to further select the same or uniform agronomic characteristics of the local upland rice cultivars in each seed lot. Similar with the first generation, the experiment used a Randomized Block Design (RBD) consisting of 15 seed lots as treatment and each seed lot consisted of 4 “grids” (replications). This research was conducted at the Field Laboratory, Experimental Garden II, Faculty of Agriculture, Halu Oleo University. The results showed several characters (i.e., plant height, leaf number, and tiller number etc.) of the two rice cultivars were seem more uniform as compared to the first generation of purification. This indicates that the seeds are gradually purer.

An Exploration of the Sodium Solid Electrolyte Interphase in Glyme Electrolytes with Carbonate Additives

The utilization of alkali metal anodes is hindered by an inherent instability in organic electrolytes. Sodium (Na) is of growing interest due to its high natural abundance, but the carbonate electrolytes that are popular in lithium systems are unable to form a stable solid electrolyte interphase (SEI) with a sodium metal electrode. However, the glyme (chain ether) electrolytes produce thin, predominantly inorganic SEI at sodium metal interfaces. Using half-cell and symmetric cell analysis, we identify diglyme (G2) as the best performing of the glymes, balancing the high nucleation barrier of the short glyme (G1) and the high plateau overpotential of the long glyme (G4). Based on mesoscale modeling, we capture the critical dependence of the nucleation and early-stage growth morphology on a competing set of mechanisms, including the reduction kinetics on the substrate/newly deposited Na and the surface mobility of these deposits. Through in situ optical microscopy, the onset and growth of Na dendrites is revealed in glyme electrolytes, and the addition of small quantities (~10% volume/volume) of ethylene carbonate (EC) and fluoroethylene carbonate (FEC) to G2 is shown to facilitate uniform sodium plating characteristics in the optical cell, presumably through alterations to SEI composition. X-ray photoelectron spectroscopy (XPS) analysis reveals that the FEC additive results in an SEI with similar atomic composition to that formed in G2 alone, whereas addition of EC to G2 results in an entirely different SEI composition, despite the molecular similarity of the carbonate additives. We have determined that the SEI formed by glyme alone may not support extensive or extreme cycling conditions, but the addition of FEC provides a much more robust SEI at the Na metal surface to facilitate numerous consistent sodium plating and stripping cycles.

Nature-inspired spider web shaped UHF RFID reader antenna for IoT and healthcare applications

This paper proposes a nature-inspired spider web-shaped ultra-high frequency (UHF) radio frequency identification (RFID) reader antenna and battery-free sensor-based system for healthcare applications. This antenna design consists of eight concentric decagons of various sizes and five straight microstrip lines.These lines are connected to the ground using 50 Omega resistors from both ends, except for one microstrip line that is reserved for connecting a feeding port. The reader antenna design features fairly strong and uniform electric and magnetic field characteristics. It also exhibits wideband characteristics, covering whole UHF RFID band (860–960 MHz) and providing a tag reading volume of 200 times 200 times 20 mm{^3}. Additionally, it has low gain characteristics, which are necessary for the majority of nearfield applications to prevent the misreading of other tags. Moreover, the current distribution in this design is symmetric throughout the structure, effectively resolving orientation sensitivity issues commonly encountered in low-cost linearly polarized tag antennas. The measurement results show that the reader antenna can read medicine pills tagged using low-cost passive/battery-free RFID tags, tagged expensive jewelry, intervenes solution, and blood bags positioned in various orientations. As a result, the proposed reader antenna-based system is a strong contender for near-field RFID, healthcare, and IoT applications.

Electrochemical Growth and Structural Study of the AlxGa1−xAs Nanowhisker Layer on the GaAs Surface

This work presents a novel, cost-effective method for synthesizing AlxGa1−xAs nanowhiskers on a GaAs surface by electrochemical deposition. The process begins with structuring the GaAs surface by electrochemical etching, forming a branched nanowhisker system. Despite the close resemblance of the crystal lattices of AlAs, GaAs, and AlxGa1−xAs, our study highlights the formation of nanowhiskers instead of layer-by-layer film growth. X-ray diffraction analysis and photoluminescence spectrum evaluations confirm the synthesized structure’s crystallinity, uniformity, and bandgap characteristics. The unique morphology of the nanowhiskers offers promising implications for solar cell applications because of the increased light absorption potential and reduced surface recombination energy losses. We conclude by emphasizing the need for further studies on the growth mechanisms of AlxGa1−xAs nanowhiskers, adjustments of the “x” parameter during electrochemical deposition, and detailed light absorption properties of the formed compounds. This research contributes to the field of wideband materials, particularly for solar energy applications, highlighting the potential of electrochemical deposition as a flexible and economical fabrication method.

Urban Expansion and The Microclimate Characteristics Evolution of Lhasa

Urban expansion is the process of growing urban population and expanding land for residential and productive use. Microclimates are small-scale climates with relatively uniform and changeable climatic characteristics. In the context of climate change on the Tibetan Plateau, the microclimate of Lhasa will respond to urban expansion. With the support of landset8 OLI_TIRS data, this study uses the unsupervised classification method ISO-data algorithm to extract information on construction land and calculate the intensity of urban sprawl. In order to analyze and investigate the evolution of urban expansion and microclimate characteristics in Lhasa city from 2014 to 2021, the radiative transfer equation method was chosen to invert the surface temperature and calculate the heat island effect characteristic-related index. The results of the study show that the area of built-up land in Lhasa city increases and the heat island intensity rises during 2014-2021. This study contributes to urban planning in Lhasa and provides a case study of climate change and cities on the Tibetan Plateau.

Flexible Transparent Planar Heater Comprising ZnO/Cu/Al2O3

In this study, we fabricated transparent heaters composed of an ultrathin Cu-layer heating element sandwiched between a ZnO underlayer and an Al2O3 overlayer. With the Cu layer thickness fixed at 8.5 nm, the thicknesses of the ZnO and Al2O3 layers were independently varied to reach the optimum antireflecting condition (maximum transmittance of 88.3% and average visible light transmittance of 79.8% were achieved). The sheet resistances for the ZnO/Cu/Al2O3 heaters can be varied by simply modulating the Cu layer thicknesses. In order to assess the flexibility of the transparent heaters, we constructed a ZnO/Cu/Al2O3 structure on flexible polyimide substrates, and the thermal, electrical, optical and mechanical characteristics were evaluated. Because of the planar heating element of the Cu layer, the thermal response was found to be extremely high, i.e., less than 10 s were required to reach 90% of the target temperatures. Once the target temperatures were reached, the heater temperatures were highly stable with no degradation of electrical and optical properties. Furthermore, the heating capability was maintained under severe mechanical deformation, e.g., at a bending radius of 4 mm. The structure also exhibited highly sustainable optoelectronic properties under repetitive mechanical deformation, confirming the potential for commercialization. Finally, we demonstrated that ZnO/Cu/Al2O3 rolled around a human finger exhibited highly uniform heating characteristics, rendering the heaters suitable for wearable, healthcare electronics.

Bolus 3D printing for radiotherapy with conventional PLA, ABS and TPU filaments: Theoretical-experimental study

A theoretical-experimental study of the interaction of electron beams with 3 filaments conventionally used for 3D printing is presented in this paper. Pieces of polylactic acid (PLA), acrylonitrile butadiene styrene (ABS) and thermoplastic polyurethane (TPU) are studied using Monte Carlo simulation with Geant4 and experimental measurements with plane-parallel ionization chambers and radiochromic films. Using different printing parameters and computed tomography, the presence of air gaps and the uniformity in the bolus density made with the different materials are evaluated. The main parameters in the Percentage Depth Dose (PDDs) are determined, the manufacturing process is standardized and the printing profiles are generated for each of the materials in order to obtain uniform attenuation characteristics in the pieces and improve adaptation to irregular anatomical areas.

Uniform exhaust characteristics of new-type airbox components of continuous miner

When the dust removal system of the continuous mining machine works, the exhaust air volume cannot meet the design requirements due to the different pressure and uneven air speed in the exhaust duct. These will lead to an increase in the energy consumption of the fan. In this paper, the uniform exhaust mathematical model was established. A novel resistance plate member was developed on the basis of a uniform exhaust pipe with variable cross sections. The uniform exhaust characteristics of two different exhaust ducts were discussed. The influence of adding a resistance plate on the vibration characteristics of airbox components was analyzed. The results show that adding resistance plate members could significantly reduce the airflow resistance, deviation, and unevenness of the exhaust rate. When the excitation frequency is 130 Hz, the vibration response of the airbox components is stronger, and operation at this frequency should be avoided.

Preparation of Nitrogen-Doped ZnFe2O4-Modified Carbon Composite and Its Collaborative Energy Storage Mechanism

The pyrolytic carbon of polymer adsorbent resin (SAP) is used as a waste carbon source, which can be used as a porous carbon network via pyrolysis to remove surface sodium carbonate and other substances. In this paper, a ZnFe2O4/nitrogen-doped porous carbon composite was prepared using the template method. Through the high-temperature carbonization of a polymer and crystallization of inorganic elements, the morphology of the composite showed uniform load characteristics. This well-defined structure and morphology facilitate the transport of Li+, enhance the effective contact area with the electrolyte, and provide a wealth of active sites. For the SAP-Fe/Zn anode, at a high current density of 0.1 A g−1, the reversible capacity of the anode reached 753 mAh g−1 after 200 cycles, showing excellent magnification performance. The final modified SAP-Fe/Zn&NC electrode had a reversible capacity of 205.6 mAh g−1 after 1000 cycles at the high current density of 2 A g−1, and the cycle retention rate was as high as 80.7%. The enhanced electrochemical performance can be attributed to the abundant active sites and shortened diffusion pathway of the composite. This ensures adequate conversion reactions during the Li-litization process between Zn, Fe, and Li+, alleviates volume expansion, and prevents comminution/aggregation during long cycles at high current densities.

Underwater polarization image restoration based on a partition method

The quality of underwater polarization imaging is mainly affected by the polarization properties of the target and impurity particles. Traditional methods often assume uniform polarization characteristics of the target, which make it difficult to address the restoration issues of complex targets. In response, a partition-based method for recovering underwater polarization images is proposed. The method involves pre-processing the image using the Gaussian curvature filtering algorithm, partitioning the image based on polarization information. In addition, a joint image evaluation method is used to achieve restoration of complex polarized characteristic targets. The method estimates the value of the reflected light polarization of one partition to estimate the value of the next partition and links the polarization values of each partition. Our approach achieves clear restoration results for multiple targets or complex structural objects underwater. Achieving significant improvement in image quality in multi-target underwater scenes, our method is highly effective for complex underwater environments. Experimental results show that our method, when compared with three other newer methods on multiple images of different targets and under varying scattering conditions, achieves an average increase of 617% in the standard deviation image evaluation index and a 61% optimization in the natural image quality evaluator index. Furthermore, our method is robust for different degrees of water turbidity.

Highly uniform resistive switching characteristics of Ti/TaOx/ITO memristor devices for neuromorphic system

In this study, we focused on the uniformity of resistance states of Ti/TaOx/ITO devices and the possibility of using them in neuromorphic applications under DC and pulse measurement conditions. The thickness and chemical composition of the devices was verified by transmission electron microscopy (TEM). First, the I-V curves of the devices were controlled with the compliance current and reset voltage. In addition, the multi-level characteristics were demonstrated through DC sweeps and pulses for high-density memory and neuromorphic systems. The linearity of potentiation and depression was then improved to seek high accuracy of pattern recognition in a neural network. Finally, spike-timing-dependent plasticity (STDP) was performed (including potentiation and depression) to mimic Hebbian learning of the nerve system.

The squaretail mullet Ellochelon vaigiensis (Quoy & Gaimard, 1825) a complex of cryptic species?

Abstract The teleost family Mugilidae is speciose with uniform morpho-anatomical characteristics, which render species identification difficult. The dna barcoding technique has, however, proven to be a precise and reliable approach for species delineation. To date, dna barcoding flags numerous polyphyletic species in Mugilidae that probably correspond to species complexes and that call for further taxonomical investigation. Among these species, the squaretail mullet Ellochelon vaigiensis is an interesting case study because, unlike other mullet species, it is easily identified from its unique phenotype. Recent studies of genetic diversity in this monotypic species have revealed two lineages, located either in the Indo-Pacific (Polynesia and Taiwan waters) or along Australian shores. In this study, a third lineage is described in the North of the Indian Ocean, based on nucleotide polymorphisms of Cytochrome c oxidase 1 and barcodes available in bold and Cytochrome b. Despite genetic divergences that exceed the intraspecific threshold, there was no morpho-anatomical difference among specimens of the north Indian Ocean vs. Indo-Pacific or Australia. These molecular results suggest nominal species of Ellochelon vaigiensis within a cryptic species complex.

Biochemical differentiation between cancerous and normal human colorectal tissues by micro-Raman spectroscopy

Human colorectal tissues obtained by ten cancer patients have been examined by multiple micro-Raman spectroscopic measurements in the 500–3200 cm−1 range under 785 nm excitation. Distinct spectral profiles are recorded from different spots on the samples: a predominant ‘typical’ profile of colorectal tissue, as well as those from tissue topologies with high lipid, blood or collagen content. Principal component analysis identified several Raman bands of amino acids, proteins and lipids which allow the efficient discrimination of normal from cancer tissues, the first presenting plurality of Raman spectral profiles while the last showing off quite uniform spectroscopic characteristics. Tree-based machine learning experiment was further applied on all data as well as on filtered data keeping only those spectra which characterize the largely inseparable data clusters of ‘typical’ and ‘collagen-rich’ spectra. This purposive sampling evidences statistically the most significant spectroscopic features regarding the correct identification of cancer tissues and allows matching spectroscopic results with the biochemical changes induced in the malignant tissues.

Effect of Dispersion Method on Ink Rheology and Microstructure of Microporous Layer for PEMFCs

In the modern design of proton exchange membrane fuel cells (PEMFCs), a microporous layer (MPL) is often introduced between the gas diffusion layer and catalyst layer to facilitate water management and reduce contact resistance. In this study, an experimental investigation of MPL fabrication, particularly on ink preparation, is carried out to assess the relationship between ink properties and MPL’s microstructure. Two dispersion methods for ink preparation, i.e., sonication and ball-milling, are employed. Rheological and agglomerate size measurements of the inks are performed. Structural properties of the MPL are characterized by the Brunauer–Emmett–Teller method. The MPL inks prepared by ball-milling and sonication dispersion are found to have different rheological properties. The viscosity of ball-milled inks is around 20 mPa·s, whereas for sonicated inks it is about one order of magnitude lower. The surface cracks of the MPL by ball-milling appear to be more extensive and fewer in number than those by sonication. A distinct layer structure forms when the inks are dispersed by ball-milling, whereas sonicated inks penetrate the gas diffusion substrate. The MPL fabricated by a ball-milled ink for 2 h has the most uniform microstructural characteristics among the cases tested.

An Interface‐Type Memristive Device for Artificial Synapse and Neuromorphic Computing

Interface‐type (IT) metal/oxide Schottky memristive devices have attracted considerable attention over filament‐type (FT) devices for neuromorphic computing because of their uniform, filament‐free, and analog resistive switching (RS) characteristics. The most recent IT devices are based on oxygen ions and vacancies movement to alter interfacial Schottky barrier parameters and thereby control RS properties. However, the reliability and stability of these devices have been significantly affected by the undesired diffusion of ionic species. Herein, a reliable interface‐dominated memristive device is demonstrated using a simple Au/Nb‐doped SrTiO3(Nb:STO) Schottky structure. The Au/Nb:STO Schottky barrier modulation by charge trapping and detrapping is responsible for the analog resistive switching characteristics. Because of its interface‐controlled RS, the proposed device shows low device‐to‐device, cell‐to‐cell, and cycle‐to‐cycle variability while maintaining high repeatability and stability during endurance and retention tests. Furthermore, the Au/Nb:STO IT memristive device exhibits versatile synaptic functions with an excellent uniformity, programmability, and reliability. A simulated artificial neural network with Au/Nb:STO synapses achieves a high recognition accuracy of 94.72% for large digit recognition from MNIST database. These results suggest that IT resistive switching can be potentially used for artificial synapses to build next‐generation neuromorphic computing.

Analysis of the Terminal Response Characteristics of the Twisted Three-Wire Cable Excited by a Plane Wave Field

A twisted three-wire cable model with uniform twisting characteristics is proposed in this paper, and its terminal response under external electromagnetic wave irradiation is calculated using the TLM method based on Taylor model. The triple-stranded triple-helix structure is determined in the method and the parametric equations of the twisted wire bundle in the Cartesian coordinate system are provided. Then, the frequency domain equations for the voltage and current of the twisted three-wire cable under field-to-wire coupling are derived and extended to apply to scenarios with arbitrary polarization and irradiation in the incident direction based on the transmission-line theory. Finally, the response laws of the twisted three-wire wire with different cable lengths, termination loads, and pitches coupling under external electromagnetic wave irradiation are studied. A uniform twisted three-wire cable can suppress the increased induced current on the cable. In addition, the excellent characteristics of the twisted three-wire cable in terms of immunity to electromagnetic interference are also verified by comparing the frequency domain response with that of a parallel three-wire cable.

An efficient multi-state evaluation approach for lithium-ion pouch cells under dynamic conditions in pressure/current/temperature

The current analytical and simulation models for lithium-ion pouch cells encounter challenges in accuracy and efficiency for battery management applications. This paper proposes an analytical model and decoupling algorithm for lithium-ion pouch cells. It can evaluate the multi-state distribution and evolution in gas/heat generation, temperature, pressure, and deformation. Analytic differential equations are formulated, including mechanical, thermal circuit and reaction sub-models. The analysis framework considers dynamic conditions (e.g., mechanical pressure, charging/discharging, heat dissipation) and uniform characteristics (e.g., local heating, anisotropic heat conduction, shell deformation). A sequential decoupling algorithm from the global to the local is proposed to address the convergence issue from the high-dimensional and strongly nonlinear equations. Iterative mechanisms are established to determine the solving parameters for eliminating confusion in engineering applications. The numerical and experimental results on three commercial pouch cells verified the approach performances, including stable convergence, millisecond efficiency, and 2% temperature error. The performances suggest its application prospects in energy storage and vehicle power systems.

Quantitative Evaluation of Maize Emergence Using UAV Imagery and Deep Learning

Accurate assessment of crop emergence helps breeders select appropriate crop genotypes, and farmers make timely field management decisions to increase maize yields. Crop emergence is conventionally quantified by manual calculations to quantify the number and size of seedlings, which is laborious, inefficient, and unreliable and fails to visualize the spatial distribution and uniformity of seedlings. Phenotyping technology based on remote sensing allows for high-throughput evaluation of crop emergence at the early growth stage. This study developed a system for the rapid estimation of maize seedling emergence based on a deep learning algorithm. The RGB images acquired from an unmanned aerial vehicle (UAV) were used to develop the optimal model for the recognition of seedling location, spacing, and size, and the prediction performance of the system was evaluated in three stations during 2021–2022. A case study was conducted to show the evaluation of the system for maize seedlings and combined with TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) analysis. The results show that the system has good prediction performance for maize seedling count with an average R2 value of 0.96 and an accuracy of 92%; however, shadows and planting density influence its accuracy. The prediction accuracy reduces significantly when the planting density is above 90,000 plants/ha. The distribution characteristics of seedling emergence and growth were also calculated based on the average value and variation coefficient of seedling spacing, seedling area, and seedling length. The estimation accuracies for the average value of seedling spacing, the coefficient of variation of seedling spacing, the average value of the seedling area, the coefficient of variation of the seedling area, and the average value of the seedling length were 87.52, 87.55, 82.69, 84.51, and 90.32%, respectively. In conclusion, the proposed system can quickly analyze the maize seeding growth and uniformity characteristics of experimental plots and locate plots with poor maize emergence.