Rectangular Device Research Articles

A comparison of the electrochemical performance between novel donut-like and rectangular-like supercapacitors made with La0.5Pr0.5Fe0.7Mn0.3O3 perovskite

Novel donut-like supercapacitors (SCs) were fabricated from recycled plastics. To enhance their electrochemical performance, La0.5Pr0.5Fe0.7Mn0.3O3 (LAFE) redox powder was added on their electrodes. This powder had an orthorhombic structure and was formed by porous grains with sizes of 40–120 nm according to the microscopy and X-ray diffraction analyses. Donut-like SCs (contained acidic electrolyte) made with and without LAFE had capacitances of 182.8 and 334.7 F g−1, respectively. Although the device made with LAFE had lower capacitance, it presented a battery component (prolonged discharge at a stable voltage of 1.2 V), which produced a high capacity of 1555 mAh g−1. In contrast, the donut-like SC made without LAFE had a lower capacity of 260 mAh g−1. Other donut-like SCs were made with an amber electrolyte derived from recycled lithium-ion battery (LIB) electrodes (collected from expired LIBs). Those devices had lower capacitances and energy-densities of 96–230 F g−1 and 36–42 Wh kg−1, respectively. For comparison purposes, rectangular SCs were fabricated with and without LAFE redox powder and obtained capacitances/energy-densities of 970.8 F g−1/194.2 Wh kg−1 and 562.5 F g−1/112.5 Wh kg−1, respectively. Thus, adding the LAFE powder to the rectangular SCs incremented their capacitance by ⁓73 %. Those rectangular devices were also immersed in water at room temperature or under cold water (5 °C); consequently, the capacitance decreased by 45–53 %. The analysis by Raman spectroscopy, optical-absorption, and XPS spectroscopy demonstrated the existence of Fe3+/Fe2+ and Mn4+/Mn3+ species as well as oxygen-vacancy defects on the SC electrodes made with LAFE. Those ones promoted the storage of charge by redox-reactions. Hence, the results of this work revealed that donut-like energy sources can be fabricated from recycled six-pack rings, which avoids the contamination of the environment by microplastics. We also demonstrated that electrolytes can be produced from recycled LIB electrodes and could be used to fabricate efficient SCs. Both, the novel electrolyte and donut-like devices pave the way for the design of low-cost energy sources that can be used in wearable electronics.

Parallelization of Curved Inertial Microfluidic Channels to Increase the Throughput of Simultaneous Microparticle Separation and Washing

The rising global need for clean water highlights the importance of efficient sample preparation methods to separate and wash various contaminants such as microparticles. Microfluidic methods for these purposes have emerged but they mostly deliver either separation or washing, with very low throughputs. Here, we investigate parallelization of a curved-channel particle separation and washing device in order to increase its throughput for sample preparation. A curved microchannel applies inertial forces to focus larger 10 µm microparticles at the inner wall of the channel and separate them from smaller 5 µm microparticles at the outer wall. At the same time, Dean flow recirculation is used to exchange the carrier solution of the large microparticles to a clean buffer (washing). We increased the number of curved channels in a stepwise manner from two to four to eight channels in two different arraying designs, i.e., rectangular and polar arrays. We examined efficient separation of target 10 µm particles from 5 µm particles, while transferring the larger microparticles into a clean buffer. Dean flow recirculation studies demonstrated that the rectangular arrayed device performs better, providing solution exchange efficiencies of more than 96% on average as compared to 89% for the polar array device. Our 8-curve rectangular array device provided a particle separation efficiency of 98.93 ± 0.91%, while maintaining a sample purity of 92.83 ± 1.47% at a high working flow rate of 12.8 mL/min. Moreover, the target particles were transferred into a clean buffer with a solution exchange efficiency of 96.81 ± 0.54% in our 8-curve device. Compared to the literature, our in-plane parallelization design of curved microchannels resulted in a 13-fold increase in the working flow rate of the setup while maintaining a very high performance in particle separation and washing. Our microfluidic device offers the potential to enhance the throughput and the separation and washing efficiencies in applications for biological and environmental samples.

Hourglass transistor: An alternative and improved MOS structure robust to total ionization dose radiation

This paper presents a novel MOSFET layout named the “hourglass transistor”, aimed to improve its electrical behavior under Total Ionizing Dose (TID) effects. The new radiation-tolerant device is based on augmenting parasitic channel resistance, alteration of the electric field by the longitudinal corner effect (LCE), and reducing channel resistance within the central gate region. The radiation-robust MOS structure design was implemented in a 130 nm CMOS bulk process and its performance was analyzed through simulations using 3D physical models. The proposed hourglass transistor was compared with rectangular, diamond, dog bone and H-gate devices, showing a reduction in the post-radiation Ioff current of 8.77, 4.6, 1.85 and 13.7 times, respectively; and a pre-radiation normalized saturation current of 2.29, 1.04, 1.58 and 1.52 times greater with an increase of 4.84, 1, 2.47 and 2.03 times the gate area, respectively.

Study on electrochemical corrosion dynamics of cathode dic shield in concrete crack

Abstract Corrosion of steel reinforcement is a primary factor that negatively impacts the service life and safety of bridges made of concrete. Cathodic protection techniques are widely used to protect reinforcing bars in concrete against corrosion. However, it is inevitable that corrosion cracks will develop in the concrete during long-term operation, which will significantly shorten the cathodic current protection distance and increase the degree of corrosion of the rebar within the cracks. Therefore, electrochemical experiments and characterization of corrosion forms were carried out based on the company’s design of a rectangular connection device, we studied HRB500 steel in 3 wt.% corrosion behavior in rectangular joints under different CP current densities in NaCl solution. The results showed that with increasing experimental time, the corrosion in the crevice transitioned from activation corrosion to oxygen concentration corrosion, with the open-pore potential of the HRB500 steel inside the crevice appearing as a positive shift and the open-pore potential outside the crevice shifting from positive to negative. When implementing cathodic protection, the corrosion of HRB500 steel within the crevice is activated, while the corrosion outside the crevice changes from anodic to mixed controlled corrosion and from full to pitting corrosion. With the increase of CP current density, the corrosion process of HRB500 steel outside the gap is mainly dominated by cathode control, then gradually weakens, and the corrosion form changes from pitting to comprehensive corrosion.

Вплив форми дозвукової частини надзвукового вхідного пристрою на коефіцієнт збереження повного тиску

The subject of this study is the total pressure conservation coefficient. The object of this study is the channel of the subsonic part of a supersonic input device of rectangular and oval shape, equivalent in size. The purpose of this study is to study the shape of the subsonic part of a supersonic external compression input device. To achieve this purpose, the following tasks were solved: modeling the flow in the subsonic part of a supersonic inlet external compression input device of rectangular and oval shape; calculation of the total pressure conservation coefficient in the subsonic part of the rectangular and oval supersonic inlet external compression input device. When studying the shape of the subsonic part of the supersonic inlet external compression device, the method of numerical experiment was used. The studies were conducted at an estimated altitude of 12 km and an estimated Mach number M = 2.5. The influence of the fuselage on the operation of the input device was not considered. To study the influence of the cross-sectional shape of the studied subsonic parts of the inlet device, the coefficient of conservation of total pressure in 7 cross sections along the length of the inlet device was calculated. To obtain the initial data for modeling the flow in a subsonic channel, an analytical calculation of the flow parameters in the supersonic part of the input device was performed. The results of flow modeling showed that the total pressure conservation coefficient of the subsonic part of the studied inlet devices when operating at an altitude of 12 km was 0.982 in the subsonic part of the supersonic inlet device with oval sections and 0.993 in the subsonic part of the supersonic inlet device with rectangular sections. The resulting visualization of streamlines in the studied channels demonstrates the presence of a paired vortex formed in the initial section of the channel with oval cross-sections, which leads to significant losses in total pressure. The scientific novelty and practical significance of this study lie in the fact that new data were obtained regarding the comparison of the total pressure conservation coefficient for equivalent subsonic parts of a supersonic oval and rectangular inlet device. Recommendations on the rational form of the subsonic part of the supersonic inlet external compression device were obtained.

Skin Expander for Scalp Reconstruction: Reappraisal of a Reconstructive Procedure for Aplasia Cutis Congenita.

Aplasia cutis congenita (ACC) is a heterogeneous group of congenital disorders characterized by the absence of epidermis, dermis, appendages, subcutaneous tissue, and bone. The aim of the study is to describe a clinical report of ACC of the scalp treated with skin expanders. In October 2019, a 16-year-old female patient underwent scalp expansion with 2 rectangular devices (150 and 250cm3; Radovan Mentor-Johnson&Johnson). The inflation started 30 days after surgery and continued once every 7 to 10 days to gain 10% of overexpansion. After 3 months, the patient underwent the second surgical step with the expanded scalp transposed to close the defect. Clinical examination 6 months after surgery revealed an acceptable cosmetic result with a hidden surgical scar and hair growth in the previous area of frontoparietal alopecia. Skin expander for the reconstruction of extensive ACC defects of the scalp is a valid procedure.

Borehole transient electromagnetic response calculation and experimental study in coal mine tunnels

Water damage seriously threatens the safe production of coal mines, so it is necessary to carry out advanced detection to determine the hydrogeological situation, and the preliminary survey often involves the drilling of on-site drill holes in the tunnel. The use of directional drill holes, combined with advanced geophysical prospecting technology, enables advanced water disaster detection with long distance and high precision and is independent of the tunnel environment influence. The transient electromagnetic method (TEM) is highly sensitive to low-resistivity anomalies and plays a crucial role in water damage detection. To address the size limitation of borehole detection, in this study, a small rectangular multi-turn loop borehole advanced detection method was developed (borehole TEM, BTEM) to detect low-resistivity anomalies within 10 m of the borehole in the radial direction. To satisfy the size requirements for borehole detection and the detection distance, a small rectangular multi-turn loop device with a width of 6 cm and a length of 50 cm was designed. To resolve the issue of self-inductance and mutual inductance enhancement caused by multi-turn coils, a uniform full-space low-resistivity abnormal body model was established using the Ansys Maxwell software, and we analyzed the vertical magnetic field component of the rectangular multi-turn small loop at different time points and the transient electromagnetic response of the different turns. Then, we determined the appropriate parameters for the transmitting and receiving device. The developed method was applied to several different experimental scenarios to obtain the electrical distribution of the anomalous body in front of the device, and the measured data were inverted and interpreted to obtain the apparent resistivity-depth profile. The results demonstrate that the inversion results align well with the actual situation, confirming the effectiveness of the BTEM. This research offers a potential solution for borehole advance detection and provides a solid theoretical foundation for further studies.

A Design Method for Rectangular Waveguide-Typed Microwave Devices Based on a Novel Origami Process.

A novel design method based on a novel origami process that can create a solid structure swiftly and at a low cost is presented for rectangular waveguide-type microwave devices in this paper. A planar structure was fabricated by the lamination and laser cutting of polystyrene membranes and aluminum foils and was converted into a solid structure via origami in accordance with the selective absorption of infrared light. A rectangular waveguide, a rectangular waveguide-type coupler, and a power divider based on an origami structure with a multi-layer structure and a single-layer structure were fabricated and tested, demonstrating easy assembly and good microwave performance. The measured results of the rectangular waveguide indicated that the insertion loss was superior to -0.9 dB. Meanwhile, the results of the coupler showed that the coupling degree increased from -12.8 dB to -8.9 dB in the range of 11.0 GHz to 12.0 GHz. Correspondingly, the prepared power divider demonstrated that the return loss dwindled from -8.9 dB to -11.3 dB and that the insertion loss of one output port was approximate to that of the remaining one, varying between -3.5 dB and -5.2 dB in the range of 10.5 GHz to 11.5 GHz-verifying the effectiveness of the origami-based design method.

Investigation of the Asyogh's rectangular device for learning and memory testing in Wistar rats.

This study aimed to design Asyogh's rectangular device that is used for memory testing in rodents. It was found that scopolamine (3 mg/kg i.p.) and diazepam (1 mg/kg i.p.) caused significant memory deficits in rats, as evidenced by increased transfer latency times. However, these memory deficits were significantly reversed when the rats were pretreated with Donepezil. It further demonstrates that pretreated donepezil is able to effectively restore the memory deficits induced by scopolamine and diazepam, as indicated by the significant recovery in TLT. The present study showed that the device used to measure transfer latency time that was a valuable tool for assessing memory and cognitive function in rodents.

Advanced Modeling of Rectangular Waveguide Devices With Smooth Profiles by Hierarchical Model Reduction

We present a new method for the analysis of smoothly varying tapers, transitions, and filters in rectangular waveguides. With this aim, we apply a hierarchical model (HiMod) reduction to the vector Helmholtz equation. We exploit a suitable coordinate transformation and, successively, we use the waveguide modes as a basis for the HiMod expansion. This allows us to model the electromagnetic field efficiently and compactly without incurring on relevant simplifications. We show that accurate results can be obtained with an impressive speed-up factor when compared with standard commercial software based on a 3-D finite element discretization.

The single power law relationship between coercivity and width in pointed composite element magnetic barcodes

Pointed magnetic elements are introduced as an improvement upon rectangular strips currently employed in composite element magnetic barcodes. The coercivity of these elements, as measured using the magneto-optic Kerr effect, is found to strictly adhere to a single power law relationship with the element width, where the power law exponent is dependent on the length of the pointed region and takes values between −0.98 and −0.91. The steeper gradients here, along with the absence of the crossover region seen in rectangular devices, present these structures as a strict improvement in terms of potential device applications. These improvements are found to be present for all structures where the pointed region is as long as, or longer than, the magnetic element is wide. The remanent magnetization configuration, imaged using photo-emission microscopy with contrast from x-ray magnetic circular dichroism (XMCD-PEEM), is compared to the results of micromagnetic simulations. It is found to cant inward in the pointed section of the strip, aligning with the edges of the point, pinning the magnetization and giving a consistent magnetization reversal behavior for all element widths investigated.

Experimental study of thermal performance in a rectangular finned-tube latent heat storage device with composite polyethylene wax/expanded graphite

Phase change materials and geometric structure of latent heat storage (LHS) devices constitute crucial factors affecting the performance of phase change thermal energy storage systems. In this study, focusing on the LHS system with a heat source temperature of 150 °C, a rectangular finned-tube latent heat storage device was designed and fabricated. Polyethylene wax (PEW) with a 10% mass fraction of expanded graphite was adopted to prepare the composite phase change material. A series of experiments was conducted to evaluate the thermodynamic performance of the device with varying inlet temperatures and mass flow rates. The experimental results showed that the process of heat storage and release was predominantly governed by thermal conduction due to the high viscosity of PEW. Although the temperature variations in various directions within the LHS device remain nearly consistent, the heat transfer in the non-fin regions on the rectangular LHS device walls and corners was comparatively inferior due to the absence of natural convective heat transfer. In comparison to the mass flow rate, the inlet temperature exerts a more significant impact on accelerating the heat storage/release processes. While an increase in the mass flow rate enhanced the heat transfer capacity, its slightly accelerates the heat transfer duration. Moreover, the heat release ratio of the device exhibits an initial increase followed by a decrease with an increasing mass flow rate. In practical applications, prioritizing an increase in inlet temperature difference proves to be more effective than adjusting mass flow rate to enhance the heat storage performance.

Extra-High Mechanical and Phononic Anisotropy in Black Phosphorus Blisters.

Strain is an effective strategy to modulate the electrical, optical, and optoelectronic properties of 2D materials. Conventional circular blisters could generate a biaxial stretching of 2D membranes with notable strain gradients along the hoop direction. However, such a deformation mode cannot be utilized to investigate mechanical responses of in-plane anisotropic 2D materials, for example, black phosphorus (BP), due to its crystallographic orientation dependence. Here, a novel rectangular-shaped bulge device is developed to uniaxially stretch the membrane, and further provide a promising platform to detect orientation-dependent mechanical and optical properties of anisotropic 2D materials. Impressively, the derived anisotropic ratio of Young's modulus of BP flakes is much higher than the values obtained via the nanoindentation method. The extra-high strain-dependent phononic anisotropy in Raman modes along different crystalline orientations is also observed. The designed rectangular budge device expands the uniaxial deformation methods available, allowing to explore the mechanical, and strain-dependent physical properties of other anisotropic 2D materials more broadly.

Lightweight design of temporary support device of rectangular shield for the robot system of coal mine roadway excavation

Owing to the existing problems of the temporary shield support device in a coal mine, such as considerable component weight, difficult disassembly, and large chamber installation, the design of the temporary rectangular shield support device was optimized. A module division method combining the functional analysis method and a similar feature clustering method was proposed, which completes the division of the functional module and establishes the structural module. A structural optimization method of “variable density topology optimization, parameter sensitivity analysis and Optimal Space-Filling Design (OSF)” was proposed. A variable-density topology optimization model of the device was established using the variable-density topology optimization method. The key variables of the device were determined using a parameter sensitivity analysis. The sample points of the critical variables were generated using the optimal space-filling design method, the approximate response surface models of mass, displacement, and stress were constructed, and the optimal solution of the device’s weight was obtained under the constraint conditions of pressure and displacement. A lightweight matching method of modularization based on transportability, disassembly, maintainability, and reliability was proposed, and the optimal matching scheme for the volume and mass of the device was determined. As a result, the weight of the temporary shield support device was reduced by 11.2%, and the maximum stress was reduced by 13.4%, under the premise of ensuring reliability. It realizes the convenience of transportation and high efficiency of assembly and disassembly in different design requirements, which is of great significance to accelerate the intelligent construction of coal mine.

An Integrated Circuit Placement Algorithm Considering Exposure Optimization

Objective: Exposure is one of the important steps in semiconductor production. During exposure, semiconductor devices should be kept at a small geometric distance to improve space utilization. How to consider the exposure optimization in the placement process and reduce the process error is a valuable problem. Methods: In this paper, we studied the optimization of wafer exposure pattern, and divided the IC layout optimization problem into two steps. Firstly, based on the idea of greed, orthogonal rectangular devices are packaged into rectangles to improve the local space utilization as much as possible. For rectangle splicing, we have designed a set of prior rules to make the wafer exposure mode tend to be similar in aspect ratio and small in total area. At the same time, we have designed an improved pheromone storage structure to optimize the two-dimensional layout through ant colony algorithm. Results: In the experimental stage, we use the ant colony algorithm to optimize the overall two-dimensional placement combined with prior rules to test. Experiments show that our ant colony algorithm performs better in technical indicators, especially in the aspect ratio control is very strict. In the layout test of 10 rectangular devices and 9 polygonal devices, the area utilization reaches 0.87, takes 9 seconds, and the aspect ratio is 1.02. Conclusions: We tested the algorithm on the multi project wafer placement test data provided by Huada Jiutian, and achieved better results than the baseline ant colony algorithm.

Application of a novel rectangular filtering microfluidic device for microfilarial detection.

The rectangular filtering microfluidic chip was invented using microfluidics device fabrication technology and can separate living microfilariae from blood samples without a syringe pump. The diagnostic results are highly effective. The device is based on the principle of separating millions of blood cells from microfilariae using a rectangular filter structure. It disperses fluid evenly into the flow-passage channel, and its rectangular filter structure is the key to success in reducing the pressure and separating blood cells from microfilariae effectively. The flow rate and blood cell concentration were optimized in our study. The chip is intended to be a point-of-care device that can reduce the use of superfluous instrumentation in the field. The technology is designed to be rapid, accurate, and easy-to-use for all users, especially those in remote areas.

Simulated and experimental analyses of the thermal dissipation of organic light-emitting diodes

Thermal management is important for organic light-emitting diodes (OLED). Thermal dissipation will significantly affect the electroluminescence and lifetime of OLEDs. In this work, we established a simple thermal resistance model to calculate the thermal distribution of OLEDs and theoretically simulated the results through COMSOL finite element simulation. We find that the maximum temperature for the circular OLED with a diameter of 400 µm is more than 20 ℃ higher than that of the OLED with a smaller diameter of 200 µm. Moreover, the maximum temperature of the rectangular device is 8 ℃ lower than that of the square device with the same active area. Most interestingly, the temperature at the center of the luminescence is about 12 ℃ higher than that of the edge under the same conditions. The simulation well matches the experiment without requiring the use of fitting parameters. The results represented an important advance in the thermal distribution of OLEDs and the potential design of alternative substrates for thermal management applications.

Heat transfer performance of a phase-change material in a rectangular shell-tube energy storage tank

Rectangular shell-tube thermal storage systems have a wide range of applications in both industrial waste heat recovery and solar power plants. Mastering the heat transfer mechanism and improving the heat transfer efficiency can considerably enhance the energy-utilization. In this study, we experimentally investigated the dynamic thermal behavior of a visualized rectangular shell-tube type phase-change heat storage device containing natural convection, using paraffin wax as the phase-change material. Subsequently, the corresponding numerical simulation was completed. The two results agreed well, within a maximum error of ± 5%. In addition, the theoretical parameters of paraffin wax were examined experimentally. The impact of inlet temperature, flow rate of the heat transfer fluid, and the length-to-diameter ratio of the heat flow tube on the efficiency of the system was studied. It was observed that a rise in inlet temperature from 353 K to 363 K increased the melting rate by 21.43%. When the inlet flow rate was increased from 2 L/min to 5 L/min, the melting rate was raised by 16%. However, reduction in tube length-to-diameter ratio from G = 14 to G = 12 shortened the melting time of the PCM by 6.64%. The equation for the liquid phase fraction of the PCM with dimensionless Ste and Ra numbers was fitted. The research results have a specific guiding significance for utilizing rectangular shell-tube energy storage systems.

Design and application of a new type of long snake moxibustion box

Long snake moxibustion, a kind of indirect moxibustion therapy for stimulating the midline part of the back of the patient's body after playing a layer of ginger or garlic mud, is frequently used to treat spine disorders and deficiency-cold type syndromes. In the present paper, we introduced our newly made moxibustion box for applying long snake moxibustion which is safe and easy to operate and can be freely moved at any time in the treatment of vertebral diseases, and conveniently makes the ignited-moxa close to the locus. This newly-designed moxibustion box is made of two lines of paralleled flexible connection side plates hinged ends to ends and two U-like connection plates at the opposite two ends to construct a rectangular frame device. The hinged design makes the long snake moxibustion box conform to the physiological curvature of human body and its length can be adjusted according to the height of patients. When used in clinical practice, it can enhance the patients' safety and reduce the operator's working intensity, and may be helpful to the popularization and development of long snake moxibustion therapy.

Experimental study on the explosion characteristics of methane-air mixtures initiated by RDX in a rectangular venting chamber

Methane-air mixtures initiated by Hexogen (RDX) were experimentally investigated in a custom-designed rectangular venting device. By changing the methane concentration, the overpressure characteristics and flame propagation were studied under the conditions of RDX detonation and electric spark ignition, respectively. The results indicate that, compared with spark ignition, the RDX explosion shock wave leads to the structural vibration and interacts with the flame, shortening the methane reaction time and substantially increasing the explosion overpressure. When the methane concentration is close to the equivalence ratio of unity, only one pressure peak occurs after the vent plate opening. The pressure peak caused by the interaction between acoustic waves and flames, P3, appears only at methane concentrations of 8 vol% and 13 vol% under RDX detonation. The acoustic vibration of the structure induced by different masses of RDX has a nonlinear impact on the increase of P3. The long reaction duration and the weakening of the shock wave result in a relatively small frequency of high-frequency oscillations at high concentrations.