Single-layer Design Research Articles

Study on crack propagation of functionally graded ultra-high performance cementitious composite

This study investigates the damage process and crack propagation of functionally graded ultra-high-performance cementitious composite (FGUHPCC) with different layers (two and three layers) and fibers types (steel and PVA) through four-point bending test. The evolution process of surface displacement and strain of the sample was analyzed by digital image correlation (DIC) technology, and the influence of the top, middle and bottom layers of FGUHPCC on the damage pattern are also investigated by RFPA3D program. The results indicate that functionally graded design improves the equivalent flexural strength and deflection capacity of the specimens compared with the UHPCC with single layer design. FGUHPCC with three layers and mixed steel and polyvinyl alcohol fibers exhibited best flexural behavior. According to the recorded DIC data and corresponding analyses, the crack opening displacement (COD) profile of functionally graded design with three layers is mutable and nonlinear, and the maximum crack propagation speed is 0.096 L/s, which is the lowest compared with other tested specimens, and the largest crack area ratios are about 0.04% and 0.147% at LOP and MOR, respectively. Based on RFPA3D results, with the change of fiber content, the cumulative AE energy growth rate (k) of bottom layer is about 2.7 times and 1.5 times of that of the middle layer and the top layer, respectively.

Analisa Pengaruh Desain 6 Fasa dengan Sistem 1 Lapis dan 3 Medan Fluks pada Motor Induksi 3 Fasa Terhadap Torsi dan Kecepatan Motor

This study aims to examine the effect of a 6-phase design on the torque and speed of a 3-phase induction motor with a symmetrical single-layer design system. The research was conducted in the Power Systems Laboratory of Electrical Engineering, Padang Institute of Technology by continuing to operate a 3-phase induction motor with this 6-phase design in this 3-phase electric power system. Then it is compared with the performance of a conventional 3-phase induction motor and focuses on the torque and speed of the motor. The induction motors that are the object of research are 3-phase induction motors, 0.75 KW, 1 HP, 380 V/Y, 1.3A, 50 HZ, and 2880 RPM. The results of the study indicate that there is a decrease in torque in the 1-layer symmetrical 6-phase design motor with 3 flux fields due to a decrease in the ability of the motor with increasing speed. This is due to the occurrence of a flux field attached to one of the two coils which is serialized to the other 2 coils with different types of magnetic poles so that they weaken each other which affects the decrease in the ability to drive the motor so that the torque prod. used decreases

Research of Single-Event Burnout in 1.2-kV Rated CoolSiC Trench MOSFET

This paper presents the two-dimensional (2-D) numerical simulation results of heavy-ion induced reverse drain current degradation and single-event burnout (SEB) in the 1.2-kV rated CoolSiC Trench metal-oxide-semiconductor field-effect transistor (MOSFET). The physics models employed in simulations and critical failure conditions were validated by the heavy-ion irradiation experiments of the commercially available 1.2-kV rated SiC planar-gate MOSFET devices. The CoolSiC Trench MOSFET was proven to behave comparative SEB performance compared with the SiC planar-gate MOSFET. The robustness of the CoolSiC Trench MOSFET with different single buffer layer (SBL) designs against a heavy ion was simulated. Furthermore, the SBL-CoolSiC Trench MOSFET with low carrier lifetime control was investigated. According to the simulation results, the severe degeneration failure tolerance increased to 800 V; the SEB failure tolerance could reach 900 V.

A fast temperature-programmed second-dimension column for comprehensive two-dimensional gas chromatography.

The short analysis time and constant temperature environment in the second dimension of two-dimensional comprehensive chromatography frequently causes wraparound problems, especially for complex high boilers. This problem can be solved by temperature programming on the second column, but since this requires heating and cooling the column in a matter of seconds, it is difficult to implement. In this study, we describe a method of accomplishing rapid heating and cooling with a resistively heated column cooled by compressed air. Critical to this method is minimizing the lag time between the actual temperature and the reported temperature by using the column heating element as the temperature sensor, virtually eliminating the danger of overshooting the temperature setpoint. This technique facilitates a ramp rate of up to 100°C/s with minimal overshooting-well beyond the requirements of gas chromatography. A single-layer column bundle design allows a compressed-air cooling device to cool the column from 200 to 50°C at an average rate of -21°C/s. The secondary dimension temperature programming is facilitated by the longer secondary dimension time made possible by the direct flow modulation method. We evaluated the performance of the single-layer column bundle and demonstrated this method by applying it to a gasoline sample. We also compared this method with the traditional isothermal approach and found that use of the secondary temperature program reduced the naphthalene retention time from 12.1 to 6.3s and its peak width at half height from 846 to 126ms.

A novel passive polymer-sorbent thermal battery for low-temperature energy applications: A numerical feasibility study

Sorption thermal energy storage (STES) systems offer great potential for meeting the growing energy needs and increasing the use of renewable energy resources. However, the complexity and large-scale of current STES technologies lead to relatively low-efficiency systems, severely limiting their widespread implementation. To address this challenge, this study presents a novel and compact smart-polymer sorbent (SPS) thermal battery with passive material-enabled mechanisms for controlled low-temperature thermal energy storage applications. A numerical model is established to investigate the coupled heat and mass transport processes underlying the working behavior of the SPS battery. It is also used to reveal the interdependence of the two processes and the limiting factors for the battery's thermal performance. The heating performance of several SPS battery designs was studied as an example, focusing on their application for cold environment thermal protection. Moreover, the influence of various design parameters was examined, including sorbent selection, void fraction, relative humidity, gate thickness, and gate-to-sorbent area, along with their implications to the coupled mass-heat transport processes. The results revealed that diffusion-based mass transport is the limiting process affecting the SPS battery thermal performance. The numerical simulation results also indicated that the sorbent selection should consider their low recharge temperature (40 °C–100 °C) and less pronounced temperature-dependent adsorption behavior to maximize the heating performance of the SPS battery. In addition, the SPS battery heating efficiency could be enhanced by increasing the sorbent void fraction to 0.35, relative humidity (RH) to 40 %, and gate-to-sorbent area to 60 % while decreasing the gate thickness to 0.1 μm effectively, which facilitate the diffusion-controlled mass transport process. Lastly, a single layer SPS battery is beneficial for thermal regulation at low temperatures; however, using distributed battery designs had a significant thermal performance enhancement benefit of 90 % compared to the single layer design. Hence, our study reveals the complex coupling effects of the heat and mass transport processes within the proposed SPS battery and provides insights and guidance (e.g., materials selections and SPS design) for engineering emergent small-scale passive STES applications.

Ka-Band Single-Layer High-Efficiency Circular Aperture Microstrip Array Antenna

Based on microstrip antenna technology, a compact single-layer circular aperture array is proposed in this paper. The proposed method is suitable for designing large-scale and high-efficiency patch array in Ka band. By using the high-impedance characteristic of the coupled microstrip line, a novel multi-stage feeding network that can realize large power division ratio is proposed, and its structure is center-symmetrical and is fed through a coaxial probe at the center. The parallel branch of the multi-stage divider is connected to the row array, and the array elements can obtain uniform excitation through the design of the division ratio of each stage. A 256-element patch array operating at 35 GHz is proposed, the length and width of the antenna unit are 2.74 mm and 3 mm, respectively, the horizontal spacing between the array elements is 0.742λ0, the vertical spacing varies from 0.677λ0 to 0.737λ0, and the radius of the proposed array is 60 mm (7λ0 at 35 GHz). At the end, a prototype is fabricated and measured, the measured results show that the maximum gain is 29.5 dBi at 35 GHz, which correspond to the radiation efficiency and aperture efficiency of 61.66% and 46.07%, respectively, and the results show that the proposed antenna achieves high efficiency in Ka band, which verifies the correctness of the design. The proposed array antenna is compact in structure and only needs single-layer design, which can achieve high efficiency and low in manufacture cost, which is an excellent candidate for millimeter-wave large-scale array application.

SLMGAN: Single-layer metasurface design with symmetrical free-form patterns using generative adversarial networks

The metasurfaces offering the required spectral responses have ushered in a revolution of manipulating the light in a prescribed manner. A single-layer metasurface design is more appealing than a multi-layer one due to the fabrication complexities. To date, various research groups have explored on architected metasurfaces with general shapes of cubes, crosses, or octothorpes, while a few works utilized evolutionary algorithms to search for metasurfaces with free-form patterns, which relied on the quality of the initial guess. In this paper, a solution is presented to replace the intuition-based approach with generative adversarial networks. The constructed generative networks mathematically formulate the virtual mappings between the pairs of optical spectra and symmetrical patterns with user-defined geometric structures. When fed a time sequence of spectra, the designed networks assimilate the physical property and generate on-demand patterns to match the desired responses. The output patterns are proved to yield matching optical responses with an average accuracy of 0.9. Generative Adversarial Networks are firstly applied to single-layer metasurface designs with symmetrical free-form patterns for desired optical spectra in an inverse-design system.

Modeling the diffusion of muonium in silica aerogel and its application to a novel design of multi-layer target for thermal muon generation

The generation of thermal muons by laser ionization of muonium (μ+e−) confined in multi-layer silica aerogel structures is simulated. Thermal muonium generated inside the silica aerogel is emitted into the sandwiched vacuum regions between the aerogel layers separated by a few millimeters. The model for muonium emission is validated against emission measurements from single aerogel samples. The efficiency of thermal muon generation in this configuration is predicted to increase by several times compared with a single-layer design.

A novel efficient coplanar QCA full adder and full subtractor design

ABSTRACT Quantum-dot Cellular Automata (QCA) nanotechnology is an alternative technology with high speed, high density and low power for designing nanoscale circuits. A novel design of Full Adder-Subtractor based on full subtractor using single layer is proposed. The proposed architecture has a major advantage in terms of complexity, area, latency, and power consumption as compared to previous designs. The proposed QCA full subtractor showed higher performance concerning area with a reduction of 66%, and complexity with a reduction of 51% over best existing circuit designs. However, the proposed design of full Adder-Subtractor achieved a reduction of 74% in area, with 70% improvement in complexity, 33% reduction in latency by using two clock phases, and 95% improvement in cost needed over the best reported circuits using single-layer design. Total cell area and cost for the Full Adder-Subtractor were 0.01 μm2 and 0.07, respectively. Results showed that power consumption for the novel design was minimal. Therefore, the suggested Full Adder-Subtractor provides 86% less total energy consumption for 0.5Ek tunnelling energy level. These designs were tested and simulated using the freely known QCA Designer tool version 2.0.3. The energy dissipation result was realised by using the QCAPro energy estimation tool.

Scalable 3D Silicon Optical Switch Based on CLOS Architecture

To achieve complex functionality with small size, weight and power, photonic integrated circuits (PIC) are expanded from two-dimensional (2D) to three-dimensional (3D). In this paper, a new design for a scalable 3D silicon optical switch is proposed. Key elements, including silicon electro-optic switches, crossings, and interlayer transitions are used to define and optimize the 3D optical switching network. The architecture is based on CLOS architecture, which can be extended to multiple layers. Silicon-based two- and three-layer switches are carefully designed and analyzed as an example based on the transfer matrix technique (TMT). In a 4×4 two-layer optical switch, the average insertion loss at 1550 nm wavelength is ∼4.16 dB, and ∼3.69 dB for the “all-cross” and “all-bar” states, respectively. In a 4×4 three-layer optical switch, the average insertion loss at 1550 nm wavelength is ∼5.96 dB, and ∼5.41 dB for the “all-cross” and “all-bar” states, respectively. The architecture also shows the scalability of both the port number and the layer number. The scalable 3D architecture proposed could improve the interconnect density twice and thrice in a single-layer design.

Simulation of Anti Reflecting Coating for Improving External Quantum Efficiency of Photovoltaic Cell

Due to a dramatic drop in solar module prices/watt peaks, photovoltaic (PV) electricity has become more concentrated over the last decade. Crystallized silicon (c-Si) solar cells have dominated the solar market since their creation, outperforming all other photovoltaic technologies. PV modules are frequently required to work in inclement weather. Outdoor photovoltaic performance is affected by a number of factors, including 1) solar radiation, 2) the shape of the absorbed solar spectrum, 3) ambient temperature, 4) location, 5) wind speed, and 6) aerosols. These parameters, on the other hand, are out of our hands. It does not prevent solar panels from becoming heated on hot days, which has a negative impact on their electrical performance and longevity. To protect the solar cell from various external variables, multiple layers are applied to solar cell modules, including EVA (Ethylene Vinyl Acetate), polyvinyl fluoride sheet (Tedlar), front solar glass, metal frame, and side water seal. One of the main causes of the absorber layer temperature in solar modules rising is this. For single-layer and multi-layer ARC designs, a range of materials are used in the ARC of solar modules. Instead of functioning as a radiative cooler, the ARC can be changed or simple tweaks can be made to improve absorption and lower the temperature of the solar module. Based on light and radiation properties, choose materials for SR-ARC design of solar cells and modules. The chosen material must have very low absorption between 300 and 1200 nm and emit between 8 and 13 m. The annual power generation of a 1kW system in India's complicated environment is determined with the aforesaid efficiency increases and temperature reductions. From a single layer c-Si solar module system, the double layer module of the 1kW system generates 54kWh. Furthermore, the cooling effect was calculated, with the failed component losing 80% of its initial efficiency by the end of 2014, but the two- and three-layer components reached this level by the end of 36. The dual layer SR-ARC coated module system will start producing single layer modules at the end of 26 or 36, with or without replacement.

Electro-Chemical-Mechanical Coupled Modeling of Oxygen Electrodes in Solid Oxide Electrolyzer Cells

Solid oxide electrolyzer cell (SOECs), which is an electrochemical device to split water with electricity to generate hydrogen, have received widespread attention for multi-day or seasonal energy storage to integrate variable renewable energy (VRE) into the grid [1]. Even though there have been tremendous material development and performance improvement of the technology in the past decade [2], challenges remain in understanding its degradation mechanism, especially the delamination of oxygen electrode/electrolyte interface [3-5]. Developing new oxygen electrodes which could decelerate the degradation and extend the stack lifetime beyond 60,000 hours at 1.5A/cm2 would significantly drive the stack price down to $100/kW and hydrogen cost down to $2/kg [6].In the state-of-the-art SOECs, pure ionic conductor 8 mol% Y2O3 doped ZrO2 (YSZ) and Gadolinium-doped Ceria (GDC) are usually used as the dense electrolyte and the buffer layer; mixed electronic and ionic conductor (MIEC) La1-xSrxCo1-yFeyO3-d (LSCF) is widely used as the oxygen electrode [7]. Such cells still suffer from short lifetimes with current densities over 1A/cm2. To overcome the challenge, a bilayer oxygen electrode structure, consisting of a commercial LSCF-GDC porous backbone coated by a thin SrCo0.9Ta0.1O3- d (SCT10) film (denoted as LSCF-SCT bilayer design), has been proposed and demonstrated with much higher performance compared to traditional LSCF electrode (single layer design) [8]. The new oxygen electrode has an inherently fast oxygen evolution reaction (OER) electrokinetics (or high oxygen evolution rate) and can mitigate the delamination problem by minimizing the accumulation of oxygen in oxygen evoluation reaction (OER) electrode lattice and thus chemical stresses.In this study, based upon an Electro-Chemical-Mechanical coupled model, we will correlate the crack length at the oxygen electrode/electrolyte interface with the electrochemical performance of the cell, specifically the voltage-current curve (Fig.1a). We will use J-integral (Fig.1b) as the fracture criteria to evaluate the crack growth rate under different current densities and with different oxygen electrode designs. LSCF single layer design is the baseline of the study. The long-term performance improvement of LSCF-SCT bilayer design will be compared against the baseline and its degradation mechanism will be investigated. The model will also be validated by long-term overpotential testing data as a function of time under 1A/cm2. It will be used as an optimization tool to mitigate delamination and extend the cell lifetime under higher current densities. Key Words: Electrolysis, Oxygen Electrode (OE), Delamination, Chemical Expansion, J integral, Crack Growth Rate Figure 1

Simulation of Anti Reflecting Coating for Improving External Quantum Efficiency of Photovoltaic Cell

Due to a dramatic drop in solar module prices/watt peaks, photovoltaic (PV) electricity has become more concentrated over the last decade. Crystallized silicon (c-Si) solar cells have dominated the solar market since their creation, outperforming all other photovoltaic technologies. PV modules are frequently required to work in inclement weather. Outdoor photovoltaic performance is affected by a number of factors, including 1) solar radiation, 2) the shape of the absorbed solar spectrum, 3) ambient temperature, 4) location, 5) wind speed, and 6) aerosols. These parameters, on the other hand, are out of our hands. It does not prevent solar panels from becoming heated on hot days, which has a negative impact on their electrical performance and longevity. To protect the solar cell from various external variables, multiple layers are applied to solar cell modules, including EVA (Ethylene Vinyl Acetate), polyvinyl fluoride sheet (Tedlar), front solar glass, metal frame, and side water seal. One of the main causes of the absorber layer temperature in solar modules rising is this. For single-layer and multi-layer ARC designs, a range of materials are used in the ARC of solar modules. Instead of functioning as a radiative cooler, the ARC can be changed or simple tweaks can be made to improve absorption and lower the temperature of the solar module. Based on light and radiation properties, choose materials for SR-ARC design of solar cells and modules. The chosen material must have very low absorption between 300 and 1200 nm and emit between 8 and 13 m. The annual power generation of a 1kW system in India's complicated environment is determined with the aforesaid efficiency increases and temperature reductions. From a single layer c-Si solar module system, the double layer module of the 1kW system generates 54kWh. Furthermore, the cooling effect was calculated, with the failed component losing 80% of its initial efficiency by the end of 2014, but the two- and three-layer components reached this level by the end of 36. The dual layer SR-ARC coated module system will start producing single layer modules at the end of 26 or 36, with or without replacement.

Simulation of Anti Reflecting Coating for Improving External Quantum Efficiency of Photovoltaic Cell

Due to a dramatic drop in solar module prices/watt peaks, photovoltaic (PV) electricity has become more concentrated over the last decade. Crystallized silicon (c-Si) solar cells have dominated the solar market since their creation, outperforming all other photovoltaic technologies. PV modules are frequently required to work in inclement weather. Outdoor photovoltaic performance is affected by a number of factors, including 1) solar radiation, 2) the shape of the absorbed solar spectrum, 3) ambient temperature, 4) location, 5) wind speed, and 6) aerosols. These parameters, on the other hand, are out of our hands. It does not prevent solar panels from becoming heated on hot days, which has a negative impact on their electrical performance and longevity. To protect the solar cell from various external variables, multiple layers are applied to solar cell modules, including EVA (Ethylene Vinyl Acetate), polyvinyl fluoride sheet (Tedlar), front solar glass, metal frame, and side water seal. One of the main causes of the absorber layer temperature in solar modules rising is this. For single-layer and multi-layer ARC designs, a range of materials are used in the ARC of solar modules. Instead of functioning as a radiative cooler, the ARC can be changed or simple tweaks can be made to improve absorption and lower the temperature of the solar module. Based on light and radiation properties, choose materials for SR-ARC design of solar cells and modules. The chosen material must have very low absorption between 300 and 1200 nm and emit between 8 and 13 m. The annual power generation of a 1kW system in India's complicated environment is determined with the aforesaid efficiency increases and temperature reductions. From a single layer c-Si solar module system, the double layer module of the 1kW system generates 54kWh. Furthermore, the cooling effect was calculated, with the failed component losing 80% of its initial efficiency by the end of 2014, but the two- and three-layer components reached this level by the end of 36. The dual layer SR-ARC coated module system will start producing single layer modules at the end of 26 or 36, with or without replacement.

Garbage collection and data recovery for N2DB

Non-Volatile Memory (NVM) offers byte-addressability and persistency Because NVM can be plugged into memory and provide low latency, it offers a new opportunity to build new database systems with a single-layer storage design. A single-layer NVM-Native DataBase (N2DB) provides zero copy and log freedom. Hence, all data are stored in NVM and there is no extra data duplication and logging during execution. N2DB avoids complex data synchronization and logging overhead in the two-layer storage design of disk-oriented databases and in-memory databases. Garbage Collection (GC) is critical in such an NVM-based database because memory leaks on NVM are durable. Moreover, data recovery is equally essential to guarantee atomicity, consistency, isolation, and durability properties. Without logging, it is a great challenge for N2DB to restore data to a consistent state after crashes and recoveries. This paper presents the GC and data recovery mechanisms for N2DB. Evaluations show that the overall performance of N2DB is up to 3.6× higher than that of InnoDB. Enabling GC reduces performance by up to 10%, but saves storage space by up to 67%. Moreover, our data recovery requires only 0.2% of the time and half of the storage space of InnoDB.

A Bilateral Coding Metabsorber Using Characteristic Mode Analysis

Coding is an effective method of designing wideband metabsorber, but the resultant metabsorbers are usually associated with complicated shapes that hinders clear physics understanding of the wideband principle behind the scene. This study presents characteristic mode analysis (CMA) of two types of coding metabsorber composed of single-layer and bilateral resonators, respectively, generated by the genetic algorithm optimization methods. Compared with the conventional single-layer design, CMA results illustrate the wideband principle of the bilateral design introducing additional absorption modes. With a fractional bandwidth of 143.5%, the proposed bilateral metabsorber measures an absorption bandwidth of 5.9–35.9 GHz for 90% absorptance. CMA provides a low-threshold method to analyze the metabsorber with complicated resonators, thereby paving the way for the physical-oriented coding optimization improvement.

Graphene-based multilayer metasurface solar absorber with parameter optimization and behavior prediction using Long Short-Term Memory model

Most of the solar absorbers are absorbing visible spectrum energy and are not focused on the ultraviolet spectrum and infrared spectrum energies. Here we propose a solar absorber that absorbs most of the energy of the available solar spectrum including visible spectrum and ultraviolet spectrum energies. The multilayer metasurface solar absorber design is analyzed and its results are compared with the single-layer metasurface solar absorber design. Both design results are also compared with AM 1.5 solar spectral irradiance plot for a wavelength range of 0.2 μm–1.5 μm. The graphene is used as a spacer to increase the absorption response of the proposed structure. The efficiency of multilayer design is high in both visible spectrum regions and ultraviolet spectrum regions compared to single-layer design. The parameter optimization for substrate thickness and resonator thickness is analyzed for improvement of absorption of the proposed design. The design results in the form of absorption, a normalized electric field. The proposed solar absorber with its high efficiency in visible and ultraviolet regions can be used in solar energy harvesting devices. The novel part of this research is predicting absorption values for assorted variations in substrate thickness, resonator thickness for forthcoming wavelengths using a Long Short-Term Memory model. The results of the experiments show that prediction may accurately anticipate absorption values, reducing simulation time and resource requirements. The visual comparison of simulated and predicted values is also presented in the paper.

Coronary artery perforation after bioresorbable scaffold implantation treated with a new generation covered stent\u2014OCT insights

BackgroundCoronary artery perforation is a rare but potentially lethal complication of percutaneous coronary intervention (PCI) with an associated mortality of 7–17%. We report the case of coronary artery perforation complicating Absorb bioresorbable vascular scaffold (BVS) implantation and the associated technical challenges with managing this life-threatening complication.Case reportA 46-year-old male was referred to our institution and underwent PCI with an Absorb bioabsorbable vascular scaffold (BVS) to a proximal LAD long segment bifurcation lesion. Following pre-dilation and deployment of the 3.5 × 28 mm Absorb BVS, high pressure post-dilation of the distal scaffold was complicated by a large, Ellis type III coronary perforation with no flow to the distal LAD beyond the rupture, and associated with a large pericardial effusion confirmed on bedside transthoracic echocardiogram (TTE). The insult was temporised with prolonged balloon inflation within the Absorb BVS immediately proximal to the site of perforation, permitting urgent insertion of a pericardial drain. After deflation of the balloon, a 3.0 × 21 mm BeGraft covered stent was deployed across the perforation, restoring normal LAD flow and abolishing the perforation. Cardio-pulmonary resuscitation was not required and the patient remained conscious throughout the procedure. TTE demonstrated normal left ventricular function and the patient was discharged 3 days later. Repeat angiography at 3 months showed patent stents with TIMI III flow, and optical coherence tomography (OCT) showed good expansion and apposition of the proximal Absorb BVS and BeGraft. The patient has remained well 4 years after PCI with no major cardiovascular events.ConclusionThe utility of bioresorbable scaffold technology remains controversial although meticulous implantation techniques are associated with improved clinical outcomes. Adoption of the Pre-dilatation, Sizing and Post-dilatation (‘PSP’) method of BVS implantation with routine aggressive vessel preparation and scaffold optimization however may contribute to a higher risk of vessel perforation. The case emphasises the importance of accurate sizing of the vessel with intracoronary imaging and demonstrates the value of newer generation covered stents with single-layer design and slimmer crossing profile producing improved deliverability and procedural success.

High-performance polarization-independent black phosphorus refractive index sensors enabled by a single-layer pattern design

The in-plane orientation-dependent electrical and optical properties of two-dimensional (2D) anisotropic materials attract significant attention because of the intriguing underlying physics. However, this feature limits their further development in polarization-independent applications such as refractive index sensors and light absorbers. In this paper, polarization-independent optical properties of black phosphorous (BP) metadevices are achieved by the design of a single-layer pattern of 2D anisotropic material. Finite-difference time-domain (FDTD) simulation results indicate that the absorption spectrum remains unchanged as the polarization angle of the incident light varies from 0° to 360°. The performance of the BP metadevices when used as refractive index sensors is also studied. The results show that the polarization-independent BP sensors exhibit high sensitivity and figures of merit (FOMs). This work opens up the possibility of fabricating optically polarization-independent devices based on a single-layer pattern of 2D anisotropic material.

Production of Re doped La2Zr2O7 based TBCs and numerical analysis of their use on IC engine piston surface

In this study, first of all, a metallic bond layer was coated on the metal substrate using the HVOF method. Then, Gd and Yb doped La2Zr2O7 powders, which were specially produced to obtain a low thermal conductivity value, were coated on the metallic bond layer by atmospheric plasma spraying method. The coatings were produced in single-layer and double-layer designs using YSZ as the buffer layer. In the microstructure analysis, it was observed that the coatings exhibited the characteristic microstructure properties of the materials produced by atmospheric plasma spraying method. In the phase analysis, it was found that the Gd and Yb doped La2Zr2O7 was in the form of defect fluorite type structure after plasma spraying. The thermal conductivity of the YSZ coating ranged from 0.88 to 1.00 W/mK, while the thermal conductivity of the doped La2Zr2O7 coatings was measured between 0.38 and 0.68 W/mK. Especially, the lowest thermal conductivity values were obtained in the double-layer Gd doped coating. As a result of modeling these coatings on the piston surface of a diesel engine using the finite element method, it was found that the maximum and minimum surface temperatures of the pistons increased by 69% and 60%, respectively. There was also a reduction of up to 6.5% in the temperature of the piston substrate surface.