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Laboratory and clinical reliability of two spectrophotometers
摘要： Objective: To evaluate the repeatability, interexaminer, and interdevice reliability of two clinically applicable spectrophotometers under laboratory and clinical conditions. Material and Methods: For the in vitro part of the study, measurements were performed by the use of Vita Easyshade Advance 4.0 (ES-A) and the Easyshade V (ES-V) at identical positions on different shade tabs (3D-Master; Vita Zahnfabrik, Bad S?ckingen, Germany). To test repeatability, one shade tab was measured 50 times by one operator. To determine interrater and interdevice agreement, two operators used both devices to perform 10 measurements on five different shade tabs. Clinical interdevice and interexaminer reliability was checked with a positioning jig used (15 participants). Measurement accuracy of both devices was evaluated for the recommended color of shade tabs. Results: Repeatability of results from both Easyshades was excellent for all color components (maximum deviation between measurements was ≤0.1 units). Interrater agreement was also perfect (intraclass correlation, ICC = 1.000). Interdevice agreement was lower, but still good (ICC ≥ 0.834). In the clinical environment, interrater and interdevice agreements were similar (ICC > 0.964 and ICC > 0.873). Accuracy was satisfactory for both devices, with both observers in full agreement for nearly 80% of ratings. Conclusions: Both Easyshades produced reliable and accurate measurements and can therefore be recommended for clinical determination of tooth color. Clinical Significance: The outcome of this study might help clinicians estimate the performance of a new digital shade determination device.
关键词： L*a*b*,accuracy,reliability,Easyshade,spectrophotometer
更新于2025-09-23 15:23:52
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[IEEE 2017 IEEE International Integrated Reliability Workshop (IIRW) - Fallen Leaf Lake, CA (2017.10.8-2017.10.12)] 2017 IEEE International Integrated Reliability Workshop (IIRW) - Silicon dioxide degradation in strongly non-uniform electric field
摘要： The new experimental evidence of field-induced trap generation in the tunnel oxide of SuperFlash? memory cells has been presented. It was shown that the negative voltage stress generates the highest local electric field in the oxide close to the floating gate tip. The effect of electric stress on the degradation of tunneling characteristics has been studied for the cells with the different tunneling geometry. The reliability aspects of field-induced trap generation are discussed. It has been concluded that the analyzed degradation mechanism is not critical for the SuperFlash technology.
关键词： floating gate,program-erase cycling endurance,memory reliability,oxide degradation,electron tunneling,Flash memory,electron trapping
更新于2025-09-23 15:23:52
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Novel research on reliability of silica-based PLC optical splitters
摘要： Environmental, mechanical and optical reliability are basic premises for application of PLC optical splitters. According to temperature and humidity cycling experiment, it demonstrated that insertion loss of PLC optical splitter varies with temperature. Compared to performance at room temperature, the maximum insertion loss change of device is 0.472 dB at 75 °C, and 0.486 dB at ?40 °C. A three-dimensional ?nite element model of PLC chip coupled with ?ber array was established to study the e?ects of temperature on insertion loss. The simulation results match experimental results, indicating that misalignment of PLC chip and ?ber array is the main reason for insertion loss change. It is signi?cant to consider the in?uences of global temperature rather than only paying attention to performance at static temperature when we evaluate the reliability of PLC optical splitters.
关键词： PLC optical splitter,Temperature and humidity,Finite element method,Optical waveguide,Reliability
更新于2025-09-23 15:23:52
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Improved stability of silver nanowire (AgNW) electrode for high temperature applications using selective photoresist passivation
摘要： Metal nanostructure arrays have been progressed as an alternative to the conventional oxides-based transparent conductive electrodes. Herein, we demonstrate the improved reliability of silver nanowire (AgNW) electrodes by photoresist encapsulation. The incorporation of photoresist followed by photolithography is beneficial to selectively pattern the AgNWs on poly[ether sulfone]. By varying the development or removal time of the ultraviolet (UV)-exposed photoresist, the properties of the AgNWs in the electrode are significantly varied. The optical parameters such as transmittance, haziness, and the yellow index of the electrodes have been extensively studied to reveal the advantage of the selective photoresist patterning. The AgNW electrodes patterned under 120 s of development time explored superior optical and electrical properties with high durability. The electrical properties of the AgNW electrodes at high temperatures (250 °C) demonstrate the photoresist-induced stability as compared to bare samples. Further, the morphological examination after the high temperature treatment reveals the reduced Rayleigh instability effects in 120s developed AgNWs that facilitate the reliability under harsh conditions.
关键词： photoresist selective passivation,development time,high reliability,Silver nanowire (AgNW) electrode
更新于2025-09-23 15:23:52
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24.4: High Performance Top-gate Self-aligned Coplanar a-IGZO TFTs with Light Shielding Metal Design
摘要： The TG-SA a-IGZO TFTs with different light shielding metal (SM) layers design were demonstrated and compared in this paper. Their electrical characteristics have been measured in order to systematically analyze the effect that the SMs ever made on. The relationship between device instability and different SMs design have been systematically analyzed. Then the prototype 14” OLED display with an excellent performance using TG-SA a-IGZO TFTs backplane have been made successfully, which indicates an excellent mass-production prospect.
关键词： reliability,light shielding metal,top-gate self-aligned coplanar structure,a-IGZO TFTs
更新于2025-09-23 15:23:52
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Integrated sizing of hybrid PV-wind-battery system for remote island considering the saturation of each renewable energy resource
摘要： The proliferation of renewable energy particularly the combination of solar-wind power and storage bank, is likely to be occupied throughout the world, to mitigate the local energy concerns, improve the energy supply opportunities for off-grid communities and vitiate environmental pollution concerns as well as ease the intensity of energy consumption. To mitigate the disharmony between renewable energy (RE) generation and supply, a cost-optimal autonomous hybrid renewable energy system is developed and comparatively analyzed, considering the saturation level of each involved RE source based on various technical and economic key indicators. This study proposes a mathematical model to comprehensively analyze the effect of varying saturation, i.e. increasing the saturation of one resource meanwhile decreasing the ratio of other resource, on battery bank size, state of charge (SOC), loss of power supply, excess energy, net present cost, levelized cost of energy (COE) and payback time. A saturation factor is introduced, from 0 to 1 value with step size 0.02, where zero represents the wind-only system and one represents the solar-only system. Three different systems are considered, with different wind turbine sizes (total 150 configurations), to comparatively analyze the different energy systems and the result reveals that smaller wind turbine size (2 kW) with 90% saturation of wind energy is the most cost-effective system for the proposed remote island. In addition, the solar-alone and wind-alone systems are compared, showing that the wind-only system can provide good performance as compare to solar-only. Furthermore, the effects of the saturation factor on COE, battery bank size, SOC, excess energy, system reliability and different load demands are analyzed. Energy balance analysis of whole year and simulation performance of the system is accomplished to verify the system reliability. Sensitivity analysis reveals that wind energy, battery cost and load has a significant impact on COE than other factors.
关键词： Hybrid Renewable system reliability,Cost of energy,Net present cost,Renewable energy saturation,Energy balance,Solar-wind-battery system
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - High-Efficiency Weight-Optimized Fault-Tolerant Modular Multi-Cell Three-Phase GaN Inverter for Next Generation Aerospace Applications
摘要： The aircraft industry demands a significant increase in terms of efficiency and gravimetric power density of power converters for next generation aerospace applications. Between the two minimum targets, i.e. an efficiency > 98 % and a gravimetric power density > 10 kW/kg, the specification concerning the converter weight is the most challenging to fulfill. Since cooling systems and magnetic components dominate the weight breakdown of conventional converter concepts, multi-cell topologies, enabling improved semiconductors performance and reduced filtering requirements, are foreseen as promising solutions for the power electronics on board of More Electric Aircraft. On the other hand, the necessary simultaneous operation of a high number of cells inevitably limits the reliability of multi-cell converters if redundancy is not provided. In this paper, a favorable scaling trend of power density with respect to reliability, aiming to guarantee fault-tolerant operation without affecting the performance figures, is identified in modular multi-cell converters. Thus, a 45 kW weight-optimized modular multi-cell three-phase inverter featuring a redundant power stage is optimized, achieving an efficiency of 99 % and a gravimetric power density of 22.8 kW/kg.
关键词： Multi-Objective Optimization,Figure of Merit of Power Semiconductors,Power Converters Reliability,Modular Multi-Cell Inverter,More Electric Aircraft
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Third Ecuador Technical Chapters Meeting (ETCM) - Cuenca, Ecuador (2018.10.15-2018.10.19)] 2018 IEEE Third Ecuador Technical Chapters Meeting (ETCM) - Reliability in GaN-based devices for power applications
摘要： This paper analyzes two important reliability issues in AlGaN/GaN devices: positive bias temperature instability (PBTI) and time-dependent dielectric breakdown (TDDB). The summarized results of our previous PBTI studies in MOS-HEMTs show that the threshold voltage degradation in devices with SiO2 as gate dielectric is characterized by a universal decreasing behavior of the trapping rate parameter and is ascribed to charge trapping in the SiO2 and at the SiO2/GaN interface. On the contrary, the degradation observed in Al2O3- and AlN/Al2O3-gate stacks is mainly attributed to charge capture in the pre-existing dielectric traps with a negligible interface state generation. Additionally, the insertion of a thin AlN layer impacts on the device reliability because larger trap density, faster charge trapping, wider trap energy distribution and slower charge release are observed compared with devices without this layer. The dielectric importance of GaN-based devices has been also investigated in Schottky Barrier Diodes (SBDs) with a gated edge termination (GET). Our recent TDDB results indicate a narrower Weibull distribution, and a longer time to failure in devices with a double GET layer structure and with a thick passivation layer (2 GET-THICK) than in single GET devices with a thin passivation (1 GET-THIN). Therefore, the former structure is more suitable for high-power and high-temperature applications.
关键词： TDDB,AlGaN/GaN SBD,trapping,de-trapping,reliability,PBTI,breakdown voltage,GET,MOS-HEMT
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Power & Energy Society General Meeting (PESGM) - Portland, OR, USA (2018.8.5-2018.8.10)] 2018 IEEE Power & Energy Society General Meeting (PESGM) - An Innovative Methodology for Load and Generation Modelling in a Reliability Assessment with PV and Smart Meter Readings
摘要： With a paradigm shift from centralized to decentralized integration of distributed generation, particularly the photovoltaic (PV) systems made significant impacts on the reliability of power systems. The intermittency of PV and the stochastic nature of load results in a complex interaction of PV and load profiles, in a reliability assessment. In order to reduce the complexities of intermittent power generation interaction with smart meter customer consumptions, this paper presents an innovative methodology for the modeling of intermittent PV generation and smart meter readings in a reliability assessment in a power system. A case study was performed incorporating different scenarios of PV integrations with real-world smart meter load data, and climate projections weather in a UK environment. The results validate robustness of the proposed modeling framework for the reliability assessment in a power system with an accuracy of more than 99.5% and 97.5%, compared with actual generation and load profiles respectively.
关键词： PV modelling,Reliability assessment,Load modelling,Expected energy not supplied
更新于2025-09-23 15:23:52
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Influence of GaN- and Si?N?-Passivation Layers on the Performance of AlGaN/GaN Diodes With a Gated Edge Termination
摘要： This paper analyses the influence of the GaN and Si3N4 passivation (or 'cap') layer on the top of the AlGaN barrier layer on the performance and reliability of Schottky barrier diodes with a gated edge termination (GET-SBDs). Both GaN cap and Si3N4 cap devices show similar dc characteristics but a higher density of traps at the SiO2/GaN interface or/and an increase of the total dielectric constant in the access region result in higher RON-dispersion in GaN cap devices. The leakage current at medium/low temperatures in both types of devices shows two low-voltage-independent activation energies, suggesting thermionic and field-emission processes to be responsible for the conduction. Furthermore, a voltage-dependent activation energy in the high-temperature range occurs from low voltages in the GaN cap devices and limits their breakdown voltage (VBD). Time-dependent dielectric breakdown measurements show a tighter distribution in Si3N4 cap devices (Weibull slope β = 3.3) compared to GaN cap devices (β = 1.8). Additional measurements in plasma-enhanced atomic layer deposition (PEALD)-Si3N4 capacitors with different cap layers and TCAD simulations show an electric field distribution with a strong peak within the PEALD-Si3N4 dielectric at the GET corner, which could accelerate the formation of a percolation path and provoke the device breakdown in GaN cap SBDs even at low-stress voltages.
关键词： Si3N4 cap,GaN cap,AlGaN/GaN Schottky diode,reliability,breakdown voltage,passivation layer,off-state,Activation energy
更新于2025-09-23 15:23:52