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- 摘要
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- 实验方案
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[IEEE 2018 IEEE SENSORS - New Delhi, India (2018.10.28-2018.10.31)] 2018 IEEE SENSORS - Patterning and Annealing Effects of Aerosol Deposited Hygroscopic Films for Humidity Sensors
摘要： In this study, three inter-digital capacitors (IDCs) and one spiral structure is decorated with aerosol-deposited (AD) BaTiO3 thin film layer. Further, these structures have used for capacitive sensing applications. All, the results have been measured at 1 MHz frequency in room temperature. The obtained results indicate that the annealed aerosol-deposited based BaTiO3 thin film has presented higher capacitive intensity as well as the improvement in dielectric performances. The dissimilar finger width inter-digital capacitors (IDCs) and a spiral structure have evaluated with different open area ratio (OAR). The obtained results clearly indicate that the fourth sensor design gives best results before annealing due to its structural property. Whereas, second sensor design gives best results after annealing process. The sensitivity of second sensor design enhanced from 15.83 to 1300 after annealing. Hysteresis loss result has also been used to verify the highly sensitive design. Through minimum hysteresis loss and high correlated absorption and desorption value indicates highly sensitive sensing design. The structural property of aerosol-deposited BaTiO3 film has evaluated by SEM and XRD measurements. These measurements show the high grain size, good crystallization and high surface to volume ratio after thermal treatment. Our research also shows that good design structure with thermally modified AD BaTiO3 film can be used to design an attractive sensor in future.
关键词： hysteresis loss,Aerosol Deposition (AD),inter-digital capacitors (IDCs),open area ratio (OAR)
更新于2025-09-19 17:15:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Harp Hype Ran Gular Imaging Polarimeter and the Need for Small Satellite Payloads with High Science Payoff for Earth Science Remote Sensing
摘要： The largest uncertainties on estimating climate change revolve around the lack of quantitative information on aerosol and cloud microphysical properties, which limits our understanding of cloud-aerosol interaction processes and cloud feedbacks in the climate system. Part of this limitation comes from the small number of global satellite sensors which in turn only measures a restricted subset of aerosol and cloud microphysical properties. Enabling small satellites to perform high quality cloud and aerosol microphysical measurements is an important pathway to resolve this puzzle. The reduced cost of small satellites can enable the use of multiple platforms or even constellations to increase spatial and temporal coverage for the required measurements. The HARP (HyperAngular Rainbow Polarimeter) is a 3U CubeSat sensor designed for the measurement of aerosol, clouds and surface properties with a wide FOV that enables nearly global coverage from multiple wavelengths and tens of different along track viewing angles. The technology developed for HARP allows for all these characteristics to be packaged within the envelope of a CubeSat sensor while preserving strict science requirements.
关键词： Multi-Angle,Aerosol,Clouds,CubeSat,Polarimeter
更新于2025-09-19 17:15:36
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Joint retrieval of surface reflectance and aerosol properties with continuous variation of the state variables in the solution space – Part 1: theoretical concept
摘要： This paper presents a new algorithm for the joint retrieval of surface reflectance and aerosol properties with continuous variations of the state variables in the solution space. This algorithm, named CISAR (Combined Inversion of Surface and AeRosol), relies on a simple atmospheric vertical structure composed of two layers and an underlying surface. Surface anisotropic reflectance effects are taken into account and radiatively coupled with atmospheric scattering. For this purpose, a fast radiative transfer model has been explicitly developed, which includes acceleration techniques to solve the radiative transfer equation and to calculate the Jacobians. The inversion is performed within an optimal estimation framework including prior information on the state variable magnitude and regularisation constraints on their spectral and temporal variability. In each processed wavelength, the algorithm retrieves the parameters of the surface reflectance model, the aerosol total column optical thickness and single-scattering properties. The CISAR algorithm functioning is illustrated with a series of simple experiments.
关键词： continuous variation,radiative transfer model,joint retrieval,aerosol properties,surface reflectance,CISAR algorithm,solution space,optimal estimation
更新于2025-09-19 17:15:36
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A depolarisation lidar-based method for the determination of liquid-cloud microphysical properties
摘要： The fact that polarisation lidars measure a depolarisation signal in liquid clouds due to the occurrence of multiple scattering is well known. The degree of measured depolarisation depends on the lidar characteristics (e.g. wavelength and receiver field of view) as well as the cloud macrophysical (e.g. cloud-base altitude) and microphysical (e.g. effective radius, liquid water content) properties. Efforts seeking to use depolarisation information in a quantitative manner to retrieve cloud properties have been undertaken with, arguably, limited practical success. In this work we present a retrieval procedure applicable to clouds with (quasi-)linear liquid water content (LWC) profiles and (quasi-)constant cloud-droplet number density in the cloud-base region. Thus limiting the applicability of the procedure allows us to reduce the cloud variables to two parameters (namely the derivative of the liquid water content with height and the extinction at a fixed distance above cloud base). This simplification, in turn, allows us to employ a fast and robust optimal-estimation inversion using pre-computed look-up tables produced using extensive lidar Monte Carlo (MC) multiple-scattering simulations. In this paper, we describe the theory behind the inversion procedure and successfully apply it to simulated observations based on large-eddy simulation (LES) model output. The inversion procedure is then applied to actual depolarisation lidar data corresponding to a range of cases taken from the Cabauw measurement site in the central Netherlands. The lidar results were then used to predict the corresponding cloud-base region radar reflectivities. In non-drizzling condition, it was found that the lidar inversion results can be used to predict the observed radar reflectivities with an accuracy within the radar calibration uncertainty (2–3 dBZ). This result strongly supports the accuracy of the lidar inversion results. Results of a comparison between ground-based aerosol number concentration and lidar-derived cloud-droplet number densities are also presented and discussed. The observed relationship between the two quantities is seen to be consistent with the results of previous studies based on aircraft-based in situ measurements.
关键词： Monte Carlo simulations,cloud-base region,aerosol-cloud interactions,retrieval procedure,depolarisation lidar,liquid-cloud microphysical properties,multiple scattering,radar reflectivity
更新于2025-09-19 17:15:36
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Thin Dielectric Layer Enabled Low Voltage Operation of Fully Printed Flexible Carbon Nanotube Thin Film Transistors
摘要： Quality of printable dielectric layer has become one of the major obstacles to achieve high performance fully printed transistors. A thick dielectric layer will require high gate voltage to switch on and off the transistors, which will cause high power dissipation in printed devices. In response to this challenge, fully printed carbon nanotube (CNT) based thin film transistors (TFTs) have been fabricated on flexible membranes such as polyimide and liquid crystal polymer using aerosol jet printing (AJP). These devices can be operated at bias voltages below ±10 V (drain/gate voltages around ±6 V). It is much smaller than the previously reported values for fully printed CNT-TFTs using xdi-dcs (mixture of poly(vinylphenol)/poly (methylsilsesquioxane)) as dielectric and using a single printing method. This is enabled because of thin dielectric layer (~300 nm) and good uniformity in printed CNT network. The printed CNT-TFTs show on/off ratio > 105, and mobility > 5 cm2V-1s-1. Layer-by-layer deposition of CNT allows highly uniform and dense network formation, and the optimization of the xdi-dcs concentration using natural butyl alcohol provides a high-yield printing of a thin dielectric layer. Collectively, this work shows a potential of using fully printed CNT-TFTs in various flexible electronic applications such as wearable sensors, actuators, artificial skins, displays and wireless tags and antennas.
关键词： xdi-dcs,aerosol jet printing,printed dielectric,flexible electronics,fully printed thin film transistors,carbon nanotube network
更新于2025-09-19 17:13:59
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Light absorption by organic aerosol emissions rivals that of black carbon from residential biomass fuels in South Asia
摘要： Solid biomass fuel-based residential cookstoves are the largest source of aerosol emissions in the Indian subcontinent. For assessing radiative forcing due to this pollutant source, laboratory-generated cookstove performance datasets are currently used, which have established black carbon (BC) as the dominant atmospheric warming aerosol species. We report findings on the strong near-ultraviolet wavelength absorption characteristics of emitted organic carbon (OC) aerosol from household stove combustion of nationally-representative biomass fuels. OC emission from cookstoves have been conventionally parameterized in emission inventory and regional climate models to be non-light-absorbing in the visible solar spectra. We conclude that light-absorbing OC contributes roughly as much as BC to total absorption cross-sections, thereby enhancing the associated positive forcing estimates. Our findings underscore the importance of including light-absorbing OC within the subcontinent’s air quality and climate impact assessment frameworks.
关键词： South Asia,black carbon,radiative forcing,biomass fuels,organic carbon,light absorption,cookstoves,aerosol emissions
更新于2025-09-19 17:13:59
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Structure-dependent performance of single-walled carbon nanotube films in transparent and conductive applications
摘要： We investigate a complex relationship between structural parameters of single-walled carbon nanotubes (namely, mean length, diameter, and defectiveness) and optoelectrical properties (equivalent sheet resistance) of thin films composed of the nanotubes. We obtained a systematic dataset describing the influence of CO2 concentration and growth temperature. On the basis of the experimental results, we prove the high Raman peak ratio (IG/ID), length, and diameter of the nanotubes to decrease the equivalent sheet resistance of the nanotube-based film. The approach employed highlights the change in the nanotube growth mechanism at the temperature coinciding with the phase transition between α-Fe and γ-Fe catalyst phases. We believe this work to be of high interest for researchers working not only in the field of transparent and conductive films based on nanocarbons, but also for those who reveals the fundamentals of the nanotube growth mechanism.
关键词： aerosol CVD,nanotube growth mechanism,optoelectronic properties,transparent conductive films,single-walled carbon nanotubes
更新于2025-09-19 17:13:59
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Accurate Output Forecasting Method for Various Photovoltaic Modules Considering Incident Angle and Spectral Change Owing to Atmospheric Parameters and Cloud Conditions
摘要： Because semiconductors absorb wavelengths dependent on the light absorption coefficient, photovoltaic (PV) energy output is affected by the solar spectrum. Therefore, it is necessary to consider the solar spectrum for highly accurate PV output estimation. Bird’s model has been used as a general spectral model. However, atmospheric parameters such as aerosol optical depth and precipitable water have a constant value in the model that only applies to clear days. In this study, atmospheric parameters were extracted using the Bird’s spectrum model from the measured global spectrum and the seasonal fluctuation of atmospheric parameters was examined. We propose an overcast spectrum model and calculate the all-weather solar spectrum from clear to overcast sky through linear combination. Three types of PV modules (fixed Si, two-axis tracking Si, and fixed InGaP/GaAs/InGaAs triple-junction solar cells) were installed at the University of Miyazaki. The estimated performance ratio (PR), which takes into account incident angle and spectral variations, was consistent with the measured PR. Finally, the energy yield of various PVs installed across Japan was successfully estimated.
关键词： output forecasting,incident angle,energy yield,photovoltaic,precipitable water,aerosol optical depth
更新于2025-09-19 17:13:59
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Quantifying and improving the optical performance of the Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) instrument
摘要： Single particle mass spectrometer (SPMS) instruments have been used for in-situ chemical characterization of atmospheric aerosols, both in the field and laboratory, for over two decades. SPMSs typically combine precise optical particle sizing with laser desorption and ionization followed by time of flight mass spectrometry. Among the advantages of SPMSs over other aerosol chemistry measurement techniques are their single particle resolution and high sensitivity counting efficiency in the size range 500-2000 nm vacuum aerodynamic diameter. We also present mass spectral performance for characterizing atmospherically-relevant particles in a comparison to a current SPMS design, the Particle Analysis by Laser Mass Spectrometry. The AeroMegt Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) is a commercially available member of this instrument class, aiming for a compact size and simplicity for the end user. This paper quantifies the performance of LAAPToF with an emphasis on optical counting efficiency. Recommendations for improving detection compared to the base LAAPToF hardware are described. Our results show that changes to the optical detection scheme can lead to over two orders of magnitude improvement in optical counting efficiency.
关键词： aerosol chemistry,LAAPToF,Single particle mass spectrometer,optical counting efficiency,time of flight mass spectrometry
更新于2025-09-19 17:13:59
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Laser and Optical Sounding of the Atmosphere
摘要： Lidar and searchlight instruments and techniques for atmospheric research developed at the V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in recent years are described. Key results obtained using these techniques are presented.
关键词： aerosol,atmosphere,gas impurities,lidar,scattering
更新于2025-09-19 17:13:59