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Measuring bulk density variations in a moving powder bed via terahertz in-line sensing
摘要： Monitoring the relative density of static or moving powder inside a process line is essential for manufacturing high-quality products. The aim of this study was to predict density variations in a moving powder bed using terahertz reflection technology. We systematically investigated three grades (varying true density and particle size) of two materials: lactose and silicified microcrystalline cellulose (SMCC). These six powders specifically differ in their compressibility, which can be applied to assess the sensitivity and applicability of our method. The powders were filled into a round container, and terahertz reflection measurements were acquired continuously during the container's rotation. The setup allowed to adjust the relative density by compacting the powders into specific powder bed heights. Each powder was compacted to various relative densities (compression pressures up to 100 kPa). We calculated the surface refractive index based on the in-line terahertz measurements acquired during rotation, which has a linear dependence on the relative density of the powder. This was confirmed by correlating the refractive index values with the theoretical relative densities based on the bulk and true densities of the powder. The coefficient of determination (R2) was larger than 0.962 (Lactohale 100) for all six powders, with the highest coefficients for Lactohale 220 (R2 = 0.996) and SMCC 50 LD (R2 = 0.995). The results suggest that the proposed method can resolve relative densities averaged across the powder bed that are as small as 0.3% (Lactohale 100). The high acquisition rate of the terahertz system (15 Hz) made it possible to determine the powder density in 230 positions uniformly distributed throughout the container, facilitating the investigation of the relative density uniformity in the container as a function of the powder bed height. It was observed that SMCC powders undergo a smaller change in the relative density variations upon compaction than the lactose powders. Moreover, the relative density maps clearly indicate local density differences in the powder bed for all powders. The relative density variations that were introduced by packing of the container prevailed throughout the compaction process for all samples with the exception of Lactohale 220. The presented approach allows a precise resolution of the spatial distribution of relative density, which facilitates an in-depth analysis of powder behavior upon compaction.
关键词： Powder density,Process monitoring,Process analyzer,Terahertz in-line sensing,Capsule filling
更新于2025-09-23 15:23:52
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Large-Area Gap Filling of Landsat Reflectance Time Series by Spectral-Angle-Mapper Based Spatio-Temporal Similarity (SAMSTS)
摘要： Landsat time series commonly contain missing observations, i.e., gaps, due to the orbit and sensing geometry, data acquisition strategy, and cloud contamination. A spectral-angle-mapper (SAM) based spatio-temporal similarity (SAMSTS) gap-filling algorithm is presented that is designed to fill small and large area gaps in Landsat data, using one year or less of data and without using other satellite data. Each gap pixel is filled by an alternative similar pixel that is located in a non-missing region of the image. The alternative similar pixel locations are identified by comparison of reflectance time series using a SAM metric revised to be adaptive to missing observations. A time series segmentation-and-clustering approach is used to increase the search efficiency. The SAMSTS algorithm is demonstrated using six months of Landsat 8 Operational Land Imager (OLI) reflectance time series over three 150 × 150 km (5000 × 5000 30 m pixels) areas in California, Minnesota and Kansas. The three areas contain different land cover types, especially crops that have different phenology and abrupt changes due to agricultural harvesting, which make gap filling challenging. Fillings on simulated gaps, which are equivalent to 36% of 5000 × 5000 images in each test area, are presented. The gap filling accuracy is assessed quantitatively, and the SAMSTS algorithm is shown to perform better than the simple closest temporal pixel substitution gap filling approach and the sinusoidal harmonic model-based gap filling approach. The SAMSTS algorithm provides gap-filled data with five-band reflective-wavelength root-mean-square differences less the 0.02, which is comparable to the OLI reflectance calibration accuracy.
关键词： Landsat,reflectance,time series,spectral angle mapper,gap filling
更新于2025-09-23 15:23:52
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Combining Adaptive Thresholding and Region Filling for Xylene Spills Detection from Ultraviolet Images
摘要： Numerous marine chemical spill accidents have caused enormous damage to the marine ecological environment. Multiple researchers are engaged in providing effective method to detect chemical spill detection. In this paper, we compare the properties between ultraviolet (UV) images and visible images. It turns out that the characteristics of UV images help eliminate the background influence. Then, we develop a new algorithm for segmenting chemical spills from UV imagery. This algorithm, combining adaptive thresholding and region filling, can effectively solve the problem of uneven illumination than the Otsu and FCM algorithms. Moreover, this algorithm does well in time consuming. Experimental results on UV imagery demonstrate that our approach can accurately segment chemical spill without producing too much false alarms.
关键词： region filling,UV images,segmentation,adaptive thresholding,chemical spill
更新于2025-09-23 15:22:29
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[IEEE 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Shanghai (2018.8.8-2018.8.11)] 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Effect of Pretreatment on Copper Filling of High Aspect Ratio Through-Silicon Via (TSV)
摘要： Ultrasound and vacuum pretreatment with pure water as prewetting solution could achieve good wetting effect, not only improving the filling quality but filling rate as well. In this paper, we studied the effects of pretreatment with SPS(Na2(SO3(CH2)3S)2) as prewetting solution on the filling processes in three commercial bath systems. By means of LSV and EIS, we analyzed the functional mechanism of the SPS in the pretreatment. According to the electrochemical test results, electroplating experiments were further carried out under different current densities to analyze the filling process and finally put forward a feasible proposal to optimize the proportion of additives and the electric parameters used in the void-free electro deposition.
关键词： TSV filling,pretreatment,electrodeposition,3D integration
更新于2025-09-23 15:22:29
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Novel Gap Filling BARC with High Chemical Resistance
摘要： In the recent of the semiconductor manufacturing process, variety of properties (narrow gap-filling and planarity etc.) are required to organic BARC in addition to the conventional requirements. Moreover, SC-1 resistance is also needed because BARC is often used as a wet etching mask when TiN processing. But conventional BARC which include crosslinker does not have enough SC-1 resistance, and we found that it is also difficult to obtain good gap-filling and good planarity because of outgassing and film shrinkage derived from the crosslinker. In this study, we have developed the new self-crosslinking BARC. The new crosslinking system shows low outgassing and film shrinkage because of not including crosslinker. So, novel BARC has better gap filling property and planarity and over 3 times higher SC-1 resistance than that of conventional BARC. Moreover, by adding the low molecular weight additive which has high adhesive unit to TiN surface, the novel BARC has over 10 times higher SC-1 resistance than that of conventional BARC. And this novel BARC can be applied both ArF & KrF lithography process because of broad absorbance, high etching rate, chemical resistance (SC-1, SC-2, DHF, and others) and good film thickness uniformity. In this paper, we will discuss the detail of new self-crosslinking BARC in excellent total performance and our approach to achieve high chemical resistance.
关键词： KrF,ArF,Self-crosslinking,Gap filling,Planarity,Chemical resistance,BARC
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Singapore, Singapore (2019.12.10-2019.12.13)] 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Conformal Leaky-Wave Antenna Based on Partially Filled Rectangular Waveguide
摘要： The present paper is devoted to the development of a conformal leaky-wave antenna based on a curved rectangular waveguide. The process of obtaining the required beam position is about longitudinal tailoring the phase velocity. This is achieved with choosing the thickness of dielectric, which partially fills the slotted waveguide. The difference between wavelengths in curved and straight waveguides is taken into account. An amplitude distribution function is realized by means of traditional adjusting the each particular slot parameters. The results of computer simulation validate the proposed design technique.
关键词： rectangular waveguide,dielectric filling,phase velocity,conformal antenna,leaky-wave antenna,beam forming
更新于2025-09-23 15:21:01
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[IEEE IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - Yokohama, Japan (2019.7.28-2019.8.2)] IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - GLRT Detectors for Airborne Radar Based on Knowledge-Aided and Compressive Sensing
摘要： The influences of the intermediate band (IB) filling, the absorption coefficient constants, and the IB position on the efficiency of a quantum dot intermediate band solar cell (QD-IBSC) are investigated considering the spatial variation of subbandgap generation rates. A new definition of optimal intermediate band filling is proposed. A mathematical model is developed to optimize the intermediate band solar cell (IBSC) structure under idealized conditions, which calculates the optimal ratio of the subbandgap absorption coefficient constants and the optimal position of IB.
关键词： optimal filling,conversion efficiency,Intermediate band solar cell (IBSC),IB position,absorption coefficients
更新于2025-09-23 15:21:01
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[IEEE 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - Erode (2018.2.15-2018.2.16)] 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - STORE WHEN BLOCKED AFTER FAIR PRIORITIZED PREEMPTION (SBFPP) PROTOCOL FOR NON BLOCKING OPTICAL BURST SWITCHED NETWORKS
摘要： Just Enough Time is the most promising protocol of optical burst switched network, Different prioritization on the basis of fairness algorithms have been given for increasing the utilization of link. Still there is probability of blocking in the network at high load. In this Paper we have proposed a none blocking Optical Burst Switched network by proposing a new protocol for optical Burst switched network. In this paper we have also compared the blocking probabilities of JET with some fairness protocols with our proposed protocol. A simulated output for effective bandwidth utilization and dropping probabilities of all the outputs are also presented and compared.
关键词： Fair Prioritized Preemption (FPP),Acoustic Optical tunable filter (AOTF),Optical Burst Switching,Last available unscheduled channel with void filling (LAUC-VF)
更新于2025-09-23 15:21:01
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Structural and Quantitative Investigation of Perovskite Pore Filling in Mesoporous Metal Oxides
摘要： In recent years, hybrid organic–inorganic perovskite light absorbers have attracted much attention in the field of solar cells due to their optoelectronic characteristics that enable high power conversion efficiencies. Perovskite-based solar cells’ efficiency has increased dramatically from 3.8% to more than 20% in just a few years, making them a promising low-cost alternative for photovoltaic applications. The deposition of perovskite into a mesoporous metal oxide is an influential factor affecting solar cell performance. Full coverage and pore filling into the porous metal oxide are important issues in the fabrication of highly-efficient mesoporous perovskite solar cells. In this work, we carry out a structural and quantitative investigation of CH3NH3PbI3 pore filling deposited via sequential two-step deposition into two different mesoporous metal oxides—TiO2 and Al2O3. We avoid using a hole conductor in the perovskite solar cells studied in this work to eliminate undesirable end results. Filling oxide pores with perovskite was characterized by Energy Dispersive X-ray Spectroscopy (EDS) in Transmission Electron Microscopy (TEM) on cross-sectional focused ion beam (FIB) lamellae. Complete pore filling of CH3NH3PbI3 perovskite into the metal oxide pores was observed down to X-depth, showing the presence of Pb and I inside the pores. The observations reported in this work are particularly important for mesoporous Al2O3 perovskite solar cells, as pore filling is essential for the operation of this solar cell structure. This work presents structural and quantitative proof of complete pore filling into mesoporous perovskite-based solar cells, substantiating their high power conversion efficiency.
关键词： STEM-TEM,mesoporous,perovskite,pore filling,XRD
更新于2025-09-23 15:21:01
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[IEEE 2019 European Space Power Conference (ESPC) - Juan-les-Pins, France (2019.9.30-2019.10.4)] 2019 European Space Power Conference (ESPC) - Potential of the three-terminal heterojunction bipolar transistor solar cell for space applications
摘要： Cooperative communication suffers from multiplexing loss and low spectral efficiency due to the half duplex constraint of relays. To improve the multiplexing gain, successive relaying, which allows concurrent transmission of the source and relays, has been proposed. However, the severe inter-relay interference becomes a key challenge. In this paper, we propose a channel aware successive relaying protocol, also referred to as CAO-SIR, which is capable of thoroughly mitigating inter-relay interference by carefully adapting relays’ transmission order and rate. In particular, a relay having a poorer link to the source is scheduled first to forward a message, the data rate of which is adapted to the link quality of the source-relay and relay-destination channels. By this means, each relay may decode the messages intended for the preceding relays, and then cancel these relays’ interference in a low complexity which is equal to that of Decision Feedback Equalizer (DFE). To further optimize and analyze CAO-SIR, we present its equivalent parallel relay channel model, based upon which the adaptive relay selection and power allocation schemes are proposed. By employing M half duplex relays, CAO-SIR is capable of achieving an diversity-multiplexing tradeoff (DMT) given by 1 ? M +2 and r denote the diversity and multiplexing gains, respectively. Its DMT asymptotically approaches the DMT upper bound achieved by (M + 1) × 1 MISO systems or M full duplex relays, when M is large.
关键词： diversity-multiplexing tradeoff,rate adaptation,Successive relaying,relay selection,interference cancellation,power allocation,water filling,opportunistic communications,relay ordering
更新于2025-09-23 15:19:57