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Experimental investigation for temperature and emissivity by flame emission spectrum in a cavity of rocket based combined cycle combustor chamber

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DEFENCE technolOGY 2024年第9期39卷 114-122页

作者： Cai, Weiguang Zheng, Shu Wang, Yan Liu, Bing Zhu, Shaohua Zhao, Li Lu, Qiang North China Elect Power univ Natl Engn Res Ctr New Energy Power Generat Beijing 102206 Peoples R China Northwestern Polytech univ Internal Flow & Thermal Struct Lab Sci & Technol Combust Xian 710072 Peoples R China

Flame temperature and spectral emissivity were the important parameters characterizing the sufficient degree of fuel combustion and the particle radiative characteristics in the Rocket Based Combined Cycle (RBCC) combustor. To investigate the combustion characteristics of the complex supersonic flame in the RBCC combustor, a new radiation thermometry combined with Levenberg-Marquardt (LM) algorithm and the least squares method was proposed to measure the temperature, emissivity and spectral radiative properties based on the flame emission spectrum. In-situ measurements of the flame temperature, emissivity and spectral radiative properties were carried out in the RBCC direct-connected test bench with laser-induced plasma combustion enhancement (LIPCE) and without LIPCE. The flame average temperatures at fuel global equivalence ratio (a) of 1.0b and 0.6 with LIPCE were 4.51% and 2.08% higher than those without LIPCE. The flame combustion oscillation of kerosene tended to be stable in the recirculation zone of cavity with the thermal and chemical effects of laser induced plasma. The differences of flame temperature at a = 1.0b and 0.6 were 503 K and 523 K with LIPCE, which were 20.07% and 42.64% lower than those without LIPCE. The flame emissivity with methane assisted ignition was 80.46% lower than that without methane assisted ignition, due to the carbon-hydrogen ratio of kerosene was higher than that of methane. The spectral emissivities at 600 nm with LIPCE were 1.25%, 22.2%, and 4.22% lower than those without LIPCE at a = 1.0a (with methane assisted ignition), 1.0b (without methane assisted ignition) and 0.6. The effect of concentration in the emissivity was removed by normalization to analyze the flame radiative properties in the RBCC combustor chamber. The maximum differences of flame normalized emissivity were 50.91% without LIPCE and 27.53% with LIPCE. The flame radiative properties were stabilized under the thermal and chemical effects of laser induced plasma

关键词： Rocket-based combined-cycle Supersonic combustion Flame temperature measurement Emissivity Laser induced plasma combustion enhancement STOKES-RAMAN SPECTROSCOPY

Harvesting Energy Via Water Movement and Surface Ionics in Microfibrous Ceramic Wools

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 332-341页

作者： Kaur, Manpreet Alagumalai, Avinash Mahian, Omid Osman, Sameh M. Nagao, Tadaaki Wang, Zhong Lin Natl Inst Mat sci NIMS Res Ctr Mat Nanoarchitecton WPI MANA 1-1 Namiki Tsukuba Ibaraki 3050044 Japan univ Calgary Dept Chem & Petr Engn 2500 Univ Dr NW Calgary AB T2N 1N4 Canada Hokkaido univ Dept Condensed Matter Phys Sapporo Hokkaido 0600810 Japan GMR Inst technol Dept Mech Engn Rajam 532127 Andhra Pradesh India Ningbo univ Fac Mech Engn & Mech Zhejiang Prov Engn Res Ctr Safety Pressure Vessel Ningbo 315211 Peoples R China Imperial Coll London Dept Chem Engn London SW7 2AZ England Chinese Acad sci Beijing Inst Nanoenergy & Nanosyst Beijing 100083 Peoples R China Tomsk State univ Lab Convect Heat & Mass Transfer Tomsk 634045 Russia Georgia Inst technol Sch Mat Sci & Engn Atlanta GA 30332 USA King Saud univ Coll Sci Chem Dept POB 2455 Riyadh 11451 Saudi Arabia

Due to the push for carbon neutrality in various human activities, the development of methods for producing electricity without relying on chemical reaction processes or heat sources has become highly significant. Also, the challenge lies in achieving microwatt-scale outputs due to the inherent conductivity of the materials and diverting electric currents. To address this challenge, our research has concentrated on utilizing nonconductive mediums for water-based low-cost microfibrous ceramic wools in conjunction with a NaCl aqueous solution for power generation. The main source of electricity originates from the directed movement of water molecules and surface ions through densely packed microfibrous ceramic wools due to the effect of dynamic electric double layer. This occurrence bears resemblance to the natural water transpiration in plants, thereby presenting a fresh and straightforward approach for producing electricity in an ecofriendly manner. The generator module demonstrated in this study, measuring 12 x 6 cm(2), exhibited a noteworthy open-circuit voltage of 0.35 V, coupled with a short-circuit current of 0.51 mA. Such low-cost ceramic wools are suitable for ubiquitous, permanent energy sources and hold potential for use as self-powered sensors and systems, eliminating the requirement for external energy sources such as sunlight or heat. Electrokinetic power generation through ceramic *** this work, microfibrous ceramic wools are being explored for electrokinetic power generation through water transpiration. The generator module measuring 12 x 6 cm(2), demonstrated a noteworthy open-circuit voltage of 0.35 V, coupled with a short-circuit current of 0.51 mA. This scalable ceramic wool device generates electricity without relying on sunlight or heat.

关键词： ceramic microfibers energy harvesting power generation self-powered systems water evaporation POWER-GENERATION GRAPHENE OXIDE TRIBOELECTRIC NANOGENERATOR CONTACT-ELECTRIFICATION ELECTRICITY LIQUID DRIVEN FLOW

Boron Nitride-Integrated Lithium Batteries: Exploring Innovations in Longevity and Performance

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 13-40页

作者： Angizi, Shayan Alem, Sayed Ali Ahmad Torabian, Mahdi Khalaj, Maryam Golberg, Dmitri Pakdel, Amir McMaster univ Dept Chem Engn 1280 Main St W Hamilton ON L8S 4L7 Canada Montan univ Leoben Inst Chem Polymer Mat Otto Glockel Str 2 A-8700 Leoben Austria Politecn Milan Dept Chem Mat & Chem Engn Piazza Leonardo Vinci 32 I-20133 Milan Italy Northwestern univ Dept Mat Sci & Engn Evanston IL 60208 USA Queensland univ technol QUT Ctr Mat Sci 2 George Brisbane Qld 4000 Australia Queensland univ technol QUT Sch Chem & Phys 2 George Brisbane Qld 4000 Australia Natl Inst Mat sci NIMS Res Ctr Mat Nanoarchitecton MANA Namiki 1 Ibaraki 3050044 Japan univ Dublin Trinity Coll Dublin Dept Mech Mfg & Biomed Engn Dublin D02PN40 Ireland

The current global warming, coupled with the growing demand for energy in our daily lives, necessitates the development of more efficient and reliable energy storage devices. Lithium batteries (LBs) are at the forefront of emerging power sources addressing these challenges. Recent studies have shown that integrating hexagonal boron nitride (h-BN) nanomaterials into LBs enhances the safety, longevity, and electrochemical performance of all LB components, including electrodes, electrolytes, and separators, thereby suggesting their potential value in advancing eco-friendly energy solutions. This review provides an overview of the most recent applications of h-BN nanomaterials in LBs. It begins with an informative introduction to h-BN nanomaterials and their relevant properties in the context of LB applications. Subsequently, it addresses the challenges posed by h-BN and discusses existing strategies to overcome these limitations, offering valuable insights into the potential of BN nanomaterials. The review then proceeds to outline the functions of h-BN in LB components, emphasizing the molecular-level mechanisms responsible for performance improvements. Finally, the review concludes by presenting the current challenges and prospects of integrating h-BN nanomaterials into battery research. Integrating h-BN into lithium batteries enhances safety, longevity, and mechanical integrity of battery components by mitigating dendritic growth and side reactions. Its high ionic and thermal conductivities improve lithium transference and heat management, enhancing performance and reliability. image

关键词： electrode electrolyte hexagonal boron nitride lithium battery separator METAL BATTERIES H-BN ION BATTERIES 2-DIMENSIONAL MATERIALS POLYMER ELECTROLYTE HIGH-TEMPERATURE ANODES NANOSHEETS DENDRITE FUNCTIONALIZATION

Continuous Lithium-Ion Extraction From Seawater and Mine Water With a Fuel Cell System and Ceramic Membranes

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 254-261页

作者： Koek, Cansu Wang, Lei Ruthes, Jean Gustavo A. Quade, Antje Suss, Matthew E. Presser, Volker INM Leibniz Inst New Mat Campus D2 2 D-66123 Saarbrucken Germany Saarland univ Dept Mat Sci & Engn Campus D2 2 D-66123 Saarbrucken Germany Saarene Saarland Ctr Energy Mat & Sustainabil Campus C4 2 D-66123 Saarbrucken Germany Leibniz Inst Plasma sci & technol Felix Hausdorff Str 2 D-17489 Greifswald Germany Technion Israel Inst technol Fac Mech Engn IL-3200003 Haifa Israel Technion Israel Inst technol Wolfson Dept Chem Engn IL-3200003 Haifa Israel Technion Israel Inst technol Grand Technion Energy Program IL-3200003 Haifa Israel

The demand for electronic devices that utilize lithium is steadily increasing in this rapidly advancing technological world. Obtaining high-purity lithium in an environmentally friendly way is challenging by using commercialized methods. Herein, we propose the first fuel cell system for continuous lithium-ion extraction using a lithium superionic conductor membrane and advanced electrode. The fuel cell system for extracting lithium-ion has demonstrated a twofold increase in the selectivity of Li+/Na+ while producing electricity. Our data show that the fuel cell with a titania-coated electrode achieves 95% lithium-ion purity while generating 10.23 Wh of energy per gram of lithium. Our investigation revealed that using atomic layer deposition improved the electrode's uniformity, stability, and electrocatalytic activity. After 2000 cycles determined by cyclic voltammetry, the electrode preserved its stability. To achieve high purity and selectivity in lithium-ion extraction, using ceramic membranes that are selective to lithium is ideal, and titania can be employed as a protective layer on the gas diffusion electrode to improve the catalyst's durability. Our data show that a lithium superionic conductor can be used in fuel cells for extracting lithium. A fuel cell-based lithium extraction system can achieve a purity level of 95% while generating 0.12 Wh of energy. image

关键词： atomic layer deposition cation selectivity electrochemical lithium-ion extraction fuel cell ATOMIC LAYER DEPOSITION RECOVERY BATTERY ELECTROCATALYSTS PRINCIPLES ENERGY TIO2

Organic X-Ray Image Sensors Using a Medium Bandgap Polymer Donor with Low Dark Current

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 230-237页

作者： Ha, Jong-Woon Eom, Seung Hun Cha, Bo Kyung Song, Seyeong Eun, Hyeong Ju Kim, Jong H. Park, Jong Mok Kim, Bongsoo Park, Byoungwook Ko, Seo-Jin Yoon, Sung Cheol Lee, Changjin Jung, In Hwan Hwang, Do-Hoon Pusan Natl univ Chem Inst Funct Mat Dept Chem Busan 46241 South Korea Korea Res Inst Chem technol KRICT Div Adv Energy Mat Res Ctr Daejeon 34114 South Korea Korea Electrotechnol Res Inst KERI Electromed Device Res Ctr Ansan 15588 South Korea Ulsan Natl Inst sci & technol UNIST Grad Sch Carbon Neutral Sch Energy & Chem Engn Ulsan 44919 South Korea Ajou univ Dept Mol Sci & Technol Suwon 16449 South Korea Korea Res Inst Chem technol Res Ctr Adv Specialty Chem Ulsan 44412 South Korea Ulsan Natl Inst sci & technol UNIST Dept Chem Ulsan 44919 South Korea Hanyang univ Dept Organ & Nano Engn Human Tech Convergence Program 222 Wangsimni Ro Seoul 04763 South Korea

The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations. However, this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors. The weight and thickness of X-ray detectors can be reduced by replacing the silicon layer with an organic photodetectors. This study presents a novel bithienopyrroledione-based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer (similar to 700 nm), owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione. The ability of bithienopyrroledione-based polymer donor to strongly suppress the dark current density (J(d) similar to 10(-10) A cm(-2)) at a negative bias (-2.0 V) while maintaining high responsivity (R = 0.29 A W-1) even at a thickness of 700 nm results in a maximum shot-noise-limited specific detectivity of D-sh* = 2.18 x 10(13) Jones in the organic photodetectors. Printed organic photodetectors are developed by slot-die coating for use in X-ray detectors, which exhibit D-sh* = 2.73 x 10(12) Jones with clear rising (0.26 s) and falling (0.29 s) response times upon X-ray irradiation. Detection reliability is also proven by linear response of the X-ray detector, and the X-ray detection limit is 3 mA.

关键词： low dark current low detection limit organic photodetector printable X-ray DETECTORS PHOTOCONDUCTORS SENSITIVITY

Dual-blockchain based multi-layer grouping federated learning scheme for heterogeneous data in industrial IoT

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BLOCKCHAIN-RESEARCH AND APPLICATIONS 2024年第3期5卷 11-21页

作者： Wang, Xin Zhang, Haoji Wu, Haoyu Yu, Hongnian Shaanxi univ sci & technol Sch Elect Informat & Artificial Intelligence Xian 710021 Peoples R China Edinburgh Napier univ Sch Engn & Built Environm Edinburgh EH10 5DT Scotland

Federated learning (FL) allows data owners to train neural networks together without sharing local data, allowing the industrial Internet of Things (IIoT) to share a variety of data. However, traditional FL frameworks suffer from data heterogeneity and outdated models. To address these issues, this paper proposes a dualblockchain based multi-layer grouping federated learning (BMFL) architecture. BMFL divides the participant groups based on the training tasks, then realizes the model training by combining synchronous and asynchronous FL through the multi-layer grouping structure, and uses the model blockchain to record the characteristic tags of the global model, allowing group-manners to extract the model based on the feature requirements and solving the problem of data heterogeneity. In addition, to protect the privacy of the model gradient parameters and manage the key, the global model is stored in ciphertext, and the chameleon hash algorithm is used to perform the modification and management of the encrypted key on the key blockchain while keeping the block header hash unchanged. Finally, we evaluate the performance of BMFL on different public datasets and verify the practicality of the scheme with real fault datasets. The experimental results show that the proposed BMFL exhibits more stable and accurate convergence behavior than the classic FL algorithm, and the key revocation overhead time is reasonable.

关键词： Federal learning Multi-level grouping Editable blockchain Data heterogeneity Industrial Internet of Things (IIOT) PRIVACY INTERNET

Study on thermal cycling ageing resistance of performances of polypropylene/elastomer/boron nitride nanocomposites for high voltage direct current cable insulation

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HIGH VOLTAGE 2024年第3期9卷 556-565页

作者： Li, Jing Gao, Yu Song, Zheng Liu, Baixin Guo, Chenyi Chen, Yu Gao, Junguo Du, Boxue Tianjin univ Sch Elect & Informat Engn Tianjin Peoples R China State Grid Tianjin Chengxi Elect Power Supply Bran Tianjin Peoples R China Xi An Jiao Tong univ State Key Lab Elect Insulat & Power Equipment Xian Peoples R China Harbin univ sci & technol Key Lab Engn Dielect & Its Applicat Minist Educ Harbin Peoples R China

The influences of thermal cycling ageing on structures and insulation performances of polypropylene (PP)/elastomer/boron nitride (BN) nanocomposites are investigated. The Melt blending method was used to prepare the nanocomposites, in which propylene-based elastomer (PBE) or ethylene-octene copolymer elastomer (EOC) was contained for comparison. Then, the samples were treated using a thermal cycling process with a temperature range from -30 to 150 degrees C, and the number of thermal cycles was set from 0 to 15. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry and X-ray diffraction measurements were taken to facilitate the comprehension of structural changes. Additionally, measurements were taken to assess the trap distribution and direct current (DC) breakdown strength of the samples. The obtained results revealed that following thermal cycling ageing, the morphology and crystallinity of PP/PBE/BN remained almost unchanged. In contrast, PP/EOC/BN exhibited substantial microstructural damage accompanied by a significant reduction in crystallinity. As the number of thermal cycles increased, the trap level and DC breakdown strength of PP/PBE/BN were maintained at high levels, while those of PP/EOC/BN initially remained stable but then experienced a sharp decline. It is suggested that the addition of BN nanoparticles enhances the thermal cycling ageing resistance of the PP/PBE blend, whereas it weakens this resistance of the PP/EOC blend.

关键词： POLYPROPYLENE IRRADIATION BEHAVIOR DEGRADATION

Enhanced detection algorithm for apple bruises using structured light imaging

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ARTIFICIAL INTELLIGENCE IN AGRICULTURE 2024年第1期11卷 50-60页

作者： Zhu, Haojie Yang, Lingling Wang, Yu Wang, Yuwei Hou, Wenhui Rao, Yuan Liu, Lu Anhui Agr univ Coll Engn Hefei 230036 Peoples R China Anhui Agr univ Key Lab Agr Sensors Minist Agr & Rural Affairs Hefei 230036 Peoples R China Chinese Acad sci Hefei Inst Technol Innovat Engn Hefei 230094 Peoples R China

Bruising reduces the edibility and marketability of fresh apples, inevitably causing economic losses for the apple industry. However, bruises lack obvious visual symptoms, which makes it challenging to detect them using imaging techniques with uniform or diffuse illumination. This study employed the structured light imaging (SLI) technique to detect apple bruises. First, the grayscale reflection images were captured under phase-shifted sinusoidal illumination at three different wavelengths (600, 650, and 700 nm) and six different spatial frequencies (0.05, 0.10, 0.15, 0.20, 0.25, and 0.30 cycles mm-1). Next, the grayscale reflectance images were demodulated to produce direct component (DC) images representing uniform diffuse illumination and amplitude component (AC) images revealing bruises. Then, by quantifying the contrast between bruised regions and sound regions in all AC images, it was found that bruises exhibited the optimal contrast when subjected to sinusoidal illumination at a wavelength of 700 nm and a spatial frequency of 0.25 mm-1. In the AC image with optimal contrast, the developed h-domes segmentation algorithm to accurately segment the location and range of the bruised regions. Moreover, the algorithm successfully accomplished the task of segmenting central bruised regions while addressing the challenge of segmenting edge bruised regions complicated by vignetting. The average Intersection over Union (IoU) values for the three types of bruises were 0.9422, 0.9231, and 0.9183, respectively. This result demonstrated that the combination of SLI and the h-domes segmentation algorithm was a viable approach for the effective detection of fresh apple bruises. (c) 2023 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Apple bruises Bruise enhancement Image segmentation Structured illumination COMPUTER VISION DETECTION DEFECTS IMAGES SYSTEM DAMAGE

An overview of Web3 technology: Infrastructure, applications, and popularity

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BLOCKCHAIN-RESEARCH AND APPLICATIONS 2024年第1期5卷 97-106页

作者： Huang, Renke Chen, Jiachi Wang, Yanlin Bi, Tingting Nie, Liming Zheng, Zibin Sun Yat Sen univ Sch Software Engn Guangzhou 510275 Peoples R China Data61 Canberra ACT 2601 Australia Zhejiang sci Tech univ Hangzhou 310018 Peoples R China Nanyang technol univ Singapore 639798 Singapore

Web3, the next generation of the Internet, represents a decentralized and democratized web. Although it has garnered significant public interest and found numerous real-world applications, there is a limited understanding of people's perceptions and experiences with Web3. In this study, we conducted an empirical study to investigate the categories of Web3 applications and their popularity, as well as the potential challenges and opportunities within this emerging landscape. Our research was carried out in two phases. In the first phase, we analyzed 200 popular Web3 projects associated with 10 leading Web3 venture capital firms. In the second phase, we collected and examined code-related data from GitHub and market-related data from blockchain browsers (e.g., Etherscan) for these projects. Our analysis revealed that the Web3 ecosystem can be categorized into two groups, i.e., Web3 infrastructure and Web3 applications, with each consisting of several subcategories or subdomains. We also gained insights into the popularity of these Web3 projects at both the code and market levels and pointed out the challenges in the Web3 ecosystem at the system, developer, and user levels, as well as the opportunities it presents. Our findings contribute to a better understanding of Web3 for researchers and developers, which in turn promotes further exploration and advancement in this innovative field.

关键词： Web3 Blockchain Empirical study Survey