检索结果-内蒙古大学图书馆

Estimation of the main air pollutants from different biomasses under combustion atmospheres by artificial neural networks

引用

Chemosphere 2024年 352卷 141484页

作者： Monteiro, Thalyssa Oliveira Alves, Pedro Augusto Araújo da Silva de Almeida Nava Barradas Filho, Alex Oliveira Villa-Vélez, Harvey Alexander Cruz, Glauber Postgraduate Program in Mechanical Engineering (PPGMEC) Department of Mechanics and Materials Federal Institute of Education Science and Technology of Maranhão (IFMA) Maranhão São Luís Brazil Postgraduate Program in Computer Science and Computational Mathematics (PPG-CCMC) Department of Computer Science University of São Paulo (USP) São Carlos São Paulo Brazil Data Analysis and Artificial Intelligence Laboratory (DARTi) Department of Computational Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil Department of Chemical Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil Processes and Thermal Systems Laboratory (LPSisTer) Department of Mechanical Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil

The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, CO2, NOx, SOx, and other pollutants), affecting living organisms and requiring careful assessments. H... 详细信息

The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, CO₂, NO_x, SO_x, and other pollutants), affecting living organisms and requiring careful assessments. However, obtaining such information experimentally for data evaluation is costly and time-consuming and its in situ obtaining for regional biomasses (e.g., those from Northeast Brazil (NEB) is still a major challenge. This paper reports on the application of artificial neural networks (ANNs) for the prediction of the main air pollutants (CO, CO₂, NO, and SO₂) produced during the direct biomass combustion (N₂/O₂:80/20%) with the use of ultimate analysis (carbon, hydrogen, nitrogen, sulfur, and oxygen). 116 worldwide biomasses were used as input data, which is a relevant alternative to overcome the lack of experimental resources in NEB and obtain such information. Cross-validation was conducted with k-fold to optimize the ANNs and performance was analyzed with the use of statistical errors for accuracy assessments. The results showed an acceptable statistical performance for all architectures of ANNs, with 0.001–12.41% MAPE, 0.001–5.82 mg Nm⁻³ MAE, and 0.03–52.30 mg Nm⁻³ RMSE, highlighting the high precision of the emissions studied. On average, the differences between predicted and real values for CO, CO₂, NO, and SO₂ emissions from NEB biomasses were approximately 0.01%, 10⁻⁶%, 0.14%, and 0.05%, respectively. Pearson coefficient provided consistent results of concentration of the ultimate analysis in relation to the emissions studied and effectiveness of the test set in the developed models. © 2024 Elsevier Ltd

关键词： Brazilian northeastern Environmental statistics Evaluation metrics Gaseous emissions Predictive models Thermoconversion

来源：评论

学校读者我要写书评

暂无评论

Synthesis of Polycrystalline Diamond Compact with Selenium:Discovery of a New Se–C Compound

引用

Chinese Physics Letters 2020年第5期37卷 102-105页

作者： Wen-Dan Wang Ao Li Guo-Heng Xu Pei Wang Yue-Gao Liu Li-Ping Wang School of Physical Science and Technology Southwest Jiaotong UniversitChengdu 610031 Materials Research Center Institute of Modern PhysicsChinese Acadermy of SciencesLanzhou 730000 Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology(SUSTech)Shenzhen 518055 CAS Key Laboratory for Experimental Study under Deep-Sea Extreme Conditions Institute of Deep-Sea Science and EngineeringChinese Academy of SciencesSanya 572000

Sintering of polycrystalline diamond with selenium was investigated under pressure of 6.5-10.5 GPa at a constant temperature of 1850℃.A new carbon-selenium compound with a most plausible chemical formula of SeC and a WC-type hexagonal structure(space group P6m2)has been discovered in the recovered samples sintered at 10.5 GPa and 1850℃.Refined lattice parameters are as follows:a=2.9277(4)A,c=2.8620(4)A,V=21.245(4)A^*** diamond compacts hot-pressed at 10.5 GPa have excellent mechanical properties with a Vickers hardness of about 68 GPa at a loading force of 19.6 *** intergrowths observed in these samples may have benefited from the catalytic effects of Se/SeC on the nucleation and crystal growth of diamond.

关键词： Diamond hexagonal Vickers

来源：评论

学校读者我要写书评

暂无评论

A Decision-Making Model for Retired Li-Ion Batteries

SSRN

引用

SSRN 2023年

作者： Zhuang, Jihan Bach, Amadeus van Vlijmen, Bruis H.C. Reichelstein, Stefan J. Chueh, William Onori, Simona Benson, Sally M. Materials Science and Engineering Department Stanford University 450 Serra Mall StanfordCA94305 United States Mannheim Institute for Sustainable Energy Studies University of Mannheim Mannheim Germany SLAC National Accelerator Laboratory Menlo ParkCA94025 United States Graduate School of Business Stanford University StanfordCA94305 United States Energy Science and Engineering Department Stanford University 450 Serra Mall StanfordCA94305 United States

The growth of electric vehicles (EVs) has raised concerns about the disposition of their batteriesonce they reach their end of life. Currently, recycling is regarded as the potential solution forretired Li-ion batteries (LIBs). However, these LIBs still retain around 80% of their originalcapacity, which can be repurposed for other energy storage system (ESS) applications in their"second life" before recycling. Yet, there is no guidance for deciding whether to reuse or recyclethem. Here, we propose developing a decision-making model that evaluates retired batteriesfrom both technical and economic perspectives. We develop data-driven models and combinethem with an equivalent circuit model (ECM) to build module-level aging models. Simulationsshow that limiting the State of Charge (SOC) operating range and charge current in second lifeapplications can extend the lifetime of LIBs. Upon when and how to use the battery in secondlife, the simulated lifetime is between 1-6 years. From an economic perspective, we find thatthe most profitable application is frequency regulation, which has a value of 273.4$ kW h −1 .Wepresent a comprehensive comparison of different end-of-life strategies to demonstrate the mosteconomically way to handle a retired battery. © 2023, The Authors. All rights reserved.

关键词： Lithium-ion batteries

来源：评论

学校读者我要写书评

暂无评论

Large-Scale Multidisciplinary Design Optimization of an eVTOL Aircraft Using Comprehensive Analysis

Large-Scale Multidisciplinary Design Optimization of an eVTO...

引用

AIAA SciTech Forum and Exposition, 2023

作者： Sarojini, Darshan Ruh, Marius L. Sperry, Mark Yan, Jiayao Fletcher, Andrew Joshy, Anugrah Jo Scotzniovsky, Luca Ivanov, Alexander Orndorff, Nicholas Gandarillas, Victor Asher, Isaac Chambers, Jeff Gill, Hyunjune Lee, Seongkyu Cheng, Zeyu Rodriguez, Gabriel Zhao, Shuofeng Mi, Chunting Nascenzi, Thomas Cuatt, Timothy Winter, Tyler Guibert, Alexandre Cronk, Ashley Kim, Alicia Meng, Shirley Hwang, John T. Department of Mechanical and Aerospace Engineering University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Flight Physics Aurora Flight Sciences A Boeing Company 9950 Wakeman Drive ManassasVA20110 United States Engineering Department Aurora Flight Sciences A Boeing Company 9950 Wakeman Drive ManassasVA20110 United States Department of Mechanical and Aerospace Engineering University of California Davis 1 Shields Avenue DavisCA95616 United States Department of Electrical and Computer Engineering San Diego State University 5500 Campanile Dr San Diego92182 United States Research and Development M4 Engineering Inc 4020 Long Beach Blvd # 2 Long BeachCA90807 United States Structural Engineering Department University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Materials Science and Engineering Program University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Department of NanoEngineering University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States

ISBN: (数字)9781624106996

ISBN: (纸本)9781624106996

This paper presents a framework under development for enabling large-scale multi-fidelity modeling and optimization of electric vertical takeoff and landing concepts (eVTOL). The key features of the framework are a geometry-centric approach to multidisciplinary design optimization (MDO), a modular functional-form representation of the disciplines involved in aircraft design, and fully automated derivative computations thereby allowing efficient gradient-based optimization. The framework is first presented in a general manner agnostic to the vehicle concept or the physics-based analyses used. The key disciplines involved in the design of eVTOL aircraft and the couplings between the disciplines are described. The framework is then applied to the design of the NASA lift-plus-cruise concept. Low-fidelity solvers of aerodynamics, propulsion, structural estimation, acoustics, powertrain, and battery are coupled together. The optimization considers 108 design variables and 16 constraints. It is shown that MDO considering geometric variables results in a design with lower gross mass than when the geometric variables are not considered. The optimization turnaround time of 30 minutes on a standard workstation demonstrates the capabilities of fully-coupled large-scale MDO using gradient-based optimization. The framework is under development and an open-source version will be released in the near future. © 2023, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Geometry

来源：评论

学校读者我要写书评

暂无评论

Effects of elevated temperature on basalt and glass FRP bars in prismatic beams under flexural loading

引用

Composites Part C: Open Access 2025年 17卷

作者： Ghazal Aswad, Nour Al Dawood, Mohammed Abed, Farid Materials Science and Engineering Program American University of Sharjah Sharjah United Arab Emirates Department of Civil Engineering American University of Sharjah Sharjah United Arab Emirates

Fiber-reinforced polymer (FRP) reinforcement has gained significant attention in research and structural applications due to its desirable mechanical properties and durability. Advances have been made in understanding FRP's resistance to elevated temperatures;however, uncertainties persist due to inconsistencies in the available experimental data. This study presents an experimental investigation into the effects of various parameters on the performance of reinforced concrete (RC) prismatic beams exposed to elevated temperatures. Key parameters included reinforcement type (steel, Glass FRP (GFRP), and Basalt FRP (BFRP), bar diameter (16 mm and 20 mm), surface texture (ribbed and sand-coated), and concrete cover (40 mm and 60 mm). The prismatic beams were subjected to target temperatures of 200, 400, and 700 °C, followed by testing in a four-point loading setup. The experimental results revealed that BFRP-reinforced prismatic beams exhibited a 17 % higher residual load-carrying capacity and 32.3 % greater toughness at 200 °C and 400 °C, but a 22 % lower capacity and 26.9 % reduction in toughness at 700 °C compared to their GFRP-reinforced counterparts. Additionally, prismatic beams reinforced with sand-coated GFRP bars showed up to a 27 % improvement in load-carrying capacity compared to those with ribbed GFRP bars, and a larger concrete cover contributed to better overall flexural performance of the prismatic beams under elevated temperatures. © 2025 The Author(s)

关键词： BFRP Elevated temperatures Fire GFRP RC Prismatic beams

来源：评论

学校读者我要写书评

暂无评论

Coherent Acoustic Phonons in Bi2Se3 Ultrathin Films Probed by Femtosecond, Optical Pump-Probe Spectroscopy

Coherent Acoustic Phonons in Bi2Se3 Ultrathin Films Probed b...

引用

CLEO: Fundamental science, CLEO:FS 2024 - Part of Conference on Lasers and Electro-Optics, CLEO 2024

作者： Cheng, Jing Niherysh, Kiryl A. Francis, Peter Chakraborty, Debamitra Lombardi, Floriana Erts, Donats Prischepa, Serghej L. Laszcz, Adam Komissarov, Ivan V. Sobolewski, Roman Materials Science Graduate Program University of Rochester RochesterNY14627 United States Laboratory for Laser Energetics University of Rochester RochesterNY14623-1299 United States Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden Institute of Chemical Physics University of Latvia Riga Latvia Department of Electrical and Computer Engineering University of Rochester RochesterNY14627 United States Dipartimento di Fisica "E.R. Caianiello" Università degli Studi di Salerno Sa FiscianoI-84084 Italy Lukasiewicz Research Network Institute of Microelectronics and Photonics WarszawaPL-02668 Poland

ISBN: (纸本)9781957171395

The dynamics of coherent acoustic phonons in the Bi2Se3 layered crystal system are investigated. The findings reveal that the frequency evolution of breathing modes with the number of the material quintuple layers and the dispersion relation both can be explained by a modified chain model with a nonuniform coupling force. © Optica Publishing Group 2024, © 2024 The Author(s)

关键词： Ultrathin films

来源：评论

学校读者我要写书评

暂无评论

EEG dataset classification using CNN method 5

EEG dataset classification using CNN method

引用

5th International Conference on Technology and Vocational Teachers, ICTVT 2019

作者： Mao, W.-L. Fathurrahman, H.I.K. Lee, Y. Chang, T.W. Department of Electrical Engineering Graduate School of Engineering Science and Technology National Yunlin University of Science and Technology Douliu64002 Taiwan Bachelor Program in Interdisciplinary Studies College of Future National Yunlin University of Science and Technology Taiwan Department of Digital Media Design National Yunlin University of Science and Technology Taiwan

This paper proposes a simple Convolutional Neural Network (CNN) program to classify epileptic seizure. The diagnosis of epileptic seizure involves the identification and different characteristic of the Electroencephalography (EEG) signal. As such, it needs a method for identifying and classifying epileptic seizure. Deep learning is part of a neural network that has the ability and pattern to identify and classify epileptic seizure. CNN has been demonstrated high performance on image classification and pattern detection. In this paper, we combine the continuous wavelet transform (CWT) and CNN to classify epileptic seizure. This experiment uses the wavelet transform to convert signal data of EEG to time-frequency domain images. The output of the wavelet transform is an image that will classify into five attributes. In this experiment, we develop a simple program that will compare with other CNN approach (AlexNet and GoogleNet). The results of this experiment are two kinds of data, accuracy, and loss. The resulting accuracy is 72.49%, and the loss is 0.576. This result has a better learning time than GoogleNet and smaller loss result than AlexNet. © Published under licence by IOP Publishing Ltd.

关键词： Electroencephalography

来源：评论

学校读者我要写书评

暂无评论

Hyperuniformity of maximally random jammed packings of hyperspheres across spatial dimensions

引用

Physical Review E 2023年第6期108卷 064602-064602页

作者： Charles Emmett Maher Yang Jiao Salvatore Torquato Department of Chemistry Princeton University Princeton New Jersey 08544 USA Materials Science and Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA Department of Physics Princeton University Princeton New Jersey 08544 USA Princeton Materials Institute Princeton University Princeton New Jersey 08544 USA Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA

The maximally random jammed (MRJ) state is the most random (i.e., disordered) configuration of strictly jammed (mechanically rigid) nonoverlapping objects. MRJ packings are hyperuniform, meaning their long-wavelength density fluctuations are anomalously suppressed compared to typical disordered systems, i.e., their structure factors S(k) tend to zero as the wave number |k| tends to zero. Here we show that generating high-quality strictly jammed states for Euclidean space dimensions d=3,4, and 5 is of paramount importance in ensuring hyperuniformity and extracting precise values of the hyperuniformity exponent α>0 for MRJ states, defined by the power-law behavior of S(k)∼|k|α in the limit |k|→0. Moreover, we show that for fixed d it is more difficult to ensure jamming as the particle number N increases, which results in packings that are nonhyperuniform. Free-volume theory arguments suggest that the ideal MRJ state does not contain rattlers, which act as defects in numerically generated packings. As d increases, we find that the fraction of rattlers decreases substantially. Our analysis of the largest truly jammed packings suggests that the ideal MRJ packings for all dimensions d≥3 are hyperuniform with α=d−2, implying the packings become more hyperuniform as d increases. The differences in α between MRJ packings and the recently proposed Manna-class random close packed (RCP) states, which were reported to have α=0.25 in d=3 and be nonhyperuniform (α=0) for d=4 and d=5, demonstrate the vivid distinctions between the large-scale structure of RCP and MRJ states in these dimensions. Our paper clarifies the importance of the link between true jamming and hyperuniformity and motivates the development of an algorithm to produce rattler-free three-dimensional MRJ packings.

关键词： Granular solids

来源：评论

学校读者我要写书评

暂无评论

Understanding the effect of preparation technique and compaction pressure on the microstructure, sinterability and mechanical properties of the Cu-20 wt% WC composite prepared with recycled WC

Journal of Alloys and Compounds Communications

引用

Journal of Alloys and Compounds Communications 2025年 6卷

作者： Rafael A. Raimundo Franciné A. Costa Marco A. Morales Daniel A. Macedo Angelus G.P. Silva Uílame U. Gomes Federal University of Paraíba Department of Materials Science and Engineering João Pessoa PB 58051-900 Brazil TEMA – Centre for Mechanical Technology and Automation Department of Mechanical Engineering University of Aveiro Aveiro 3810-193 Portugal Mechanical Engineering Postgraduate Program UFRN Natal 59078-970 Brazil Department of Theoretical and Experimental Physics UFRN Natal 59078-970 Brazil Materials Science and Engineering Postgraduate Program UENF Campos dos Goytacazes 28015-620 Brazil Materials Science and Engineering Postgraduate Program UFRN Natal 59078-970 Brazil

The study investigated the impact of different preparation techniques (Mechanical Mixing - MM and High Energy Milling - HEM) and compaction pressures on the microstructure, sinterability and mechanical properties of the Cu-20 %WC composite using recycled WC. The results indicated that HEM promotes greater homogeneity, dispersion and refinement of the WC phase in copper, resulting in denser and more uniform microstructures after sintering. Although higher pressures increased the density of green compacts, they reduced densification during sintering, especially for powders prepared by MM, due to the segregation of the Cu and WC phases. On the other hand, compacts sintered with HEM powders prsented higher Vickers microhardness and better magnetic properties, attributed to the uniform distribution of WC particles and the increase in the interaction between the phases. Furthermore, the study highlights the influence of metallic impurities (Fe, Co and Ni) on the magnetic properties of the composite materials.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Phase equilibria, thermodynamic assessment, and the mechanical property of B2 phase of the Al-Ga-Ni ternary system

引用

Intermetallics 2024年 165卷

作者： Yang, Chih-han Wu, Fang-yao Lin, Shih-kang Department of Materials Science and Engineering National Cheng Kung University Tainan City70101 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Research Center National Cheng Kung University Tainan City70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan

Ni-based alloys, known for their exceptional mechanical properties and high corrosion resistance in harsh environments, are extensively utilized in gas-turbine engines for propulsion and energy generation. Of particular interests are the L12-Ni3Al and B2-NiAl phases in Al-Ni alloy, which can be the strengthening phases for superalloy and high temperature structural materials, respectively. After Ga addition in the Al-Ni system, these promising intermetallic compounds form a continuous compositional range encompassing the L12-Ni3(Al, Ga) and B2-Ni(Al, Ga) phases. They exhibited distinct mechanical properties contingent on the ratio of Al to Ga. Additionally, Ni and Al are the commonly used substrates in the electronic package and Ga has been used as a filler material for interconnection. Hence, the Al-Ga-Ni phase equilibria are of practical importance for designing L12-Ni3(Al, Ga) and/or B2-Ni(Al, Ga) phase-dispersed Ni-based alloys as well as for evaluating interfacial reactions in the Al/Ga/Ni contacts. However, the Al-Ga-Ni ternary system remains relatively unexplored. In this study, Al-Ga-Ni isothermal sections at 600 (Ni-lean), 900, and 1000 (Ni-rich) °C were experimentally constructed based on equilibrated alloys. Additionally, a CALPHAD-type thermodynamic assessment for the Al-Ga-Ni ternary system was comprehensively performed based on all available experimental information. Furthermore, the Young's modulus and hardness of four B2-Al(Ga, Ni) compounds were determined, revealing that the addition of Ga to B2-NiAl phase would lead to a significant decrease in Young's modulus but a notable enhancement in hardness. © 2023 Elsevier Ltd

关键词： Nickel alloys

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：