检索结果-内蒙古大学图书馆

Numerical investigation of granular flow similarity in rotating drums

Particuology 2015年第5期13卷 119-127页

作者： Huabiao Qi Ji Xu Guangzheng Zhou Feiguo Chen Wei Ge Jinghai Li State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences University of Chinese Academy of Sciences

The theory of flow similarity has not been well established for granular flows, in contrast to the case for conventional fluids, owing to a lack of reliable and general constitutive laws for their continuum descrip- tion. A rigorous investigation of the similarity of velocity fields in different granular systems would he valuable to theoretical studies. However, experimental measurements face technological and physical problems. Numerical simulations that employ the discrete element method （DEM） may be an alterna- tive to experiments by providing similar results, where quantitative analysis could be implemented with virtually no limitation. In this study, the similarity of velocity fields is investigated for the rolling regime of rotating drums by conducting simulations based on the DEM and using graphics processing units. For a constant Froude number, it is found that the particle-to-drum size ratio plays a dominant role in the determination of the velocity field, while the velocity field is much more sensitive to some material properties than to others. The implications of these findings are discussed in terms of establishing theoretical similarity laws for granular flows.

关键词： Discrete element method Granular flow Similarity Rotating drum Scale up Graphics processing unit

来源：评论

学校读者我要写书评

暂无评论

Residual-Evasive Attacks on ADMM in Distributed Optimization

arXiv

引用

arXiv 2025年

作者： Bruckmeier, Sabrina Mo, Huadong Qin, James Ciyu Graduate School of Mathematics ETH Zurich Zurich Switzerland School of Systems and Computing University of New South Wales NSW Australia Reliability and Risk Engineering Laboratory Institute of Energy and Process Engineering Department of Mechanical and Process Engineering ETH Zurich Zurich Switzerland

This paper presents two attack strategies designed to evade detection in ADMM-based systems by preventing significant changes to the residual during the attacked iteration. While many detection algorithms focus on identifying false data injection through residual changes, we show that our attacks remain undetected by keeping the residual largely unchanged. The first strategy uses a random starting point combined with Gram-Schmidt orthogonalization to ensure stealth, with potential for refinement by enhancing the orthogonal component to increase system disruption. The second strategy builds on the first, targeting financial gains by manipulating reactive power and pushing the system to its upper voltage limit, exploiting operational constraints. The effectiveness of the proposed attack-resilient mechanism is demonstrated through case studies on the IEEE 14-bus system. A comparison of the two strategies, along with commonly used naive attacks, reveals trade-offs between simplicity, detectability, and effectiveness, providing insights into ADMM system vulnerabilities. These findings underscore the need for more robust monitoring algorithms to protect against advanced attack strategies. © 2025, CC BY-NC-ND.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Enhanced glycerol steam reforming using Ni-doped CaZrO3, SrZrO3, and BaZrO3 perovskite oxides

引用

International Journal of Hydrogen Energy 2025年 128卷 574-588页

作者： Luisetto, Igor Charisiou, Nikolaos D. Tsiotsias, Anastasios I. Latsiou, Angeliki I. Siakavelas, Georgios Sebastian, Victor Zhang, Runduo Di Bartolomeo, Elisabetta Polychronopoulou, Kyriaki Goula, Maria A. Department of Energy Technologies Production Conversion and Efficient Use of Energy Division Process and Energy Systems Engineering Laboratory ENEA Research Center Casaccia S.M. di Galeria Rome00123 Italy Department of Chemical Engineering University of Western Macedonia GR-50100 Greece Department of Chemical Engineering and Environmental Technology Universidad de Zaragoza Campus Río Ebro-Edificio I+D Zaragoza50018 Spain Universidad de Zaragoza- CSIC c/ María de Luna 3 Zaragoza50018 Spain Networking Research Center on Bioengineering Biomaterials and Nanomedicine CIBERBBN Madrid28029 Spain State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical Technology Beijing100029 China Department of Chemical Science and Technologies University of Rome Tor Vergata Via della Ricerca Scientifica 1 Rome00133 Italy Center for Catalysis and Separations Khalifa University of Science and Technology Abu DhabiP.O. Box 127788 United Arab Emirates Department of Mechanical Engineering Khalifa University of Science and Technology Abu DhabiP.O. Box 127788 United Arab Emirates

This study investigates the catalytic activity and time-on-stream stability of Ni catalysts supported on CaZrO3, SrZrO3, and BaZrO3 perovskite oxides for the glycerol steam reforming (GSR) reaction, which aims to convert the crude glycerol obtained from the transesterification of vegetable and microalgae oils (during bio-diesel production) into hydrogen gas. We employed XRD, N2 physisorption, H2-TPR, H2 pulse chemisorption, CO2-TPD, Raman, TPO, and TEM/HAADF-STEM to examine the surface and bulk properties of the catalysts before and after the reaction. Regarding catalytic activity evaluation, the Ni catalysts supported on CaZrO3 and SrZrO3 can effectively eliminate all liquid products (acetol, acetone, allyl alcohol, acetaldehyde, and acetic acid) at reaction temperatures higher than 500 °C, converting all glycerol to gaseous products (>6 mol H2/mol of glycerol for the best performing Ni/SrZrO3). This is due to a higher Ni dispersion, increased availability of active sites for the dissociation of C3H8O and H2O molecules, and a more favorable and stronger Ni-support interaction. Notably, the activity of Ni supported on SrZrO3 is among the highest reported in the literature. Furthermore, due to its unique Ni-support interaction, the Ni catalyst supported on SrZrO3 demonstrated remarkable catalytic stability. Apparently, some Ni2+ cations are solubilized into the perovskite lattice following high-temperature calcination. After being incorporated into the perovskite lattice, these cations then migrate to the surface via the exsolution process upon high-temperature reduction. During the glycerol steam reforming reaction, this helps prevent carbon growth on the exposed metallic Ni surface, thereby prolonging the catalyst lifetime and ensuring reliable H2 production during long-term operation and under harsh reaction conditions. © 2025 Hydrogen Energy Publications LLC

关键词： Steam

来源：评论

学校读者我要写书评

暂无评论

Extending EMMS-based models to CFB boiler applications

引用

Particuology 2012年第6期10卷 663-671页

作者： Bona Lu Nan Zhang Wei Wang Jinghai Li State Key Laboratory of Multi-phase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Recently, EMMS-based models are being widely applied in simulations of high-throughput circulating fluidized beds （CFBs） with fine particles. Its use for low flux systems, such as CFB boiler （CFBB）, still remains unexplored. In this work, it has been found that the original definition of cluster diameter in EMMS model is unsuitable for simulations of the CFB boiler with low solids flux. To remedy this, we propose a new model of cluster diameter. The EMMS-based drag model （EMMS/matrix model） with this revised cluster definition is validated through the computational fluid dynamics （CFD） simulation of a CFB boiler.

关键词： EMMS Cluster Circulating fluidized bed Boiler CFD Simulation

来源：评论

学校读者我要写书评

暂无评论

Open semantic revision control with R43ples: Extending SPARQL to access revisions of named graphs 2016

Open semantic revision control with R43ples: Extending SPARQ...

引用

12th International Conference on Semantic systems, SEMANTiCS 2016

作者： Graube, Markus Hensel, Stephan Urbas, Leon Department of Process Control Systems Engineering Technische Universität Dresden Germany

ISBN: (纸本)9781450347525

The Semantic Web provides mechanisms to interlink data in a fast and efficient way and build complex information networks. However, one of the most important features missing for industrial application is version control which allows recording changes and rolling them back at any time if necessary. It is not sufficiently supported by today's triplestores and recent version control systems are not very well integrated into the Semantic Web. This paper shows a way of dealing with version and revision control using SPARQL. It presents R43ples as an approach using named graphs for semantically storing the differences between revisions. Furthermore it allows a direct access and manipulation of revisions with extended version of SPARQL. Smart mechanisms for restoring old revisions relying on query rewriting provide a fast way of querying old revisions of big datasets. A prototypical implementation of the system prove an appropriate performance under different conditions. © 2016 Copyright held by the owner/author(s).

关键词： Semantic Web

来源：评论

学校读者我要写书评

暂无评论

RETROFIT OF SOPHISTICATED control INTO AN EXISTING CHEMICAL COMPLEX.

RETROFIT OF SOPHISTICATED CONTROL INTO AN EXISTING CHEMICAL ...

引用

Proceedings - Thirty-Ninth Annual Symposium on Instrumentation for the process Industries.

作者： Groves, D.M. Exxon Chemical Co Process Control Systems Baytown TX USA Exxon Chemical Co Process Control Systems Baytown TX USA

ISBN: (纸本)0876648014

This paper examines the retrofit of a sophisticated control system into an existing petrochemical complex. Exxon has been pursuing modern process control systems development since the early 1960's. These systems generally include improved instrumentation, control computers, and the expanded use of analyzers, all aimed at improved higher level control. In the 1963-1965 time frame, Exxon began to explore the use of electronic instrumentation coupled with computers.

关键词： CHEMICAL PLANTS

来源：评论

学校读者我要写书评

暂无评论

USER INTERFACES FOR MATHEMATICAL-PROGRAMMING BASED MULTIPURPOSE PLANT OPTIMIZATION systems

引用

COMPUTERS & CHEMICAL engineering 1995年第0期19卷 S765-S772页

作者： SHAH, N KURIYAN, K LIBERIS, L PANTELIDES, CC PAPAGEORGIOU, LG RIMINUCCI, P Centre for Process Systems Engineering Imperial College London SW7 2BY UK.

This paper is concerned with the design and implementation of an integrated software package for the optimisation of general multipurpose batch and semi-continuous plants. In particular, we describe a sophisticated graphical user interface that supports the rapid specification of scheduling, planning, design and retrofit problems in an error-free manner. These problems are posed graphically and solved under a unified framework based on the state-task network process representation and a general characterisation of all production resources, such as processing and storage equipment, utilities and manpower. This representation facilitates the specification of processing recipes of arbitrary complexity, involving material recyles, shared intermediates, batch splitting and mixing and multiple routes to the same end-product. The architecture employed shields the users from the complex mathematical. models and solution procedures that are employed, freeing lip their time for problem specification and results analysis.

关键词： PRODUCTION SCHEDULING PLANT DESIGN GRAPHICAL USER-INTERFACES

来源：评论

学校读者我要写书评

暂无评论

Architectures for integrating functional safety into modular process plants 9

Architectures for integrating functional safety into modular...

引用

9th IFAC Symposium on Fault Detection, Supervision and Safety for Technical processes, SAFEprocess 2015

作者： Pfeffer, Annett Urbas, Leon Department of Process Control Systems Engineering Technische Universität Dresden Germany

As an approach to cope with rising volatility of sales markets and increasingly shorter development cycles, process industries are expecting much from the concept of modularization. However, a topic that is still rarely focused in this context is safety. Therefore, this paper is focused on the expected challenges of engineering functional safety including the architectures of safety instrumented systems, and the requirements of modularization. Possible architectures are presented and discussed in relation to the requirements of functional safety in modular process plants. © 2015, IFAC (International Federation of Automatic control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Safety engineering

来源：评论

学校读者我要写书评

暂无评论

TOWARDS A SPECIALIZED SHELL FOR DIAGNOSTIC EXPERT systems FOR CHEMICAL-PLANT

引用

JOURNAL OF LOSS PREVENTION IN THE process INDUSTRIES 1988年第2期1卷 84-91页

作者： VENKATASUBRAMANIAN, V Intelligent Systems in Process Engineering Laboratory Department of Chemical Engineering Columbia University NY 10027 USA

Recent developments on the application of artificial intelligence (Al) concepts and techniques for the automation of chemical process fault diagnosis has met with some success. However, the process of developing such systems, called knowledge engineering, is time-consuming and expensive involving specialized labour. This bottleneck presents a serious barrier that must be overcome if the benefits of Al-based approaches are to be realized at large in the process industry. Towards that goal, we present an analysis of the knowledge engineering process in the context of process diagnosis and a possible solution strategy. By viewing the knowledge engineering activity at different levels of abstraction, one is able to identify how the different aspects of the bottleneck emerge and also clarify methodological issues from formalization- and implementation-related ones. The analysis suggests that a specialized environment or shell, that already possesses the diagnostic methodology and the related modelling constructs, is the natural way of circumventing the bottleneck. As a potential knowledge core of such a shell, a diagnostic methodology that has the characteristics to facilitate rapid prototyping, easy modification, and maintenance of diagnostic expert systems is described.

关键词： expert systems fault administration modelling

来源：评论

学校读者我要写书评

暂无评论

R43ples: Revisions for triples an approach for version control in the semantic web 1

R43ples: Revisions for triples an approach for version contr...

引用

1st Workshop on Linked Data Quality, LDQ 2014, Co-Located with 10th International Conference on Semantic systems, SEMANTiCS 2014

作者： Graube, Markus Hensel, Stephan Urbas, Leon Department for Process Control Systems Engineering Technische Universität Dresden Germany

For most use cases, the Semantic Web provides essential mechanisms to interlink data in a fast and efficient way. However, it is still not widely accepted in industry since some important features are not mature enough. Requirements include easier model transformation and access to dynamic data. One of the most missing important features is version control which would make it possible to record changes in a way that they can be rolled back at any time. Recent version control system are not very well integrated into the Semantic Web. This paper shows a novel way of dealing with version control for Linked Data. It presents R43ples as an approach using named graphs to semantically store the differences between revisions. Furthermore it allows direct access and manipulation of revisions with SPARQL. Thus, the access is almost transparent for the clients which can still use known SPARQL queries enhanced with some additional keywords. A prototypical implementation of the system shows a proof of concept and performance considerations. Copyright is held by the author/owner(s).

关键词： Linked data Named graphs Query Revision SPARQL Versioning

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：