检索结果-南通市图书馆

Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1346-1353页

作者： Jens müller Sebastian Leonow Johannes Schulz Christian Hansen martin monnigmann Ruhr-Universitat Bochum Universit atsstraûe 150Bochum44801Germany SeePeX GmbH Scharnh olzstraûe 344Bottrop46240Germany

This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation.

关键词： Backflow Progressing cavity pump Virtual sensor Wear

维普期刊数据库

A reduced model for particle calcination for use in Dem/CFD simulations

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第10期93卷 316-327页

作者： Lucas mieg Torben Bergold enric Illana mahiques Viktor Scherer martin mönnigmann Automatic Control and System Theory Ruhr University BochumGermany energy Plant Technology Ruhr University BochumGermany

We treat the accurate simulation of the calcination reaction in particles,where the particles are large and,thus,the inner-particle processes must be *** these processes need to be described with coupled partial differential equations(PDes)that must be solved numerically,the computation times for a single particle are too high for use in simulations that involve many *** of this type arise when the Discrete element method(Dem)is combined with Computational Fluid Dynamics(CFD)to investigate industrial systems such as quicklime production in lime shaft *** show that,based on proper orthogonal decomposition and Galerkin projection,reduced models can be derived for single particles that provide the same spatial and temporal resolution as the original PDe models at a considerably reduced computational *** the finite volume particle models with the reduced models results in an overall reduction of the reactor simulation time by about 40%for the sample system treated here.

关键词： Calcination Reactive bulk model reduction Discrete element method Galerkin projection

In situ apatite and carbonate Lu-Hf and molybdenite Re-Os geochronology for ore deposit research:method validation and example application to Cu-Au mineralisation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第5期15卷 339-354页

作者： Alexander Simpson Stijn Glorie martin Hand Sarah e.Gilbert Carl Spandler marija Dmitrijeva Greg Swain Angus Nixon Jacob mulder Carsten münker Department of earth Sciences University of AdelaideSA 5005Australia mineral exploration Cooperative Research Centre University of AdelaideSA 5005Australia Adelaide microscopy University of AdelaideSA 5005Australia Fortescue Level 287Adelaide TerraceEast PerthWA 6005Australia Institute of Geology und mineralogy University of Köln50674 KölnGermany British Geological Survey NottinghamUK

The development of laser ablation inductively coupled plasma quadrupole tandem mass spectrometry(LA-ICP-Q-mS/mS)opens new opportunities to rapidly date a variety of hydrothermal *** we present in situ Lu-Hf and Re-Os dates for hydrothermal apatite and molybdenite,*** further report the first in situ Lu-Hf dates for bastnäsite,dolomite,and siderite,and assess their potential for constraining ore deposit *** method validation,we report isotope-dilution Lu-Hf dates for apatite reference material Bamble-1(1102±5 ma)and calcite reference material me-1(1531±7 ma),enabling improved accuracy on matrix-matched calibration for LA-ICP-mS/mS Lu-Hf *** new methods are applied to the Vulcan Iron-Oxide Copper-Gold(IOCG)prospect in the Olympic Cu-Au Province of South *** deposits have been difficult to accurately date,given the general lack of reliable mineral geochronometers that are cogenetic with IOCG *** apatite Lu-Hf dates and molybdenite Re-Os dates demonstrate that mineralisation at Vulcan largely occurred at ca.1.6 Ga,contemporaneous with the world class Olympic Dam *** data also indicates that the Lu-Hf system in apatite is more robust than the U-Pb system for determining the timing of primary apatite formation in an IOCG *** further demonstrate that dolomite can retain Lu-Hf growth ages over an extended time period(>1.5 billion years),providing constraints on the timing of primary ore mineral crystallisation during brecciation and IOCG ***,late Neoproterozoic(ca.589–544 ma)and Carboniferous(ca.334±7 ma)Lu-Hf dates were obtained for texturally late Cubearing carbonate veins,illustrating that the carbonate Lu-Hf method allows direct dating of Cu remobilisation *** has important implications for mineral exploration as the remobilised Cu may have been transferred to younger deposits hosted in Neoproterozoic sedimentary basins overlaying the Olympic IOCG provi

关键词： Reaction-cell ICP-mS In-situ geochronology Lu-Hf Re-Os Iron Oxide Copper Gold metal fluids

enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第2期76卷 62-73页

作者： m Setodeh Kheirabady m K Tavassoly m Rafeie e Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of electrical engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a Bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. more interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement Bell-statemeasurement

维普期刊数据库

CO_(2)capture costs of chemical looping combustion of biomass:A comparison of natural and synthetic oxygen carrier

在线全文

学校读者我要写书评

暂无评论

Journal of energy Chemistry 2024年第5期92卷 296-310页

作者： Benjamin Fleiß Juraj Priscak martin Hammerschmid Josef Fuchs Stefan müller Hermann Hofbauer Institute of Chemical Environmental and Bioscience EngineeringTU WienVienna1060 ViennaAustria BeST–Bioenergy and Sustainable Technologies GmbH Graz8010 StyriaAustria

Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate *** this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of *** commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid *** oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural *** determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was *** synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were *** techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic *** synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling *** comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.

关键词： Chemical looping combustion BeCCS Techno-economic assessment CO_(2)capture costs Oxygen carrier development Synthetic materials Ilmenite

维普期刊数据库

Dynamic convergent shock compression initiated by return current in high-intensity laser-solid interactions

在线全文

学校读者我要写书评

暂无评论

matter and Radiation at extremes 2024年第4期9卷 40-53页

作者： Long Yang martin Rehwald Thomas Kluge Alejandro LasoGarcia Toma Toncian Karl Zeil Ulrich Schramm Thomas e.Cowan Lingen Huang Helmholtz-Zentrum Dresden-Rossendorf 01328 DresdenGermany Technische Universitat Dresden 01062 DresdenGermany

We investigate the dynamics of convergent shock compression in solid cylindrical targets irradiated by an ultrafast relativistic laser *** particle-in-cell simulations and coupled hydrodynamic simulations reveal that the compression process is initiated by both magnetic pressure and surface ablation associated with a strong transient surface return current with density of the order of 10^(17) A/m^(2) and lifetime of 100 *** results show that the dominant compression mechanism is governed by the plasma β,i.e.,the ratio of thermal pressure to magnetic *** targets with small radius and low atomic number Z,the magnetic pressure is the dominant shock compression *** to a scaling law,as the target radius and Z increase,the surface ablation pressure becomes the main mechanism generating convergent ***,an indirect experimental indication of shocked hydrogen compression is provided by optical shadowgraphy measurements of the evolution of the plasma expansion *** results presented here provide a novel basis for the generation of extremely high pressures exceeding Gbar(100 TPa)to enable the investigation of high-pressure physics using femtosecond J-level laser pulses,offering an alternative to nanosecond kJ-laser pulse-driven and pulsed power Z-pinch compression methods.

关键词： shock convergent return

Identifying the validity domain of machine learning models in building energy systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

energy and AI 2024年第1期15卷 328-341页

作者： martin Rätz Patrick Henkel Phillip Stoffel Rita Streblow Dirk müller RWTH Aachen University E.ON Energy Research CenterInstitute for Energy Efficient Buildings and Indoor ClimateMathieustraβe 10Aachen52074Germany

The building sector significantly contributes to climate *** improve its carbon footprint,applications like model predictive control and predictive maintenance rely on system ***,the high modeling effort hinders practical *** learning models can significantly reduce this modeling *** ensure a machine learning model’s reliability in all operating states,it is essential to know its validity *** states outside the validity domain might lead to extrapolation,resulting in unpredictable *** paper addresses the challenge of identifying extrapolation in data-driven building energy system models and aims to raise knowledge about *** that,a novel approach is proposed that calibrates novelty detection algorithms towards the machine learning *** novelty detection algorithms are identified through a literature review and a benchmark test with 15 candidates.A subset of five algorithms is then evaluated on building energy ***,on two-dimensional data,displaying the results with a novel visualization *** on more complex multi-dimensional use *** methodology performs well,and the validity domain could be *** visualization allows for a profound analysis and an improved understanding of the fundamental effects behind a machine learning model’s validity domain and the extrapolation regimes.

关键词： extrapolation detection Validity domain Novelty detection machine learning Artificial neural network Data-driven model predictive control Building energy systems

Comprehensive euler/Lagrange modelling including particle erosion for confined gas-solid flows

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第1期84卷 209-235页

作者： Guiherme A.Novelletto Ricardo martin Sommerfeld multiphase Flow Systems Institute of Process EngineeringOtto-von-Guericke-University MagdeburgHoher Weg 7b06120Halle(Saale)Germany

The present research aims to assess the capability of a comprehensive euler/Lagrange approach for predicting gas-solid flows and the associated solid particle *** open-source code OpenFOAm®4.1 was used to carry out the numerical simulations,where the standard Lagrangian libraries were substantially extended to account for all necessary *** are tracked considering both translational and rotational motion as well as all relevant forces,such as gravity/buoyancy,drag and transverse lift due to shear and particle *** tracking time step was dynamically adapted ac-cording to the locally relevant time scales,which drastically reduces computational *** approaches are adopted to model particle turbulent dispersion,particle collisions with rough walls and particle-particle *** solid particle erosion models,available in the literature,were considered to estimate pipe bend *** study cases are provided to validate the adopted nu-merical approach and erosion models *** first case intends to evaluate the ability of the extended CFD code to predict the behaviour of gas-solid flows in pneumatic conveying *** goal is achieved by comparing the numerical results with the experimental data obtained by Huber(1997)and Huber and Sommerfeld(1994,1998)in a pneumatic conveying ***,the importance of considering inter-particle collisions and surface roughness for predicting particle velocity,mass flux and mean diameter distributions in gas-solid flows is *** second and third case intend to evaluate the ability of the erosion models in estimating bend erosion in diluted gas-solid *** erosion data obtained experimentally by mazumder et al.(2008)and Solnordal et al.(2015)in very dilut pneumatic conveying systems is used for validating the numerical results,neglecting now inter-particle collisions and two-way *** a comprehensive analysis of the different influential properti

关键词： Pneumatic conveying Pipe bend Numerical calculation(CFD) euler/Lagrange approach erosion models Wall roughness

Novel Framework for an Intrusion Detection System Using multiple Feature Selection methods Based on Deep Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 948-958页

作者： A.e.m.eljialy mohammed Yousuf Uddin Sultan Ahmad Department of Information Systems College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia Department of Computer Science College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabiaand also with University Center for Research and Development(UCRD)Department of Computer Science and EngineeringChandigarh UniversityPunjabIndia

Intrusion detection systems (IDSs) are deployed to detect anomalies in real time. They classify a network’s incoming traffic as benign or anomalous (attack). An efficient and robust IDS in software-defined networks is an inevitable component of network security. The main challenges of such an IDS are achieving zero or extremely low false positive rates and high detection rates. Internet of Things (IoT) networks run by using devices with minimal resources. This situation makes deploying traditional IDSs in IoT networks unfeasible. machine learning (mL) techniques are extensively applied to build robust IDSs. many researchers have utilized different mL methods and techniques to address the above challenges. The development of an efficient IDS starts with a good feature selection process to avoid overfitting the mL model. This work proposes a multiple feature selection process followed by classification. In this study, the Software-defined networking (SDN) dataset is used to train and test the proposed model. This model applies multiple feature selection techniques to select high-scoring features from a set of features. Highly relevant features for anomaly detection are selected on the basis of their scores to generate the candidate dataset. multiple classification algorithms are applied to the candidate dataset to build models. The proposed model exhibits considerable improvement in the detection of attacks with high accuracy and low false positive rates, even with a few features selected.

关键词： random forest feature selection decision tree software-defined network logistic regression intrusion detection system XGB classifier AdaBoost