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Automated bolting and meshing on a continuous miner for roadway development

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International Journal of Mining Science and Technology 2013年第1期23卷 55-61页

作者： van duin Stephen Meers Luke Donnelly Peter Oxley Ian University of Wollongong Northfields Avenue Gwynneville NSW Australia

Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining. Although the broader manufacturing sector has benefited from automation, several challenges exist within the Australian underground coal industry which makes it difficult to fully exploit these technologies. At the University of Wollongong a series of reprogrammable electromechanical manipulators have been designed to overcome these challenges and automatically handle the installation of roof and rib containment consumables on a continuous miner. The automated manipulation removes personnel from hazards in the immediate face area, particularly those associated with working in a confined and unstable working environment in close proximity to rotating and moving equipment. In a series of above ground trials the automated system was successfully demonstrated without human intervention and proven to be capable of achieving cycle times at a rate of 10 m per operating hour, consistent with that required to support high capacity longwall mines. The trials also identified a number of refinements which could further improve both cycle times and system reliability when considering the technology for underground use. The results have concluded that conventional manual handling practices on a continuous miner can be eliminated, and that the prototypes have significantly reduced the technical risk in proceeding to a full underground trial.

关键词： Automation Robotics Roadway development Manipulation Roof support

Enhanced interface strength in steel-nickel bimetallic component fabricated using wire arc additive manufacturing with interweaving deposition strategy

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Journal of Materials Science & Technology 2020年第17期52卷 226-234页

作者： Bintao Wu Zhijun Qiu Zengxi Pan Kristin Carpenter Tong Wang Donghong Ding Stephen van duin Huijun Li Key Laboratory of Ningxia for Photovoltaic Material Ningxia UniversityYinchuan750021China School of Mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongWollongongNSW2522Australia School of Mechatronic Engineering Foshan UniversityFoshan528000China

Realizing improved strength in composite metallic materials remains a challenge using conventional welding and joining systems due to the generation and development of brittle intermetallic compounds caused by complex thermal profiles during ***,wire arc additive manufacturing(WAAM)process was used to fabricate a steel-nickel structural component,whose average tensile strength of 634 MPa significantly exceeded that of feedstock materials(steel,537 MPa and nickel,455 MPa),which has not been reported *** as-fabricated sample exhibited hierarchically structural heterogeneity due to the interweaving deposition *** improved mechanical response during tensile testing was due to the inter-locking microstructure forming a strong bond at the interface and solid solutions strengthening from the intermixing of the Fe and Ni increased the interface strength,beyond the sum of *** research offers a new route for producing high-quality steel-nickel dissimilar structures and widens the design opportunities of monolithic components,with site-specific properties,for specific structural or functional applications.

关键词： Wire arc additive manufacturing(WAAM) Steel-nickel bimetallic-component Interweaving deposition Material properties

Enhancing the Faradaic efficiency of solid oxide electrolysis cells: progress and perspective

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npj Computational Materials 2023年第1期9卷 803-816页

作者： Prashik S.Gaikwad Kunal Mondal Yun Kyung Shin Adri C.T.van duin Gorakh Pawar Department of Material Science and Manufacturing Engineering Idaho National LaboratoryIdaho FallsID 83415USA Department of Mechanical Engineering Pennsylvania State UniversityUniversity ParkPA 16802USA

To reduce global warming,many countries are shifting to sustainable energy production *** oxide electrolysis cells(SOECs)are being considered due to their high hydrogen generation ***,low faradaic efficiency in scaling SOEC technology affects costs and limits large-scale adoption of hydrogen as *** review covers SOECs’critical aspects:current state-of-the-art anode,cathode,and electrolyte materials,operational and materials parameters affecting faradaic efficiency,and computational modeling techniques to resolve bottlenecks affecting SOEC faradaic efficiency.

关键词： shifting electrolyte solid

Skewed superstatistical distributions from a Langevin and Fokker-Planck approach

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Chinese Science Bulletin 2011年第34期56卷 3633-3638页

作者： van DER STRAETEN erik BECK Christian Queen Mary University of London School of Mathematical Sciences

The superstatistics concept is a useful statistical method to describe inhomogeneous complex systems for which a system parameter βfluctuatesonalargespatio-temporal scale. Inthispaper weanalyze ameasuredtimeseriesofwindspeed fluctuationsandextract the superstatistical distribution function f(β) directly from the data. We construct suitable Langevin and Fokker-Planck models with a position dependent β-field and show that they reduce to standard type of superstatistics in the overdamped limit.

关键词：普朗克复杂系统统计方法时间尺度分布函数位置相关不均匀过阻尼

INDEEDopt:a deep learning-based ReaxFF parameterization framework

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npj Computational Materials 2021年第1期7卷 610-618页

作者： Mert Y.Sengul Yao Song Nadire Nayir Yawei Gao Ying Hung Tirthankar Dasgupta Adri C.T.van duin Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPAUSA Department of Statistics and Biostatistics Rutgers UniversityNew BrunswickNJUSA Department of Mechanical Engineering The Pennsylvania State UniversityUniversity ParkPAUSA Department of Physics Karamanoglu Mehmetbey UniversityKaramanTurkey Two-Dimensional Crystal Consortium(2DCC) Materials Research InstituteThe Pennsylvania State UniversityUniversity ParkPAUSA

Empirical interatomic potentials require optimization of force field parameters to tune interatomic interactions to mimic ones obtained by quantum chemistry-based *** optimization of the parameters is complex and requires the development of new ***,we propose an INitial-DEsign Enhanced Deep learning-based OPTimization(INDEEDopt)framework to accelerate and improve the quality of the ReaxFF *** procedure starts with a Latin Hypercube Design(LHD)algorithm that is used to explore the parameter landscape *** LHD passes the information about explored regions to a deep learning model,which finds the minimum discrepancy regions and eliminates unfeasible regions,and constructs a more comprehensive understanding of physically meaningful parameter *** demonstrate the procedure here for the parameterization of a nickel–chromium binary force field and a tungsten–sulfide–carbon–oxygen–hydrogen quinary force *** show that INDEEDopt produces improved accuracies in shorter development time compared to the conventional optimization method.

关键词： optimization chromium nickel

Atomistic fracture in bcc iron revealed by active learning of Gaussian approximation potential

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npj Computational Materials 2023年第1期9卷 135-145页

作者： Lei Zhang Gábor Csányi erik van der Giessen Francesco Maresca Engineering and Technology Institute Groningen Faculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AG GroningenThe Netherlands Engineering Laboratory University of CambridgeCambridge CB21PZUK Zernike Institute for Advanced Materials University of GroningenNijenborgh 49747 AG GroningenThe Netherlands

The prediction of atomistic fracture mechanisms in body-centred cubic(bcc)iron is essential for understanding its semi-brittle *** atomistic simulations of the crack-tip under mode-I loading based on empirical interatomic potentials yield contradicting predictions and artificial *** enable fracture prediction with quantum accuracy,we develop a Gaussian approximation potential(GAP)using an active learning strategy by extending a density functional theory(DFT)database of ferromagnetic bcc *** apply the active learning algorithm and obtain a Fe GAP model with a converged model uncertainty over a broad range of stress intensity factors(SIFs)and for four crack *** learning efficiency of the approach is analysed,and the predicted critical SIFs are compared with Griffith and Rice *** simulations reveal that cleavage along the original crack plane is the atomistic fracture mechanism for{100}and{110}crack planes at T=0 K,thus settling a long-standing *** work also highlights the need for a multiscale approach to predicting fracture and intrinsic ductility,whereby finite temperature,finite loading rate effects and pre-existing defects(e.g.,nanovoids,dislocations)should be taken explicitly into account.

关键词： approximation potential apply

Self-expandable metal stents for malignant gastric outlet obstruction: A pooled analysis of prospective literature

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World Journal of Gastroenterology 2015年第43期21卷 12468-12481页

作者： Emo E van Halsema erik AJ Rauws Paul Fockens Jeanin E van Hooft Department of Gastroenterology and Hepatology Academic Medical Center

AIM: To provide an overview of the clinical outcomes of self-expandable metal stent(SEMS) placement for malignant gastric outlet obstruction(MGOO).METHODS: A systematic literature search was performed in Pub Med of the literature published between January 2009 and March 2015. Only prospective studies that reported on the clinical success of stent placement for MGOO were included. The primary endpoint was clinical success,defined according to the definition used in the original article. Data were pooled and analyzed using descriptive statistics. Subgroup analyses were performed for partially covered SEMSs(PCSEMSs) and uncovered SEMSs(UCSEMSs) using Fisher's exact ***: A total of 19 studies,including 1281 patients,were included in the final analysis. Gastric(42%) and pancreatic(37%) cancer were the main causes of MGOO. UCSEMSs were used in 76% of patients and PCSEMSs in 24%. The overall pooled technical success rate was 97.3% and the clinical success rate was 85.7%. Stent dysfunction occurred in 19.6% of patients,mainly caused by re-obstruction(12.6%) and stent migration(4.3%),and was comparable between PCSEMSs and UCSEMSs(21.2% vs 19.1%,respectively,P = 0.412). Re-obstruction was more common with UCSEMSs(14.9% vs 5.1%,P < 0.001) and stent migration was more frequent after PCSEMS placement(10.9% vs 2.2%,P < 0.001). The overall perforation rate was 1.2%. Bleeding was reported in 4.1% of patients,including major bleeding in 0.8%. The median stent patency ranged from 68 to 307 d in five studies. The median overall survival ranged from 49 to 183 d in 13 ***: The clinical outcomes in this large population showed that enteral stent placement was feasible,effective and safe. Therefore,stent placement is a valid treatment option for the palliation of MGOO.

关键词： Stents Gastric outlet obstruction Stomach neoplasm

Increasing phosphorus fertilizer value of recycled iron phosphates by prolonged flooding and organic matter addition

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Pedosphere 2024年第3期34卷 631-640页

作者： Rochelle Joie SARACANLAO Hannah van RYCKEL Mieke VERBEECK Maarten EVERAERT erik SMOLDERS Division of Soil and Water Management Department of Earth and Environmental ScienceKU LeuvenKasteelpark Arenberg 20Heverlee B-3001(Belgium) Soil Service of Belgium.Willem De Croylaan 48 Leuven 3001(Belgium)

Iron(Fe)minerals are commonly used to remove phosphorus(P)from waste streams,producing P-loaded Fe(Ⅲ)oxides or Fe(Ⅱ)phosphate minerals(e.g.,vivianite).These minerals may be used as fertilizers to enhance P circularity if solubilized in ***,we tested the P fertilizer value of recycled Fe phosphates(FePs)in a pot trial and in an incubation experiment,hypothesizing that P release from FePs is possible under Fe(Ⅲ)-reducing ***,a pot trial was set up with rice(Oryza sativa)in all combinations of soil flooding or not,three P-deficient soils(acid,neutral,and calcareous),and six FePs(three Fe(Ⅲ)Ps and three Fe(Ⅱ)Ps)referenced to triple superphosphate(TSP)or zero *** P uptake responded to TSP application in all treatments but only marginally to *** redox potential did not decrease to-200 mV by flooding for a brief period(13 d)during the pot trial.A longer incubation experiment(60 d)was performed,including a treatment of glutamate addition to stimulate reductive conditions,and P availability was assessed with CaCl_(2)extraction of *** addition and/or longer incubation lowered soil redox potential to<-100 *** the longer term,Fe(Ⅲ)minerals released P,and adequate P was reached in the calcareous soil and in the neutral soil amended with Fe(Ⅲ)*** can be concluded that prolonged soil flooding and organic matter addition can enhance the P fertilizer efficiency of ***,application of FeP in powder form may enhance P availability.

关键词： agronomic efficiency circular economy P-loaded Fe(Ⅲ)oxides paddy soil vivianite redox

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初始碳烟颗粒形成的反应分子动力学模拟

工程热物理学报 2017年第5期38卷 1087-1091页

作者：毛倩罗开红 van duin Adri C.T. 清华大学燃烧能源中心和热科学与动力工程教育部重点实验室北京100084 英国伦敦大学学院机械工程系美国宾夕法尼亚州立大学机械与核能工程系宾夕法尼亚州16802

本文采用ReaxFF反应分子动力学模拟的方法研究了温度对PAH生成初始碳烟颗粒的路径的影响。低温时(400 K),PAH单体分子通过物理成核的方式形成初始碳烟颗粒。中等温度时(1600 K),PAH只能形成二聚物或三聚物,无法发生从气相单体到固相碳... 详细信息

本文采用ReaxFF反应分子动力学模拟的方法研究了温度对PAH生成初始碳烟颗粒的路径的影响。低温时(400 K),PAH单体分子通过物理成核的方式形成初始碳烟颗粒。中等温度时(1600 K),PAH只能形成二聚物或三聚物,无法发生从气相单体到固相碳烟颗粒的转变。当温度升高到2500 K,PAH通过化学成核形成碳烟颗粒,PAH分子首先分解形成碳链分子,碳链分子相互链接进一步形成富勒烯结构的碳烟颗粒。

关键词：多环芳烃(PAH) 碳烟成核 ReaxFF 分子动力学模拟(MD)