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Effect of cylinder wall parameters on the final packing density of mono-disperse spheres subject to three-dimensional vibrations Author links open overlay panel

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Particuology 2024年第8期91卷 211-225页

作者： Jack r.Grogan Andrei L.Nicuşan christopher r.k.windows-yule School of chemical Engineering The University of BirminghamEdgbastonBirminghamB152TTUK

Achieving densely packed particles is desirable within the industries of ceramics,pharmaceuticals,defence and additive *** this work,we use the discrete element method(DEM)to determine the effect of wall parameters on the final packing density of mono-disperse spheres subject to 4 varying three-dimensional vibration and fill *** focus specifically on the impact of the container wall parameters on the particles'final packing *** on from the validation of the DEM simulation the particle-wall coefficient of restitution,the particle-wall coefficient of rolling friction and the particle-wall coefficient of sliding friction were varied individually and the effect on the final packing density *** relatively low particle-particle friction glass beads,the effect of these wall properties had no discernible effect on the final packing density *** on from these findings the particle-wall properties were varied at the extreme values of particle-particle coefficient of rolling friction and particle-particle coefficient of sliding *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of restitution resulted in a minor increase in the final packing density of particles though this was not statistically *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of rolling friction resulted in a minor decrease in the final packing density of the particles though again not to a degree where the trend can,with complete certainty,be distinguished from the random error across the ***,when the particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of sliding friction resulted in a significant decrease in the final packing density of *** decrease was attributed to the propagation of force chains throughout the *** significant decrease in final packing density with

关键词： Vibropacking Packing Densification Vibration Discrete element method Friction Wall friction restitution

Positron Emission Projection Imaging:A technique for concentration field measurements in opaque industrial systems

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Particuology 2024年第11期94卷 1-15页

作者： roberto Hart-Villamil Jack Sykes Andy Ingram christopher r.k.windows-yule Santosh kumar Gupta School of chemical Engineering University of BirminghamB152TTUK School of Physics and Astronomy University of BirminghamB152TTUK Hindustan Unilever r&D BengaluruKarnataka560066India

A novel Positron Emission Projection Imaging(PEPI)algorithm designed to compute the plane-projected spatial distribution of radiolabelled materials without the need for collimation is *** leveraging improved data efficiency,we have achieved a technique with enhanced spatial resolution and temporal resolution compared to previous PEPI *** of this algorithm was conducted using synthetic data generated from a digital twin of a PET scanner,demonstrating its accuracy for practical *** industrial advantage of this novel algorithm was applied in the imaging of laminar flow mixing within a ploughshare mixer,with the experimental results compared against those obtained from validated computational fluid dynamics(cFD)*** comparison highlights an important use case for PEPI as a robust validation tool for cFD simulations,crucial for enhancing industrial ***,which uses deeply penetrating gamma-photons,is now capable of imaging opaque fluids and solids in industrial *** directions for this work include further algorithmic refinements and expanding its application across various industrial systems,establishing PEPI as a robust tool for in-depth industrial process *** advancements presented here allow for optimized mixer design and enhanced process efficiency,extending the frontiers of tomographic imaging in industrial applications.

关键词： Positron emission projection imaging Positron emission particle tracking computational fluid dynamics Mixing Ploughshare mixer

Evaluation of coarse-grained cFD-DEM models with the validation of PEPT measurements

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Particuology 2023年第11期82卷 48-63页

作者： Hanqiao che Dominik Werner Jonathan Seville Tzany kokalova Wheldon kit windows-yule School of chemical Engineering University of BirminghamB152TTUK School of Physics and Astronomy University of BirminghamBirminghamB152TTUK

computational Fluid Dynamics coupled with Discrete Element Method (cFD-DEM) is a commonly used numerical method to model gas-solid flow in fluidised beds and other multiphase systems. A significant limitation of cFD-DEM is the feasibility of the realistic simulation of large numbers of particles. coarse-graining (cG) approaches, through which groups of multiple individual particles are represented by single, larger particles, can substantially reduce the total number of particles while maintaining similar system dynamics. As these three cG models have not previously been compared, there remains some debate, however, about the best practice in the application of cG in cFD-DEM simulations. In this paper, we evaluate the performance of three typical cG methods based on simulations of a bubbling fluidised bed. This is achieved through the use of a numerical validation framework, which makes full use of the high-resolution 3D positron emission particle tracking (PEPT) measurements to rigorously validate the outputs of cFD-DEM simulations conducted using various different coarse-graining models, and various different degrees of coarse-graining. The particle flow behaviours in terms of the particle occupancy field, velocity field, circulation time, and bubble size and velocity, are comprehensively analysed. It is shown that the cG simulation starts to fail when the size ratio between the bed chamber and the particles decreases to approximately 20. It is also observed, somewhat surprisingly, that the specific cG approach applied to interparticle contact parameters does not have a substantial effect on the simulation results for the bubbling bed simulations across a wide range of cG factors.

关键词： coarse-graining Discrete element method computational fluid dynamics cFD-DEM Positron emission particle tracking(PEPT) Bubbling fluidised bed

Modulation of phase boundary and domain structures to engineer strain properties in BNT-based ferroelectrics

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Journal of Advanced ceramics 2024年第7期13卷 967-975页

作者： yule Yang Zhiyong Liu Pengrong ren Yuqing Mao Haijun Sun Bingliang Liang Pu Mao kun Guo Bing Xie Longlong Shu School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China School of Materials Science and Engineering Xi'an University of TechnologyXi’an 710048China School of Aircraft Engineering Nanchang Hangkong UniversityNanchang 330063China School of Physics and Materials Science Nanchang UniversityNanchang 330031China

Bismuth sodium titanate(BNT)ceramics exhibit outstanding strain responses but are unfavorable for application in high-sensitivity displacement actuators due to the large negative strain resulting from irreversible changes in their phase transition and domain ***,(1−x)Bi_(0.50)Na_(0.41)k_(0.09)TiO_(3)-xNaNbO_(3)(BNkT−xNN)solid solutions were prepared to improve the strain properties through the strategy of modulating the phase boundary and domain *** introduction of sodium niobate could effectively regulate the relative content of the tetragonal(P4bm)and rhombohedral(r3c)phases in the phase boundary *** ferroelectric-to-relaxor phase transition(T_(F−r))was reduced,and the ergodic relaxor(Er)state was nurtured at room *** zero-negative strain properties of S=0.41%and d_(33)^(*)=742 pm/V were achieved from the reversible transition between the Er and ferroelectric states under an applied electric field(x=0.04).Additionally,understanding the domain states via piezoelectric force microscopy(PFM)and firstorder reversal curve(FOrc)revealed that the superior strain responses originated from the reversible inter-transformation of substable macrodomains and polar nanoregions(PNrs)in the phase *** study provides new insight into the interplay between the evolution of phase boundaries and domain structures and the strain properties of BNT-based ceramics.

关键词： bismuth sodium titanate(BNT) domain structure phase boundary strain response relaxor state

Expression of human hepatitis c virus core antigen in tobacco plants by tobacco mosaic virus-based vector system

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chinese Science Bulletin 2000年第1期45卷 44-48页

作者： HAN Aidong LIU yule XIAO Li kANG Liangyi ZHANG Yuman LI Dongtian TIAN Bo Institute of Microbiology Chinese Academy of SciencesBeijing 100080China Tianjin Medical University Tianjin 300070China

Tobacco mosaic virus (TMV) has the potential to highly express foreign gene. A novel TMV-based in trans expression system was constructed. A TMV mutant TSHc had its coat protein replaced with hepatitis c vir黶 (HcV) core antigen gene. Anotherr TMV mutant TSBD was repli-case-defective. coinfection of the two mutants could cause systemic infection in tobacco plants by in trans complementation of their functions. TSHc could effectively replicate and assemble to viral particles, which were a little longer than that of wild-type TMV. HcV core antigen was expressed in whole tobacco plants. A similar expression level of HcV core antigen was detected on serial passages, which suggested that this viral expression system be stable.

关键词： TMV vector complementation systemic infection HcV core antigen.

Using a global reference sample set and a cropland map for area estimation in china

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Science china Earth Sciences 2017年第2期60卷 277-285页

作者： yule LI Xuecao LI congcong ZHAO YuanYuan NIU ZhenGuo HUANG HuaBing WANG Jie cHENG YuQi LU Hui SI YaLi YU chaoQing FU HaoHuan GONG Peng Ministry of Education key Laboratory for Earth System Modeling Center for Earth System ScienceTsinghua UniversityBeoing 100084China Joint center for Global change Studies Beijing 100875China State key Laboratory of remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100101China Ministry of Education key Laboratory for Geospatial Technology for the Middle and Lower Yellow river regions college of Environment and Planning Henan UniversityKaifeng 475004China

A technically transparent and freely available reference sample set for validation of global land cover mapping was recently established to assess the accuracies of land cover maps with multiple *** sample set can be used to estimate areas because of its equal-area hexagon-based sampling *** capabilities of these sample set-based area estimates for cropland were investigated in this paper.A 30-m cropland map for china was consolidated using three thematic maps(cropland,forest and wetland maps)to reduce confusion between cropland and forest/*** compared three area estimation methods using the sample set and the 30 m cropland *** methods investigated were:(1)pixel counting from a complete coverage map,(2)direct estimation from reference samples,and(3)model-assisted estimation combining the map with *** results indicated that all three methods produced generally consistent estimates which agreed with cropland area measured from an independent national land use *** estimated from the reference sample set were less biased by comparing with a National Land Use Dataset of china(NLUD-c).This study indicates that the reference sample set can be used as an alternative source to estimate areas over large regions.

关键词： cropland mapping Sampling china 30 meters

A novel signal processing algorithm for measurement while drilling（MWD） system

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A novel signal processing algorithm for measurement while dr...

cotton Leaf curl Multan virus c4 protein suppresses both transcriptional and post-transcriptional gene silencing by interacting with SAM synthetase

第40届中国控制会议

作者： ShiLong cheng yule Hu School of Automation China University of Geosciences Hubei key Laboratory of Advanced control and Intelligent Automation for complex Systems Engineering research center of Intelligent Technology for Geo-Exploration Ministry of Education Faculty of Engineering China University of Geosciences

Measurement while drilling（MWD） is a widely used signal transmission technology in the drilling *** present,the domestic pulse identification method is relatively simple,using the basic threshold method to identify,only set the threshold which will leading a number of missing detection mud pulse in the complex working *** this paper,a novel data processing algorithm is proposed for measurement while drilling *** method designed in this paper identifies the start time of data frame by using correlation coefficient and synchronization head model,then,based on the principle that the amplitude of mud pulse signal is larger than that of noise pulse signal,the maximum pulse signal in the length of a group of mud pulse series is extracted as mud pulse *** simulation is executed using the data from the actual drilling process and the results show the effectiveness of the proposed method.

关键词： Measurement while drilling Pulse recognition correlation coefficient Sliding time window

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Cotton Leaf Curl Multan virus C4 protein suppresses both tra...

Influence of La3+ ion in the yttria matrix in improving the microhardness of infrared transparent nano LaxY2-xO3 sintered via hybrid heating

2018全国植物生物学大会

作者： Asigul Ismayil Yakupjan Haxim yule Liu MOE key Laboratory of Bioinformatics Center for Plant BiologyTsinghua-Peking Joint Center for Life SciencesSchool of Life SciencesTsinghua University

Gene silencing is a natural antiviral defense mechanism in *** effective infection,plant viruses encode viral silencing suppressors to counter this plant antiviral *** geminivirus-encoded c4 protein has been identified as a gene silencing suppressor,but the underlying mechanism of action has not been ***,we report that cotton Leaf curl Multan virus(cLcuMuV) c4 protein interacts with S-adenosyl methionine synthetase(SAMS),a core enzyme in the methyl cycle,and inhibits SAMS enzymatic *** contrast,an r13 A mutation in c4 abolished its capacity to interact with SAMS and to suppress SAMS enzymatic *** of wild-type c4,but not mutant c4 r13 A,suppresses both transcriptional gene silencing(TGS) and posttranscriptional gene silencing(PTGS).Plants infected with cLcuMuV carrying c4 r13 A show decreased levels of symptoms and viral DNA accumulation associated with enhanced viral DNA ***,silencing of NbSAMS2 reduces both TGS and PTGS,but enhanced plant susceptibility to two geminiviruses cLcuMuV and Tomato yellow leaf curl china *** data suggest that cLcuMuV c4 suppresses both TGS and PTGS by inhibiting SAMS activity to enhance cLcuMuV infection in plants.

关键词： Geminivirus c4 SAM synthetase gene silencing

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Journal of Advanced ceramics 2017年第3期6卷 240-250页

作者： Jijimon k. THOMAS Mathew c. T. Jacob kOSHY Sam SOLOMON Electronic Materials research Laboratory Department of Physics Mar Ivanios College Thiruvananthapuram 695015 Kerala India

In the present work, hybrid sintering technique which couples the resistive heating and microwave heating is employed to sinter infrared transparent La0.15Y1.85O3 to 99.2% of the theoretical density for the first time to the best of our knowledge. The presence of La3+ in the yttria matrix improves the hardness properties to a greater extent without affecting the transmittance properties, but there is a deterioration in the thermal properties of the sample. So we have limited our studies to La0.15Y1.85O3 which shows better optical, thermal, and hardness properties. The pellets fabricated from the ultra-fine nano powder with average particle size of ~12 nm synthesized by combustion technique and sintered at 1430 ℃ with an average grain size of 0.22 μm show ~80.1% transmittance in the UV–visible region and 81% in mid infrared region. For a comparative study of the optical, mechanical, and thermal properties, two other variants of sintering strategies namely conventional sintering and microwave sintering are also employed. A comprehensive analysis on the hardness reveals that the hardness of the pellets sintered via hybrid heating is 9.73 GPa and is superior to the pellets sintered using the other two techniques. The thermal conductivity of the sample is also analyzed in detail. The results clearly indicate that the La0.15Y1.85O3 ultra-fine nano powder synthesised by the single-step combustion method and sintered via microwave hybrid heating shows better transmittance properties without compromising the mechanical properties, and can be used very effectively for the fabrication of infrared transparent windows and domes.

关键词： La3+ concentration microhardness hybrid sintering infrared transparent ceramics thermal conductivity