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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1113-1125页

作者： Warnakulasuriya Sonal Prashenajith Fernando Mostafa Barzegar-Kalashani Md apel Mahmud Shama Naz Islam Nasser Hossenzadeh Faculty of Engineering and Environment Northumbria UniversityNewcastleUK School of Software and Electrical Engineering Swinburne University of TechnologyHawthornAustralia School of Engineering Deakin UniversityWaurn PondsAustralia

An nonlinear model predictive controller(NMPC)is proposed in this paper for compensations of single line-to-ground(SLG)faults in resonant grounded power distribution networks(RGPDNs),which reduces the likelihood of power line bushfire due to electric *** current compensation(RCC)inverters with arc suppression coils(ASCs)in RGPDNs are controlled using the proposed NMPC to provide appropri-ate compensations during SLG *** proposed NMPC is incorporated with the estimation of ASC inductance,where the estimation is carried out based on voltage and current measure-ments from the neutral point of the power distribution *** compensation scheme is developed in the discrete time using the equivalent circuit of *** proposed NMPC for RCC inverters ensures that the desired current is in-jected into the neutral point during SLG faults,which is veri-fied through both simulations and control hardware-in-the-loop(CHIL)*** results are also presented against an integral sliding mode controller(ISMC)by demon-strating the capability of power line bushfire mitigation.

关键词： Fault current phase voltage nonlinear model predictive controller(NMPC) parameter adaptation parametric uncertainty power line bushfire

多阅片者试验性研究:应用非线性混合千伏影像数据的肝脏双能量CT扫描降低放射剂量的可能性

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国际医学放射学杂志 2011年第3期 298-298页

作者： a.apel J.G.Fletcher J.L.Fidler D.M.Hough L.S.Guimaraes 庞国栋 Department of Radiology Mayo Clinic200 First Street SWRochesterMN 55905USA

目的确定应用曲线性混合千伏影像降低肝脏双能(DE)CT扫描剂量的可能性。材料与方法对34例临床申请采用常规CT剂量指数(CTDIvol)检查的病人,重建其多期对

关键词： X线 CT 放射剂量 X线摄影双能量扫描投照减影技术肝脏

1O2-Mediated and EXECUTER-Dependent Retrograde Plastid-to-Nucleus Signaling in Norflurazon-Treated Seedlings of Arabidopsis thaliana

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Molecular Plant 2013年第5期6卷 1580-1591页

作者： Chanhong Kim Klaus apel Boyce Thompson Institute for Plant Research Ithaca NY 14853-1801 USA

Chloroplast development depends on the synthesis and import of a large number of nuclear-encoded pro- teins. The synthesis of some of these proteins is affected by the functional state of the plastid via a process known as retrograde signaling. Retrograde plastid-to-nucleus signaling has been often characterized in seedlings of Arabidopsis thaliana exposed to norflurazon （NF）, an inhibitor of carotenoid biosynthesis. Results of this work suggested that, throughout seedling development, a factor is released from the plastid to the cytoplasm that indicates a perturbation of plastid homeostasis and represses nuclear genes required for normal chloroplast development. The identity of this factor is still under debate. Reactive oxygen species （ROS） were among the candidates discussed as possible retrograde signals in NF-treated plants. In the present work, this proposed role of ROS has been analyzed. In seedlings grown from the very beginning in the presence of NF, ROS-dependent signaling was not detectable, whereas, in seedlings first exposed to NF after light-dependent chloroplast formation had been completed, enhanced ROS production occurred and, among oth- ers, 1O2-mediated and EXECUTER-dependent retrograde signaling was induced. Hence, depending on the developmental stage at which plants are exposed to NF, different retrograde signaling pathways may be activated, some of which are also active in non-treated plants under light stress.

关键词： retrograde signaling singlet oxygen Executer norflurazon programmed cell death photo-oxidative stress.

Rock fracture density characterization using measurement while drilling(MWD) techniques

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International Journal of Mining Science and Technology 2018年第6期28卷 859-864页

作者： Mohammad Babaei Khorzoughi Robert Hall Derek apel Norman B.Keevil Institute of Mining Engineering University of British Columbia School of Mining and Petroleum Engineering University of Alberta

Accurate determination of rock mass properties is a critical part of open-pit mine planning activities to enable more prescriptive blast designs to achieve improved loading and hauling and downstream process efficiency. Better and more accurate blast practice that delivers enhanced outcomes(better fragmentation, improved diggability, less dilution, etc.) is a critical and fundamental element of being able to achieve an effective Mine-Mill approach at a mining operation. Based on previous work, it has been demonstrated that an accurate representation of the rock mass properties can be obtained from the analysis of variations in blasthole drill performance as derived from measurement while drilling(MWD) systems when using tricone bits. This paper further investigates how monitored rate of penetration,pulldown force, rotary torque, rotary speed and bailing air pressure responses can be used to determine the presence of open and partially open fractures having varying dip angles. Based on a correlation of geophysically measured fracture logs and monitored drill performance variables in the same blastholes, the results show that the latter responses can accurately determine open versus closed fractures. The results also identified that variations in rate of penetration and rotary torque show the most sensitivity in the presence of open fractures that intersect a vertical blasthole at near orthogonal angles.

关键词： Measurement while drilling Fractures Rotary blasthole drill Drill performance variables Fracture frequency Logging

Shear behavior of ultrafine magnetite tailings subjected to freeze-thaw cycles

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International Journal of Mining Science and Technology 2019年第4期29卷 609-616页

作者： Chong Wei Derek B.apel Yunhai Zhang School of Mining and Petroleum Engineering University of AlbertaEdmontonAlberta T6G 2R3Canada School of Resources and Safety Engineering Central South UniversityChangsha 410083China

To study the shear behavior of the ultrafine magnetite tailings subjected to freeze-thaw cycles,unconsolidated-undrained shear tests were conducted on ultrafine-grained tailings that were subjected to 1-11 cycles of freeze-thaw and defined as a type of clayey silt under confining pressures of 100,200,and 300 *** the number of freeze-thaw cycles,cooling temperature,initial dry density,and moisture content as the four main influencing factors of shear behavior of the tailings samples,the shear stress-strain curve,compression modulus,failure strength,cohesion,and internal friction angle were *** results show that the freeze-thaw cycle has an obvious weakening effect on the shear behavior of the tailings material,and the shear mechanical parameters are affected by a combination of confining pressure,freeze-thaw cycle condition,and initial physical-mechanical properties of the tailings *** the microstructural analysis of the tailings samples subjected to freeze-thaw cycles,it shows that the freeze-thaw cycle mainly affects the porosity,bound water,and arrangement of the tailings ***,the macroscopic changes in shear strength indexes emerge,and then the stability of the tailings dam will decrease.

关键词： Ultrafine magnetite tailings(UMT) Freeze-thaw cycle Shear behavior Triaxial shear test

Performance evaluation of near real-time condition monitoring in haul trucks

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International Journal of Mining Science and Technology 2020年第6期30卷 909-915页

作者： Hemanth Reddy Alla Robert Hall Derek B.apel University of Alberta Edmonton T6G 2H5Canada

Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks,and as equipment began to grow more complex towards the end of the 20th century,there was a need for a proactive maintenance strategy,which led to the development of condition-based *** condition monitoring(RTCM)is the ability to perform condition monitoring in real-time and has the ability to alert maintenance and operations of abnormal *** alarms can be used as an indication leading to a problem,and if a suitable corrective action is initiated in time,it could result in significant savings of equipment downtime and repair *** study aims to compare some maintenance performance indicators prior to and after implementation of RTCM strategy at a mine site using some tests of statistical *** study also indicated the presence of seasonality in the data,and thus the data was deseasonalized and detrended prior to being subjected to the statistical ***,the results indicated that RTCM strategy has proven to be successful in improving the availability for some of the failure categories chosen in this study.

关键词： Haul trucks Real-time condition monitoring Performance indicators

Shear properties of cemented rockfills

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 635-644页

作者： Bob A.Lingga Derek B.apel Department of Civil and Environmental Engineering School of Mining and Petroleum University of Alberta

Application of cemented rockfilling to underground mining could not be separated from the corresponding backfill’s shear strength properties. The shear of cemented rockfill(CRF)-rock wall and the shear interaction occurring within CRFs both have some disadvantageous failure chances. In this study,we tried to investigate the complete shear properties of CRFs using direct shear and triaxial tests of cemented granite rockfill. Large-scale triaxial testing was held to accommodate the large CRF *** shear testing on the prepared flat and smooth surfaces was assessed with brief conversions and their corrections were used to approximate the shear strength envelopes of CRF joint interfaces. Two types of CRFs with the same aggregate size and distribution but different unconfined compressive strengths(UCSs) due to different mixture designs indicated insignificant differences between their basic friction angles, and also their asperity inclination angles. Nevertheless, investigation between direct shear test and triaxial test showed that the specimen with higher UCS tended to have a slightly lower friction angle but a higher cohesion than the other one.

关键词： Cemented rockfill (CRF) Shear tests Shear strength Friction angle Cohesion Backfill interface

Machine learning methods for rockburst prediction-state-of-the-art review

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International Journal of Mining Science and Technology 2019年第4期29卷 565-570页

作者： Yuanyuan Pu Derek B.apel Victor Liu Hani Mitri School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2R3Canada Department of Mining and Materials Engineering McGill UniversityMontreal H3A 2T6Canada

One of the most serious mining disasters in underground mines is rockburst *** can lead to injuries and even fatalities as well as damage to underground openings and mining *** has forced many researchers to investigate alternative methods to predict the potential for rockburst ***,due to the highly complex relation between geological,mechanical and geometric parameters of the mining environment,the traditional mechanics-based prediction methods do not always yield precise *** the emergence of machine learning methods,a breakthrough in the prediction of rockburst occurrence has become possible in recent *** paper presents a state-ofthe-art review of various applications of machine learning methods for the prediction of rockburst ***,existing rockburst prediction methods are introduced,and the limitations of such methods are highlighted.A brief overview of typical machine learning methods and their main features as predictive tools is then *** current applications of machine learning models in rockburst prediction are surveyed,with related mechanisms,technical details and performance analysis.

关键词： Rockburst prediction Burst liability Artificial neural network Support vector machine Deep learning

Assessment of digital image correlation method in determining large scale cemented rockfill strains

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International Journal of Mining Science and Technology 2019年第5期29卷 771-776页

作者： Bob A.Lingga Derek B.apel Mohammadali Sepehri Yuanyuan Pu School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2W2Canada

A conventional contact method(using linear transducers)and a non-contact method are deployed to measure the axial and lateral deformations of large scale cylindrical cemented rockfill *** works incorporating two pinhole cameras to create one stereovision by digital image correlation shows that the non-contact method is as reliable for testing large cylindrical specimens as measurements done by using linear variable displacement transformer and string *** this particular large specimen,the experiment resulted in the acceptable mean difference between lateral strain using both methods is 5.1 percent,and 14.5 percent for the axial *** occurrence is inevitable due to the heterogeneity of the concrete system and the placement of the monitoring point in digital image correlation method,although the comparison of stress-strain relationship in both methods still indicates a *** on the results of the present experiments,the authors recommend the noncontact method for a detailed investigation of the material behavior during the uniaxial compressive strength *** field strain measurement enables this digital method to examine local strains near cracks at any point,a very useful tool for studying material deformation behavior.

关键词： Experimental testing Cemented rockfill Digital image correlation Strain measurement Mine backfill

Evaluation of the performance of yielding rockbolts during rockbursts using numerical modeling method

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International Journal of Coal Science & Technology 2022年第6期9卷 25-50页

作者： Jun Wang Derek B.apel Huawei Xu Chong Wei School of Mining and Petroleum Engineering University of AlbertaT6G 2R3 EdmontonABCanada

Rockburst;Rockburst damage;Yielding rockbolt;Numerical modeling;UDEC;Underground miningThe assessment of yielding rockbolt performance during rockbursts with actual seismic loading is essential for rock-burst supporting *** this paper,two types of yielding rockbolts(D-bolt and Roofex)and the fully resin-grouted rebar bolt are modeled via the"rockbolt"element in universal distinct element code(UDEC)after an exact calibration procedure.A two-dimensional(2D)model of a deep tunnel is built to fully evaluate the performance(e.g.,capacity of energy-absorption and control of rock damage)of yielding and traditional rockbolts based on the simulated *** influence of different rockburst magnitudes is also *** results suggest that the D-bolt can effectively control and mitigate rockburst damage during a weak rockburst because of its high strength and deformation *** Roofex is too"soft"or"smooth"to limit the movement of ejected rocks and restrain the large deformation,although it has an excellent deformation *** resin-grouted rebar bolt can maintain a high axial force level during rockbursts but is easy to break during dynamic shocks,which fails to control rapid rock bulking or *** types of rockbolts cannot control the large deformation and mitigate rockburst damage effectively during violent *** rockburst damage severity can be significantly reduced by additional support with cable *** study highlights the effectiveness of numerical modeling methods in assessing the complex performance of yielding rockbolts during rockbursts,which can provide some references to improve and optimize the design of rock supporting in burst-prone grounds.

关键词： Rockburst Rockburst damage Yielding rockbolt Numerical modeling UDEC Underground mining