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Applicability of Gravity Separation Method on the Ashashire Gold Ore Deposit from Benishangul Gumuz Region, Western Ethiopia

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International Journal of Nonferrous Metallurgy 2024年第2期11卷 21-31页

作者： Misganu Kabeta Mulugeta Sisay Cheru Goitom Gebreyohannes Berhe School of Chemical and Bio Engineering Center for Ethio-Mines Development AAiT Addis Ababa University Addis Ababa Ethiopia Mineral Industry Development institute Ministry of Mines Addis Ababa Ethiopia School of Materials Science and Engineering Jimma Institute of Technology Jimma University Jimma Ethiopia College of Natural and Computational Sciences Mekelle University Mekelle Ethiopia

The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide sufficient mass for this study and experiment, including sample preparation, mineralogical analysis of gold and associated elements, gravity concentration, and data interpretation and analysis. During the study, a grind optimization was conducted on the composites sample with varying grind size to evaluate the effect of grind size on gold recovery. The ore was moderately ground to the standard grind size of 80%, passing 106 µm, 75 µm, 53 µm and this nominal size was selected for the preliminary assessment for concentration optimization for this deposit. The gravity testing comprised three-stage concentration using Knelson concentrator. High recovery of gold from the gravity concentrates was achieved from the second gravity concentration. Based on the laboratory experimental result analysis, a grind size of P80 75 µm is selected as optimal size for the Ashashire gold deposit. Increasing the grind size from P80 of 75 µm to 106 µm decreases the recovery rate from 75% to 54%, or decreasing the grind size from P80 of 75 µm to 53 µm decreases the gold recovery rate to 37%. The native gold grain in the ores is mostly associated with quartz and fine gold is closely associated with pyrite. According to analysis of the fire assay, chemical, and mineralogical data, only gold and telluride is commercially valuable elements in the ores. Predominantly gold was occurred in the native form of Au-Te. The sample subjected to gravity separation assayed about 2.6 g/t Au.

关键词： Ore Gangue Ashashire Gravity Method Gold Telluride Concentration Knelson

Multistage analysis method for detection of effective herb prescription from clinical data

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Frontiers of Medicine 2018年第2期12卷 206-217页

作者： Kuo Yang Runshun Zhang Liyun He Yubing Li Wenwen Liu Changhe Yu Yanhong Zhang Xinlong Li Yan Liu Weiming Xu Xuezhong Zhou Baoyan Liu School of Computer and Information Technology and Beijing Key Lab of Traffic data Analysis and Mining Beijing Jiaotong UniversityBeijing 100044 China Guanganmen Hospital. China Academy of Chinese Medical Sciences Beijing 100-053 China institute of Basic Clinical Medicine China Academy of Chinese Medical Sciences Beijing 100700 China data Center of Traditional Chinese Medicine China Academy of Chinese Medical Sciences Beijing 100700 China institute of Basic Theory of Traditional Chinese Medicine ChinaAcademy of Chinese Medical Sciences Beijing 100700 China

Determining effective traditional Chinese medicine （TCM） treatments for specific disease conditions or particular patient groups is a difficult issue that necessitates investigation because of the complicated personalized manifestations in real-world patients and the individualized combination therapies prescribed in clinical settings. In this study, a multistage analysis method that integrates propensity case matching, complex network analysis, and herb set enrichment analysis was proposed to identify effective herb prescriptions for particular diseases （e.g., insomnia）. First, propensity case matching was applied to match clinical cases. Then, core network extraction and herb set enrichment were combined to detect core effective herb prescriptions. Effectiveness-based mutual information was used to detect strong herb symptom relationships. This method was applied on a TCM clinical data set with 955 patients collected from well-designed observational studies. Results revealed that groups of herb prescriptions with higher effectiveness rates （76.9% vs. 42.8% for matched samples; 94.2% vs. 84.9% for all samples） compared with the original prescriptions were found. Particular patient groups with symptom manifestations were also identified to help investigate the indications of the effective herb prescriptions.

关键词： effective prescription detection herb set enrichment analysis core network extraction insomnia personalized treatment

Simulation of goaf heating law and the fire cooling effect during methane drainage in high level laneway

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Journal of Coal Science & Engineering(China) 2013年第3期19卷 325-331页

作者： Xing-Kui LIU Hong-Qing ZHU Peng-Fei LIU safety Engineering Department Henan Institute of Engineering Zhengzhou 451191 China Faculty of Resource and safety Engineering China University of Mining & Technology (Beijing) Beijing 100083 China Heilongjiang Longmay Mining Holding Group Co. Ltd. Harbin 150000 China

For spontaneous combustion possibilities under large flux methane drainage in the goal, dynamic permeability in combination with the Forchheimer nonlinear equation was used to solve the problem of 3D oxygen distribution, heating law in goaf and to forecast the effects of fire protection by taking the fifth section face of the No. 18 coal seam in Nanshan Coal Mine as the basis for this study. The results demonstrate that if the vertical position of the drainage laneway is so low as to cause serious air leakage, a high oxygen concentration area exists in the return side of the goaf, and there is also a high temperature region which has faster heating rate than in the other areas. The effect of methane drainage on goal heating can be alleviated dramatically by simultaneous plugging and nitrogen injection. The results show that gas data in the return side of the goaf must be detected carefully in the work face, which is of similar drainage arrangement. Therefore, comprehensive fire protection measures should be carried out if conditions permit.

关键词： spontaneous combustion drainage laneway high temperature region heating fire protection

Integrated Experimental and Simulation Investigation of Breakdown Voltage Characteristics Across Electrode Configurations in SF_(6) Circuit Breakers

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Journal of Electronic Research and Application 2024年第4期8卷 133-142页

作者： Bo Guan Qi Yu Qingpeng Yuan Shiwen Chen Lailin Chen Su Guo Peilong Zhu Xiangshan Research institute Ningbo University of TechnologyNingbo 315799China Lotus Cars Ningbo 315336China Naisen Electric Ningbo 315712China

This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element *** a sphere-sphere electrode configuration,we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 *** simulations,conducted using COMSOL Multiphysics,mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance *** simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength,electric potential contours,and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 *** the analysis,the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm,identifying the maximum electric field strength.A comprehensive comparison of five different electrode configurations(sphere-sphere,sphere-rod,sphere-plane,rod-plane,rod-rod)at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown ***,the research contrasts the breakdown voltage in SF6 with that in air,emphasizing SF6’s superior insulating *** investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases,steering future advancements in high-voltage circuit breaker technology.

关键词： SF6 circuit breaker Breakdown voltage Electrode configurations COMSOL simulation Electrical insulation

The pitch-catch nonlinear ultrasonic imaging techniques for structural health monitoring

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Science China(Technological Sciences) 2021年第12期64卷 2608-2617页

作者： CHENG JingWei DRINKWATER Bruce W. CHEN XueDong FAN ZhiChao CHEN Wei WANG Zhe National safety Engineering Technology Research Centre for Pressure Vessels and Pipelines Hefei General Machinery Research Institute Co.Ltd.Hefei 230031China Department of Mechanical Engineering University of BristolBristol BS81TRUnited Kingdom

Nonlinear ultrasonic imaging techniques in pulse-echo configuration have recently shown their potential to allow the effective separation of nonlinear and linear features in a nonlinear *** this study,two ultrasonic phased arrays are implemented to produce an image of elastic nonlinearity through the parallel-sequential subtraction of the coherently scattered components in the through-transmission acoustic field at the transmission or subharmonic *** parallel mode,a physical focus at each pixel is achieved by firing the transmitters with a predefined delay *** sequential mode,each transmitter is fired in sequence and all the receivers are employed to capture the data *** full matrix captured data can be post-processed and focused synthetically at the target *** images of parallel focusing and sequential focusing are expected to be linearly identical and hence any differences remained on the subtracted image can be related to the nonlinearities arising from the ***,the imaging metric here is defined as the difference between parallel and sequentially focused amplitudes obtained from forward coherently scattered fields at each target ***,the negative influences due to the instrumentation nonlinearities are investigated by studying the remaining relative phase and amplitude at undamaged pixels.A compensation method is implemented to suppress these noises,significantly enhancing the selectivity of nonlinear scattering *** proposed techniques are then implemented to monitor fatigue crack growth in order to explore the capability of these methods as measures of elastic nonlinearity induced by different sizes of small closed *** promising results suggest that nonlinear imaging can be used to monitor crack growth and improve the detectability at early stages.

关键词： pitch-catch coherent measurement nonlinear imaging fatigue crack monitoring ultrasonic phased array nonlinearities decoupling

Clinical Study of Tianji Robotic-Assisted Surgery for Upper Cervical Spine Fractures

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Natural Science 2024年第9期16卷 150-161页

作者： Chengkua Huang Yuanjian Huang Weikang Yang Qianhou Zhou Xianhai Zeng Junlei Tan Mei Zhang Guosheng Su Sheng Nong Baise City Peoples Hospital (Affiliated Southwest Hospital of Youjiang Medical University for Nationalities) Baise China Graduate School of Yirong National Medical College Baise China The Clinical Laboratory Department of the Peoples Hospital of Guangxi-ASEAN Economic and Technological Development Zone (Nanning No. 10 Peoples Hospital) Nanning China School of public Health Management Youjiang Medical University for Nationalities Baise China

Object: To compare the safety, clinical efficacy, and complication rate of “Tianji” robot-assisted surgery with traditional open surgery in the treatment of cervical vertebrae fracture. Methods: 60 patients with upper cervical vertebrae fracture admitted to Baise People’s Hospital between November 2018 and April 2024 were retrospectively analyzed. Among these patients, 29 underwent “Tianji” robot-assisted surgery (Robot group), and 31 underwent traditional C-arm fluoroscopy-assisted open surgery (Open group). Statistical analysis of the data was performed using SPSS 27.0 software to compare general data (gender, age, BMI), preoperative and postoperative visual analogue scale (VAS) scores, neck disability index (NDI), intraoperative blood loss, accuracy of screw placement on imaging, and the number of complications in both groups for comprehensive evaluation. A P value < 0.05 was deemed to have achieved statistical significance. Results: There was no significant difference in preoperative VAS scores between the two groups (Robot group: 8.34 ± 0.61;Open group: 8.26 ± 0.68, P = 0.317). There was also no significant difference in VAS scores at 1 week postoperatively (Robot group: 6.90 ± 0.31;Open group: 6.94 ± 0.36, P = 0.3237). Preoperative NDI scores showed no significant difference between the two groups (Robot group: 43.31 ± 2.67;Open group: 43.84 ± 2.67, P = 0.2227), and the difference in NDI scores at 1 week postoperatively was also not significant (Robot group: 35.69 ± 4.24;Open group: 37.35 ± 3.48, P = 0.0509). Intraoperative blood loss in the Robot group was significantly lower than in the Open group (246.21 ± 209 ml vs 380.65 ± 328.04 ml, P = 0.0308), with a statistically significant difference. The operation time was longer in the Robot group (3.75 ± 0.74 h) compared to the Open group (2.74 ± 0.86 h). In terms of screw placement accuracy, the Robot group had a higher accuracy rate for Class A screws compared to the Open group (102 screws vs 94 screws, P = 0.0

关键词： Tiangui Robot Assisted Surgery Upper Cervical Spine Fracture Clinical Study Fracture Repair

Risk factors for major gastrointestinal bleeding in the general population in Finland

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World Journal of Gastroenterology 2022年第18期28卷 2008-2020页

作者： Pareen Vora Ronald Herrera Arto Pietila Ulrich Mansmann Gunnar Brobert Markku Peltonen Veikko Salomaa Integrated Evidence Generation Bayer AGBerlin 13353Germany institute for Medical Information Processing Biometryand EpidemiologyLudwig Maximilians UniversitätMunich 81337Germany Pettenkofer School of public Health Ludwig Maximilians UniversitätMunich 81337Germany Department of public Health and Welfare National Institute for Health and Welfare(THL)Helsinki FI-00271Finland Medical Affairs Bayer ABSolna 17165Sweden

BACKGROUND data on non-drug related risk-factors for gastrointestinal bleeding(GIB)in the general population are limited,especially for life-style factors,clinical measurements and laboratory *** To identify and investigate non-drug risk factors for major GIB in the general population of *** We performed a retrospective cohort study using data from the FINRISK health examination surveys,which have been conducted every 5 years across Finland from 1987 to *** were adults aged 25 years to 74 years,excluding those with a previous hospitalization for ***-up from enrollment was performed through linkage to national electronic health registers and ended at an event of GIB that led to hospitalization/death,death due to any other cause,or after 10 *** included demographics,socioeconomic and lifestyle factors,clinical measurements,laboratory parameters and *** selection was undertaken using Least Absolute Shrinkage and Selection Operator(LASSO)and factors associated with GIB were identified using Cox *** Among 33,508 participants,403(1.2%)experienced GIB[256 men(63.5%);mean age,56.0 years(standard deviation(SD)±12.1)]and 33105 who did not experience GIB[15768 men(47.6%);mean age,46.8(SD±13)years],within 10 years of *** associated with a significantly increased risk of GIB were baseline age[per 10-year increase;hazard ratio(HR)1.62,95%confidence interval(CI):1.42-1.86],unemployment(HR:1.70,95%CI:1.11-2.59),body mass index(BMI)(HR:1.15,95%CI:1.01-1.32),gamma-glutamyl transferase(GGT)(HR:1.05,95%CI:1.02-1.09),precursors of GIB(HR:1.90,95%CI:1.37-2.63),cancer(HR:1.47,95%CI:1.10-1.97),psychiatric disorders(HR:1.32,95%CI:1.01-1.71),heart failure(HR:1.46,95%CI:1.04-2.05),and liver disorders(HR:3.20,95%CI:2.06-4.97).Factors associated with a significantly decreased risk of GIB were systolic blood pressure(SBP)(HR:0.78,95%CI:0.64-0.96),6-10 cups of coffee a day(HR:0.67,95%CI:0.46-0

关键词： Risk factors Gastrointestinal hemorrhage General population Finland Life style Population health

Governance interactions of spatial data infrastructures: an agent-based modelling approach

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International Journal of Digital Earth 2021年第6期14卷 696-713页

作者： Jaap-Willem Sjoukema Jalal Samia Arnold K.Bregt Joep Crompvoets Laboratory of Geo-Information Science and Remote Sensing Wageningen University&ResearchWageningenThe Netherlands KU Leuven public Governance institute LeuvenBelgium Department of Geography and Urban Planning University of MazandaranBabolsarIran

In order to facilitate and coordinate spatial data sharing and exchange,many organisations have developed spatial data infrastructures(SDIs).SDI governance plays a pivotal role in the development and evolution of an SDI,but as SDIs are complex adaptive systems,governing is a *** research therefore proposes a complexity perspective to SDI governance by exploring the use of agent-based modelling to simulate and examine SDI governance *** this agent-based simulation,we examine interactions between SDI stakeholders,data availability and the effects of different governance styles(hierarchical,network and laissez-faire governance)and budget *** simulation shows that it is possible to mimic SDI governance dynamics through agent-based *** running different scenarios,it appears that a network approach is more successful compared to a hierarchical or laissez-faire *** validation shows that overall the results of the simulation are credible and insightful,although improvements can be made to make the model more *** agent-based modelling,SDI governance becomes more tangible and visible,which facilitates discussion and ***-based modelling therefore appears to be a helpful new approach in a better understanding of the complexities and dynamics of SDI governance.

关键词： Governance spatial data infrastructure(SDI) agentbased modelling funding models complex adaptive systems

Statistical Modelling of Extreme Precipitation Indices Supporting Urban Spatial Planning Processes

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Journal of Environmental Science and Engineering(A) 2024年第3期13卷 90-99页

作者： Annunziata Palermo Lucia Chieffallo Elenio Avolio Department of Civil Engineering University of CalabriaRende 87036Italy institute of Atmospheric Sciences and Climate National Research CouncilLamezia Terme 88046Italy

In this paper,we analyze how statistical modelling of extreme precipitation indices can support urban planners in the analysis and classification of the level of climate sensitivity of the territory and in the subsequent definition of sustainable adaptive planning and design *** activities are part of a research project that addresses the issue of climate change from the urban planning perspective to identify solutions to current and future environmental challenges,increasing the climate resilience of infrastructures and communities in urban,rural and coastal *** research activities are based on the desire to promote integration between the approaches commonly adopted by urban planners and climate specialists to plan adequate joint risk reduction *** part of this study,the focus will be on the risks produced by the greater frequency and intensity of floods,assessed by the IPCC(Intergovernmental Panel on Climate Change)as one of the key risks for ***,our attention focuses on pluvial flooding,proposing the definition of a statistical modelling of indices related to extreme precipitation and its application to the context of the Calabria Region,in *** indices are recommended by the ETCCDI(Expert Team on Climate Change Detection and Indices)and elaborated starting from official historical data recorded by 146 telemetry active rain gauges,disseminated in the experimentation context.

关键词： Urban areas climate change extreme precipitation