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Journal of Environmental Sciences 2006年第2期18卷 263-269页

作者： Awni T. Batayneh hani A. Qassas Geophysics Division Natural Resources Authority P.O. Box 7 Amman Jordan. Energy and Water Department Arab Potash Co mpany Ghor Safi Jordan

The demand for water resources in the area south of the Dead Sea due to continued development, especially at the Arab Potash Company （APC） for production and domestic purposes necessitates that water quality in the area be monitored and evaluated based on the local geology and hydrogeology. The objective of this paper is to monitor seasonal fluctuations of groundwater and to determine how fluctuation in the water levels will affect the groundwater quality. Groundwater levels were found to be influenced by rainfall and pumping of water from the wells for domestic and industrial use. Twenty water samples were collected from different wells and analyzed for major chemical constituents both in pre- and post-seasons to determine the quality variation. Chemical constituents are significantly increased after post-season recharge. According to the overall assessment of the area, water quality was found to be useful for drinking, irrigation and industry.

关键词： water level fluctuations seasonal variations quality Dead Sea coastal aquifers Jordan

高精度经颅直流电刺激联合上肢机器人对缺血性脑卒中上肢功能的效果

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中国康复理论与实践 2025年第2期31卷 218-224页

作者：王潇珺王哈妮俞红李元梅周煜达浙江中医药大学附属康复医院(浙江康复医疗中心) 康复评定与治疗中心浙江杭州市310051 浙江中医药大学附属康复医院(浙江康复医疗中心)神经康复科浙江杭州市310051

目的探讨高精度经颅直流电刺激(HD-tDCS)联合上肢机器人对缺血性脑卒中上肢功能的影响。方法2023年1月至2024年3月,选择浙江康复医疗中心住院治疗缺血性脑卒中后伴上肢功能障碍患者56例,随机分为对照组和试验组,每组28例。两组均接受综... 详细信息

目的探讨高精度经颅直流电刺激(HD-tDCS)联合上肢机器人对缺血性脑卒中上肢功能的影响。方法2023年1月至2024年3月,选择浙江康复医疗中心住院治疗缺血性脑卒中后伴上肢功能障碍患者56例,随机分为对照组和试验组,每组28例。两组均接受综合治疗和上肢机器人训练,对照组给予伪HDtDCS,试验组给予HD-tDCS,共4周。分别于治疗前后采用Fugl-Meyer评定量表上肢部分(FMA-UE)、Wolf运动功能测试(WMFT)、改良Barthel指数(MBI)进行评定,记录经颅磁刺激运动诱发电位皮质振幅、皮质潜伏期和中枢运动传导时间(CMCT),并进行相关性分析。结果治疗后,两组FMA-UE、WMFT、MBI评分,皮质振幅、皮质潜伏期和CMCT明显改善(t>3.177,P3.610,P0.448,P<0.001)。结论HD-tDCS可进一步提高患者上肢运动功能和日常生活活动能力,并改善皮质脊髓运动传导功能。

关键词：缺血性脑卒中上肢高精度经颅直流电刺激康复机器人运动诱发电位

Determination of mining-induced stresses using diametral rock core deformations

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International Journal of Coal Science & Technology 2022年第6期9卷 13-24页

作者： Yizhuo Li hani S.Mitri Department of Mining and Materials Engineering McGill UniversityMontrealCanada

Knowledge of ground stresses is crucial for ground control activities such as the design of underground openings,selec-tion of support systems,and analysis for ***,it is a known fact that far field stresses experience changes in orientation and magnitude due to the presence of geological structures and due to the excavations created by mining *** a result,in-situ stresses around drifts,ramps,and stopes in underground mines are quite different from far field or pre-mining *** purpose of this research is to develop a simple and practical methodology for determining in-situ *** relief occurs once the rock core is drilled *** relief is a function of the surrounding stress *** study uses exploration rock cores that are drilled off for the purpose of orebody definition in the underground *** method measures and analyzes the diametral core deformations in *** case studies from operating underground mines are presented for *** these case studies,rock core deformations are measured with a customized test apparatus and rock samples were prepared and tested for Young's modulus and Poisson's *** differential stress,namely the difference between the local principal stresses in the plane perpendicular to the core rock axis is *** is shown that this methodology is useful for determining the brittle shear ratio in the rock mass,which is of primary interest to ground control studies.

关键词： In-situ stresses Rock core diametral deformation Strain relief Core-based stress measurement Brittle shear ratio

Quantitative analysis with plastic strain indicators to estimate damage induced by fault-slip

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 1-10页

作者： Atsushi Sainoki hani S.Mitri International Research Organization for Advanced Science and Technology Kumamoto University Department of Mining and Materials Engineering McGill University

In the present study, methodologies to evaluate damage around an underground opening due to seismic waves arising from mining-induced fault-slip are examined. First, expressions for an associated flow rule with a failure criterion are developed for biaxial stress conditions, which are implemented into FLAC3D code. A three-dimensional(3D) mine model encompassing a fault running parallel to a steeply dipping orebody is constructed, whereby static and dynamic analyses are performed to extract stopes and simulate fault-slip in dynamic condition, respectively. In the analysis, the developed biaxial model is applied to the stope wall. The fault-slip simulation is performed, considering shearing of fault surface asperities and resultant stress drop driving the fault-slip. Two methodologies to evaluate damage caused by seismic waves arising from the simulated fault-slip are examined:(i) the ratio of dynamic plastic strain increment to elastic strain limit and(ii) plastic strain energy density. For the former one, two types of strain increments are tested, namely effective shear strain increment and volumetric strain *** results indicate that volumetric strain increment is a suitable index for detecting damage near the stope wall, while effective shear strain increment is appropriate for evaluating damage in backfill. The evaluation method with plastic strain energy density is found to be capable of assessing damage accumulated in an extensive area caused by rock mass oscillation due to seismic wave propagation. Possible damage to mine developments in the proximity of a stope is clearly described with the index. The comparison of the two methods clarifies that the former one assesses "instantaneous" damage, which is found to be different from "accumulated" damage calculated using plastic strain energy density, in terms of damage area and its location. It is thus concluded that the combination of the two methodologies leads to more accurate damage assessment as a pr

关键词： Stability of mine opening Mining-induced fault-slip Seismic waves Biaxial stress condition

Towards high-entropy alloys with high-temperature corrosion resistance and structural stability

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Journal of Materials Science & Technology 2024年第7期174卷 133-144页

作者： Meifeng Li hani Henein Chungen Zhou Jing Liu Department of Chemical and Material Engineering University of AlbertaEdmonton T6G 2R3AlbertaCanada Department of Materials Science and Engineering Beihang UniversityBeijing 100191China

Complex component alloys(CCAs)consisting of multiple principal elements potentially encompass su-perior mechanical properties and good corrosion *** high-entropy alloys(EHEAs)stand out from CCAs as the desired candidates for high-temperature(HT)applications due to the combined advantages of HEA alloys and unique equilibrium eutectic *** work first explores the ther-modynamic calculation route toward HEAs with eutectic *** of pseudo-binary diagrams of transition metal(TM)CCAs were calculated with the Calphad approach to locate the potential eutectic *** representatives of a CrFeCoNi_(2.2)Al alloy with eutectic structure and a non-eutectic CrFeCoNiCu alloy were cast,and their HT performance was further evaluated by hot corrosion with Na_(2)SO_(4)+25 wt%NaCl molten salts at 700,800 and 900℃,*** HT degradation mechanism was explicitly revealed from a comprehensive thermodynamic *** between the HT performance and the inherent physicochemical properties of the constituent phases and the alloying components were addressed for the first *** was found that the mixing enthalpy(△H_(mix))and valance electron concen-tration(VEC)played more decisive roles in the hot corrosion resistance than the mixing entropy(△S_(mix))of CCAs.A strategy for tailoring and developing HEAs for HT application by modulating alloy chemistry and microstructural features was proposed.

关键词： CCAs HEAs EHEAs Hot corrosion Phase stability Calphad

Laboratory investigation into the use of soundless chemical demolitions agents for the breakage of hard rock

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International Journal of Coal Science & Technology 2022年第5期9卷 71-80页

作者： Kelly‑Meriam Habib Isaac Vennes hani Mitri Department of Mining and Material Engineering McGill UniversityMontrealCanada

The method of drilling and blasting with explosives is widely used in rock fragmentation applications in the mining industry for mine development and ore ***,the use of explosives is associated with rigorous safety and environmental constraints as blasting creates toxic fumes,ground vibrations,and *** study is focused on the use of Soundless Chemical Demolition Agents(SCDA)as a more environmentally friendly method for rock breakage and a potential replacement of *** this paper,the results of a series of experimental tests are reported to identify the efect of SCDA on hard rock breakage under no load and under uniaxial loading *** granite prismatic specimens of 152.4 mm(6″)×152.4–203.2 mm(6–8″)×406.4 mm(16″)are used to test the infuence of borehole size on the time to fracturing with SCDA borehole size of 25.4 mm(1″),31.75 mm(1.25″)and 38.1 mm(1.5″).It is shown that the fracturing time decreases with increasing borehole *** is also shown that specimens subjected to uniaxial compression of 5 MPa fracture as early as 7 h after SCDA mixing.A borehole spacing to borehole diameter ratio of 12.8 to 14.6 is suggested for practical applications.

关键词： Explosive-free Hard rock fragmentation Soundless chemical demolition agents Uniaxial loading

Large-scale destress blasting for seismicity control in hard rock mines:A case study

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International Journal of Mining Science and Technology 2020年第2期30卷 141-149页

作者： Isaac Vennes hani Mitri Damodara Reddy Chinnasane Mike Yao Department of Mining and Materials Engineering McGill UniversityMontrealQuebec H3A 0E8Canada Copper Cliff Mine Vale Canada LtdSudbury P0M 1N0Canada

Destress blasting is a rockburst control technique where highly stressed rock is blasted to reduce the local stress and stiffness of the rock,thereby reducing its burst *** technique is commonly practiced in deep hard rock mines in burst prone developments,as well as in sill or crown pillars which become burst-prone as the orebody is ***-scale destressing is a variant of destress blasting where panels are created parallel to the orebody strike with a longhole,fanning blast pattern from cross cut drifts situated in the host *** aim of panel destressing is to reduce the stress concentration in the ore blocks or pillars to be *** paper focuses on the large-scale destress blasting program conducted at Vale's Copper Cliff Mine(CCM)in Ontario,*** merits of panel destressing are examined through field measurements of mining induced stress changes in the *** destressing mechanism is simulated with a rock fragmentation factor(a)and stress reduction/dissipation factor(b).A 3D model is built and validated with measured induced stress *** is shown that the best correlation between the numerical model and field measurements is obtained when the combination of a and b indicates that the blast causes high fragmentation(a=0.05)and high stress release(b=0.95)in the destress *** is demonstrated that the burst proneness of the ore blocks in the panel stress shadow is reduced in terms of the brittle shear ratio(BSR)and the burst potential index(BPI).

关键词： Destress blasting Preconditioning Rockbursts Strainbursts Numerical modeling

Methodology for the estimation of expansive cement borehole pressure

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International Journal of Mining Science and Technology 2023年第1期33卷 73-81页

作者： Kelly-Meriam Habib Isaac Vennes hani S.Mitri Department of Mining and Materials Engineering McGill UniversityMontreal H3A 0E8Canada

This work is part of a multi-phase project which aims to develop a sound methodology for rock fragmen-tation in underground mines using expansive *** specifically,it is the first phase of the project which focuses on laboratory tests to investigate the mechanical performance of expansive cement,also known as soundless chemical demolition agents(SCDA).This paper reports the results of laboratory tests conducted on instrumented thick-walled cylinders filled with expansive *** pressure evo-lution and temperature variation with time are first examined for different borehole *** clas-sical analytical method for expansive pressure estimation is validated with direct pressure measurement using high-capacity pressure sensor,and an empirical model is obtained.A new methodology based on iterative procedure is developed using axisymmetric finite element modelling and test results to derive the modulus of elasticity of the expansive cement at peak *** results of this study show that the expansive pressure increases with borehole diameter when the rigidity of the steel cylinder is constant reaching 83 MPa for a 38.1 mm *** is also shown that the expansive pressure decreases signif-icantly with increased cylinder rigidity for the same borehole *** newly developed methodol-ogy revealed that the modulus of elasticity of expansive cement at peak pressure is estimated at 8.2 GPa.A discussion on the extension of the findings of this work to hard rock mining applications is presented.

关键词： Rock fragmentation Soundless chemicaldemolitionagents Expansive cement

A laboratory study of stress arching around an inclusion due to pore pressure changes

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 678-693页

作者： hani Asaei Mahdi Moosavi Mohammad Ali Aghighi University of Tehran TehranIran

When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane *** stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory *** numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.

关键词： Stress arching Laboratory test Large-scale sample Synthetic sandstone

Numerical modeling of destress blasting for strata separation

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2238-2249页

作者： Petr Konicek Tuo Chen hani S.Mitri Institute of Geonics Czech Academy of SciencesOstrava70800Czech Republic Department of Mining and Materials Engineering McGill UniversityMontrealH3A 0E8Canada

Destress blasting(DB)implemented along the perimeter of safety pillars is a special application of destressing in coal longwall *** goal is to separate relatively more deformed mined areas from safety pillars,such as shaft pillars or cross-cut pillars,to reduce the transfer of high stresses to the protective *** case study aims to numerically simulate selected destress blasts in the Czech part of the Upper Silesian Coal Basin and examine its impact on stress transfer to the safety pillar *** separate the area between the protective pillar and the longwall(LW),two fans of five 93-mm blast holes(length of 93e100 m)were drilled from the gate roads into the overburden *** set of blast holes was fired separately in two stages without time *** explosive charge(gelatin-type of explosive)of each stage is 3450 *** two DB stages were fired when the longwall face was approximately 158 m and 152 m away from the blast.A 3D mine-wide model is built and validated with in situ stress measured with *** and destressing in three 5-m thick coal seams are simulated in the *** modeling of DB is successfully conducted using a rock fragmentation factor a of 0.05 and a stress reduction/dissipation factor β of *** of transfer of additional stress from the mining area into the safety pillar is evaluated by comparison of yielding volume before and after *** is shown that yielding volume drops after DB by nearly 80%in the area of the destressing panel and near the safety shaft pillar.

关键词： Rockburst hazard Destress blasting(DB) Strata separation Safety pillar Numerical modeling Fragmentation factor Stress dissipation factor Longwall mining