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Rehabilitation of Mining Sites: The Case of the Gora/Sabodala Gold Mine in Senegal Prospects for Sustainable Development of a Mine
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作者 Dieye Pathé Mall Ibrahim +1 位作者 Samb Mansour Ndong Robert 《Journal of Environmental Protection》 2021年第10期784-807,共24页
The southeastern part of Senegal, in West Africa, is home to the country’s first major gold mine owned by Sabodala gold operations SGO, as subsidiary of Teranga Gold Corporation during the timeframe of this study. As... The southeastern part of Senegal, in West Africa, is home to the country’s first major gold mine owned by Sabodala gold operations SGO, as subsidiary of Teranga Gold Corporation during the timeframe of this study. As part of its expansion, the company opened and operated the Gora satellite mine for 4 years’ exploitation. At the end of the mine’s life, the authorities decided to close the site. In this context, SGO in compliance with its legal, regulatory and normative obligations, has commissioned a study of rehabilitation activities for a better environmental and social management of the Gora gold mine. This study is a first in Senegal and presents the general framework for the rehabilitation of a gold mine which will allow scientists to have several research perspectives in this field. The methodological approach consisted of a participatory process of collecting field data and data from stakeholders directly involved in mine rehabilitation and closure;these data were analyzed and coupled with international best practices in rehabilitation, closure, and post-mine management. Results of the selected options are based on known experiences from around the world, coupled with analysis of the SGO’s field activities results and those obtained from the synthesis of the interview guides from the numerous consultations. This synthesis made possible to align them with international guidelines presented in this document. In this context, the aspects related to the open-pit mine equipment, processing facilities and related infrastructure were a particular interest to the various stakeholders. Thus, the following rehabilitation options were retained by the group constituted by the populations: 1) Backfilling pits, for cultivation practices and development of agribusiness and the establishment of grazing land for livestock;2) Setting up water storage basins for the sustainable development of certain activities around the mine and aquifer recharge while respecting the protection and safety standards of the basin in order to avoid the risks of accidents;3) Returning certain facilities to the communities and the competent State services. These few measures will allow the indigenous populations affected by the mine to participate in the rehabilitation program by integrating all relevant ideas and discussions on the issues of rehabilitation as perceived by the actors involved in the study, as well as the implementation of the best international strategic orientations in this field for sustainable development. In addition, it will be necessary to set up an internal technical committee within the mining company to coordinate the rehabilitation and closure operations with the various departments, and an external technical committee composed of the relevant government departments, the local community, and civil society, among others, to examine and validate the closure options. A closure clearance should be issued to operators who have responsibly closed their mines. 展开更多
关键词 REHABILITATION Mine Closure gora Sabodala Environment Sustainable Development
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Pricing Multi-Strike Quanto Call Options on Multiple Assets with Stochastic Volatility, Correlation, and Exchange Rates
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作者 Boris Ter-Avanesov Gunter Meissner 《Applied Mathematics》 2025年第1期113-142,共30页
Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign cur... Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign currencies each with a different strike price in the payoff function. We carry out a comparative performance analysis of different stochastic volatility (SV), stochastic correlation (SC), and stochastic exchange rate (SER) models to determine the best combination of these models for Monte Carlo (MC) simulation pricing. In addition, we test the performance of all model variants with constant correlation as a benchmark. We find that a combination of GARCH-Jump SV, Weibull SC, and Ornstein Uhlenbeck (OU) SER performs best. In addition, we analyze different discretization schemes and their results. In our simulations, the Milstein scheme yields the best balance between execution times and lower standard deviations of price estimates. Furthermore, we find that incorporating mean reversion into stochastic correlation and stochastic FX rate modeling is beneficial for MC simulation pricing. We improve the accuracy of our simulations by implementing antithetic variates variance reduction. Finally, we derive the correlation risk parameters Cora and Gora in our framework so that correlation hedging of quanto options can be performed. 展开更多
关键词 Quanto Option Multi-Strike Option Stochastic Volatility (SV) Stochastic Correlation (SC) Stochastic Exchange Rates (SER) CORA gora Correlation Risk
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不同质子泵抑制剂联合替戈拉生对胃溃疡的治疗效果及安全性分析
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作者 张志宏 马丽君 张芳芳 《山西医药杂志》 2025年第12期894-899,共6页
目的 探讨不同质子泵抑制剂联合替戈拉生对胃溃疡的治疗效果及安全性。方法 回顾性分析我院2021年8月至2024年8月收治的胃溃疡患者,根据患者所用质子泵抑制剂的不同分为奥美拉唑组、兰索拉唑组、雷贝拉唑组、艾司奥美拉唑组。对比4组患... 目的 探讨不同质子泵抑制剂联合替戈拉生对胃溃疡的治疗效果及安全性。方法 回顾性分析我院2021年8月至2024年8月收治的胃溃疡患者,根据患者所用质子泵抑制剂的不同分为奥美拉唑组、兰索拉唑组、雷贝拉唑组、艾司奥美拉唑组。对比4组患者治疗8周后的临床疗效,症状缓解时间,血清指标水平变化情况,胃黏膜病理组织学积分及溃疡病变程度变化,并比较其不良反应情况。结果 4组总有效率比较,差异无统计学意义(P>0.05);4组症状缓解时间比较差异有统计学意义,雷贝拉唑组患者上腹部灼烧、腹痛缓解时间短于奥美拉唑组、兰索拉唑组、艾司奥美拉唑组(P<0.05),雷贝拉唑组、艾司奥美拉唑组患者反酸、腹痛缓解时间短于奥美拉唑组、兰索拉唑组(P<0.05);与治疗前相比,4组患者治疗后血清指标水平均明显改善(P<0.05),但4组组间比较,差异无统计学意义(P>0.05);4组治疗后胃黏膜病理组织学积分、溃疡面积均降低,雷贝拉唑组低于其他3组(P<0.05);奥美拉唑组患者不良反应发生率高于兰索拉唑组(χ^(2)=3.96,P=0.047)和艾司奥美拉唑组(χ^(2)=5.42,P=0.020)。结论 不同质子泵抑制剂联合替戈拉生对胃溃疡治疗效果显著,均可减轻机体炎症反应,其中,雷贝拉唑联合替戈拉生在缩短症状持续时间、减轻胃溃疡严重程度方面表现出一定优势。 展开更多
关键词 质子泵抑制剂 替戈拉生 胃溃疡 炎性因子 不良反应
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西伯利亚阿芳托娃戈拉遗址旱獭与古环境研究
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作者 武仙竹 陈育芝 《第四纪研究》 CAS CSCD 北大核心 2023年第3期856-867,共12页
阿芳托娃戈拉(Afontova Gora)遗址位于俄罗斯西伯利亚叶尼塞河上游右岸的3级阶地,地理坐标北纬55.9°94′83″,东经92.5°08′31″。该遗址出土有晚期智人化石和丰富的打制石器、骨制品、动物化石等,是西伯利亚地区旧石器时代... 阿芳托娃戈拉(Afontova Gora)遗址位于俄罗斯西伯利亚叶尼塞河上游右岸的3级阶地,地理坐标北纬55.9°94′83″,东经92.5°08′31″。该遗址出土有晚期智人化石和丰富的打制石器、骨制品、动物化石等,是西伯利亚地区旧石器时代晚期的重要文化遗址之一。遗址剖面第12层约17.0 ka B.P.。从该层出土的哺乳动物化石中,鉴定出4个个体的西伯利亚旱獭(Marmota sibirica)化石材料。西伯利亚旱獭颅骨呈松鼠型,眶上突和矢状嵴发达;腭面宽大,左右颊齿间距在M1处最宽;下颌骨粗壮,水平支较高,冠状突较短而粗壮;颅骨全长113.5 mm,眶间距28.8 mm,P4~M3长27.8 mm。从颅骨、颊齿测量数据上比较发现,西伯利亚旱獭(M.sibirica)明显大于早更新世绝灭种小旱獭(Marmota parva)和现生种草原旱獭(Marmota bobak)。牙齿形态特征上,西伯利亚旱獭具有一定原始性,其下颊齿下中尖粗壮,与早更新世小旱獭有一定相似性;但与小旱獭相比也有明显进步性,如P4臼齿化、下颊齿下后脊高度退化等。遗址动物群生态和地层堆积综合分析显示,阿芳托娃戈拉遗址古环境属于温带森林草原环境,与现今相比,其植被类型、植被丰度、降水量及野生动物种群多样性等更显丰富。阿芳托娃戈拉遗址动物群,是西伯利亚旧石器时代遗址中动物种属最丰富的地点,该遗址动物群面貌一年四季均具有代表属种的特点。该特点反映西伯利亚旧石器时代晚期古人类曾长期定居此地;对本区域动物资源非常熟悉,并掌握有常年获取肉类资源的生产技术。遗址中批量存在的旱獭动物遗存,是该遗址古人类春季食物资源的重要组成成分。可能是在春季待旱獭出蛰后,对刚刚性成熟发情期间疏于自我防卫的青年个体进行捕获。该发现丰富了我们对西伯利亚古人类开发食物资源生产方式的认识,也反映更新世晚期古人类对西伯利亚地区具有很强的环境适应能力。 展开更多
关键词 晚更新世 西伯利亚旱獭(Marmota sibirica) 动物考古 阿芳托娃戈拉(Afontova gora)遗址 西伯利亚
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《戈拉》的思想内容新解
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作者 王一玫 《襄樊职业技术学院学报》 2006年第3期99-101,共3页
泰戈尔是一个追求统一性的思想家,他注重现象背后的本质。理解《戈拉》也应透过题材和事象,探寻蕴含其中的意义。结合泰戈尔的宗教哲学思想,从整体上把握泰戈尔文学创作的内涵,更能接近泰戈尔创作的初衷。
关键词 戈拉 内涵 阐释
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