All methods of rock burst hazard evaluation and control are classified as rock burst prevention. The prevention methods can be divided in two general categories – the passive (non-active) and active ones. Active methods of rock burst prevention focus generally on reducing of stress level in the area of its concentration through controlled tremors and rock bursts by blasting works. Among the active methods the hydraulic fracturing can be noted. Traditional hydraulic fracturing techniques generally form main hydraulic cracks. However, when we combine hydraulic fracturing with blasting we might obtain much better results. For example, the hydraulic crack range becomes wider than by using only conventional methods. In coal seams it is possible to increase permeability which makes gas drainage to be more effective. It is because water shockwaves and bubble pulsations induced by the explosion, cause a high strain rate in the rock mass surrounding the bore hole. When hydraulic fracturing is used, a micro seismic event takes place. This is why micro seismic technologies are used to monitor the range of hydraulic fracturing process. This article is only mentioning the issue which in the Author opinion, deserves more attention.
{"title":"Hydraulic fracturing technology in rock burst hazard controlling","authors":"W. Karkocha","doi":"10.5277/MS150202","DOIUrl":"https://doi.org/10.5277/MS150202","url":null,"abstract":"All methods of rock burst hazard evaluation and control are classified as rock burst prevention. The prevention methods can be divided in two general categories – the passive (non-active) and active ones. Active methods of rock burst prevention focus generally on reducing of stress level in the area of its concentration through controlled tremors and rock bursts by blasting works. Among the active methods the hydraulic fracturing can be noted. Traditional hydraulic fracturing techniques generally form main hydraulic cracks. However, when we combine hydraulic fracturing with blasting we might obtain much better results. For example, the hydraulic crack range becomes wider than by using only conventional methods. In coal seams it is possible to increase permeability which makes gas drainage to be more effective. It is because water shockwaves and bubble pulsations induced by the explosion, cause a high strain rate in the rock mass surrounding the bore hole. When hydraulic fracturing is used, a micro seismic event takes place. This is why micro seismic technologies are used to monitor the range of hydraulic fracturing process. This article is only mentioning the issue which in the Author opinion, deserves more attention.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"92 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79430625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling and simulation analysis of mine production in 3D environment","authors":"S. Checiński, Andrzej Witt","doi":"10.5277/MSC152215","DOIUrl":"https://doi.org/10.5277/MSC152215","url":null,"abstract":"","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"25 1","pages":"181-189"},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84370731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The research areas were selected in the regions heavily polluted by wastes from the former washing plant, flotation waste dump and by non-sulphide Zn-Pb ores from open pit mining in the Olkusz region. The submicroscopic phases occurring in the surface of plant roots and in the rhizospheres were investigated by XRD and SEM/EDS methods. Morphology of submicroscopic metalliferous phases and their manner of occurrence were the subject of study. The analysis of EDS spectra enabled to identify phases and mineral aggregates including Zn, Pb, Fe, Mn, Cd in their structure. The soils from the washing plant and areas of open pit exploitation are contaminated by diverse complexes of minerals. The occurrence of unstable Fe, Pb, Ca sulphates indicate that these wastes are still intensively geochemically active.
{"title":"Forms of heavy metals (Zn, Pb, Cd) occuring in rhizospheres from the areas of former and contemporary Zn-Pb ore mining","authors":"D. Rożek, W. Nadłonek, J. Cabała","doi":"10.5277/MS150210","DOIUrl":"https://doi.org/10.5277/MS150210","url":null,"abstract":": The research areas were selected in the regions heavily polluted by wastes from the former washing plant, flotation waste dump and by non-sulphide Zn-Pb ores from open pit mining in the Olkusz region. The submicroscopic phases occurring in the surface of plant roots and in the rhizospheres were investigated by XRD and SEM/EDS methods. Morphology of submicroscopic metalliferous phases and their manner of occurrence were the subject of study. The analysis of EDS spectra enabled to identify phases and mineral aggregates including Zn, Pb, Fe, Mn, Cd in their structure. The soils from the washing plant and areas of open pit exploitation are contaminated by diverse complexes of minerals. The occurrence of unstable Fe, Pb, Ca sulphates indicate that these wastes are still intensively geochemically active.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"85 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80519920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The article presents the role of geostatistical research in identification (and minimization) of a geological risk against the background of the concept presented, aiming at assessing the value of lignite deposits from the perspective of integrated entities, i.e. mines and power stations. A detailed review of the solutions in geostatistics is to prove their usefulness and convince about the purposefulness of their application. The issue of optimization of sampling the deposit is important in defining its value, and at the same time its future development. In addition, on each stage of the chain of creating the value, the areas were defined of uncertainties and a number of risk which are attached with reference to the solution proposed of assessing the deposit value.
{"title":"The meaning of geostatistical research in the light of the concept of assessing values of lignite deposits","authors":"K. Pactwa, J. Woźniak","doi":"10.5277/MS150208","DOIUrl":"https://doi.org/10.5277/MS150208","url":null,"abstract":": The article presents the role of geostatistical research in identification (and minimization) of a geological risk against the background of the concept presented, aiming at assessing the value of lignite deposits from the perspective of integrated entities, i.e. mines and power stations. A detailed review of the solutions in geostatistics is to prove their usefulness and convince about the purposefulness of their application. The issue of optimization of sampling the deposit is important in defining its value, and at the same time its future development. In addition, on each stage of the chain of creating the value, the areas were defined of uncertainties and a number of risk which are attached with reference to the solution proposed of assessing the deposit value.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"72 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87735200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Młynarczyk, P. Mertuszka, L. Ziętkowski, M. Bodlak
{"title":"The evolution of mechanized excavating systems in LGOM mines conditions","authors":"J. Młynarczyk, P. Mertuszka, L. Ziętkowski, M. Bodlak","doi":"10.5277/MS150220","DOIUrl":"https://doi.org/10.5277/MS150220","url":null,"abstract":"","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"10 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89013541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Production of electricity / heat through the use of biomass is one of the possible ways to increase energy production from renewable energy sources and promote sustainable development by reduc-ing direct greenhouse gas emissions chich is associated with the energy sector (Moraisi et al., 2011). In the coming years, biomass will have important role as a natural source of renewable energy, due to the rising cost of fossil fuels, highly questionable safety of nuclear energy and the need of carbon dioxide emissions reduction. (Callejón-Ferre et al., 2014). According to 2009/28/EC Directive about the promotion of use of energy from renewable sources, Biomass is defined as the biodegradable fraction of products, waste and residues from the agricultural industry (including also substances coming from plant and animals), forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste. Increasingly frequent use of alternative fuels, including biomass, in different areas of the industry cause a large production of new waste materials. Economic and environmental considerations are the cause of increased interest in the use of the economic potential of ash generated in these processes. In the article possibility of using new waste materials, which are fly ash from the combustion of mixed agricultural and forest biomass as hydraulic backfill material, solidifying and gobs caulking was analyzed. chemical composition by emissional spectroscopy with inductively
:通过使用生物质生产电力/热能是增加可再生能源能源生产和通过减少与能源部门相关的直接温室气体排放促进可持续发展的可能方法之一(Moraisi et al.， 2011)。在未来几年，由于化石燃料的成本不断上升，核能的安全性备受质疑，以及减少二氧化碳排放的需要，生物质能将作为可再生能源的天然来源发挥重要作用。(Callejón-Ferre et al.， 2014)。根据2009/28/EC关于促进使用可再生能源的指令，生物质被定义为农业工业(也包括来自植物和动物的物质)、林业和相关产业的产品、废物和残留物的可生物降解部分，以及工业和城市废物的可生物降解部分。在工业的不同领域日益频繁地使用替代燃料，包括生物质，造成大量新的废料的产生。出于经济和环境方面的考虑，人们对利用这些过程中产生的灰烬的经济潜力越来越感兴趣。本文分析了利用农林混合生物质燃烧产生的粉煤灰作为水力回填材料、固化材料和采空区填缝材料的可能性。用电感发射光谱法测定化学成分
{"title":"Properties of fly ash from agro-forestry biomass combustion in the aspect of their use in mining technology","authors":"A. Pawluk, Piotr Kasprzyk, Dušan Terpák","doi":"10.5277/MS150221","DOIUrl":"https://doi.org/10.5277/MS150221","url":null,"abstract":": Production of electricity / heat through the use of biomass is one of the possible ways to increase energy production from renewable energy sources and promote sustainable development by reduc-ing direct greenhouse gas emissions chich is associated with the energy sector (Moraisi et al., 2011). In the coming years, biomass will have important role as a natural source of renewable energy, due to the rising cost of fossil fuels, highly questionable safety of nuclear energy and the need of carbon dioxide emissions reduction. (Callejón-Ferre et al., 2014). According to 2009/28/EC Directive about the promotion of use of energy from renewable sources, Biomass is defined as the biodegradable fraction of products, waste and residues from the agricultural industry (including also substances coming from plant and animals), forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste. Increasingly frequent use of alternative fuels, including biomass, in different areas of the industry cause a large production of new waste materials. Economic and environmental considerations are the cause of increased interest in the use of the economic potential of ash generated in these processes. In the article possibility of using new waste materials, which are fly ash from the combustion of mixed agricultural and forest biomass as hydraulic backfill material, solidifying and gobs caulking was analyzed. chemical composition by emissional spectroscopy with inductively","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"27 20 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73474322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soufiane Bouabdallah, M. Bounouala, Abdeslam Chaib, Badji Mokhtar-Annaba
: To improve the quality of raw materials from North East Algeria and their application in the field of flat glass manufacturing, the sandstone of El-Aouana (Jijel) was subjected to a physicochemical characterization. Analysis techniques such as X-ray diffraction, atomic absorption spectrophotometry and a chemical analysis of size fractions by sieving were used. According to this characterization it is noticed that sandstone feedstock contains primarily quartz (SiO 2 ), as well as ferriferous minerals considered as impurities during glass manufacturing. This work concerns the removal of iron oxide from silica sandstone to obtain a material acceptable for flat glass manufacturing. For this, we have studied the silica enrichment process using a magnetic separation. Moreover, a leaching process by using hydrochloric acid has been studied under various experimental conditions; the parameters studied were: hydrochloric concentration, temperature, and time of contact. The results obtained show that the leaching studied presents a better removal of iron oxide after 150 min of treatment at temperature 90°C with a 3 mol/L, a concentrate obtained final of 99.16% SiO 2 with a content of 0.01% Fe 2 O 3 .
{"title":"Removal of iron from sandstone by magnetic separation and leaching: case of El-Aouana deposit (Algeria)","authors":"Soufiane Bouabdallah, M. Bounouala, Abdeslam Chaib, Badji Mokhtar-Annaba","doi":"10.5277/MSC152203","DOIUrl":"https://doi.org/10.5277/MSC152203","url":null,"abstract":": To improve the quality of raw materials from North East Algeria and their application in the field of flat glass manufacturing, the sandstone of El-Aouana (Jijel) was subjected to a physicochemical characterization. Analysis techniques such as X-ray diffraction, atomic absorption spectrophotometry and a chemical analysis of size fractions by sieving were used. According to this characterization it is noticed that sandstone feedstock contains primarily quartz (SiO 2 ), as well as ferriferous minerals considered as impurities during glass manufacturing. This work concerns the removal of iron oxide from silica sandstone to obtain a material acceptable for flat glass manufacturing. For this, we have studied the silica enrichment process using a magnetic separation. Moreover, a leaching process by using hydrochloric acid has been studied under various experimental conditions; the parameters studied were: hydrochloric concentration, temperature, and time of contact. The results obtained show that the leaching studied presents a better removal of iron oxide after 150 min of treatment at temperature 90°C with a 3 mol/L, a concentrate obtained final of 99.16% SiO 2 with a content of 0.01% Fe 2 O 3 .","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"70 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87403289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article presents an optimization of Ø0.21/0.16 hydraulic leg system operating in a powered roof support Glinik 13/25 Pp type, working at longwall 6, seam 501, KWK Bobrek – Centrum in hazard conditions of mining tremors. The process included numerical modelling and computer software, ANSYS CFX. The optimization allows to achieve an adequate capacity and performance of the hydraulic system which increases workplace safety in the mines. The article provides basic requirements that must be provided in order to conduct an analysis in ANSYS CFX. The software was used to carry out 10 simulations, which allowed to determine an optimal flow for the subject leg.
{"title":"Numerical analysis for an optimization of a powered roof support operating in hazard conditions of minig tremors","authors":"D. Szurgacz","doi":"10.5277/MS150216","DOIUrl":"https://doi.org/10.5277/MS150216","url":null,"abstract":"The article presents an optimization of Ø0.21/0.16 hydraulic leg system operating in a powered roof support Glinik 13/25 Pp type, working at longwall 6, seam 501, KWK Bobrek – Centrum in hazard conditions of mining tremors. The process included numerical modelling and computer software, ANSYS CFX. The optimization allows to achieve an adequate capacity and performance of the hydraulic system which increases workplace safety in the mines. The article provides basic requirements that must be provided in order to conduct an analysis in ANSYS CFX. The software was used to carry out 10 simulations, which allowed to determine an optimal flow for the subject leg.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"23 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84969523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mining of rock minerals, constitutes a strong stimulus for economic development and at the same time, can significantly and negatively affect the state of natural environment, roads and well-being of local communities. This paper presents methodology for studies of spatial impact of rock minerals mining in the Lower Silesia region (SW Poland). In the region majority of magmatic, metamorphic and other rock minerals occur in Poland and their intensive mining is an important sector of regional economy. The concept of mining density (mineral production per unit area) has been introduced and the changes of rock minerals mining in the period of the last 8 years (2006-2013) have been analysed and presented graphically with GIS-based methodology. Mining density increased from 2006 to 2011 and decreased from 2011 to 2013. Change in the spatial pattern of mining density between 2006 and 2013, despite comparable volume of rock minerals production, has been identified. In addition proximity of mines to human settlements, nature protection areas and railways (potential transport routes) has been analysed. Comprehensive and coherent information on rock minerals mining for the area of Lower Silesia provided in this study has been used in developing and implementing regional spatial development policy and attaining the balance between the economic needs, nature protection requirements and the well-being of its citizens.
{"title":"GIS-based spatial assessment of rock minerals mining - a case study of the Lower Silesia Region (SW Poland)","authors":"J. Blachowski","doi":"10.5277/MSC152201","DOIUrl":"https://doi.org/10.5277/MSC152201","url":null,"abstract":"Mining of rock minerals, constitutes a strong stimulus for economic development and at the same time, can significantly and negatively affect the state of natural environment, roads and well-being of local communities. This paper presents methodology for studies of spatial impact of rock minerals mining in the Lower Silesia region (SW Poland). In the region majority of magmatic, metamorphic and other rock minerals occur in Poland and their intensive mining is an important sector of regional economy. The concept of mining density (mineral production per unit area) has been introduced and the changes of rock minerals mining in the period of the last 8 years (2006-2013) have been analysed and presented graphically with GIS-based methodology. Mining density increased from 2006 to 2011 and decreased from 2011 to 2013. Change in the spatial pattern of mining density between 2006 and 2013, despite comparable volume of rock minerals production, has been identified. In addition proximity of mines to human settlements, nature protection areas and railways (potential transport routes) has been analysed. Comprehensive and coherent information on rock minerals mining for the area of Lower Silesia provided in this study has been used in developing and implementing regional spatial development policy and attaining the balance between the economic needs, nature protection requirements and the well-being of its citizens.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"11 1","pages":"7-22"},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75885839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Integration strategy is one option in the development of mining companies and is implemented through a connection of either processes or economic entities which operate or may operate separately. Usually this strategy is carried out by companies that occupy a very strong competitive position. Considering its direction, it may be horizontal or vertical. Horizontal integration strategy stems from a desire to increase market share by an entrepreneur or create a new company based on common know-how and combined operational processes. It can be realized in an external dimension through a merger or takeover, as well as in the internal dimension based on its own resources. The external dimension is based on capital or contractual integration of a company with external economic entities performing related or conglomerate activity. The targets of such integration have a resource, a market effectiveness, or a competence nature. In the case of mining companies, it covers all important activity areas, including geology, mining, processing, environmental protection, and waste management, and is carried out with due diligence. In the internal dimension, the strategy of horizontal integration consists in consolidating the strategic targets of all business units around the company’s (corporation’s) targets. The authors focused on two trends most relevant to pursuing a horizontal integration strategy, including increasing the company’s flexibility and undertaking joint activities. Flexibility consists in the potential ability of the company to adapt quickly to changed environment conditions. Joint activity includes cooperation of its respective units in terms of products, markets, and functions; its implementation should be preceded by a detailed analysis of the company’s competences.
{"title":"Horizontal integration in the development strategy of mining companies","authors":"J. Kudełko, H. Wirth, C. Bachowski, J. Gacek","doi":"10.5277/MSC152209","DOIUrl":"https://doi.org/10.5277/MSC152209","url":null,"abstract":"Integration strategy is one option in the development of mining companies and is implemented through a connection of either processes or economic entities which operate or may operate separately. Usually this strategy is carried out by companies that occupy a very strong competitive position. Considering its direction, it may be horizontal or vertical. Horizontal integration strategy stems from a desire to increase market share by an entrepreneur or create a new company based on common know-how and combined operational processes. It can be realized in an external dimension through a merger or takeover, as well as in the internal dimension based on its own resources. The external dimension is based on capital or contractual integration of a company with external economic entities performing related or conglomerate activity. The targets of such integration have a resource, a market effectiveness, or a competence nature. In the case of mining companies, it covers all important activity areas, including geology, mining, processing, environmental protection, and waste management, and is carried out with due diligence. In the internal dimension, the strategy of horizontal integration consists in consolidating the strategic targets of all business units around the company’s (corporation’s) targets. The authors focused on two trends most relevant to pursuing a horizontal integration strategy, including increasing the company’s flexibility and undertaking joint activities. Flexibility consists in the potential ability of the company to adapt quickly to changed environment conditions. Joint activity includes cooperation of its respective units in terms of products, markets, and functions; its implementation should be preceded by a detailed analysis of the company’s competences.","PeriodicalId":43629,"journal":{"name":"Mining Science","volume":"16 1","pages":"101-114"},"PeriodicalIF":1.3,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84328803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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