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Na+/K+ ATPase α1 and β3 subunits are localized to the basolateral membrane of trophectoderm cells in human blastocysts.
Get PDF秋田大学博士（医学
秋田・青森地域の黒鉱鉱床における金銀鉱作用
Get PDF秋田大学博士（資源学）In the Neogene Northeast Japan Arc, there are many Kuroko deposits formed in the middle Miocene. In particular, large-scale Kuroko deposits with an ore reserve of more than 10 million tons have been explored and studied for their economic potential, including the Uchinoutai deposit and the Matumine deposit. These deposits have been reported to yield yellow ore and black ore, that contain minerals such as bornite, Cu-S mineral, and enargite, which represent high-sulfidation environments. It is also known that these ores are associated with concentrations of gold and silver minerals such as stromeyerite, mckinstryite and electrum. On the other hand, the small-scale Kuroko deposits, which have an ore reserve of less than one million tons, produced gold and silver rich ores but ore production were limited. Many hydrothermal deposits have been discovered in the Okinawa Trough and the Izu-Bonin Arc, and the presence of gold and silver rich ores is also known in these deposits. In the Okinawa Trough, there are many presenting submarine hydrothermal deposits containing pyrrhotite and cubanite, which are estimated to have formed at low sulfur fugacity compared to the Kuroko deposits in the Hokuroku area.
This study, we investigated a total of 27 deposits in the Akita-Aomori area, where Kuroko deposits of various types are deusely distributed, to disucus the gold and silver mineralization of the Kuroko deposits. Mineral description, microstructure description and mineral chemical analysis of the ores in each deposit were carried out. Based on the results, I the conducted research to elucidate the causes of the formation of gold and silver rich ores and classify the deposits, and to clarify the distribution of each type of Kuroko deposit. All the minerals in the Kuroko deposit were classified as skeletal minerals and pore-filling minerals. Pyrite, sphalerite and barite are often crystallized as skeletal minerals. Gold and silver minerals, bornite and enargite all occur as pore filling minerals. Chalcopyrite, tetrahedrite group minerals, galena, and quartz occur as skeletal and pore-filling minerals.
The Kuroko deposit, 16 out of 17 deposits with an ore reserve of over 1 million tons, produced minerals such as bornite and Cu-S minerals and enargite under high sulfidation conditions. These minerals were confirmed in all the ore types such as siliceous ore, yellow ore, semi-black ore, black ore, barite ore, etc. in the studied Kuroko deposit. Among the high-sulfidation ores, bornite ores and Cu-S mineral-rich black ores are remarkably rich in gold and silver minerals, and the representative gold and silver minerals are stromeyerite, mckinstryite and electrum. Tetrahedrite (Ag), miscellaneous polybasite, and electrum-containing gold and silver rich ores without bornite and Cu-S minerals were also observed. On the other hand, there were no ores with significant concentrations of gold and silver minerals other than those containing enargite or black ore.
Neither bornite nor enargite was found in the small-scale deposits. The c from these deposits were all ore with concentrations of polybasite, tetrahedrite (Ag) and electrum. The absence bornite and pyrrhotite suggests that they formed in an intermediate sulfidation environment. The tetrahedrite group minerals in the high sulfidation ores were tetrahedrite and tennantite. The tetrahedrite group minerals in the high-sulfidation ores are tetrahedrite and tennantite, both of which are poor in silver and rarely contain more than one atomic %. Most of the minerals are tennantite, and tetrahedrite is rare. On the other hand, tetrahedrite in intermediate sulfidation ores is rich in silver, and the silver content of tetrahedrite increases in proportion to the increase in Sb content. In addition, the ores rich in tetrahedrite (Ag) tend to be rich in electrum. The gold content of the electrum was 70-80 atomic % in high-sulfidation ores, while it was less than 60 atomic % in intermediate sulfidation ores. The gold content of the intermediate sulfide ores was less than 60 atomic % in the intermediate sulfide ores, and less than 50 atomic % in the ores coexisting with miscellaneous silver ores and pyrite-poor ores. The concentration of FeS in sphalerite as a skeletal mineral is less than 0.01-0.60 mol. % FeS for intermediate sulfidation ores and 0.01-0.20 mol. % FeS for high sulfidation ores. The FeS concentrations of pore filling sphalerite are 0.5-6.00 mol. % for intermediate sulfide ores and 0.1-0.60 mol. % for high sulfide ores. The range of FeS concentration in intermediate-sulfidation ores is larger than that in high-sulfidation ores.
From the above observations, the Kuroko deposit can be classified into two types : ore formed in a high sulfidation environment and the other formed in an intermediate sulfidation environment. The large-scale Kuroko deposits ore, are a high to intermediate sulfidation type, while the small-scale deposit are intermediate sulfidation type. Gold and silver mineralization in the Kuroko deposit is caused by the circulation of hydrothermal fluids through a porous ore body consisting mainly of skeletal minerals formed on the seafloor.
In summary high-sulfidation gold and silver rich ores are contain of stromeyerite, mckinstryite, and gold-rich electrum, with silver-poor tetrahedrite group minerals, bornite Cu-S minerals and galena. Such ores were produced in Fukazawa deposit, furutobe deposit, uchinotai deposit. Intermediate-sulfidation gold and silver rich ores are contain of tetrahedrite (Ag), polybasite, and silver-rich electrum, with chalcopyrite and galena. Such ores were produced in Mizusawa deposit, Tanosawa deposit, Shimotai deposit, Kowariswa deposit and Uchinotai deposit.
All of the gold and silver rich ores are rich in voids until the end of mineralization, indicating that they formed in the upper part of the deposit where hydrothermal fluids cooled rapidly
Effects of oral function and depressive tendencies on nutritional status in older adults requiring support or low-level care : An investigation through path analysis
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Associations Between the 2011 Great East Japan Earthquake and Tsunami and the Sleep and Mental Health of Japanese People: A 3-Wave Repeated Survey
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Quantitative Modelling of Long-term Mineral Resource Availability and Environmental Impact Based on the Total Material Requirement
Get PDF秋田大学博士（工学）Historically, mineral resources have been vital in engineering the modern society. However, over the last few decades, the surge in demand of these resources for their specific usage changing the market landscape, has raised concern of their future availability. As the demand for metals rise, the metal prices simultaneously rise, further increasing the anxiety in physical scarcity and quality of these metals. In addition, the absolute decoupling of the environment from resource activity is a necessity to ensure that economic development progresses without harming the environment.
To sustainably plan for our future resource requirements, creating a supply model for these metals is critical to understand how much resources will be economically accessible at a given grade, which is a measure of the metal quality. If there is a shortage, how much recycling production quantities are needed to meet the increasing demand of these exhaustible metals. Vulnerability to the environment caused by these anthropogenic activities is a confronting issue in the society that also requires attention through modelling their sustainable projections based on future metal production patterns.
There remain few studies that examine long term trends in mining production and linking them to environmental sustainability based on factors such as ultimate recoverable resources, increasing production quantities, declining ore grade, and mine waste (overburden and mine muck) and ultimately how recycling promotion will ameliorate the shortage of primary metal supply to satisfy metal demand. Therefore, the study investigates the future resources and their grade qualities by geographic location, their supply and demand long term trends, and the degree of vulnerability on the environment created by these metals during metal mining activities. The analysis period of this study ranges between 1990-2070.
The long term future availability of resources proposes a quasi-dynamic approach that measures economically extractable reserves to determine the physical scarcity of resources. The limit of future reserves is determined by ultimate recoverable reserves at a given cut off grade. The deteriorating metal ore grade creates a concern of future resource quality and ultimately how this inherent nature harms the environment. The environmental impact is tracked based on the total material requirement indicator. This indicator is dependent on changes of strip ratio and ore grade during metal mining production. A comparative analysis of six metals namely copper, gold, iron, lead, nickel and zinc whose importance to the basic applications of modern use in society has risen is evaluated to identify the resource lifetime, quantity and quality by geographic location is applied. The study identifies that physical scarcity is unlikely to occur in this century, but the physical peak of some resources will occur earlier than others as the mining industries become fully matured. Gold for example, has an early Hubbert’s peak contributed by the long historical mining history, resource size and occurrence. The total material requirement depicts that gold attributes to the largest environmental harm compared to copper, nickel, lead, zinc and iron ore with the least impact. This is because larger material volumes of gold are removed to access the low ore grades and thin veins of gold ore deposits. For copper, the Latin American region experiences high potential negative environmental impacts compared to other regions mainly because of the high global extractions in the top copper producer country, Chile, where similar high ore TMR trend patterns are experienced. Nickel, lead and zinc have similar trend patterns to copper due to their close association in occurrence. For iron, even though it has the least impact on the environment, positively spiking anomalies in the ore TMR trends in Australia synonymously with the Asian Pacific region due to historical large scale increase in production for iron from Australia for exports to consuming countries. The dynamically varying ore TMR trends therefore outlines the importance of investigating ore TMR trends with unique individuality to tackle these potential concerns on the environment.
With regards to the promotion of recycling, system dynamics modelling using STELLA software is carried out on copper, gold and iron to investigate the future total supply trends to satisfy the metal demand by application. By investigating additional supply, factors such as the recycling rate, recycling efficiency, recyclability potential and the environmental implication on the total system boundary are applied. Primary production will remain the largest contributor of copper supply to 2070 while production ratio of primary and secondary supply is almost equivalent over the same period. Finally, we observe the resource outlook based on the United Nations Environmental Programme-International Resource Panel scenarios ideal to achieve the Total Sustainability and Recycling Efficiency scenarios. By achieving these scenarios, a 25% and 17% reduction, respectively, in global extraction are proposed. The study outlines these adjustments relative to increasing consumption as primary production declines whilst maintaining the same current demand levels. The appreciation of these to manage our future resource would ultimately reduce the outcome of future ore TMR patterns during metal mining production.
From a sustainability perspective this study demonstrates that the trends of primary production will increase the environmental footprint in the future as the total economic and non-economic material flows increase and the associated metal ore grades decline. However, the promotion of secondary metal sources will provide an alternative supply source should availability of primary resources be constrained. Therefore, tracking of both economic and non-economic material flows is crucial for effectively decoupling resource activity from the environment.
Mineral resources are a fundamental component to the global society and economic growth. Although the combination of forecast trends on mineral production based on the URR values and promotion of recycling as a secondary metal supply source outline that a supply risk is not eminent to 2070, this study did not include other factors of uncertainty such as economic, technological and social factors in which future systems modelling could be improved. However, the study provided and important basis towards the total material flow of resources to establish material efficiency in the quantities and quality of resource use. Further, accountability of resources through material flow tracking is discussed, providing a basis for quantitative assessment on environmental implications