scholarly journals Dynamically Adjusting the Mining Capacity in Cryptocurrency with Binary Blockchain

Author(s):  
Yoohwan Kim ◽  
Ju-Yeon Jo
Keyword(s):  
Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2918
Author(s):  
Liang Zhang ◽  
Songhe Geng ◽  
Jun Kang ◽  
Jiahao Chao ◽  
Linchao Yang ◽  
...  

Self-circulation wellbore is a new technique for geothermal development in hot dry rocks (HDR), which uses a U-shape channel composed of tubing and casing as the heat exchanger. In this study, a self-circulation wellbore in HDR on a laboratory scale was built, and a serial of experiments were conducted to investigate the heat exchange law and the influencing factors on the heat mining rate of the wellbore. A similarity analysis was also made to estimate the heat-mining capacity of the wellbore on a field scale. The experimental results show that the large thermal conductivity and heat capacity of granite with high temperature can contribute to a large heat-mining rate. A high injection rate can cause a high convective heat transfer coefficient in wellbore, while a balance is needed between the heat mining rate and the outlet temperature. An inner tubing with low thermal conductivity can significantly reduce the heat loss to the casing annulus. The similarity analysis indicates that a heat mining rate of 1.25 MW can be reached when using a 2000 m long horizontal well section in a 150 °C HDR reservoir with a circulation rate of 602.8 m3/day. This result is well corresponding to the published data.


2020 ◽  
Author(s):  
Veniamin Ya. Dashevskii ◽  
Aleksandr A. Aleksandrov ◽  
Vladimir I. Zhuchkov ◽  
Leopold I. Leontˋev ◽  
Akim G. Kanevskii

The mineral resources base of manganese ores is sufficiently large in Russia. However, their mining capacity is almost absent. This is due to the low quality of domestic manganese ores and the high content of phosphorus. To date, Russia has been obliged to import the commercial manganese ore, manganese-containing ferroalloys, metallic manganese, and manganese dioxide. To produce the high-carbon ferromanganese the composition of charge was developed. The optimum variant was that where 10–15% of manganese-containing raw materials were changed for waste slag. In this case, the phosphorus content in the high-carbon ferromanganese is lower by approximately 20 rel. % in comparison with the production of ferromanganese only from the manganese-containing raw materials. About 50–60 rel. % of manganese can be extracted from the waste slag of silicon-thermal production. To produce the hot metal, the composition of iron-bearing burden material was developed. The optimum variant was that where 100% of manganese raw materials were changed for the waste slag. In this case, upon production of hot metal, the specific consumptions of manganese raw materials and limestone were decreased by 100 and 20%, respectively. The phosphorus concentration in metal was lower by about 10 rel. % as compared to the production of hot metal only from the manganese raw materials. Up to 55% of manganese can be extracted from the waste slag of silicothermic production, which is irretrievably lost at present. Keywords: manganese ferroalloys, manganese-containing raw materials, waste slag, hot metal


1989 ◽  
Vol 15 (2) ◽  
pp. 149-155
Author(s):  
Jerry Krim
Keyword(s):  

2013 ◽  
Vol 387 ◽  
pp. 227-230
Author(s):  
Ning Zhang ◽  
Shu Chen Wang ◽  
Na Shi ◽  
Hao Chen

The cutting pick is primarily used in footing excavation such as coal mining and roadway excavation, so the performance of cutting tooth directly affect the mining capacity, the driving efficiency, and the service life of the tool. The quality of domestic mining pick is lower than that abroad, especially the tooth body wear of the whole shearer picks accounts for half of its overall failure. Thus tooth body 40Cr was treated by various heat treatment processes in this experiment, so as to improve the hardness and wear resistance of cutting tooth, analysis the surface wear scar of morphology, research the wear mechanism, that made for reducing the consumption of cutting tooth, improving work efficiency, and easing the labor intensity of workers undergound.


2014 ◽  
Vol 65 (12) ◽  
pp. 2995-3003 ◽  
Author(s):  
Lingyun Cheng ◽  
Xiaoyan Tang ◽  
Carroll P. Vance ◽  
Philip J. White ◽  
Fusuo Zhang ◽  
...  

1987 ◽  
Vol 109 (1) ◽  
pp. 33-38
Author(s):  
J. Adinarayana ◽  
R. C. Tiwari

SummaryThe moisture use pattern and efficiency (MUE) of four barley cultivars (two hulled and two hull-less) were studied when the crops were grown in winter under unirrigated conditions at Varanasi, India, with different rates of application of nitrogen fertilizer. Increase in moisture use with age of the crop due to vegetative growth was recorded. Influence of varieties on consumptive use of water was found to be negligible except in the 1st year between 65 days after sowing and after harvest of the crop, when differences were due to differences in duration of the crop growth and rainfall which was received at the time of maturity. The moisture mining capacity of the barley crop from the profile (up to 120 cm) was increased with increase in the rate of nitrogen application. MUE of barley cultivars closely paralleled the grain yields, being more with hulled cultivars than hull-less ones. Higher MUE of barley was observed in the 2nd than in the 1st year of experimentation because of a better distribution of rainfall and moisture availability at the time of sowing, which boosted yields. Nitrogen application increased both yield and MUE of barley.


2012 ◽  
Vol 524-527 ◽  
pp. 421-425 ◽  
Author(s):  
Wen Yu Lv ◽  
Zhi Hui Zhang

This paper introduces the classification of the coal backfill mining method and analyzes current technology statuses of several coal backfill mining technologies: waste backfill mining technology, paste backfill mining technology and abscission layer grouting backfill mining technology. Based on the analysis of current backfill mining technology statuses, this paper puts forth that the backfill mining technology should focus on the problem of the lack of coal backfill mining capacity, research on the role of backfill mining rock movement needing to be strengthened, filling efficiency and economy needed to improved through reasonable optimization of backfill mining parameter, so it can provide the theoretical basis for backfill mining design.


iScience ◽  
2020 ◽  
pp. 102025
Author(s):  
Ryosuke Yokoi ◽  
Keisuke Nansai ◽  
Kenichi Nakajima ◽  
Takuma Watari ◽  
Masaharu Motoshita

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 5) ◽  
Author(s):  
Liang Zhang ◽  
Linchao Yang ◽  
Songhe Geng ◽  
Shaoran Ren

Abstract Based on the principle of wellbore self-circulation heat mining, the evaluation experiments of local wellbore self-circulation heat exchange laws and influencing factors were carried out. Water, SCCO2, R134a, and heat transfer oil were screened as the heat-carrying fluids. The heat exchange laws and heat mining capacity of these four heat carrying fluids were analyzed and compared, and their heat mining rates at the field scale were estimated using the similarity criterion method according to the experimental results. The results show that R134a and heat transfer oil can obtain the largest outlet temperature and the largest heat loss ratio, while the water can achieve a higher heat mining rate and a larger convective heat transfer coefficient than the other three fluids. The heat mining capacity of CO2 is significantly affected by the injection pressure. It is necessary to optimize the injection pressure larger than critical point to achieve the best heat mining performance. When the water is selected as the heat-carrying fluid, the heat mining rate can reach more than 1 MW if a horizontal wellbore with a length of 2000 m is applied for wellbore self-circulation at the field scale.


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