Organic aerosol is formed in coal mines due to heat release and evaporation of organics from coal during the longwall operation.This frictional heating occurs when a metallic cutting bit strikes a rock.Thus formed org...Organic aerosol is formed in coal mines due to heat release and evaporation of organics from coal during the longwall operation.This frictional heating occurs when a metallic cutting bit strikes a rock.Thus formed organic aerosol can contribute significantly to the explosivity of methane/air atmosphere in coal mines.In this paper,the flammable limits for the methane-air mixtures with organic aerosol are determined.For this purpose,organic aerosol is synthesizes from the coal-tar pitch in a laboratory evaporation-nucleation flow chamber.Aerosol particles synthesized under laboratory conditions are aggregates consisting of small primary particles with the fractal-like dimension Df=2.0±0.1,which is close to Df=2.1±0.1 of coal mine aerosol.It is shown that the flammability of organic aerosol/methane mixture in air is in good agreement with the Le Chatelier additive principle.The lower ignition limit for the pure organic aerosol in air is 44 g/m^3.展开更多
This study investigates speculative bubbles in the cryptocurrency market and factors affecting bubbles during the COVID-19 pandemic.Our results indicate that each cryptocurrency covered in the study presented bubbles....This study investigates speculative bubbles in the cryptocurrency market and factors affecting bubbles during the COVID-19 pandemic.Our results indicate that each cryptocurrency covered in the study presented bubbles.Moreover,we found that explosive behavior in one currency leads to explosivity in other cryptocurrencies.During the pandemic,herd behavior was evident among investors;however,this diminishes during bubbles,indicating that bubbles are not explained by herd behavior.Regarding cryptocurrency and market-specific factors,we found that Google Trends and volume are positively associated with predicting speculative bubbles in time-series and panel probit regressions.Hence,investors should exercise caution when investing in cryptocurrencies and follow both crypto currency and market-related factors to estimate bubbles.Alternative liquidity,volatility,and Google Trends measures are used for robustness analysis and yield similar results.Overall,our results suggest that bubble behavior is common in the cryptocurrency market,contradicting the efficient market hypothesis.展开更多
基金RFBR and Novosibirsk region(Grant No.19-43-540009).
文摘Organic aerosol is formed in coal mines due to heat release and evaporation of organics from coal during the longwall operation.This frictional heating occurs when a metallic cutting bit strikes a rock.Thus formed organic aerosol can contribute significantly to the explosivity of methane/air atmosphere in coal mines.In this paper,the flammable limits for the methane-air mixtures with organic aerosol are determined.For this purpose,organic aerosol is synthesizes from the coal-tar pitch in a laboratory evaporation-nucleation flow chamber.Aerosol particles synthesized under laboratory conditions are aggregates consisting of small primary particles with the fractal-like dimension Df=2.0±0.1,which is close to Df=2.1±0.1 of coal mine aerosol.It is shown that the flammability of organic aerosol/methane mixture in air is in good agreement with the Le Chatelier additive principle.The lower ignition limit for the pure organic aerosol in air is 44 g/m^3.
文摘This study investigates speculative bubbles in the cryptocurrency market and factors affecting bubbles during the COVID-19 pandemic.Our results indicate that each cryptocurrency covered in the study presented bubbles.Moreover,we found that explosive behavior in one currency leads to explosivity in other cryptocurrencies.During the pandemic,herd behavior was evident among investors;however,this diminishes during bubbles,indicating that bubbles are not explained by herd behavior.Regarding cryptocurrency and market-specific factors,we found that Google Trends and volume are positively associated with predicting speculative bubbles in time-series and panel probit regressions.Hence,investors should exercise caution when investing in cryptocurrencies and follow both crypto currency and market-related factors to estimate bubbles.Alternative liquidity,volatility,and Google Trends measures are used for robustness analysis and yield similar results.Overall,our results suggest that bubble behavior is common in the cryptocurrency market,contradicting the efficient market hypothesis.
