A 72-h ex situ hard coal gasification test in one large block of coal was carried out.The gasifying agent was oxygen with a constant flow rate of 4.5 m^(3)/h.The surroundings of coal were simulated with wet sand with ...A 72-h ex situ hard coal gasification test in one large block of coal was carried out.The gasifying agent was oxygen with a constant flow rate of 4.5 m^(3)/h.The surroundings of coal were simulated with wet sand with 11%moisture content.A 2-cm interlayer of siderite was placed in the horizontal cut of the coal block.As a result of this process,gas with an average flow rate of 12.46 m^(3)/h was produced.No direct influence of siderite on the gasification process was observed;however,measurements of CO_(2)content in the siderite interlayer before and after the process allow to determine the location of high-temperature zones in the reactor.The greatest influence on the efficiency of the gasification process was exerted by water contained in wet sand.At the high temperature that prevailed in the reactor,this water evaporated and reacted with the incandescent coal,producing hydrogen and carbon monoxide.This reaction contributes to the relatively high calorific value of the resulting process gas,averaging 9.41 MJ/kmol,and to the high energy efficiency of the whole gasification process,which amounts to approximately 70%.展开更多
In this study,the composition of tars collected during a six-day underground coal gasification(UCG)test at the experimental mine‘Barbara’in Poland in 2013 was examined.During the test,tar samples were taken every da...In this study,the composition of tars collected during a six-day underground coal gasification(UCG)test at the experimental mine‘Barbara’in Poland in 2013 was examined.During the test,tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven(coal)tar.The obtained results were compared with each other and with the data for coal tar.As gasification progressed,a decreasing trend in the water content and an increasing trend in the ash content were observed.The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline.All tested samples were characterized by very high distillation losses,while for samples starting from the third day of gasification,a clear decrease in losses was visible.A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar.The content of polycyclic aromatic hydrocarbons(PAHs)in UCG tars is several times lower than that in coal tar.No light monoaromatic hydrocarbons(benzene,toluene,ethylbenzene and xylenes—BTEX)were found in the analysed tars,which results from the fact that these compounds,due to their high volatility,did not separate from the process gas in the liquid product separator.展开更多
In contrast to Ref.[1]studying MHD processes in a helical channel induced by a vertical rotating electric current layer,in the present report we examine another version with the rotating electric current layer orthogo...In contrast to Ref.[1]studying MHD processes in a helical channel induced by a vertical rotating electric current layer,in the present report we examine another version with the rotating electric current layer orthogonal to the helical channel axis,which leads to an increase in melt velocity with the growing pitch angle α of the helical channel.展开更多
We examine MHD processes arising in melts placed in vessels of circular and rectangular cross-sections under the action of amplitude-and-frequency modulated rotating magnetic field.It is established that besides the m...We examine MHD processes arising in melts placed in vessels of circular and rectangular cross-sections under the action of amplitude-and-frequency modulated rotating magnetic field.It is established that besides the mean turbulent flow,seven oscillations arise in the melt,whose frequency and amplitude depend on modulation parameters.展开更多
We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD pa...We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD parameters of turbulent flow on the transfer process is studied.展开更多
According to scientific evidence in general, the disappearance of the Tatras tarns as a result of external geomorphological processes has been accepted since the long term analyses of lake sediments and peat bogs, geo...According to scientific evidence in general, the disappearance of the Tatras tarns as a result of external geomorphological processes has been accepted since the long term analyses of lake sediments and peat bogs, geomorphological mapping, geophysical measurements(– all indirect methods). It is paradoxical that the direct cartographic evidence of such changes has not existed until now. In this paper, we evaluate shore line changes of the small mountain glacial lake in the High Tatras-Litworowy Staw lake using a multitemporal analysis of a series of historical orthophotomaps and a historical map. Over the last 100 years, the tarn has lost 46.4% of open water level area. Significant visual changes were caused by vegetation growth of Carex species(sedges) on the water's surface. The accumulation of fine sediments and dead plant residues in the tarn basin create suitable conditions for this process, all together causing the tarn to become more shallow.展开更多
肾动脉射频消融术（radiofrequency ablation of the renal arteries,RF-ABL）已被证明能降低已接受降压药治疗但疗效不佳的高血压患者的血压。然而,现在仍然有很多疑问关于RF-ABL怎样做到不依赖药物治疗而影响血压,和是否有必要完全去...肾动脉射频消融术（radiofrequency ablation of the renal arteries,RF-ABL）已被证明能降低已接受降压药治疗但疗效不佳的高血压患者的血压。然而,现在仍然有很多疑问关于RF-ABL怎样做到不依赖药物治疗而影响血压,和是否有必要完全去肾神经来最大限度地降低血压。为了明确这些问题,本研究检测自发性高血压大鼠（spontaneously hypertensive rats,SHR）行近端肾动脉RF-ABL后对心血管、展开更多
Background:Diabetic macular edema(DME)is a leading cause of severe visual impairments in older and the working-age population.An important target of current therapy is vascular endothelial growth factor(VEGF),which pl...Background:Diabetic macular edema(DME)is a leading cause of severe visual impairments in older and the working-age population.An important target of current therapy is vascular endothelial growth factor(VEGF),which plays a role in the pathogenesis of DME by inducing angiogenesis and increasing vascular permeability.Currently available anti-VEGF agents include off-label use of Bevacizumab,which has been shown to be effective in the treatment of DME.However,many patients with DME do not respond or demonstrate only a partial response to this agent.As of November 2016,the Canadian Health authorities approved Aflibercept as an anti-VEGF agent for treatment of DME,and the patients who are non-responders to Bevacizumab are switched to this non-off label medication.We aimed to investigate the anatomical and functional visual changes associated with response to Aflibercept in a real-life Canadian population of Bevacizumab non-responders.Methods:A retrospective review of chronic DME patients refractory to bevacizumab treatment who were switched to Aflibercept was done.Best-corrected visual acuity(BCVA),Intraocular pressure(IOP),central subfield thickness(CST),average macular thickness,and total macular volume were extracted at the visit prior to switching to Aflibercept(baseline)as well as the first,second and third follow-up visits after switching.Anatomical and functional visual changes were compared using Generalized Estimating Equations and the association between variables was tested using Pearson correlation test with significance set at P<0.05.Results:Twenty-six eyes with mean age of 63 were included.Average CST at baseline was 421.5±116.1μm and the number of Bevacizumab injections received prior to switching was 15.3±8.0.No significant changes were observed in terms of BCVA and IOP,from baseline to any of the follow-ups.Switching to Aflibercept significantly improved CST,average macular thickness,and total macular volume.From baseline to the first follow-up visit,CST decreased from 421.5±116.1 to 333.0±91.2μm展开更多
基金The research presented in this article was performed within the work"Conducting an exsitu experiment of underground coal gasification with a mineral interlayer"commissioned and funded by the Silesian University of Technology in Gliwice,Department of Applied Geology,by order sign ZP/018521/18/ZZ/01987/18.
文摘A 72-h ex situ hard coal gasification test in one large block of coal was carried out.The gasifying agent was oxygen with a constant flow rate of 4.5 m^(3)/h.The surroundings of coal were simulated with wet sand with 11%moisture content.A 2-cm interlayer of siderite was placed in the horizontal cut of the coal block.As a result of this process,gas with an average flow rate of 12.46 m^(3)/h was produced.No direct influence of siderite on the gasification process was observed;however,measurements of CO_(2)content in the siderite interlayer before and after the process allow to determine the location of high-temperature zones in the reactor.The greatest influence on the efficiency of the gasification process was exerted by water contained in wet sand.At the high temperature that prevailed in the reactor,this water evaporated and reacted with the incandescent coal,producing hydrogen and carbon monoxide.This reaction contributes to the relatively high calorific value of the resulting process gas,averaging 9.41 MJ/kmol,and to the high energy efficiency of the whole gasification process,which amounts to approximately 70%.
基金This work was a part of the HUGE 2 project and was jointly supported by the Research Fund for Coal and Steel,under contract RFCR-CT-2011-00002 and by the Polish Ministry of Science and Higher Education.
文摘In this study,the composition of tars collected during a six-day underground coal gasification(UCG)test at the experimental mine‘Barbara’in Poland in 2013 was examined.During the test,tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven(coal)tar.The obtained results were compared with each other and with the data for coal tar.As gasification progressed,a decreasing trend in the water content and an increasing trend in the ash content were observed.The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline.All tested samples were characterized by very high distillation losses,while for samples starting from the third day of gasification,a clear decrease in losses was visible.A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar.The content of polycyclic aromatic hydrocarbons(PAHs)in UCG tars is several times lower than that in coal tar.No light monoaromatic hydrocarbons(benzene,toluene,ethylbenzene and xylenes—BTEX)were found in the analysed tars,which results from the fact that these compounds,due to their high volatility,did not separate from the process gas in the liquid product separator.
基金Item Sponsored by framework of International Scientific Project No.C26/251 "MHD Liquid Metal Stirring and its Effect on the Structure of Solidifying Alloys"and Resaerch Center"Mathematical Models of the Continuous Media" (PermRussian Federation)
文摘In contrast to Ref.[1]studying MHD processes in a helical channel induced by a vertical rotating electric current layer,in the present report we examine another version with the rotating electric current layer orthogonal to the helical channel axis,which leads to an increase in melt velocity with the growing pitch angle α of the helical channel.
文摘We examine MHD processes arising in melts placed in vessels of circular and rectangular cross-sections under the action of amplitude-and-frequency modulated rotating magnetic field.It is established that besides the mean turbulent flow,seven oscillations arise in the melt,whose frequency and amplitude depend on modulation parameters.
文摘We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD parameters of turbulent flow on the transfer process is studied.
基金produced under the scientific project VEGA 1/0207/17–Development and changes of mountain landscape of the Tatrasthe tarn,and to what extent the anthropogenic factors and climate change make them conditional
文摘According to scientific evidence in general, the disappearance of the Tatras tarns as a result of external geomorphological processes has been accepted since the long term analyses of lake sediments and peat bogs, geomorphological mapping, geophysical measurements(– all indirect methods). It is paradoxical that the direct cartographic evidence of such changes has not existed until now. In this paper, we evaluate shore line changes of the small mountain glacial lake in the High Tatras-Litworowy Staw lake using a multitemporal analysis of a series of historical orthophotomaps and a historical map. Over the last 100 years, the tarn has lost 46.4% of open water level area. Significant visual changes were caused by vegetation growth of Carex species(sedges) on the water's surface. The accumulation of fine sediments and dead plant residues in the tarn basin create suitable conditions for this process, all together causing the tarn to become more shallow.
文摘肾动脉射频消融术（radiofrequency ablation of the renal arteries,RF-ABL）已被证明能降低已接受降压药治疗但疗效不佳的高血压患者的血压。然而,现在仍然有很多疑问关于RF-ABL怎样做到不依赖药物治疗而影响血压,和是否有必要完全去肾神经来最大限度地降低血压。为了明确这些问题,本研究检测自发性高血压大鼠（spontaneously hypertensive rats,SHR）行近端肾动脉RF-ABL后对心血管、
文摘Background:Diabetic macular edema(DME)is a leading cause of severe visual impairments in older and the working-age population.An important target of current therapy is vascular endothelial growth factor(VEGF),which plays a role in the pathogenesis of DME by inducing angiogenesis and increasing vascular permeability.Currently available anti-VEGF agents include off-label use of Bevacizumab,which has been shown to be effective in the treatment of DME.However,many patients with DME do not respond or demonstrate only a partial response to this agent.As of November 2016,the Canadian Health authorities approved Aflibercept as an anti-VEGF agent for treatment of DME,and the patients who are non-responders to Bevacizumab are switched to this non-off label medication.We aimed to investigate the anatomical and functional visual changes associated with response to Aflibercept in a real-life Canadian population of Bevacizumab non-responders.Methods:A retrospective review of chronic DME patients refractory to bevacizumab treatment who were switched to Aflibercept was done.Best-corrected visual acuity(BCVA),Intraocular pressure(IOP),central subfield thickness(CST),average macular thickness,and total macular volume were extracted at the visit prior to switching to Aflibercept(baseline)as well as the first,second and third follow-up visits after switching.Anatomical and functional visual changes were compared using Generalized Estimating Equations and the association between variables was tested using Pearson correlation test with significance set at P<0.05.Results:Twenty-six eyes with mean age of 63 were included.Average CST at baseline was 421.5±116.1μm and the number of Bevacizumab injections received prior to switching was 15.3±8.0.No significant changes were observed in terms of BCVA and IOP,from baseline to any of the follow-ups.Switching to Aflibercept significantly improved CST,average macular thickness,and total macular volume.From baseline to the first follow-up visit,CST decreased from 421.5±116.1 to 333.0±91.2μm
