The use of alternative fuels to generate mechanical and thermal energy in engines is a promising and sought-after technological area with its own unique advantages and characteristics.Consequently,enhancing the techni...The use of alternative fuels to generate mechanical and thermal energy in engines is a promising and sought-after technological area with its own unique advantages and characteristics.Consequently,enhancing the technical,economic,and environmental efficiency of gas engines fueled by propane-butane mixture and syngas through optimized operating cycle parameters(including valve timing,ignition timing angle,fuel mixture composition,and compression ratio)is a pressing imperative for scientific and energy sectors.The aim of the study was to investigate and compare the performance of an engine with different compression ratios running on a propane-butane mixture and laboratory syngas.The research’s primary originality lies in its joint study of syngas production technology and the evaluation of the efficiency of a mini power plant fueled by the resulting gas and conventional gas.This article presents a description of the experimental setup,data on measuring instruments,technical characteristics of the mini-power plant,the process for obtaining laboratory syngas,the properties of the gaseous fuels used,and experimental methods.Data on air and fuel consumption,as well as engine efficiency at different compression ratios when running on a propane-butane mixture and syngas,were obtained and analyzed.Converting an engine from a propane-butane mixture to syngas results in a reduction in power of almost 30% and efficiency by 13%–33%.Increasing the compression ratio by 0.9 units causes a rise in maximum efficiency from 0.177 to 0.235 for an engine running on a propane-butane mixture and an increase in maximum efficiency from 0.136 to 0.161 for a syngas engine.It has been confirmed that the compression ratio significantly impacts the technical and economic performance of an engine running on gaseous fuel.The obtained results can be used to modernize existing engines for operation on alternative fuels(syngas)and to design new mini-power plants with promising technical,economic,and environmental characteristics.展开更多
On May 1st, China National Nuclear Corporation(CNNC) announced in Beijing that unit 1 and unit 2 ofTianwan Nuclear Power Plant cooperatively constructedby China and Russia have completed in succession thefirst fuel cy...On May 1st, China National Nuclear Corporation(CNNC) announced in Beijing that unit 1 and unit 2 ofTianwan Nuclear Power Plant cooperatively constructedby China and Russia have completed in succession thefirst fuel cycle operation continuously and safely. It is展开更多
Objective The use of lasers has been an important part of urology in the treatment of stone and prostate disease.The thermal effects of lasers in lithotripsy have been a subject of debate over the years.The objective ...Objective The use of lasers has been an important part of urology in the treatment of stone and prostate disease.The thermal effects of lasers in lithotripsy have been a subject of debate over the years.The objective of this review was to assess the current state of knowledge available on the thermal effects of lasers in lithotripsy,as well as explore any new areas where studies are needed.Methods In August 2022,a keyword search on Google Scholar,PubMed,and Scopus for all papers containing the phrases“thermal effects”AND“laser”AND“lithotripsy”AND“urology”was done followed by citation jumping to other studies pertaining to the topic and 35 relevant papers were included in our study.The data from relevant papers were segregated into five groups according to the factor studied and type of study,and tables were created for a comparison of data.Results Temperature above the threshold of 43℃ was reached only when the power was>40 W and when there was adequate irrigation(at least 15–30 mL/min).Shorter lasing time divided by lithotripsy time or operator duty cycles less than 70%also resulted in a smaller temperature rise.Conclusion At least eight factors modify the thermal effects of lasers,and most importantly,the use of chilled irrigation at higher perfusion rates,lower power settings of<40 W,and with a shorter operator duty cycle will help to prevent thermal injuries from occurring.Stones impacted in the ureter or pelvi-ureteric junction further increase the probability of thermal injuries during laser firing.展开更多
In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has develope...In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor.The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals,sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor.In the meantime,the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years,resulting in minimization of losses caused by refinery downtime.展开更多
文摘The use of alternative fuels to generate mechanical and thermal energy in engines is a promising and sought-after technological area with its own unique advantages and characteristics.Consequently,enhancing the technical,economic,and environmental efficiency of gas engines fueled by propane-butane mixture and syngas through optimized operating cycle parameters(including valve timing,ignition timing angle,fuel mixture composition,and compression ratio)is a pressing imperative for scientific and energy sectors.The aim of the study was to investigate and compare the performance of an engine with different compression ratios running on a propane-butane mixture and laboratory syngas.The research’s primary originality lies in its joint study of syngas production technology and the evaluation of the efficiency of a mini power plant fueled by the resulting gas and conventional gas.This article presents a description of the experimental setup,data on measuring instruments,technical characteristics of the mini-power plant,the process for obtaining laboratory syngas,the properties of the gaseous fuels used,and experimental methods.Data on air and fuel consumption,as well as engine efficiency at different compression ratios when running on a propane-butane mixture and syngas,were obtained and analyzed.Converting an engine from a propane-butane mixture to syngas results in a reduction in power of almost 30% and efficiency by 13%–33%.Increasing the compression ratio by 0.9 units causes a rise in maximum efficiency from 0.177 to 0.235 for an engine running on a propane-butane mixture and an increase in maximum efficiency from 0.136 to 0.161 for a syngas engine.It has been confirmed that the compression ratio significantly impacts the technical and economic performance of an engine running on gaseous fuel.The obtained results can be used to modernize existing engines for operation on alternative fuels(syngas)and to design new mini-power plants with promising technical,economic,and environmental characteristics.
文摘On May 1st, China National Nuclear Corporation(CNNC) announced in Beijing that unit 1 and unit 2 ofTianwan Nuclear Power Plant cooperatively constructedby China and Russia have completed in succession thefirst fuel cycle operation continuously and safely. It is
文摘Objective The use of lasers has been an important part of urology in the treatment of stone and prostate disease.The thermal effects of lasers in lithotripsy have been a subject of debate over the years.The objective of this review was to assess the current state of knowledge available on the thermal effects of lasers in lithotripsy,as well as explore any new areas where studies are needed.Methods In August 2022,a keyword search on Google Scholar,PubMed,and Scopus for all papers containing the phrases“thermal effects”AND“laser”AND“lithotripsy”AND“urology”was done followed by citation jumping to other studies pertaining to the topic and 35 relevant papers were included in our study.The data from relevant papers were segregated into five groups according to the factor studied and type of study,and tables were created for a comparison of data.Results Temperature above the threshold of 43℃ was reached only when the power was>40 W and when there was adequate irrigation(at least 15–30 mL/min).Shorter lasing time divided by lithotripsy time or operator duty cycles less than 70%also resulted in a smaller temperature rise.Conclusion At least eight factors modify the thermal effects of lasers,and most importantly,the use of chilled irrigation at higher perfusion rates,lower power settings of<40 W,and with a shorter operator duty cycle will help to prevent thermal injuries from occurring.Stones impacted in the ureter or pelvi-ureteric junction further increase the probability of thermal injuries during laser firing.
文摘In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor.The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals,sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor.In the meantime,the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years,resulting in minimization of losses caused by refinery downtime.
