In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites.The surfactant present in flushing solutions is bound to affect the aeration efficiency.The purpose of this s...In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites.The surfactant present in flushing solutions is bound to affect the aeration efficiency.The purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MNB)aeration system.Firstly,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MNB aeration system.Then,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MNB aeration.The results showed that,for the twenty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)increased.These phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant solutions.In addition,with the presence of electric charge,MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant solutions.Furthermore,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant solutions.Besides,the modified Frossling's model predicted the effect of surfactant on kL in MNB aeration system with reasonable accuracy.展开更多
Estimating the residual heat of blast furnace slag flushing in China,classifying and introducing the current proposed methods of slag flushing waste heat utilization,and listing existing cases.In order to better save ...Estimating the residual heat of blast furnace slag flushing in China,classifying and introducing the current proposed methods of slag flushing waste heat utilization,and listing existing cases.In order to better save energy and water in the slag flushing process of blast furnaces,an ideal comprehensive cascade utilization system scheme for annual recovery of waste heat is proposed.Based on the measured waste heat data of a steel plant,design calculations are carried out to further analyze the economic feasibility of the new scheme and provide reference for its promotion and application.展开更多
To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its gas migration performance.In this research,a directional hydraulic flushing(DHF)techno...To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its gas migration performance.In this research,a directional hydraulic flushing(DHF)technology was carried out.The stress-unloading and gas migration improvement mechanism was analyzed through numerical simulation,and systematic engineering tests were conducted to verify the gas drainage effect.The results show that the improvement of gas migration performance in the SHI coal seam is caused by a combined effect of seepage-improving and diffusion-improving.After DHF,stress-unloading and plastic failure could be achieved both in the soft coal(SC)sublayer and in the hard coal(HC)sublayer.However,the gas diffusion capacity improves significantly in the SC sublayer,while the gas seepage capacity improves notably in the HC sublayer.Meanwhile,the stress-unloading and gas migration improvement effect improves with the flushing radius and the thickness of the SC sublayer.Besides,after adopting the DHF technology,the gas drainage effect improved markedly.The borehole number dropped by 49%,the gas drainage ratio increased from 26.0%to 48.2%,and the average coal roadway excavation speed increased from 2.4 to 5.6 m/d.展开更多
Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供...Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供修井服务,以降低桶油成本。本文介绍了Flush by Unit的结构组成、使用范围、现场使用效果,与传统修井机相比,可以大幅降低作业时间和成本,为后续规模使用Flush by Unit进行常规修井提供了依据,也为油田的增产稳产带来了机遇。展开更多
BACKGROUND Vancomycin flushing syndrome(VFS),also known as red man syndrome,is an allergic reaction to vancomycin.It typically presents as a rash on the face,neck,and upper torso after intravenous administration of va...BACKGROUND Vancomycin flushing syndrome(VFS),also known as red man syndrome,is an allergic reaction to vancomycin.It typically presents as a rash on the face,neck,and upper torso after intravenous administration of vancomycin.VFS is blamed on rapid intravenous infusion of vancomycin during management and rarely happens after local use.A review of the literature showed that in the last 23 years,4 such cases have been reported.Here,we add another case of VFS developed after slow local absorption of vancomycin in cement beads.CASE SUMMARY A 44-year-old male with a known case of hypertension,no history of allergies to medications,and a history of chronic osteomyelitis of the right tibia with discharging sinus over the anterolateral aspect of the leg.The pus culture grew Staphylococcus aureus,which was sensitive to clindamycin and vancomycin.The patient underwent irrigation and debridement with the placement of vancomycin cement beads made from 4 g of vancomycin powder and 40 g of polymethyl methacrylate.Three hours postoperatively,the patient developed a pruritic,erythematous,macular rash predominantly on his face,neck,chest,and lower extremities and to a lesser extent his upper extremities.A diagnosis of VFS was made and was successfully treated with cetirizine(10 mg,oral)and methylprednisolone sodium succinate(125 mg,intravenous).The patient continued to have itching with a facial rash for 12 h with gradual improvement.A decision was made to not remove the beads as the patient continued to improve.Gradually,the rash disappeared after 96 h with no further sequela.CONCLUSION VFS can occur not only after rapid intravenous injection of vancomycin but also with local release,as in our case.As orthopaedic surgeons routinely use vancomycin with polymethyl methacrylate in chronic osteomyelitis and revision arthroplasty,they should be aware of such a complication occurring.展开更多
The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbu...The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbulence model is used to calculate its internal and externalflowfields.In particular,special attention is paid to the design of theflushing nozzle.The results show that the jet originating from theflushing nozzle has a significant influence on rock cutting and blade cooling effects.In turn,the jet performances depend on geometric structure of the creaming actuator.In this framework,a conical-cylindrical nozzle with a diameter of 7 mm is initially considered as a basis to implement a strategy to optimize the structural parameters of the reaming actuator,and improve the related side tracking reconstruction technology.展开更多
基金financially supported by the National Natural Science Foundation of China(41877240)National Key Research and Development Program of China(2018YFC1802300)Scientific Research Foundation of Graduate School of Southeast University(YBPY2154).
文摘In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites.The surfactant present in flushing solutions is bound to affect the aeration efficiency.The purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MNB)aeration system.Firstly,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MNB aeration system.Then,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MNB aeration.The results showed that,for the twenty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)increased.These phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant solutions.In addition,with the presence of electric charge,MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant solutions.Furthermore,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant solutions.Besides,the modified Frossling's model predicted the effect of surfactant on kL in MNB aeration system with reasonable accuracy.
文摘Estimating the residual heat of blast furnace slag flushing in China,classifying and introducing the current proposed methods of slag flushing waste heat utilization,and listing existing cases.In order to better save energy and water in the slag flushing process of blast furnaces,an ideal comprehensive cascade utilization system scheme for annual recovery of waste heat is proposed.Based on the measured waste heat data of a steel plant,design calculations are carried out to further analyze the economic feasibility of the new scheme and provide reference for its promotion and application.
基金the financial support from the National Natural Science Foundation of China(Nos.52104210,52174217,and 51874294)the Natural Science Foundation of Shanxi Province(No.20210302124350)Project Funded by China Postdoctoral Science Foundation(No.2022M710595).
文摘To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its gas migration performance.In this research,a directional hydraulic flushing(DHF)technology was carried out.The stress-unloading and gas migration improvement mechanism was analyzed through numerical simulation,and systematic engineering tests were conducted to verify the gas drainage effect.The results show that the improvement of gas migration performance in the SHI coal seam is caused by a combined effect of seepage-improving and diffusion-improving.After DHF,stress-unloading and plastic failure could be achieved both in the soft coal(SC)sublayer and in the hard coal(HC)sublayer.However,the gas diffusion capacity improves significantly in the SC sublayer,while the gas seepage capacity improves notably in the HC sublayer.Meanwhile,the stress-unloading and gas migration improvement effect improves with the flushing radius and the thickness of the SC sublayer.Besides,after adopting the DHF technology,the gas drainage effect improved markedly.The borehole number dropped by 49%,the gas drainage ratio increased from 26.0%to 48.2%,and the average coal roadway excavation speed increased from 2.4 to 5.6 m/d.
文摘Capella油田是哥伦比亚南部重要的稠油油田,目前处于开发生产阶段,为了油田的稳产增产,需频繁对油井进行干预。Flush by Unit具有操作简单、移动高效、作业时间缩短、安全事故少等优点,作为试点引入了Flush by Unit为该油田的浅井提供修井服务,以降低桶油成本。本文介绍了Flush by Unit的结构组成、使用范围、现场使用效果,与传统修井机相比,可以大幅降低作业时间和成本,为后续规模使用Flush by Unit进行常规修井提供了依据,也为油田的增产稳产带来了机遇。
文摘BACKGROUND Vancomycin flushing syndrome(VFS),also known as red man syndrome,is an allergic reaction to vancomycin.It typically presents as a rash on the face,neck,and upper torso after intravenous administration of vancomycin.VFS is blamed on rapid intravenous infusion of vancomycin during management and rarely happens after local use.A review of the literature showed that in the last 23 years,4 such cases have been reported.Here,we add another case of VFS developed after slow local absorption of vancomycin in cement beads.CASE SUMMARY A 44-year-old male with a known case of hypertension,no history of allergies to medications,and a history of chronic osteomyelitis of the right tibia with discharging sinus over the anterolateral aspect of the leg.The pus culture grew Staphylococcus aureus,which was sensitive to clindamycin and vancomycin.The patient underwent irrigation and debridement with the placement of vancomycin cement beads made from 4 g of vancomycin powder and 40 g of polymethyl methacrylate.Three hours postoperatively,the patient developed a pruritic,erythematous,macular rash predominantly on his face,neck,chest,and lower extremities and to a lesser extent his upper extremities.A diagnosis of VFS was made and was successfully treated with cetirizine(10 mg,oral)and methylprednisolone sodium succinate(125 mg,intravenous).The patient continued to have itching with a facial rash for 12 h with gradual improvement.A decision was made to not remove the beads as the patient continued to improve.Gradually,the rash disappeared after 96 h with no further sequela.CONCLUSION VFS can occur not only after rapid intravenous injection of vancomycin but also with local release,as in our case.As orthopaedic surgeons routinely use vancomycin with polymethyl methacrylate in chronic osteomyelitis and revision arthroplasty,they should be aware of such a complication occurring.
基金support by the Marine Economy Development Foundation of Guangdong Province(Grant No.GDNRC[2022]44).
文摘The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbulence model is used to calculate its internal and externalflowfields.In particular,special attention is paid to the design of theflushing nozzle.The results show that the jet originating from theflushing nozzle has a significant influence on rock cutting and blade cooling effects.In turn,the jet performances depend on geometric structure of the creaming actuator.In this framework,a conical-cylindrical nozzle with a diameter of 7 mm is initially considered as a basis to implement a strategy to optimize the structural parameters of the reaming actuator,and improve the related side tracking reconstruction technology.
