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
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
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
Accurate determination of flushing time is crucial for maintaining sustainable production in fish culture zones (FCZs), as it represents the physical self-purification capability via tidal exchange with clean water ...Accurate determination of flushing time is crucial for maintaining sustainable production in fish culture zones (FCZs), as it represents the physical self-purification capability via tidal exchange with clean water in the outer sea. However, owing to the temporal and spatial complexity of the coastal flushing process, existing methods for determining flushing time may not be generally applicable. In this paper, a systematic method for determining the flushing time in FCZs is presented, in which bathymetry, runoff, tidal range and stratification are properly accounted for. We determine the flushing time via numerical tracer experiments, using robust 3D hydrodynamic and mass transport models. For FCZs located in sheltered and land-locked tidal inlets, the system boundary can be naturally defined at the connection with the open sea. For FCZs located in open'waters, hydrodynamic tracking is first used to assess the extent of tidal excursion and thus delimit the initial boundary between clean water and polluted water. This general method is applied to all designated marine FCZs in Hong Kong for both the dry and wet seasons, including 20 sheltered FCZs (in semi-enclosed waters of Tolo Harbour, Mirs Bay, and Port Shelter) and 6 FCZs in open waters. Our results show that flushing time is the longest in inner Port Shelter (about 40 days in dry season), and the shortest for the FCZs in open waters (less than one week in dry season). In addition, the flushing time in dry season is commonly longer than that in wet season: 20%~40% for most well-sheltered FCZs; 2.6-4 times for the others. Our results indicate a positive correlation between the flushing time and distance to open boundary, supporting the view that the flushing time of a FCZ is closely related to its location. This study provides a solid basis for mariculture management such as the determination of carrying capacity of FCZs.展开更多
Field experiments were carried out at the National Research Center farm, Nubaria area, Behura Governorate, Egypt, to study the effect of nitrogen source, flushing schedule and irrigation method on emitter clogging. Pe...Field experiments were carried out at the National Research Center farm, Nubaria area, Behura Governorate, Egypt, to study the effect of nitrogen source, flushing schedule and irrigation method on emitter clogging. Peanut Giza 5 variety (Arachishy pogaea L.) was planted in sandy soil during two successive growing seasons (2010-2011) in the 1st week of May and harvested after 130 days. Treatments used are: 1) two irrigation methods: surface drip irrigation and sub-surface drip irrigation (SDI;SSDI), 2) nitrogen source (NS):NH4NO3, (NH4)2SO4 and Ca(NO3)2 (NS1, NS2 and NS3) and 3) flushing number (FL) 0, 1 and 4 (FL1, FL2;FL3). The experiments design was split-split plot and three replicates were used. Data obtained were subjected to statistical analysis. The main effects of treatments used on clogging per cent could be written the following ascending orders: SDI 3 2 1, NS1 2 3. Concerning the 1st interaction the following ascending orders denote their effects on clogging percent: SDI × FL3 2 1, SDI × NS1 2 3, SSDI × FL3 2 1, SSDI × NS1 2 3, FL1 × NS1 1 × NS2 1 × NS3, FL2 × NS1 2 × NS2 2 × NS3 and FL3 × NS1 3 × NS2 3 × NS3. The differences between any two treatments and/or any two interactions in clogging percent were significant at the 5% level. The effect of the 2nd interaction on clogging percent was significant at the 5% level. The maximum value of clogging (20.18%) and the lowest one (3.9%) were archived in the interactions: SSDI × FL1 × NS3 and SDI × FL3 × NS1, respectively.展开更多
The activity of matrix metalloproteinases (MMPs) in the uterine flushing and endometrial tissue of normal adult women wearing FCu IUD (fixed Cu IUD) or FICu IUD (indomethacin releasing FCu IUD) was observed by us...The activity of matrix metalloproteinases (MMPs) in the uterine flushing and endometrial tissue of normal adult women wearing FCu IUD (fixed Cu IUD) or FICu IUD (indomethacin releasing FCu IUD) was observed by using zymography on SDS PAGE containing gelatin. The results showed that the activity and kinds of MMPs in FCu IUD group were increased significantly as compared with themselves before being inserted FCu IUD. However, compared with the FCu IUD group, the activity of some kinds of MMPs in the FICu IUD group was decreased significantly. These data suggest that IUD can enhance the activity of MMPs in human endometrium, intermediated by prostaglandins, and MMPs may have relation to IUD induced menorrhagia and indomethacin reduces IUD induced menorrhagia by partly inhibiting MMPs synthesis.展开更多
This paper analyzes the situation at the Iffezheim barrage along the fiver Rhine.Since the start of operation in 1977 several million cubic meters of very fine sediment have been deposited in the reservoir.Be- cause o...This paper analyzes the situation at the Iffezheim barrage along the fiver Rhine.Since the start of operation in 1977 several million cubic meters of very fine sediment have been deposited in the reservoir.Be- cause of stability problems and reduced safety in the event of flooding,an extraction of the material is neces- sary.Chemical assays showed a high concentration of HCB.Therefore flushing without any additional measures is not appropriate.In order to leam more about the morphological and chemical in...展开更多
Objective: To discuss the effect of vacuum sealing drainage combined with intermittent insulin flushing on the expression of inflammatory factors and apoptosis factors in diabetic lower limb ulcer wound. Methods: A to...Objective: To discuss the effect of vacuum sealing drainage combined with intermittent insulin flushing on the expression of inflammatory factors and apoptosis factors in diabetic lower limb ulcer wound. Methods: A total of 48 patients with diabetic lower limb ulcer who were treated in the Endocrine Department of the hospital between January 2016 and January 2017 were divided into the control group and research group by random number table, 24 cases in each group. Control group received vacuum sealing drainage, and research group received vacuum sealing drainage combined with intermittent insulin flushing. The differences in the expression of inflammatory factors and apoptosis genes in the wound exudate were compared between the two groups before and after treatment. Results: Before treatment, the differences in the inflammatory factor contents and apoptsis gene expression in wound exudate were not statistically significant between the two groups of patients. After treatment, inflammatory factors IL-6, IL-1β, TNF-α, CRP, VCAM-1 and FGF2 contents in wound exudate of research group were lower than those of control group;apoptosis gene Bcl-2 mRNA expression in wound exudate of research group was higher than that of control group while Bax, p53 and Fas mRNA expression were lower than those of control group. Conclusions: Vacuum sealing drainage combined with intermittent insulin flushing can effectively reduce the local inflammatory response and promote the granulation cell proliferation in wound of patients with diabetic lower limb ulcer.展开更多
Foam flushing is an in situ soil remediation technology based on the traditional surfactant flushing method. The contribution of mobility control to contaminant removal by foam is helpful for improving this technology...Foam flushing is an in situ soil remediation technology based on the traditional surfactant flushing method. The contribution of mobility control to contaminant removal by foam is helpful for improving this technology. Foam flushing of polychlorinated biphenyl (PCB)- contaminated unconsolidated media was performed to evaluate the effect of the partition coefficient (PC) and sweep efficiency (SE) on PCB removal. Column flushing with surfactant solution and foam with different types and concentrations of surfactant was carried out for PCB removal. Two types of quartz sand were investigated to evaluate the Jamin effect on the SE value of the washing agent. The results demonstrate that a small PC value and large SE value are necessary to achieve high PCB removal for foam flushing. Compared with solution flushing, the introduction of foam can effectively control the mobility of the washing agent. Similar to solution flushing, solubilization is a key factor which dominates the removal of PCBs in foam flushing, In addition, the SE value and PCB removal by foam flushing is less affected by particle size. Therefore, foam flushing was proved to be more effective in porous media with low hydraulic conductivity and high porosity. An integrated flushing with water, surfactant solution and foam was performed and the results prove that this technology successfully combines the advantages of solution solubilization and mobility control by foam, and thus further increases the remediation efficiency of PCBs to 94.7% for coarse sand.展开更多
Soil contamination by diesel has been often reported as a result of accidental spillage,leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydr...Soil contamination by diesel has been often reported as a result of accidental spillage,leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates(LAS, an anionic surfactant) was conducted for intact columns(15 cm in diameter and 12 cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes(representing the diesel) varied with the depth of the topsoil in the range of 14%–96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores(30–250 μm in diameter)was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores.展开更多
Flushing time of the Yangtze estuary by discharge is one of the importantfactors responsible for the transport of pollutants from various sources located along the Yangtzeestuary: Therefore, an objective of the presen...Flushing time of the Yangtze estuary by discharge is one of the importantfactors responsible for the transport of pollutants from various sources located along the Yangtzeestuary: Therefore, an objective of the present stud-y, which analysis flushing time in the case ofdifferent discharge is very helpful to evaluate the water environmental of the Yangtze estuary.Using a dissolved conservative material as a tracer in the water, a three-dimensionadvection-diffusion water exchange numerical model was used to study the flushing time by dischargeand the discharge dominated region of the Yangtze estuary. The initial tracer concentration is setto 0.0 in the numerical domain of the Yangtze estuary, and the concentration value is set to 1. 0 onthe inflow boundary. The tracer flux normal to the solid boundary is set to 0. 0. The flushing timeand the out limit of discharge dominated region can be calculated in terms of the tracerconcentration. Estuarine, Coastal and Ocean Model (ECOM) is used as the hydro-dynamic model. Theresult shows that the flushing time is approximately in inverse proportion to the discharge at theupper stream. The out limit is farther from the upper inflow boundary as discharge increases. Theout limit at the north branch is different from that of the south branch because the discharge intothe north branch is much less than that into the south branch. The data is qualitative similar tothe observed data, which show the three-dimensional advection-diffusion equation can be used toestimate the flushing time and the discharge dominated region of the Yangtze estuary.展开更多
Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabri...Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys. Wire electrochemical machining (WECM) is mainly used for workpiece cutting under the condition of different thickness plates. It has a great advantage over wire electro-discharge machining, which is the absence of heat-affected zone around the cutting area. Moreover, the wire electrode in WECM could be used repetitively because it is not worn out. Thus, much attention has been paid to WECM. The effective way of removing electrolysis products is of importance to WECM. In this paper, the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte. The Taguchi experiment is conducted to optimize the machining parameters, such as wire feedrate, machining voltage, electrolyte concentration, etc. Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy (TC1). The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.展开更多
Phytoremediation and soil washing are both potentially useful for remediating arsenic(As)-contaminated soils.We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing f...Phytoremediation and soil washing are both potentially useful for remediating arsenic(As)-contaminated soils.We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot study.The results showed that growing Pteris vittata L.(P.v.) accompanied by soil flushing of phosphate(P.v./Flushing treatment) could significantly decrease the total As concentration of soil over a 37 day flushing period compared with the single flushing(Flushing treatment).The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment,suggesting that the growth of P.vittata was beneficial for promoting the removal efficiency.We analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined process.Results showed that comparing with the control treatment,the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing treatment.As concentration in soil solution remained a high lever during the middle and later periods(51.26–56.22 mg/L),which was significantly higher than the Flushing treatment.Although soil flushing of phosphate for more than a month,P.vittata still had good accumulation and transfer capacity of As of the soil.The results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils.展开更多
A three-dimensional hydrodynamic model with the capability to deal with changing land water boundaries was developed based on ECOMSED in this study. The model was configured to numerically study the water flushing cha...A three-dimensional hydrodynamic model with the capability to deal with changing land water boundaries was developed based on ECOMSED in this study. The model was configured to numerically study the water flushing characteristics of Dahuofang Reservoir in China through the determination of spatially distributed residence times. The model successfully reproduced the intra-annual water level variations, as well as the temporal evolution and spatial distribution of water temperature. Through a series of numerical experiments, it can be concluded that (1) the water flushing of the reservoir is both temporally and spatially variable; and (2) inflows and withdrawals are the decisive factors influencing the water flushing characteristics. Heat fluxes are the controlling factors of the water flushing of a strong stratified reservoir. Wind has the weakest effect, but it still should be considered in determination of reservoir water flushing characteristics.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
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.
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.
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supported by the Hong Kong Jockey Club Charities Trust (Project Waterman)in part by a grant from the University Grants Committee of the Hong Kong Special Administrative Region (HKSAR),China (Project No. AoE/P-04/04) to the Area of Excellence in Marine Environment Research and Innovative Technology (MERIT)+1 种基金The support from the National Science Fund for Distinguished Young Scholars (Grant No. 50925932)the National Natural Science Foundation of China (Grant No.41001348)
文摘Accurate determination of flushing time is crucial for maintaining sustainable production in fish culture zones (FCZs), as it represents the physical self-purification capability via tidal exchange with clean water in the outer sea. However, owing to the temporal and spatial complexity of the coastal flushing process, existing methods for determining flushing time may not be generally applicable. In this paper, a systematic method for determining the flushing time in FCZs is presented, in which bathymetry, runoff, tidal range and stratification are properly accounted for. We determine the flushing time via numerical tracer experiments, using robust 3D hydrodynamic and mass transport models. For FCZs located in sheltered and land-locked tidal inlets, the system boundary can be naturally defined at the connection with the open sea. For FCZs located in open'waters, hydrodynamic tracking is first used to assess the extent of tidal excursion and thus delimit the initial boundary between clean water and polluted water. This general method is applied to all designated marine FCZs in Hong Kong for both the dry and wet seasons, including 20 sheltered FCZs (in semi-enclosed waters of Tolo Harbour, Mirs Bay, and Port Shelter) and 6 FCZs in open waters. Our results show that flushing time is the longest in inner Port Shelter (about 40 days in dry season), and the shortest for the FCZs in open waters (less than one week in dry season). In addition, the flushing time in dry season is commonly longer than that in wet season: 20%~40% for most well-sheltered FCZs; 2.6-4 times for the others. Our results indicate a positive correlation between the flushing time and distance to open boundary, supporting the view that the flushing time of a FCZ is closely related to its location. This study provides a solid basis for mariculture management such as the determination of carrying capacity of FCZs.
文摘Field experiments were carried out at the National Research Center farm, Nubaria area, Behura Governorate, Egypt, to study the effect of nitrogen source, flushing schedule and irrigation method on emitter clogging. Peanut Giza 5 variety (Arachishy pogaea L.) was planted in sandy soil during two successive growing seasons (2010-2011) in the 1st week of May and harvested after 130 days. Treatments used are: 1) two irrigation methods: surface drip irrigation and sub-surface drip irrigation (SDI;SSDI), 2) nitrogen source (NS):NH4NO3, (NH4)2SO4 and Ca(NO3)2 (NS1, NS2 and NS3) and 3) flushing number (FL) 0, 1 and 4 (FL1, FL2;FL3). The experiments design was split-split plot and three replicates were used. Data obtained were subjected to statistical analysis. The main effects of treatments used on clogging per cent could be written the following ascending orders: SDI 3 2 1, NS1 2 3. Concerning the 1st interaction the following ascending orders denote their effects on clogging percent: SDI × FL3 2 1, SDI × NS1 2 3, SSDI × FL3 2 1, SSDI × NS1 2 3, FL1 × NS1 1 × NS2 1 × NS3, FL2 × NS1 2 × NS2 2 × NS3 and FL3 × NS1 3 × NS2 3 × NS3. The differences between any two treatments and/or any two interactions in clogging percent were significant at the 5% level. The effect of the 2nd interaction on clogging percent was significant at the 5% level. The maximum value of clogging (20.18%) and the lowest one (3.9%) were archived in the interactions: SSDI × FL1 × NS3 and SDI × FL3 × NS1, respectively.
基金This project was supported by a grantfrom Hubei Scienceand Technology Comm ittee (No.96 1P190 1)
文摘The activity of matrix metalloproteinases (MMPs) in the uterine flushing and endometrial tissue of normal adult women wearing FCu IUD (fixed Cu IUD) or FICu IUD (indomethacin releasing FCu IUD) was observed by using zymography on SDS PAGE containing gelatin. The results showed that the activity and kinds of MMPs in FCu IUD group were increased significantly as compared with themselves before being inserted FCu IUD. However, compared with the FCu IUD group, the activity of some kinds of MMPs in the FICu IUD group was decreased significantly. These data suggest that IUD can enhance the activity of MMPs in human endometrium, intermediated by prostaglandins, and MMPs may have relation to IUD induced menorrhagia and indomethacin reduces IUD induced menorrhagia by partly inhibiting MMPs synthesis.
文摘This paper analyzes the situation at the Iffezheim barrage along the fiver Rhine.Since the start of operation in 1977 several million cubic meters of very fine sediment have been deposited in the reservoir.Be- cause of stability problems and reduced safety in the event of flooding,an extraction of the material is neces- sary.Chemical assays showed a high concentration of HCB.Therefore flushing without any additional measures is not appropriate.In order to leam more about the morphological and chemical in...
文摘Objective: To discuss the effect of vacuum sealing drainage combined with intermittent insulin flushing on the expression of inflammatory factors and apoptosis factors in diabetic lower limb ulcer wound. Methods: A total of 48 patients with diabetic lower limb ulcer who were treated in the Endocrine Department of the hospital between January 2016 and January 2017 were divided into the control group and research group by random number table, 24 cases in each group. Control group received vacuum sealing drainage, and research group received vacuum sealing drainage combined with intermittent insulin flushing. The differences in the expression of inflammatory factors and apoptosis genes in the wound exudate were compared between the two groups before and after treatment. Results: Before treatment, the differences in the inflammatory factor contents and apoptsis gene expression in wound exudate were not statistically significant between the two groups of patients. After treatment, inflammatory factors IL-6, IL-1β, TNF-α, CRP, VCAM-1 and FGF2 contents in wound exudate of research group were lower than those of control group;apoptosis gene Bcl-2 mRNA expression in wound exudate of research group was higher than that of control group while Bax, p53 and Fas mRNA expression were lower than those of control group. Conclusions: Vacuum sealing drainage combined with intermittent insulin flushing can effectively reduce the local inflammatory response and promote the granulation cell proliferation in wound of patients with diabetic lower limb ulcer.
基金supported by the National Natural Science Foundation of China (No. 40772148)
文摘Foam flushing is an in situ soil remediation technology based on the traditional surfactant flushing method. The contribution of mobility control to contaminant removal by foam is helpful for improving this technology. Foam flushing of polychlorinated biphenyl (PCB)- contaminated unconsolidated media was performed to evaluate the effect of the partition coefficient (PC) and sweep efficiency (SE) on PCB removal. Column flushing with surfactant solution and foam with different types and concentrations of surfactant was carried out for PCB removal. Two types of quartz sand were investigated to evaluate the Jamin effect on the SE value of the washing agent. The results demonstrate that a small PC value and large SE value are necessary to achieve high PCB removal for foam flushing. Compared with solution flushing, the introduction of foam can effectively control the mobility of the washing agent. Similar to solution flushing, solubilization is a key factor which dominates the removal of PCBs in foam flushing, In addition, the SE value and PCB removal by foam flushing is less affected by particle size. Therefore, foam flushing was proved to be more effective in porous media with low hydraulic conductivity and high porosity. An integrated flushing with water, surfactant solution and foam was performed and the results prove that this technology successfully combines the advantages of solution solubilization and mobility control by foam, and thus further increases the remediation efficiency of PCBs to 94.7% for coarse sand.
基金supported by Japan Society for the Promotion of Science(RONPAKU Program,No.CAS-11313)the National Key Research and Development Plan of China(No.2016YFD0800203)the National Natural Science Foundation of China(Nos.21307152 and 41471268)
文摘Soil contamination by diesel has been often reported as a result of accidental spillage,leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates(LAS, an anionic surfactant) was conducted for intact columns(15 cm in diameter and 12 cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes(representing the diesel) varied with the depth of the topsoil in the range of 14%–96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores(30–250 μm in diameter)was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores.
文摘Flushing time of the Yangtze estuary by discharge is one of the importantfactors responsible for the transport of pollutants from various sources located along the Yangtzeestuary: Therefore, an objective of the present stud-y, which analysis flushing time in the case ofdifferent discharge is very helpful to evaluate the water environmental of the Yangtze estuary.Using a dissolved conservative material as a tracer in the water, a three-dimensionadvection-diffusion water exchange numerical model was used to study the flushing time by dischargeand the discharge dominated region of the Yangtze estuary. The initial tracer concentration is setto 0.0 in the numerical domain of the Yangtze estuary, and the concentration value is set to 1. 0 onthe inflow boundary. The tracer flux normal to the solid boundary is set to 0. 0. The flushing timeand the out limit of discharge dominated region can be calculated in terms of the tracerconcentration. Estuarine, Coastal and Ocean Model (ECOM) is used as the hydro-dynamic model. Theresult shows that the flushing time is approximately in inverse proportion to the discharge at theupper stream. The out limit is farther from the upper inflow boundary as discharge increases. Theout limit at the north branch is different from that of the south branch because the discharge intothe north branch is much less than that into the south branch. The data is qualitative similar tothe observed data, which show the three-dimensional advection-diffusion equation can be used toestimate the flushing time and the discharge dominated region of the Yangtze estuary.
基金financial support from the National Natural Science Foundation of China (No. 51005120)Jiangsu Natural Science Foundation (Nos. BK2010508 and BE2010193)
文摘Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys. Wire electrochemical machining (WECM) is mainly used for workpiece cutting under the condition of different thickness plates. It has a great advantage over wire electro-discharge machining, which is the absence of heat-affected zone around the cutting area. Moreover, the wire electrode in WECM could be used repetitively because it is not worn out. Thus, much attention has been paid to WECM. The effective way of removing electrolysis products is of importance to WECM. In this paper, the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte. The Taguchi experiment is conducted to optimize the machining parameters, such as wire feedrate, machining voltage, electrolyte concentration, etc. Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy (TC1). The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.
基金supported by the National Natural Science Foundation of China(No.41271339)the National High Technology Research and Development Program(863)of China(No.2012AA06A201)Beijing Municipal Science and Technology Project(No.Z141100000914011)
文摘Phytoremediation and soil washing are both potentially useful for remediating arsenic(As)-contaminated soils.We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot study.The results showed that growing Pteris vittata L.(P.v.) accompanied by soil flushing of phosphate(P.v./Flushing treatment) could significantly decrease the total As concentration of soil over a 37 day flushing period compared with the single flushing(Flushing treatment).The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment,suggesting that the growth of P.vittata was beneficial for promoting the removal efficiency.We analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined process.Results showed that comparing with the control treatment,the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing treatment.As concentration in soil solution remained a high lever during the middle and later periods(51.26–56.22 mg/L),which was significantly higher than the Flushing treatment.Although soil flushing of phosphate for more than a month,P.vittata still had good accumulation and transfer capacity of As of the soil.The results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils.
文摘A three-dimensional hydrodynamic model with the capability to deal with changing land water boundaries was developed based on ECOMSED in this study. The model was configured to numerically study the water flushing characteristics of Dahuofang Reservoir in China through the determination of spatially distributed residence times. The model successfully reproduced the intra-annual water level variations, as well as the temporal evolution and spatial distribution of water temperature. Through a series of numerical experiments, it can be concluded that (1) the water flushing of the reservoir is both temporally and spatially variable; and (2) inflows and withdrawals are the decisive factors influencing the water flushing characteristics. Heat fluxes are the controlling factors of the water flushing of a strong stratified reservoir. Wind has the weakest effect, but it still should be considered in determination of reservoir water flushing characteristics.
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。