Effect of surfactant frequently used in soil flushing on oxygen mass transfer in micro-nano-bubble aeration system

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.

Analysis and Prospect of Waste Heat Utilization from Blast Furnace Slag Flushing

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.

Flush by Unit在哥伦比亚Capella油田的应用

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。

Stress-unloading and gas migration improvement mechanism in the soft and hard interbedded coal seam using directional hydraulic flushing technology

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.

Design and Fluid-Dynamic Analysis of a Flushing Nozzle for Drilling Applications

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.

Vancomycin flushing syndrome in orthopaedic practice:A case report

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.

基于flushing time的春季水库优化调度可行性研究

针对三峡水库支流库湾春季水华问题,通过建立三维水动力模型,探讨了利用调峰调度和潮汐式调度促进干支流水体交换的可行性。研究表明,当4月水库实施调峰调度时,整个库湾水体的flushing time较常规调度有所缩短,尤其是库湾上游至中上游区域;当5月水库开始实施潮汐式调度时,水体体积较大的库湾下游区域的flushing time较常规调度方案有所缩短。可见,两种水库优化调度方案对增大干支流水体交换均具有可行性。当水库实施调峰调度和潮汐式调度联合调度时,整个库湾水体的平均flushing time较常规调度方案有不同程度的缩短,表明该联合调度方案更能促进干支流水体的交换。研究成果可为支流库湾水环境问题的防治提供借鉴。

Flush刀和SB刀在经口内镜下肌切开术治疗贲门失弛缓症中的临床应用

背景:经口内镜下肌切开术(POEM)目前已被广泛用于治疗贲门失弛缓症(AC)且效果显著。然而,POEM手术操作难度大,术后并发症发生率高。目的:探讨Flush刀和SB刀在POEM治疗AC中的有效性和安全性。方法:选取2013年4月—2017年4月武汉大学人民医院确诊为AC且接受POEM治疗的111例患者,将其分为Flush刀组、SB刀组和Dual刀组。比较三组手术相关指标、并发症和术后随访等方面的差异。结果:111例AC患者均顺利完成了POEM,三组平均手术时间、平均止血次数和平均更换设备的次数相比差异有统计学意义(P均<0.05),进一步两两比较显示,Flush刀组和SB刀组上述手术相关指标均明显低于Dual刀组(P均<0.05)。三组术后并发症发生率相比差异有统计学意义(P=0.005),进一步两两比较显示,SB刀组显著低于Dual刀组(P=0.011),而Flush刀组与Dual刀组无明显差异(P=0.056)。三组手术治疗成功率无明显差异(P>0.05)。结论:Flush刀和SB刀能有效缩短POEM治疗AC的手术时间,且其成功率与常规Dual刀相似。

flush_action重选参数设置对数据业务用户感知的影响分析与设置优化

日常网络优化过程中往往只着重对语音无线参数进行调整优化,但随着数据业务突飞猛进的发展,GPRS承载网中同样存在设备参数的调整和优化问题。大家都知道在语音业务中用户从原来的小区进入到新的小区要进行切换,而数据业务中不存在切换流程,只有对应的小区重选,小区重选参数设置不合理会直接影响数据业务传输速率甚至会导致传输过程失败,从而对用户感知度产生较大影响,因此,合理优化小区重选参数就显得尤为重要,本文主要要对flush-ll-ack消息参数action设置不同对网络时延造成的不同影响进行论述分析,从而通过该参数调整优化来进一步提升数据业务网络质量,提升用户感知度。

First flush of storm runoff pollution from an urban catchment in China

Storm runoff pollution process was investigated in an urban catchment with an area of 1.3 km^2 in Wuhan City of China. The results indicate that the pollutant concentration peaks preceded the flow peaks in all of 8 monitored storm events. The intervals between pollution peak and flow peak were shorter in the rain events with higher intensity in the initial period than those with lower intensity. The fractions of pollution load transported by the first 30% of runoff volume （FF30） were 52.2%-72.1% for total suspended solids （TSS）, 53.0%-65.3% for chemical oxygen demand （COD）, 40.4%-50.6% for total nitrogen （TN）, and 45.8%-63.2% for total phosphorus （TP）, respectively. Runoff pollution was positively related to non-raining days before the rainfall. Intercepting the first 30% of runoff volume can remove 62.4% of TSS load, 59.4% of COD load, 46.8% of TN load, and 54.1% of TP load, respectively, according to all the storm events. It is suggested that controlling the first flush is a critical measure in reduction of urban stormwater pollution.

Flush Pin检具的检测方法研究

介绍了Flush Pin检具的外形特点及特殊的检测要求,设计制造专用夹具及检测装置对其进行检测,并总结归纳了相关的检测方法以及方法的选择原则。

基于Flush+Reload的DES算法Cache计时攻击

在数据加密标准(DES)算法上使用Flush+Reload方法的Cache计时攻击,存在难以确定S盒元素行偏移位的问题。为此,利用S盒在Cache中会发生不对齐分布的特征,提出一种偏移位确定方法。采用clflush指令刷新Cache地址行,以驱逐Cache中DES算法的S盒信息,确定S盒元素的位置信息。利用密码算法在查询S盒时泄露的Cache计时信息获取明文与密钥异或后的中间态值,并通过该值和已知明文的相关性恢复密钥。实验结果表明,该方法能够有效确定S盒元素的行偏移位,提高针对DES算法Cache计时攻击的效率。

Tidal Flushing Time of Marine Fish Culture Zones in Hong Kong

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.

Effect of drip irrigation method, nitrogen source, and flushing schedule on emitter clogging

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.

Study on the Effects of FCu-IUD and FICu-IUD on Matrix metalloproteinases in Human Uterine Flushing and Endometrium

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.

Sedimentological and Chemical Processes During Flushing Tests at Iffezheim Barrage(River Rhine)

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...

RPR环网基于流的Flush方法

当需要改变RPR环网上Strict类型报文的传输环路时,为保证Strict类型报文的顺序发送与接收以及避免被重复接收,需要进行Flush操作,确认已上传到环路上的报文都已完成传输后,才能开始在新选择的环路上恢复报文发送。802.17规范说明了Flush的实现方法,文章探讨了Flush实现的改进实现,以及基于流的Flush实现。

Logging response characteristics and formation process of flushed zone in the Orinoco heavy oil belt, Venezuela

The origins and logging responses of flushed zones in some blocks of Orinoco heavy oil belt, Venezuela are still unclear. To solve this issue, we examined the conventional logging, nuclear magnetic resonance logging, fluid viscosity, core analysis and oil field production data comprehensively to find out the logging responses and origins of the flushed zones. The results show that the main reason for the formation of flushed zone is surface water invasion, which leads to crude oil densification. The crude oil densification produces asphalt membrane(asphalt crust) which wraps up free water, causing special logging responses of the flushed zones. According to the different logging responses, we classified the flushed zones into two types and analyzed the formation processes of the two types of flushed zones. According to the characteristics of logging curves after water flush, we confirmed that the water flush began earlier than the reservoir accumulation.

Effect of vacuum sealing drainage combined with intermittent insulin flushing on expression of inflammatory factors and apoptosis factors in diabetic lower limb ulcer wound

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.

Ningxia Winemakers’ Challenge:Flushed with Success

A two-year contest with 48 winemakers from 17 nations has solidified Ningxia as China’s most promising wine region.This unprecedented contest was held in the Helan Mountain’s East Foothill wine region in Ningxia Hui Autonomous Region,in August.A panel of experts led by Ma Huiqin,