High-throughput microfluidic production of carbon capture microcapsules:fundamentals,applications,and perspectives

In the last three decades,carbon dioxide(CO_(2)) emissions have shown a significant increase from various sources.To address this pressing issue,the importance of reducing CO_(2) emissions has grown,leading to increased attention toward carbon capture,utilization,and storage strategies.Among these strategies,monodisperse microcapsules,produced by using droplet microfluidics,have emerged as promising tools for carbon capture,offering a potential solution to mitigate CO_(2) emissions.However,the limited yield of microcapsules due to the inherent low flow rate in droplet microfluidics remains a challenge.In this comprehensive review,the high-throughput production of carbon capture microcapsules using droplet microfluidics is focused on.Specifically,the detailed insights into microfluidic chip fabrication technologies,the microfluidic generation of emulsion droplets,along with the associated hydrodynamic considerations,and the generation of carbon capture microcapsules through droplet microfluidics are provided.This review highlights the substantial potential of droplet microfluidics as a promising technique for large-scale carbon capture microcapsule production,which could play a significant role in achieving carbon neutralization and emission reduction goals.

STAT3-Dependent Effects of Polymeric Immunoglobulin Receptor in Regulating Interleukin-17 Signaling and Preventing Autoimmune Hepatitis

One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between the gut microbiome and genetic factors.Dysbiosis of the gut flora and elevated polymeric immunoglobulin receptor(pIgR)levels have been observed in both patients and mouse models.Moreover,there is a direct relationship between pIgR expression and transaminase levels in patients with AIH.In this study,we aimed to explore how pIgR influences the secretion of regenerating islet-derived 3 beta(Reg3b)and the flora composition in AIH using in vivo experiments involving patients with AIH and a concanavalin A-induced mouse model of AIH.Reg3b expression was reduced in pIgR gene(Pigr)-knockout mice compared to that in wild-type mice,leading to increased microbiota disruption.Conversely,exogenous pIgR supplementation increased Reg3b expression and maintained microbiota homeostasis.RNA sequencing revealed the participation of the interleukin(IL)-17 signaling pathway in the regulation of Reg3b through pIgR.Furthermore,the introduction of external pIgR could not restore the imbalance in gut microbiota in AIH,and the decrease in Reg3b expression was not apparent following the inhibition of signal transducer and activator of transcription 3(STAT3).In this study,pIgR facilitated the upregulation of Reg3b via the STAT3 pathway,which plays a crucial role in preserving the balance of the intestinal microbiota in AIH.Through this research,we discovered new molecular targets that can be used for the diagnosis and treatment of AIH.

路基压实质量Evd评价建议标准试验研究

研究目的:Evd检测是目前国际上日益广泛采用的新型路基质量无损快速检测方法。但对我国铁路路基所使用的宽泛填料来说,Evd路基质量检测标准尚未进行系统试验研究,Evd路基质量检测标准尚未建立。本文选择有代表性的9种填料进行大型室内填筑试验,在不同压实条件下测试地基系数K30、压实度K(或孔隙率n)、动态变形模量Evd。通过对Evd与K30、K、n的相关关系研究,提出Evd路基压实质量建议标准,并通过现场测试对提出的建议标准进行验证。研究结论:建立了适用于《新建时速200公里客货共线铁路设计暂行规定》的Evd路基压实质量评价标准建议值,通过现场验证表明建立的Evd压实质量建议标准是合理的,可为相关规范修订提供依据。

Melting heat transfer enhancement of a horizontal latent heat storage unit by fern-fractal fins

The latent heat storage(LHS)technique is of crucial importance in chemical energy engineering.Inspired by multi-bifurcated fern leaves,a mimic fern-fractal fin is designed to improve the thermal energy charging efficiency.This paper develops a transient melting model of a rectangular LHS unit using fern-fractal fins,and their melting behaviors are compared with the conventional fins.Besides,a parametric optimization of fernfractal fins is conducted for maximizing the thermal efficiency based on the response surface method(RSM).The results indicate that the temperature uniformity is more superior and the melting duration is shorter for the fern-fractal LHS unit when compared with the conventional one.Interestingly,the fern-fractal LHS device presents a slower heat storage rate during the initial conduction-dominated and early convection-dominated melting stages,while a prominent melting enhancement is achieved during the later melting stage.The shortest melting time is obtained based on the RSM technique when a fern-fractal fin with length ratio α=0.94 and branch angle θ=54.7°is utilized.Compared with a conventional fin,the averaged heat storage rate increases by 88.3%,and the total melting time is declined by 40.3%for an optimized fern-fractal fin.

Investigation of spherical and concentric mechanism of compound droplets

Polymer shells with high sphericity and uniform wall thickness are always needed in the inertial confined fusion(ICF)experiments.Driven by the need to control the shape of water-in-oil(W1/O)compound droplets,the effects of the density matching level,the interfacial tension and the rotation speed of the continuing fluid field on the sphericity and wall thickness uniformity of the resulting polymer shells were investigated and the spherical and concentric mechanisms were also discussed.The centering of W1/O compound droplets,the location and movement of W1/O compound droplets in the external phase(W2)were significantly affected by the density matching level of the key stage and the rotation speed of the continuing fluid field.Therefore,by optimizing the density matching level and rotation speed,the batch yield of polystyrene(PS)shells with high sphericity and uniform wall thickness increased.Moreover,the sphericity also increased by raising the oil/water(O/W2)interfacial tension,which drove a droplet to be spherical.The experimental results show that the spherical driving force is from the interfacial tension affected by the two relative phases,while the concentric driving force,as a resultant force,is not only affected by the three phases,but also by the continuing fluid field.The understanding of spherical and concentric mechanism can provide some guidance for preparing polymer shells with high sphericity and uniform wall thickness.

Functional recovery of injured sciatic nerve by intraperitoneal injection of multiwalled carbon nanotubes

Some evidence suggests that multiwalled carbon nanotubes can promote neuronal differentiation and growth. The present study investigated the effect of functional multiwalled carbon nanotubes （MWCNTs） on functional recovery of injured sciatic nerves in mice. The results revealed that MWCNTs accelerated the recovery of functional index scores of injured sciatic nerves in mice. Moreover, the medullary sheath was significantly thicker in the injured sciatic nerve following MWCNTs administration. These effects were dose-dependent.

Fabrication and characterization of NiCr-based films with high resistivity and low temperature coefficient of resistance

As a metal alloy,NiCr films have a relatively high resistivity and low temperature coefficient of resistance (TCR) and are widely used in electronic components and sensors.However,the resistivity of pure NiCr is insufficient for high-resistance and highly stable film resistors.In this study,a quaternary NiCrAlSi target (47:33:10:10,wt.%) was successfully used to prepare resistor films with resistivities ranging from 1000 to 10 000μΩcm and TCR within±100 ppm/K.An oxygen flow was introduced during the sputtering process.The films exhibit hightemperature stability at 450℃.The films were analyzed using Auger electron spectroscopy,x-ray diffraction,time-of-flight secondary-ion mass spectrometry,and x-ray photoelectron spectroscopy.The results show that the difference in the oxide proportion of the films caused the differences in resistivity.The near-zero TCR values were considered to be due to the competition between silicon and other metals.This study provides new insights into the electrical properties of NiCr-based films containing Si,which will drive the manufacturing of resistors with high resistivity and zero TCR.

Bionic microchannels for step lifting transpiration

Those various cross-sectional vessels in trees transfer water to as high as 100 meters,but the traditional fabrication methods limit the manufacturing of those vessels,resulting in the non-availability of those bionic microchannels.Herein,we fabricate those bionic microchannels with various cross-sections by employing projection micro-stereolithography(PμSL)based 3D printing technique.The circumradius of bionic microchannels(pentagonal,square,triangle,and five-pointed star)can be as small as 100μm with precisely fabricated sharp corners.What's more,those bionic microchannels demonstrate marvelous microfluidic performance with strong precursor effects enabled by their sharp corners.Most significantly,those special properties of our bionic microchannels enable them outstanding step lifting performance to transport water to tens of millimeters,though the water can only be transported to at most 20 mm for a single bionic microchannel.The mimicked transpiration based on the step lifting of water from bionic microchannels is also achieved.Those precisely fabricated,low-cost,various cross-sectional bionic microchannels promise applications as microfluidic chips,long-distance unpowered water transportation,step lifting,mimicked transpiration,and so on.

FGF4 protects the liver from immune-mediated injury by activating CaMKKβ-PINK1 signal pathway to inhibit hepatocellular apoptosis

Immune-mediated liver injury (ILI) is a condition where an aberrant immune response due to various triggers causes the destruction of hepatocytes. Fibroblast growth factor 4 (FGF4) was recently identified as a hepatoprotective cytokine;however, its role in ILI remains unclear. In patients with autoimmune hepatitis (type of ILI) and mouse models of concanavalin A (ConA)- or S-100-induced ILI, we observed a biphasic pattern in hepatic FGF4 expression, characterized by an initial increase followed by a return to basal levels. Hepatic FGF4 deficiency activated the mitochondria-associated intrinsic apoptotic pathway, aggravating hepatocellular apoptosis. This led to intrahepatic immune hyper-reactivity, inflammation accentuation, and subsequent liver injury in both ILI models. Conversely, administration of recombinant FGF4 reduced hepatocellular apoptosis and rectified immune imbalance, thereby mitigating liver damage. The beneficial effects of FGF4 were mediated by hepatocellular FGF receptor 4, which activated the Ca^(2+)/calmodulin-dependent protein kinasekinase 2 (CaMKKβ) and its downstream phosphatase and tensin homologue-induced putative kinase 1 (PINK1)-dependent B-cell lymphoma 2-like protein 1-isoform L (Bcl-XL) signalling axis in the mitochondria. Hence, FGF4 serves as an early response factor and plays a protective role against ILI, suggesting a therapeutic potential of FGF4 and its analogue for treating clinical immune disorder-related liver injuries.

Non-genetic risk factors of Parkinson’s disease:A large meta-analysis and systematic review

To the Editor:In the recent decades,significant global endeavors have been undertaken to investigate the risk factors associated with Parkinson’s disease(PD)and to enhance the evidence on PD prevention.[1]However,the prevailing key issues in this field are the frequent occurrence of inconsistent or contradictory conclusions and the varying levels of credibility,which are primarily due to the diverse study designs employed.Observational prospective studies(OPSs)and ambidirectional cohort studies(ACSs)have fewer sources of bias and confounding factors compared with retrospective studies.[2]Therefore,we conducted a meta-analysis on prospective studies to obtain more robust results.Considering that the majority of genetic mutations or chromosomal abnormalities occur randomly during DNA replication and are challenging to prevent,this meta-analysis aims to investigate non-genetic risk factors for PD.The non-genetic risk factors encompass the aspects such as environment,lifestyle,and socio-economic that are not directly determined by an individual’s genes.[3]These factors may independently influence an individual’s health status or interact with genetic factors.

Author correction to‘FGF4 protects the liver from immune-mediated injury by activating CaMKKβ-PINK1 signal pathway to inhibit hepatocellular apoptosis’[Acta Pharm Sin B 14(2024)1605–1623]

The authors regret that due to the mistake of copying and pasting in the process of assembling figures and negligence in the proofreading,there are picture pasting errors in Fig.8 and Supporting Information Fig.S2,respectively,but the above errors did not affect the conclusion.The author has now revised Fig.8 and Fig.S2 as follows.The authors apologize for any inconvenience caused to the journal and readers.

方形截面纤维表面气溶胶粒子多机理过滤性能数值分析

采用数值方法求解绕方形截面纤维流场,考虑粒子布朗扩散、拦截效应和惯性碰撞捕集机理的联合作用,用布朗动力学方法研究方形截面纤维的过滤性能,考察了纤维迎风角(θ)、填充率(C)和过滤风速(u_∞)对捕集效率、质量因子及粒子沉积分布的影响。结果表明,小粒子的扩散捕集或大粒子的惯性捕集在方形纤维表面的粒子沉积行为均表现出显著的局部沉积特征,且与粒子捕集机理和迎风角有关。方形纤维质量因子的分析结果表明,在高填充率下,方形纤维的过滤压降虽高于圆截面纤维,但具有较高的捕集效率,综合过滤性能仍明显优于圆截面纤维,但在低填充率下,方形纤维综合过滤性能劣于圆截面纤维。

滑移效应下纤维绕流场及过滤阻力的数值计算与分析

考虑实际纳米/微米纤维表面的流体滑移效应,采用数值方法求解滑移流动机理下纳米/微米纤维绕流场及过滤阻力,分析讨论了Knudsen数Knf和填充率C对纤维近壁面速度分布及纤维过滤阻力的影响规律。结果表明,对纳米/亚微米纤维过滤情形,纤维表面流体的滑移效应导致纤维绕流场与非滑移条件下情形有显著差异,尤其在高填充率下,纤维表面最大滑移速度与来流风速相当;而对于大尺度微米级纤维,滑移效应对纤维绕流场及过滤阻力影响甚微。此外,已有纤维过滤阻力计算模型不能准确估计出具有强滑移效应的纳米纤维过滤阻力系数,且各纤维过滤阻力系数模型的估计结果存在跨数量级的偏差。根据数值分析结果,给出了一个适用于纳米/微米纤维过滤阻力系数的可靠估计式,适用参数范围为0.01≤C≤0.1,0.013≤Knf≤2。

Unique characteristics of the genetics epidemiology of amyotrophic lateral sclerosis in China

Continual discoveries of new genes and unraveling the genetic etiology in amyotrophic lateral sclerosis(ALS) have provided greater insight into the underlying pathogenesis in motor neuron degeneration, as well as facilitating the disease modeling and the testing of targeted therapeutics. While, the genetic etiology accounted for two-thirds of FALS and approximately 11% of SALS in Caucasians. However, the contributions of these causative genes to ALS vary among different populations. Furthermore, the prominent difference between Chinese population and other ethnics remains a source of ongoing debate. We systemically reviewed genetics literature of Chinese ALS populations and updated the mutation frequencies of the main ALS-implicated genes aiming to determine the genetic features of ALS in Chinese population. We also reviewed the associations between ALSimplicated single nucleotide polymorphisms(SNPs) and the risk of ALS in Chinese population. A total of 116 studies were included in this analysis(86 gene mutation study articles and 30 SNPs study articles). The results showed that the overall gene mutation rates of ALS-related causative genes were 55.0% in familial ALS(FALS) and 11.7% in sporadic ALS(SALS) in Chinese population. In Chinese FALS, the highest mutation frequency was found in SOD1 gene(25.6%), followed by FUS(5.8%), TARDBP(5.8%), DCTN1(3.6%) and C9 orf 72(3.5%). In Chinese SALS, the highest mutation frequency was also identified in SOD1 gene(1.6%), followed by ANXA11(1.4%), FUS(1.3%), SQSTM1(1.0%), OPTN(0.9%) and CCNF(0.8%).The associations between several SNPs and risk of ALS were also reported in Chinese population. The genetic features of ALS in Chinese population are significantly different from those in Caucasian population, indicating an association between genetic susceptibility and origin of population. Further explorations are required to understand the gene complexity of ALS, including the contribution of most minor genes and the molecular mechanisms in ALS pathologies.

Efficacy and Safety of 12-week Interferon-based Danoprevir Regimen in Patients with Genotype 1 Chronic Hepatitis C

Background and Aims:Genotype(GT)1 remains the predominant hepatitis c virus(HCV)GT in Chinese patients.Over 80%of those Chinese patients harbor the interferon-sensitive CC allele of IFNL4rs12979860,which is favorable for interferon-based treatment regimens.This phaseⅢclinical trial aimed to evaluate the efficacy and safety of the ritonavirboosted danoprevir plus pegylated-interferonα-2a and ribavirin regimen for 12 weeks in treatment-na(i)ve mainland Chinese patients infected with HCV GT1 without cirrhosis.Methods:One hundred and forty-one treatment-na(i)ve,non-cirrhotic HCV GT1 Chinese patients(age≥18 years)were enrolled for this single-arm,multicenter,phaseⅢMANASA study(NCT03020082).Patients received a combination of ritonavir-boosted danoprevir(100 mg/100 mg)twice a day plus subcutaneous injection of weekly pegylated-interferonα-2a(180μg)and oral ribavirin(1000/1200 mg/day body weight<75/≥75 kg)for 12 weeks.The primary end-point was sustained virologic response rate at 12 weeks after the end of treatment.The secondary end-points were safety outcomes,tolerability,virologic response over time and relapse rate.Results:All enrolled patients were HCV GT1-infected,and most among them(97.9%,123/141)had the HCV GT1b subtype.Single-nucleotide polymorphism test showed that the majority of patients were of the IFNL4 rs12979860 CC genotype(87.2%,123/141).Overall,140 patients completed the 12-week treatment,and 97.1%(136/140)patients achieved sustained virologic response at 12 weeks(per protocol population group,95%confidence interval:92.9-99.2%).Only drug-related serious adverse event occurred.Most of the adverse events were grade 1 and grade 2 alanine aminotransferase elevation or liver dysfunction.One patient discontinued treatment because of severe head injury in a car accident.Conclusions:The triple regimen of ritonavir-boosted danoprevir plus pegylated-interferonα-2a and ribavirin produced a sustained virologic response rate of 97.1%after 12 weeks treatment in noncirrhotic HCV GT1-infected Chinese patients,and was safe and well tolerated.

Efficacy and Safety of All-oral Emitasvir and Sofosbuvir in Patients with Genotype 1b HCV Infections without Cirrhosis

Publications>Journals>Journal of Clinical and Translational Hepatology>Article Full Text ORIGINAL ARTICLE OPEN ACCESS Efficacy and Safety of All-oral Emitasvir and Sofosbuvir in Patients with Genotype 1b HCV Infections without Cirrhosis Huiying Rao1,Xingxiang Yang2,Youwen Tan3,Qin Ning4,Daokun Yang5,Jiefei Wang6,Yongfeng Yang7,Sujun Zheng8,Dongliang Yang9,Jinlin Hou10,Qing Xie11,Caiyan Zhao12,Lunli Zhang13,Xiaorong Mao14,Tong Sun15,Lang Bai16,Fuchun Zhang17,Jinglan Jin18,Yingren Zhao19,Maorong Wang20,Wen Xie21,Yingjie Ma22,Jun Quan23,Xuebing Yan24,Ping An25,Feng Lin26,Jidong Jia27,Xiaoxuan Hu28,Zuojiong Gong29,Jie Wu30,Yongping Chen31,Zhansheng Jia32,Minghua Lin33,Guiqiang Wang34,Yueyong Zhu35,Yingjun Zhang*,36,Hongming Xie36,Lin Luo36,Qingyun Ren36,Rui Huang1 and Lai Wei*,37 Author information Journal of Clinical and Translational Hepatology 2020;8(3):255-261DOI:10.14218/JCTH.2020.00031 Abstract Background and Aims:Emitasvir is a new type of hepatitis C virus(HCV)nonstructural protein 5A(NS5A)inhibitor,and the data of phase 2 trial has shown emitasvir-sofosbuvir to have good safety and tolerance.We conducted this phase 3 trial to further verify the efficacy and safety.Methods:We evaluated the antiviral activity and safety of a 12-week regimen of emitasvir phosphate(100 mg)combined with sofosbuvir(400 mg)once daily in non-cirrhotic patients with genotype 1 HCV infection.The primary endpoint was a sustained virological response at 12 weeks(SVR12)after the end of treatment.Results:Of the 362 patients enrolled in the trial,39.8%were male,99.2%had HCV genotype 1b,0.8%had genotype 1a and 79.8%were treatment-naïve.The average age was 47.2 years.All patients completed the treatment and follow-up.All 3 patients with genotype 1a achieved SVR.Two genotype 1b treatment-naïve patients experienced virologic relapse.The rate of SVR12 was 99.7%(358/359),and SVR24 was 99.4%(357/359)in genotype 1b.Overall,36.2%had resistance-associated substitutions(RASs)in NS5A and 98.3%had RASs in NS5B at baseline.The RASs at baseline had no effect on the rates of response.Serious adverse events were reported in 16 patients and were not related to emitasvir-sofosbuvir.Most adverse events did not require therapy.Conclusions:The 12 weeks of treatment with emitasvir-sofosbuvir was a highly efficient and safe treatment for a wide range of patients with HCV genotype 1b infection without cirrhosis,who had not been treated or who had been treated with interferon-based regimen previously.

Aberrations of biochemical indicators in amyotrophic lateral sclerosis:a systematic review and meta-analysis

Accumulating evidence has suggested that the pathological changes in amyotrophic lateral sclerosis(ALS)are not only confined to the central nervous system but also occur in the peripheral circulating system.Here,we performed a meta-analysis based on the PubMed,EMBASE,EBSCO,and CNKI databases,to find out biochemical indicators associated with energy metabolism,iron homeostasis,and muscle injury that are altered in ALS patients and their correlations with ALS phenotypes.Forty-six studies covering 17 biochemical indicators,representing 5454 ALS patients and 7986 control subjects,were included in this meta-analysis.Four indicators,including fasting blood glucose level(weighted mean difference[WMD]=0.13,95%CI[0.06-0.21],P=0.001),serum ferritin level(WMD=63.42,95%CI[48.12-78.73],P<0.001),transferrin saturation coefficient level(WMD=2.79,95%CI[1.52-4.05],P<0.001),and creatine kinase level(WMD=80.29,95%CI[32.90-127.67],P<0.001),were significantly higher in the ALS patients,whereas the total iron-binding capacity(WMD=-2.42,95%CI[-3.93,-0.90],P=0.002)was significantly lower in ALS patients than in the control subjects.In contrast,the other 12 candidates did not show significant differences between ALS patients and controls.Moreover,pooled hazard ratios(HR)showed significantly reduced survival(HR=1.38,95%CI[1.02-1.88],P=0.039)of ALS patients with elevated serum ferritin levels.These findings suggest that abnormalities in energy metabolism and disruption of iron homeostasis are involved in the pathogenesis of ALS.In addition,the serum ferritin level is negatively associated with the overall survival of ALS patients.

Bubble breakup in a microfluidic T-junction

We conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface. The evolution of bubble mor- phology and the distributions of velocity and pressure in flow field are analyzed, and the effect of width ratio between main channel and branch on the bubble mor- phology are evaluated. The results indicate that, the ＂tun- nel＂ breakup, obstructed breakup, combined breakup and non-breakup are observed during the bubble flows through the T-junctions under different condition. The whole bub- ble breakup process undergoes the extension, squeeze and pinch-off stages, while the non-breakup process experi- ences extension and pushing stages. We find that, in the squeeze stage, a local vortex flow forms at the front edge of the bubble for the ＂tunnel＂ breakup while the velocity inside the bubble is of a parabolic distribution for the obstructed breakup. Irrespective of non-breakup regimes, there is a sudden pressure drop occurring at the gas-liquid interface of the bubble in the squeeze stage, and the pres- sure drop at the front interface is far larger than that at the depression region. The transition of the bubble breakup regime through the T-junction occurs with an increase in width ratio of main channel to the branch, which sequen- tially experiences the non-breakup regime, ＂tunnel＂ breakup regime and obstructed breakup regime. The flow regime diagrams are plotted with a power-law correlation to distinguish the bubble/droplet breakup and non-breakup regimes, which also characterize the difference between bubble and droplet breakup through a T-junction.

Characteristics of Liver Functions in Patients With COVID-19 and Construction of a Prognostic Evaluation Decision Model Based on Liver Functions

A number of studies have suggested that coronavirus disease 2019(COVID-19)can cause liver damage.However,clinical features and outcome of COVID-19 in patients with liver injury remain to be further investigated.In this study,the clinical data of 265 COVID-19 patients admitted to seven tertiary hospitals were collected.Based on a threshold for transaminase or total bilirubin levels at two times the normal upper limit,patients were divided into mild or moderate/severe liver injury groups.Among the 265 patients,183 patients showed liver injury within 48 hours of admission.Aspartate aminotransferase levels were predominantly elevated in the liver injury group,but albumin levels were reduced.Moreover,fibrinogen and D-dimer were significantly increased.Furthermore,68%of the patients with moderate/severe liver injury had one or more underlying diseases.Almost half of these patients developed acute respiratory distress syndrome(44%)and secondary infections(46%).These patients showed increased interleukin-6 and interleukin-10 levels and a decrease in PaO2 and the oxygenation index.In addition,levels of alanine aminotransferase,aspartate aminotransferase,and albumin were correlated with the oxygenation index,D-dimer and lymphocyte counts.Furthermore,a novel prognostic assessment model based on liver function was established,which accuracy reached 88%and was able to accurately assess the prognosis of COVID-19 patients.

Experimental study on the electrohydrodynamic deformation of droplets in a combined DC electric field and shear flow field

A visualization experiment was conducted to investigate the electrohydrodynamic deformation of droplets in a combined DC electric field and shear flow field.Detailed experimental data on both the transient and steady droplet deformation parameters(D)and orientations(ϕ_(d))are provided at R>S and R<S(R:conductivity ratio;S:permittivity ratio)under different electric field and shear flow field combinations.The internal flow characteristics of the deformed droplet were also examined via the digital particle image velocimetry(DPIV)method.Due to the competition of the extensional component(EC)and the rotational component(RC)of these two fields on the droplet,the response ofϕ_(d) is faster than that of D when an electric field is combined with a shear flow.Additionally,under the competition of the EC and RC at R>S and R<S,the steady-state D andϕ_(d) values exhibit distinct variations.In particular,surface charge convection plays a non-negligible role in enhancing and reducing droplet deformation at R>S and R<S,respectively.In addition,an asymmetric vortex forms inside the deformed droplet in the combined fields,and its velocity is lower under R>S and higher under R<S than in pure shear flow.The available prediction models use the experimental data to predict D,and a modified prediction model is proposed for improving the prediction accuracy ofϕ_(d).