Flow patterns of solid in water in oil (S/W/O) compound droplets formation in a microfluidic device with perpendicular shear

Dawei Pan,Qiang Chen,Lan Xu,Can Yang,Meifang Liu,Weixing Huang,Bo Li 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.75 No.-

Theflow patterns and corresponding breakup dynamics of solid in water in oil compound droplets underperpendicular shear force were experimentally investigated in a microfluidic device. Three typicalflowpatterns, namely double-encapsulation, plugs, and cobbles, were found and be quantitativelydistinguished by the capillary number (Cac) of continuous phase and theflow rate ratio (R) ofcontinuous phase to dispersed phase. It is found that, under all offlow regimes, the consecutive entry ofsolid particles leads d1 (the neck thickness along the center of the side channel) varying periodically. Inthe double-encapsulation regime, the neck thickness (d2) between thefirst and second particle increasesas the interface deformation recovers driven by the interfacial tension force, whereas the neck thickness(d3) between the second and third particle decreases to break off because the neck has been stretchedlong to become thin enough. As for the cobbles regime, hydrostatic pressure difference still remainsdominant, but not a shearing force. Specially, different from the W/O droplet formation, it suggests thatvarious breakup dynamics are always caused by a non-free deformation of S/W interface and the largediameter of solid particle. Finally, theflow pattern diagrams dependent on Cac and R are obtained.

False-Negative Results of Real-Time ReverseTranscriptase Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus 2: Role of Deep-Learning-Based CT Diagnosis and Insights from Two Cases

Dasheng Li,Dawei Wang,Jianping Dong,Nana Wang,He Huang,Haiwang Xu,Chen Xia 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.4

The epidemic of 2019 novel coronavirus, later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still gradually spreading worldwide. The nucleic acid test or genetic sequencing serves as the gold standard method for confirmation of infection, yet several recent studies have reported false-negative results of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Here, we report two representative false-negative cases and discuss the supplementary role of clinical data with rRT-PCR, including laboratory examination results and computed tomography features. Coinfection with SARS-COV-2 and other viruses has been discussed as well.

The Combination of Platelet Rich Plasma Gel, Human Umbilical Mesenchymal Stem Cells and Nanohydroxyapatite/polyamide 66 Promotes Angiogenesis and Bone Regeneration in Large Bone Defect

Liu Wei,Huang Yong,Liu Daqian,Zeng Teng,Wang Jingzhe,Li Ang,Wang Dawei,Wang Xiaoyu 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.6

BACKGROUND: In the present study, a novel tissue engineering bone graft including platelet rich plasma gel (PRP gel), human umbilical mesenchymal stem cells (HUMSCs) and nanohydroxyapatite/polyamide 66 (nHA-PA66) was constructed. We explored whether the composite scaffolds could enhance the angiogenesis and bone repair capacity in rat femoral large bone defect (LBD). This study aimed to provide evidence for the clinical application of the composite scaffold in LBD treatment. METHODS: PRP was prepared, the platelets and growth factors were measured. HUMSCs were isolated and identified. the osteogenic capacity of PRP in vitro was measured. Then HUMSCs-PRP-gel/nHA-PA66 composite scaffolds were synthesized and observed. The proliferation and osteogenesis differentiation of HUMSCs on the composite scaffold was measured. The angiogenic capacity of PRP in vitro was measured by capillary-like tube formation assay. Finally, the angiogenesis and bone repair capacity of the composite scaffolds was measured in rat LBD. RESULTS: PRP contained high level of platelets and growth factors after activation, and promoted osteogenic and angiogenic differentiation in vitro. The HUMSCs-PRP-gel/nHA-PA66 composite scaffold was porosity and promoted the proliferation and osteogenesis differentiation of HUMSCs. At 12th weeks, more micro-vessels and new bone were formed around the composite scaffolds compared with other groups, the defect was almost repaired. CONCLUSION: Our study for the first time identified that the combination of PRP gel, HUMSCs and nHA-PA66 scaffold could significantly promote angiogenesis and bone regeneration in rat LBD, which may have implications for its further application in clinical LBD treatment.

Evolution Behavior of M23C6 Carbides Under Different Hot Deformation Conditions in Alloy 602 CA

Xiaoyu Qin,Xiaojun Yan,Dawei Huang,Xiaoyong Zhang,Mingjing Qi,Stephen Yue 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6

Alloy 602 CA is a M23C6carbides strengthened Nickel-based superalloy. In this alloy, M23C6is different from that found inother superalloys because of its high volume fraction, wide size distribution and distinct precipitation locations. To investigateM23C6evolution behaviors during hot deformation in Alloy 602 CA, a series of tests are carried out in this study. Thetest temperature ranges from 900 to 1100 °C and strain rate ranges from 0.001 to 0.1 s−1, with a true strain of 0.7. It is foundthat hot deformation of the material decreases the distance between carbides which leads merging happening to changethe morphology of primary M23C6. Secondary carbides mainly come from the dissolution of large primary carbides andprecipitate along grain boundaries and twin boundaries which impede dynamic recrystallization (DRX) from happening. Volume fractions of M23C6decrease from 900 to 1100 °C. At 900 °C and 1100 °C, the precipitation equilibrium is reachedin the preheating period before hot deformation and deformation only change the size distribution of carbides. 1000 °C isa transition temperature where the volume fraction decreases as strain rate increases. The temperature rise initiated by adiabaticheating has a great influence on this precipitation behavior.

Matrix Channel Width Evolution of Single Crystal Superalloy Under Creep and Thermal Mechanical Fatigue: Experimental and Modeling Investigations

Zixu Guo,Ziyuan Song,Dawei Huang,Xiaojun Yan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

In this study, in the respect of rafting behavior of Ni-based single crystal (SC) superalloy under creep and thermal mechanicalfatigue (TMF), an image processing program is developed to investigate the probability characteristic of γ channel width, anda channel width evolution model considering non-quasi-static modification is proposed. Firstly, the fractured and interruptedtests are conducted on SC superalloy. The channel width evolution behavior under different load conditions is observed viascanning electron microscope. Then, an image processing program based on image binarization is developed to conductstatistics on channel width. The statistical results show that the stress and temperature have significant effects on raftingrate, while the phase difference has a small effect. Meanwhile, the channel width obeys lognormal distribution, and the meanvalues follow linear relationship with standard deviations. In the modeling part, a static model is established to predict themean value evolution of channel width under creep condition. To be generalized to TMF condition, the model is modifiedby considering the non-quasi-static effect. After that, the channel width evolution model is further derived to describe theprobability density distribution of channel width. The predicted channel width evolutions are in good agreement with theexperimental results. The statistical results and models can provide the basis for multiscale modeling of SC superalloy.

Radiolabeled polyoxometalate clusters: Kidney dysfunction evaluation and tumor diagnosis by positron emission tomography imaging

Ni, Dalong,Jiang, Dawei,Im, Hyung-Jun,Valdovinos, Hector F.,Yu, Bo,Goel, Shreya,Barnhart, Todd E.,Huang, Peng,Cai, Weibo Elsevier 2018 Biomaterials Vol.171 No.-

<P><B>Abstract</B></P> <P>Radiolabeled nanoprobes for positron emission tomography (PET) imaging has received special attention over the past decade, allowing for sensitive, non-invasive, and quantitative detection of different diseases. The rapidly renal clearable nanomaterials normally suffer from a low accumulation in the tumor through the enhanced permeability and retention (EPR) effect due to the rapidly reduced concentration in the blood circulation after renal clearance. It is highly important to design radiolabeled nanomaterials which can meet the balance between the rapid renal clearance and strong EPR effect within a suitable timescale. Herein, renal clearable polyoxometalate (POM) clusters of ultra-small size (∼1 nm in diameter) were readily radiolabeled with the oxophilic <SUP>89</SUP>Zr to obtain <SUP>89</SUP>Zr-POM clusters, which may allow for efficient staging of kidney dysfunction in a murine model of unilateral ureteral obstruction (UUO). Furthermore, the as-synthesized clusters can accumulate in the tumor through EPR effect and self-assemble into larger nanostructures in the acidic tumor microenvironment for enhanced tumor accumulation, offering an excellent balance between renal clearance and EPR effect.</P> <P><B>Graphical abstract</B></P> <P>Herein, renal clearable polyoxometalate clusters (POM) were readily radiolabeled with the oxophilic <SUP>89</SUP>Zr to allow for efficient staging of kidney dysfunction in a murine model. Furthermore, the as-synthesized clusters can accumulate in the tumor through enhanced permeability and retention (EPR) effect and self-assemble into larger nanostructures in the acidic tumor microenvironment for enhanced tumor accumulation, offering an excellent balance between renal clearance and EPR effect.</P> <P>[DISPLAY OMISSION]</P>

Comparative Investigation Into Field Performance of Steel Bridge Deck Asphalt Overlay Systems

Xiaoyang Jia,Baoshan Huang,Shangjiang Chen,Dawei Shi 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.7

The steel bridge deck overlay provides a smooth surface for riding and protects the deck from influence of traffic and environment factors. The presence of distress on overlay may compromise the serviceability of a bridge. A better understanding of distress is indispensable for designers to make improvements on asphalt overlay to extend the service life. A field investigation into performance of two bridge deck asphalt overlay systems was conducted. The overlay system included an epoxy asphalt overlay and a composite asphalt overlay consisting of Stone-Matrix-Asphalt (SMA) and Gussasphalt (GA). The field investigation was conducted to evaluate the difference in performance between two systems. Chemical analyses were performed on core samples from each bridge to further investigate the distress mechanism of each system. Results indicated that the two overlay systems generally exhibited similar field performance. Each bridge developed different distress, mainly due to the poor bonding between layers or between overlay and steel deck.

Stabilization of Hexaaminobenzene in a 2D Conductive Metal-Organic Framework for High Power Sodium Storage

Park, Jihye,Lee, Minah,Feng, Dawei,Huang, Zhehao,Hinckley, Allison C.,Yakovenko, Andrey,Zou, Xiaodong,Cui, Yi,Bao, Zhenan American Chemical Society 2018 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.140 No.32

<P>Redox-active organic materials have gained growing attention as electrodes of rechargeable batteries. However, their key limitations are the low electronic conductivity and limited chemical and structural stability under redox conditions. Herein, we report a new cobalt-based 2D conductive metal-organic framework (MOF), Co-HAB, having stable, accessible, dense active sites for high-power energy storage device through conjugative coordination between a redox-active linker, hexaaminobenzene (HAB), and a Co(II) center. Given the exceptional capability of Co-HAB for stabilizing reactive HAB, a reversible three-electron redox reaction per HAB was successfully demonstrated for the first time, thereby presenting a promising new electrode material for sodium-ion storage. Specifically, through synthetic tunability of Co-HAB, the bulk electrical conductivity of 1.57 S cm<SUP>-1</SUP> was achieved, enabling an extremely high rate capability, delivering 214 mAh g<SUP>-1</SUP> within 7 min or 152 mAh g<SUP>-1</SUP> in 45 s. Meanwhile, an almost linear increase of the areal capacity upon increasing active mass loading up to 9.6 mg cm<SUP>-2</SUP> was obtained, demonstrating 2.6 mAh cm<SUP>-2</SUP> with a trace amount of conducting agent.</P> [FIG OMISSION]</BR>

Compressive Properties of Electron Beam Melted Ti–6Al–4V Porous Meshes with Different Struts Distributions

Zhiwei Liu,Mingjing Qi,Xiaoyu Qin,Dawei Huang,Xiaoyong Zhang,Xiaojun Yan 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

Structural collapse caused by uneven stress distribution is one of the main failure modes of Electron Beam Melted (EBM)Ti–6Al–4V porous meshes for medical bone implantation. In this paper, two types of porous meshes with different strutsdistributions are fabricated by EBM methods and experimentally studied through uniaxial compression tests. The first type(mesh 1) with simplified struts distribution consists of horizontal, vertical and diagonal struts, which are connected by onenode. The second type (mesh 2) has relatively complicated struts distribution with four structural nodes connected by vertical,horizontal and diagonal struts, and the inclined struts with an angle of 15° to the vertical or horizontal direction. Themechanical properties of solid Ti–6Al–4V alloy are also tested as reference for model-fitting analysis and the test resultsshow that the EBM specimen can achieve comparable tensile strength (1186.5 MPa) and elastic modulus (106.4 GPa) asthat of forging specimen. For the porous meshes, the deformation behavior of the struts along the load orientation is dominatedby buckling mechanism and the deformation behavior of the struts inclined to the load orientation is governed byboth buckling and bending mechanisms. The test results indicate that mesh 1 with relatively less inclined struts can achievebetter compressive resistance than mesh 2 when taking the factor of mesh density into consideration. Such results indicate asimple yet meaningful view that struts distributions of the porous meshes should be designed and optimized based on theirstress distribution conditions.

Photocatalytic conversion of nitrite in aqueous solution over nanocomposite photocatalyst Er3+:Y3Al5O12/BiPO4 using different photosources

Yidi Wang,Bowen Li,Guanshu Li,Yingying Huang,Dawei Fang,Jun Wang,Youtao Song 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.47 No.-

Three crystal phases of BiPO4 (HBIP, nMBIP and mMBIP), corresponding photocatalysts (Er3+:Y3Al5O12/HBIP, Er3+:Y3Al5O12/nMBIP and Er3+:Y3Al5O12/mMBIP) and their nanocomposite photocatalyst (Er3+:Y3Al5O12/(H-nM-mM)BIP) were prepared by hydrothermal, ultrasonic dispersion and liquid boilingmethods. The prepared photocatalysts were characterized by X-ray diffractometer (XRD), energydispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV–vis diffuse reflectancespectra (DRS). The catalytic activity of prepared photocatalysts was evaluated via photocatalyticconversion rate of nitrite under ultraviolet-light, visible-light and simulated solar-light irradiations. These three photocatalysts all exhibited excellent performance under simulated solar-light irradiationand reached 85.36%, 84.42% and 78.53% conversion rates, respectively, for Er3+:Y3Al5O12/mMBIP, Er3+:Y3Al5O12/nMBIP and Er3+:Y3Al5O12/HBIP. Particularly, Er3+:Y3Al5O12/(H-nM-mM)BIP was also found toplay a high catalytic activity, resulting in 78.68%, 70.04% and 82.57% conversion rates, respectively, underultraviolet-light, visible-light and simulated solar-light irradiation. In addition, the study of used timesshowed that the prepared photocatalysts can be effectively recycled without an apparent inactivation onthe photocatalytic activity. This research may provide a potential way for converting nitrite and othercontaminants by utilizing solar energy efficiently.