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An experimental study of the interaction of a planar diffusion flame with a line vortex is presented. A planar diffusion flame is established between two coflowing, equal velocity streams of acetylene diluted with nitrogen and air. A line vortex is generated on demand by momentarily pulsing one of the flow streams by way of electromagnetic actuation of a piston in the flow apparatus. The flame–vortex interactions are diagnosed by planar laser-induced incandescence for soot yield and by particle image velocimetry for vortex flow characterization. The results show that soot formation and distribution are influenced by the reactant streams from which vortices are initiated. The vortices interacting with the flame from the air side produce more soot and soot is distributed in and around the vortex core in diffuse layers. In contrast, topography of soot in vortices interacting from the fuel side is such that soot is confined to thinner layers around the vortex core which does not contain any soot. The flame curvature is found to influence the local soot production with the flame regions convex to the fuel side containing more soot locally. It is also found that the overall soot yield is less sensitive to the vortex strength and is of lower magnitude when vortex is spun from the fuel side. The knowledge of this type of asymmetry in soot yield in flame–vortex interactions is useful for combustion engineering and design of practical devices.

A coaxial jet was actively controlled by a MEMS-fabricated micro flap actuator nozzle. The effect of different control modes on secondary azimuthal instabilities and the evolution of streamwise vortices were investigated by applying stereoscopic PIV to the cross-stream plane of the jet. Forcing with non-symmetric modes, in particular the least-stable helical mode, accelerates the evolution of the streamwise vortices through the enhancement of azimuthal instabilities. Although forcing is applied to the outer shear layer of the outer jet, the control effect is most pronounced in the inner shear layer of the inner jet. Unlike in the natural jet, streamwise vortices appear in the inner shear layer of the controlled jet. For forcing with the fundamental axisymmetric mode, a Strouhal number of the order of unity maximise the azimuthal instabilities and hence the counts of the streamwise vortices. The present result is in accordance with our previous experimental findings in the longitudinal plane, where the evolution of the primary vortices and mixing between the inner and the outer jets were examined through 2D-PIV and PLIF (Kurimoto et al., 2004, Active control of coaxial jet mixing with arrayed micro actuators. Transactions of the Japanese Society of Mechanical Engineers, pp. 31–38.) This emphasises the connection between primary and streamwise vortices and their significance in the mixing enhancement process. It is also found that the azimuthal wavelength under the present control scheme is almost the same as that of the natural jet and independent of the streamwise position.

Along with the rapid growth of research of microfluidics, monitoring and understanding micro flow behavior is a challenge for researchers. Particle Image Velocimetry (PIV), a powerful tool that makes flow visible, was extended to microscale by Santiago et al. 1998. In this paper, we presented the micro Particle Image Velocimetry (μPIV) system at Nanyang Technological University (NTU), its calibration and characterizations of microfluidic devices using μPIV. Since the fully developed microchannel flow has been well investigated, it is suitable to calibrate the measurements of μPIV. In our experiment, an in-channel microdispenser fabricated on printed circuit board is used to form a microchannel. A syringe pump forces water that contains fluorescent particles. The flow field is obtained by μPIV. At the same time, a three-dimensional model with ANSYS/FLOTRAN was used. The comparison between the two results demonstrates that our μPIV system works well. Furthermore we use this system to characterize a Tesla valve - a non-moving part valve. The valve consists of a fluid channel structure that has rectification property, which favors forward flow while hampers reverse flow. The velocity fields are also validated by ANSYS/FLOTRAN.

Pulsed jets have found a wide variety of applications in the area of flow control during the recent years. The goal of the current study is to identify the flow field and mixing characteristics associated with an incompressible circular jet through a flexible nozzle. The flow was self-excited over a range of conditions and produced a pulsatile flow. The frequency of excitation was found to be between 150-175Hz. Phase-locked and time averaged 2D Particle image Velocimetry (PIV) was used to study the dynamic characteristics of the flow. The flow field shows that two different modes could be excited depending on nozzle characteristic. The flapping mode was associated with alternate shedding of vortices. This introduces strong steering of the jet to one side or the other. Turbulence, Jet spread and entrainment characteristics were far more superior to the non-flapping or a pulsed jet. The second mode which was a non-flapping mode is associated with the formation of a counter rotating vortex pair. The turbulence associated with both these modes was convected along with the vortical structure in the flow. The jet vortices formed by the self-excited flow were not just convected by the flow, but these determined the flow field and mixing characteristics of the jet.

Two-phase annular flow is commonly used in both commercial and industrial heat transfer; however, we do not yet possess a thorough understanding of the nature of the fluid. Most analytical annular two-phase models are based on a relationship between the liquid film thickness, liquid film mass flux, and the axial pressure gradient or interfacial shear stress. The film thickness calculated from these models can then be utilized to determine the heat transfer coefficient of the flow. Although they are specific to certain flow regimes and fluids, empirical models remain more accurate than these analytical models. The key to understanding these flows lies with the liquid film. Therefore, to better understand the pressure drop and heat transfer of annular two-phase flow, this study involves the development of local, liquid velocity measurement techniques and their application to horizontal, wavy-annular two-phase flow. Two techniques, Bubble Streak Tracking (BST) and Thin Film Particle Image Velocimetry (TFPIV), have been developed in this study. Utilizing naturally occurring bubbles within the liquid film, the BST technique determines the liquid velocity by measuring reflected light streaks from the bubbles. A three-colored LED array creates directionally unambiguous streaks, while a strobe illuminates interfacial features that affect the liquid velocity. The TFPIV technique applies a typical micro-PIV system to a macroscopic flow with the addition of a non-trivial image processing algorithm. This algorithm successfully overcomes the image noise that occurs when applying PIV to a two-phase, thin film. Although difficulties arise when processing the BST data, the results of the BST and TFPIV methods are comparable, making BST an economical alternative to TFPIV for calculating liquid film velocities.

Vortex generator jets (VGJs) have proven to be effective in minimizing the separation losses on low-pressure turbine blades at low Reynolds numbers. Experimental data collected using phase-locked particle image velocimetry and substantiated with a hot-film anemometer were used to answer fundamental questions about the influence of VGJs on a separated boundary layer. The data were collected on the suction surface of the Pack B blade profile, which has a non-reattaching separation bubble beginning at 68% axial chord. Two VGJ pulse histories were created with different frequencies, jet durations,and duty cycles. The mechanisms responsible for boundary layer separation control were shown to be a combination of boundary layer transition and streamwise vortical structures. Jet duration and relaxation time were important VGJ characteristics in determining the extent of control. The unsteady environment characterisitic of the low-pressure turbine section in a gas turbine engine effectively reduces the time-averaged separation zone by as much as 35%. Upstream blade rows create unsteady flow disturbances (wakes) that transition the flow. This transitioned flow propagates downstream, re-attaching the separation bubbles on the subsequent blade row. Phase-locked PIV and hot-film measurements were used to document the characteristics of this separation zone when subjected to synchronized unsteady wakes and VGJs. The phase difference between VGJ actuation and the wake passing, blowing ratio, and VGJ duration were optimized to achieve the greatest timeaveraged control of the separation zone. The experimental data were used to identify the important characteristics of the wake/jet interaction. Phase-locked PIV measurements were taken to isolate the wake event.

Insoluble monolayers at the air-water interface are exposed to a gas phase containing organic hydrocarbons. The hydrocarbons are partly incorporated within the monolayer which leads to changes in orientational order and the formation of new phases of different morphology. The transition state resembles features of the air-water and oil-water interface and the control of the hydrocarbon partial pressure allows continous tuning between both interfaces. The phospholipid D,L-R-dipalmitoylphosphatidylethanolamine,DPPE, and an esterdiol hexadecanoic acid, 2,3-dihydroxypropyl ester, ESD-16, are used as amphiphiles, and pentane, n-hexane, cyclohexane, 2,2-dimethylbutane, n-heptane, n-decane, and n-dodecane are used as hydrocarbons. Both amphiphiles differ in their headgroup size. In DPPE the aliphatic tail determines the packing within the monolayer, but in the case of ESD-16 it is the headgroups.The structural changes are monitiored by surface pressure-area (ð,A) isotherms and imaging ellipsometry.The influence of the chemical nature of the hydrocarbon and the effect of the partial pressure of the hydrocarbon on the monolayer structure are assessed.

Polarization null angle (PNA) method is an accurate alternative to the commonly used polarization intensity ratio method in determination of molecular orientation at interfaces with sum frequency generation vibrational spectroscopy (SFG-VS). Here, the accuracy and sensitivity of PNA method is tested on different experimental configurations. It is found that its accuracy and sensitivity are more sensitive to the incident angle of the visible beam than the IR beam, and the range of the optimal experimental configurations is identified. This development makes better understanding of the polarization measurement in SFG-VS, and should find more applications for interface studies.

An aqueous ionic surfactant 1-dodecyl-4-dimethylaminopyridinium (DMP) bromide and the corresponding zwitterion 2-(4-dimethylaminopyridinio)-dodecanoate (DPN) were explored by means of molecular dynamics (MD) simulations and, for the ionic system, by infraredvisible sum frequency generation (IR-VIS SFG). The molecular structure of the interfacial layer was investigated for the ionic and zwitterionic systems as a function of surfactant concentration, both in water and in salt (KF or KBr) solutions, by MD simulations in a slab geometry. The build up of the surface monolayer and a sublayer was monitored, and density and orientational profiles of the surfactants were evaluated. The difference between the ionic and zwitterionic systems and the effect of the added salt were analyzed at a molecular level. The results of MD simulations were compared to those of nonlinear optical spectroscopy measurements. Infrared visible sum frequency generation (IR-VIS SFG) was employed to study the DMP ionic surfactant in water and upon addition of simple salts. The influence of added salts on the different molecular moieties at the interface was quantified in detail experimentally.

Water droplets are introduced via four spray nozzles, with the resulting size distribution being quite broad ( ¯ d = 22 μm, ¾d = 13 μm). Downstream, a Phase Doppler Interferometer (PDI) (15) simultaneously measures the diameter (di), downstream speed (vi), and arrival time (ti) of any droplets that traverse its view volume (which has a linear dimension of roughly 150 μm). The PDI system was built and calibrated by Artium Technologies, Inc. and is designed for in situ measurement, such that the instrument does not disturb the flow through the measurement volume when aligned parallel to the mean flow.

Laser-Induced Incandescence (LII) is investigated in laminar premixed flat ethylene/air flames at pressures up to 5 bar in a recently constructed high-pressure burner. Time-resolved LII signals were compared with a numerical model considering the influence of pressure on the LII signal decay. Peak particle temperatures after laser heatup were measured by the detection of the LII signal at two wavelenghts. Laser-induced emission spectra enabled to check for interfering signals. Gas-phase temperatures were requiered to compare the LII signal decay with the model and were measured using multi-line NO-LIF thermometry.

Detection and imaging of multi-reaction zones is an essential tool for understanding the detailed structure of complicated flames. In this work a combined 4-camera technique is presented for multi-reaction zones imaging. The technique combines highly advanced laser-based diagnostics tools, namely Rayleigh scattering, laser-induced predissociation fluorescence (LIPF) of OH, LIF of PAH, and LIF of formaldehyde (CH2O). The application of this combined technique in turbulent non-homogeneous hydrocarbon flames is quite new. The technique shows its ability to detect simultaneously rich, lean and diffusion reaction zones. The 3 reaction zones can be spatially resolved, providing essential information about their interaction and overall flame stability. Therefore, the detection and study of triple flame structures in non-homogeneous turbulent flames becomes possible. An example of a triple flame structure in a turbulent lifted non-premixed methane flame is presented. The present work proves that the developed technique is a powerful tool for multi-reaction zone measurements in turbulent and laminar flames.

Nitric oxide laser-induced-fluorescence (NO-LIF) 2-D imaging measurements using a new multi-spectral detection strategy are reported for high-pressure flames (1–60 bar). This work builds on previous research that identified interference LIF from O2 and CO2 in high-pressure flames and optimized the choice of excitation strategies as a function of application conditions. In this study, design rules are presented to optimize the LIF detection wavelengths for quantitative 2-D NO-LIF measurements over a wide range of pressures (1–60 bar) and temperatures. Simultaneous detection of LIF in multiple wavelength regions enables correction of the NO signal for interference from O2 and CO2 and allows simultaneous imaging of all three species. New experiments of wavelength-resolved 1-D LIF in slightly lean (/ = 0.9) and slightly rich (/ = 1.1) methane/air flames are used to evaluate the design rules and estimate the NO detection limits for a wide range of flame conditions. The quantitative 2-D measurements of NO in the burnt gas are compared with model calculations (using GRI-Mech 3.0) versus pressure for slightly lean and slightly rich flames. The discussions and demonstrations reported in this study provide a practical guideline for application of instantaneous 1-D or 2-D NO-LIF imaging strategies in high-pressure combustion systems.

In this work, we report on the direct measurement of heat release rates via simultaneous laser-induced fluorescence of OH and CH2O radicals using planar laserinduced fluorescence (PLIF). The product of the two images is shown to correlate with the forward production rate of the HCO radical, which in turn has been found to correlate well with heat release rates in premixed hydrocarbon flames. Heat release rate measurements were also taken with OH* for comparisons with the results from the laser-based technique. The measurements were made in a lean turbulent premixed flame subject to acoustic forcing; this flame mimics the instabilities encountered in lean premixed pre-vaporized combustors (LPP). As the scheme is based on probing radical species that participate in the major heat release reactions, it is the closest nonintrusive measure of heat release rate currently available and thus presents a very useful diagnostic tool in combustion research.

A parameter study was conducted to characterize the combustion of a hydrogen-rich syngas fuel in swirl-stabilized flames in a gas turbine model combustor with optical access. Three thermal power-loadings were tested and equivalence ratio was varied in a range of Φ ≈ 0.4 - 0.6 by changing the fuel flow rates at constant air flow. Velocity, heat-release and flame zone shape were studied using optical diagnostics including PIV, OH-LIF and OH* chemiluminescence imaging. A main goal of this work was the establishment of an experimental data base for the validation of numerical simulations. The syngas burned stably and without significant thermo-acoustic oscillations at all operating conditions. The inner recirculation zone is identified as a key stabilization mechanism for this burner. This is consistent with previous studies for syngas mixtures with a high CO content in the same burner. Changes in equivalence ratio and the thermal power of the flame had only a small impact on the overall flame shape and the burning behavior.

The Electric Particulate Suspension (EPS) is a combustion ignition system being developed at Iowa State University for evaluating quenching effects of powders in microgravity (quenching distance, ignition energy, flammability limits). Because of the high cloud uniformity possible and its simplicity, the EPS method has potential for ‘benchmark’ design of quenching flames that would provide NASA and the scientific community with a new fire standard. Microgravity is expected to increase suspension uniformity even further and extend combustion testing to higher concentrations (rich fuel limit) than is possible at normal gravity. Two new combustion parameters are being investigated with this new method: (1) the particle velocity distribution and (2) particle-oxidant slip velocity. Both walls and (inert) particles can be tested as quenching media. The EPS method supports combustion modeling by providing accurate measurement of flame-quenching distance as a parameter in laminar flame theory as it closely relates to characteristic flame thickness and flame structure. Because of its design simplicity, EPS is suitable for testing on the International Space Station (ISS). Laser scans showing stratification effects at 1-g have been studied for different materials, aluminum, glass, and copper. PTV/PIV and a leak hole sampling rig give particle velocity distribution with particle slip velocity evaluated using LDA. Sample quenching and ignition energy curves are given for aluminum powder. Testing is planned for the KC-135 and NASA’s two second drop tower. Only 1-g ground-based data have been reported to date.

Much progress has been made in the understanding of the phenomenon of drag reduction by dilute solutions of polymers since its discovery in 1948. While the use of advanced techniques in experiments and computational simulations have dramatically advanced our understanding of the phenomenon, a complete and conclusive explanation of the physics associated with the phenomenon is still lacking. In particular, drag reduction in boundary layers with injection has not been studied extensively to understand the processes and physics that govern the spread and mixing of the injected polymer in the flow. To overcome this limitation, in the present work, drag reduction due to polymer injection in a turbulent boundary layer is studied using simultaneous Particle Imaging Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). PIV is used to measure the velocity of the flow in the boundary layer and to calculate higher order velocity statistics. PLIF is used to study the distribution and spread of the injected polymer in the boundary layer by tracking a fluorescent dye mixed in with it. The polymer of choice, polyethylene oxide, is injected as a dilute solution into a fully turbulent Newtonian boundary layer and measurements of velocity and concentration are made at different downstream locations on the flat plate to study the effect of the polymer on the flow and the evolution of drag reduction. The data from the two measurement techniques are combined to calculate turbulent fluxes and to estimate the turbulent Schmidt number in polymer drag reduced flows.

本文给出了用时间分辨立体PIV(TRSPIV)实验解决实验室尺度内混合器中的瞬态流场结构问题。研究了漩涡结构的时间演化规律。

本文的研究及装置，较好地解决了玻璃小瓶的清洗问题。具体来说，使得洗涤液方便进出小瓶，可以对小瓶进行长时间的浸泡，使得挂壁的有机物脱落。另外，本设计的装置可以带瓶子一起放入超声波清洗池，保证超声波进入每个小瓶，进而确保瓶子的清洗的结果较清洁。同时，小瓶的托盘的材质为不锈钢，可以和小瓶一起放入马弗炉烘干。当然，也避免了清洗人员的手部与洗涤液的接触，较好的保障了洗涤人员的人身安全。

细粉末粒度分布的测定，依据国家标准GB/T 13220 -91采用声波筛分法，最小可以筛分5微米的颗粒，对粉末质量轻，密度小，粘附性强有着很明显的效果。

近期华人抗体协会发布一篇文章介绍到连续制造工艺被FDA推崇备至：连续制造工艺基于其稳定高效率的优势，已经在其它许多行业成为极其成功的生产模型。然而很长一段时间以来，制药行业以严格监管和法规要求过于保守而被行业所诟病，故多数仍以批次生产为主。近年来，随着业界对于产能效率和生产成本的不断重视，生物制药行业对于连续工艺的关注度也在不断增加，希望能借以提高生产效率和设备利用率，且已有案例表明特定连续技术整合到现有生物药生产流程后，显现了诸多优势。作为全球药物监管的领先者，FDA一直是连续制造工艺的有力倡导者。早在2017年，FDA就发布了关于连续制造（Continues manufacturing, CM）的意见征求稿；2018年FDA 向三个连续制造项目提供近六百万美元资金，旨在帮助实施创新技术以提高产品质量并实现行业现代化；2019年2月26日，FDA颁布了涉及CM的关键指南草案《Quality Considerations for Continuous Manufacturing》，必将对此技术的推动起到巨大作用，同时FDA 局长 Scott Gottlieb 和药品中心主任 Janet Woodcock 也为CM高调站台，在随指南发布的声明中一再强调连续制造的优势，由此看来CM未来或许已不远。令人高兴的是，得益于纳微科技在纳米材料及键合等多方面取得的突破性进展，UniMab Protein A亲和层析介质因其诸多独有领先优势而特别适合用于连续柱色谱体系。

METARSCAN扫描，针对大型工件，无需贴点，精度高，可以导出stl格式的数据，直接使用，用于与设计图纸进行数模比对，以及根据实际工件设计新产品，可以应用于风电，航天航空行业，操作简单

DSC方法测试终熔点时，与设备的升温速率、实验的样品量的有正相关的关系，因此测试终熔点时，要控制好条件变量

（1）替代水冷凝管； （2）节水，省水，消除了自来水使用和废水处理的费用； （3）没有淹水的风险，避免实验室水灾； （4）有助于达到可持续的节水目标

应用电化学阻抗谱研究了907钢在海水中受到阴极保护的同时，添加多元醇磷酸酯类缓释剂，其表面膜层变化的情况和缓释机理

解决了研磨过程中粘罐或者沉淀的问题，比如有些物料，比如潮湿的土壤料、沥青矿等粘性料、某些化学品、活性炭、金属粉等，在研磨完毕后物料会沉积于研磨罐底部，磨球及盖子上也粘有很多物料，难于清洗。并且一旦沉底粘罐，磨球只作用于表层物料，使得内部研磨不到，勉强用工具取下，粒度分布也不均匀。

简单，容易操作，不受条件限制，样品研磨完成后，即可清洗，可根据自己的需要选择清洗方法，温馨提示，大家不要偷懒哦，防止累积

此套解决方案使得用户可以原位的、时间分辨的对固液薄膜进行GISAXS测量与研究，包括不规则岛状分布形成规则膜层的过程。

全球首套实验室级实时监测薄膜生长的掠入射小角散射(GISAXS)系统。曝光时间仅为8s，入射角调到与临界角接近，可以达到实时沉积的亚单层灵敏度。

在实际工作中，当我们拿到一个样品，我们该怎样定性和定量，建立一套完整的分析方法是关键，下面介绍一些常规的步骤： 1、样品的来源和预处理方法 GC能直接分析的样品通常是气体或液体，固体样品在分析前应当溶解在适当的溶剂中，而且还要保证样品中不含GC不能分析的组分（如无机盐），可能会损坏色谱柱的组分。这样，我们在接到一个未知样品时，就必须了解的来源，从而估计样品可能含有的组分，以及样品的沸点范围。如果样品体系简单，试样组分可汽化则可直接分析。如果样品中有不能用GC直接分析的组分，或样品浓度太低，就必须进行必要的预处理，如采用吸附、解析、萃取、浓缩、稀释、提纯、衍生化等方法处理样品。