注意:请所有相关的材料安全数据表。用于试验的化学品是有毒和致癌性。使用个人防护装备（护目镜，手套，实验室外套，全长裤，封闭趾鞋）。 1.设置为测试<ol><li> 样品的制备 <ol><li>垂直切割织物带沿方向的纤维（以测试芯吸在纤维方向）。 注:该带的长度，以获得一个限定的纤维体积比来计算。为碳织物，以获得V F = 40％时，条带的长度为150毫米。对未处理和处理过的亚麻，达到同样的V F，长度为365毫米。每个条带的宽度将等于样本保持器，其为20毫米（ 图1）的高度。 </li><li>滚动条紧紧地允许其插入成R &lt;的圆柱形样品架/ EM&gt; = 6毫米。 </li><li>添加样品架和样品增强件之间的薄纸过滤器（为了抑制样品支架上的芯吸作用）。过滤纸的最大厚度为0.1毫米。 </li><li>插入样品进入气缸及螺杆在底部上方的钻孔盖和活塞，以确保压缩。 </li><li>夹紧样品架与织物的张力。 </li></ol></li><li> 液体制剂 <ol><li>填充容器与液体检验，并将其放置到张力的特定容器。利用容器由硼硅酸玻璃中，用直径为70毫米。 </li><li>对于第一次测试（步骤2.1）中，使用正己烷。对于第二个测试（步骤2.3），使用的水。保证在容器中的液体达到至少12毫米的高度。 </li></ol></li><li> 实验参数 <ol><li>表面检测阈值设置为8毫克和transla以0.5毫米/秒的液体容器用于检测液体的灰速度。 </li></ol></li></ol> 2.吸湿排汗测试注:样品的制备和张力参数的设置后，排汗测试可以启动。液体容器中，直至所述液体与所述样品保持器接触向上移动。然后，液体上升到样品保持器，并且所述张力测量随时间的平方液体质量增益。数据由设置有张力的软件记录。那么大众对时间的一种曲线可视化每个灯芯测试。 <ol><li> 确定几何系数最初的测试: <ol><li>使用完全润湿液体（的量，接触角为0°），如正 - 己烷。 </li><li>停止芯吸试验时的可视化曲线达到恒定值。这表明液体到达样品架的顶部，因而，该芯吸完毕。 </li><li&gt;适合芯吸曲线（ 米2（t））的与沃什伯恩方程的线性趋势: <img alt="公式3" src="/files/ftp_upload/55059/image003.jpg" /> （3） 由于前进接触角假设为0°，用正己烷，从线性拟合的斜率，确定几何常数，C（毫米5）。 注:所有测试均在20℃的标准条件下进行。在温度变化将修改液体的表面张力和结果。 </li></ol></li><li> 样本保持器的清洗为以下测试 注:除去湿织物后，将样品保持器必须被完全清洁，以防止在下面的测量中的误差。 <ol><li>浸入样品架与sulfochromic酸（重铬酸钾的饱和溶液的50％，浓硫酸的50％），持续30秒的容器中。 </li><li>用蒸馏水冲洗，并然后擦干。 </li></ol></li><li> 第二测试用于确定表观前进接触角 <ol><li>使用的量，前进接触角必须用一个新的，一致的，和干燥织物样品测定对象的液体。 注:水，以便验证该方法中使用。 </li><li>停止芯吸试验时的可视化曲线达到恒定值。这表明液体到达样品架的顶部，该毛细上升完毕。 </li><li>适合芯吸曲线（ 米2（t））的同Washburn等式（等式3）的线性部分中，由于常量，C是已知由于第一测试（步骤2.1），以线性拟合确定所述斜率前进接触角θ 一 （°）。 注:所有测试均在20℃的标准条件下进行。在温度变化将修改液体的表面张力和结果。 </li></ol></LI&gt; <li> 的液体重量贡献的评估由于样品架 注:张力，作为一个微量天平，测定的液体的总质量，包括在所述织物的液体上升和外部弯液面上的样品架的贡献，并在过滤器中的毛细作用。这些捐款必须隔离。 <ol><li>把滤纸的相同量的在步骤1.1.3用于进入样本保持器，并重复步骤2.1.1-2.1.2。 </li><li>减去从记录在步骤2.1.3中的数据获得的恒定值（M 2）和换档曲线来评估几何常数，C的正确评估。 </li><li>填写样品架只用滤纸并重复步骤2.3.1-2.3.2。 </li><li>减去从记录在步骤2.3.3中的数据获得的恒定值（M 2）和换档曲线来评估前进接触角的正确的评价，θA。 </li></ol></li>
</ol>

<ol>
	<li>Lawrence, J. M., Neacsu, V., Advani, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+the+impact+of+capillary+pressure+and+air+entrapment+on+fiber+tow+saturation+during+resin+infusion+in+lcm.">Modeling the impact of capillary pressure and air entrapment on fiber tow saturation during resin infusion in lcm.</a> Compos Part A: Appl Sci Manuf. 40 (8), 1053-1064 (2009).</li><li>Ravey, C., Ruiz, E., Trochu, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+the+optimal+impregnation+velocity+in+resin+transfer+molding+by+capillary+rise+experiments+and+infrared+thermography.">Determination of the optimal impregnation velocity in resin transfer molding by capillary rise experiments and infrared thermography.</a> Compos Sci Technol. 99, 96-102 (2014).</li><li>Verrey, J., Michaud, V., M&#229;nson, J. -. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+capillary+effects+in+liquid+composite+moulding+with+non-crimp+fabrics.">Dynamic capillary effects in liquid composite moulding with non-crimp fabrics.</a> Compos Part A: Appl Sci Manuf. 37 (1), 92-102 (2006).</li><li>Abouorm, L., Moulin, N., Bruchon, J., Drapier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monolithic+approach+of+Stokes-+Darcy+coupling+for+LCM+process+modelling.">Monolithic approach of Stokes- Darcy coupling for LCM process modelling.</a> Key Eng Mater. 554, 447-455 (2013).</li><li>Washburn, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Note+on+a+method+of+determining+the+distribution+of+pore+sizes+in+a+porous+material.">Note on a method of determining the distribution of pore sizes in a porous material.</a> Proc Natl Acad Sci USA. , 115-116 (1921).</li><li>Pucci, M. F., Liotier, P. -. J., Drapier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+effects+on+flax+fibers-modification+and+characterization+of+the+wetting+dynamics.">Capillary effects on flax fibers-modification and characterization of the wetting dynamics.</a> Compos Part A: Appl Sci Manuf. 77, 257-265 (2015).</li><li>Darcy, H., Dalmont, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Les fontaines publiques de la ville de Dijon: exposition et application. , (1856).</li><li>Pucci, M. F., Liotier, P. -. J., Drapier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+wicking+in+a+fibrous+reinforcement-orthotropic+issues+to+determine+the+capillary+pressure+components.">Capillary wicking in a fibrous reinforcement-orthotropic issues to determine the capillary pressure components.</a> Compos Part A: Appl Sci Manuf. 77, 133-141 (2015).</li><li>Pucci, M. F., Liotier, P. -. J., Drapier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+wicking+in+flax+fabrics+-+effects+of+swelling+in+water.">Capillary wicking in flax fabrics - effects of swelling in water.</a> Colloids Surf A: Physicochem Eng Aspects. 498, 176-184 (2016).</li><li>Nguyen, V. H., Lagard&#232;re, M., Park, C. H., Panier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Permeability+of+natural+fiber+reinforcement+for+liquid+composite+molding+processes.">Permeability of natural fiber reinforcement for liquid composite molding processes.</a> J Mater Sci. 49 (18), 6449-6458 (2014).</li><li>Stuart, T., McCall, R., Sharma, H., Lyons, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modelling+of+wicking+and+moisture+interactions+of+flax+and+viscose+fibres.">Modelling of wicking and moisture interactions of flax and viscose fibres.</a> Carbohydr Polym. 123, 359-368 (2015).</li></ol>

The authors have nothing to disclose.

在协议中的关键步骤涉及样品的准备。首先，在轧制采样必须紧，以使均匀的纤维体积比的假设。如果在样品中的紧密度梯度，Washburn等式5,6不能用于以适合芯吸的曲线。另外，织物和样品架之间的边界条件是难以控制。因此，过滤器纸（1.1.3）也必须仔细插入样品架8。 该技术的一些修改可以使进行分析，以评估?...

期间在液体复合成型（LSM）工艺纤维增强材料的浸渍，树脂的流动由压力梯度驱动。毛细效应有可与压力梯度，竞争取决于工艺参数的附加效果。它们对过程的影响因而具有待评估1,2。这可以通过定义一个明显的毛细压力P 帽 ，修改初始压力梯度3来完成。此参数可随后插入数字模型，以便在流程模拟流动，并准确地预测空洞形成4。 由液体（芯吸）织物的自发浸渍可以通过Washburn等式5进行说明。最初，Washburn等式中描述的液体的毛细上升的管。这个方程WA记者随后延长多孔结构，如纤维增强材料时，可以近似为一个毛细管网络。考虑具有半径R，填充有多孔介质的圆柱形样本保持器，Washburn等式中的平方质量增量（ 平方米（t））的随时间的形式被修改，如下6: <img alt="式（1）" src="/files/ftp_upload/55059/image001.jpg" /> （1） 其中，c是占迂曲的参数中，R是平均孔隙半径，ε= 1-V f是孔隙率（Ⅴf为纤维体积比）。在方括号的所有参数涉及在多孔介质的形态和结构，并且它们可以被合并到一个常数，C被称为"几何多孔介质因子"。其他参数表达毛细在介质和液体之间的相互作用（通过ρ，η依赖性，γL， 这分别是密度，粘度和表面的液体的张力，并且通过θA，表观前进接触角）。 平行地，通过多孔介质的流动通常与公知的达西定律7，其涉及的等效流体速度vð建模，通过介质，K和液体的粘度，的渗透性的压降η 。这个等式还允许质量增益在一段平方根，因此，供两个方程之间的等价的表达。从沃什伯恩方程和达西定律之间的等价，毛细管压力，然后定义如下8: （2） 这里，主要的焦点是描述的实验程序来测量的几何因素和单向织物表观前进接触角，以确定所述毛细管压力的目的。此方法依赖于使用张力进行芯吸测试（图1）。张力计是具有10微克的分辨率测量的液体物料或周围形成固体弯月面或上升纤维状介质微量天平。芯吸试验进行了考虑的一维表征（沿纤维方向）8,9。用于验证程序准单向织物是在一个V F = 40％的碳的单向（UD）织物。一旦方法进行了验证，亚麻织物提交热处理吨帽子修改纤维6的润湿行为，并分别具有不同的纤维体积比为未处理和处理亚麻织物进行芯吸测试（从30％至40％）。以确定形态和润湿参数，至少两个芯吸测试是强制性的:第一个具有完全润湿液体，如正己烷，以确定C（式1），而第二个与感兴趣的液体，以确定明显的前进接触角，一旦启用C是已知的。在第一种方法中，将水用于评估过程。 这种方法可以适用于不同的面料和液体，允许材料几何（面料的形态），孔隙率（不同纤维体积比），和粘度和在毛细管浸渍现象的液体表面张力的影响的评估。很明显，根据本沃什伯恩理论（等式1）中的步骤可以仅当芯吸立方米被采用rves（ 平方米（t））的由张力记录，具有线性的趋势。这意味着在公式1的参数必须在整个芯吸过程保持不变。如果不是这种情况下，作为在水中的亚麻增强，因为纤维离岗肿胀10，11，Washburn等式应修改成包括以描述的测试正确9肿胀的效果。处理过的织物被认为是对水吸附9不太敏感。几何因素和润湿参数可从线性拟合来测定，允许毛细管压力P 帽的计算。

<table border="0" cellpadding="0" cellspacing="0" width="700">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Carbon UD fabrics</td>
			<td style="width:167px;">Hexcel&#160;</td>
			<td style="width:151px;">48580</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Flax UD fabrics</td>
			<td style="width:167px;">Libeco</td>
			<td style="width:151px;">FLAXDRY UD 180</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">n-Hexane</td>
			<td style="width:167px;">Sigma Aldrich</td>
			<td style="width:151px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sulfochromic acid</td>
			<td style="width:167px;">home made</td>
			<td style="width:151px;"></td>
			<td>toxic and corrosive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Filter paper</td>
			<td style="width:167px;">Dataphysic</td>
			<td style="width:151px;">FP11</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tensiometer</td>
			<td style="width:167px;">Dataphysic</td>
			<td style="width:151px;">DCAT11</td>
			<td></td>
		</tr>
	</tbody>
</table>

wicking tests for unidirectional fabrics: measurements of capillary parameters to evaluate capillary pressure in liquid composite molding processes

期间在液体复合成型（LCM）的处理的纤维补强的浸渍，毛细管效应有，以便识别在复合材料部件其上形成空隙的影响可以理解。在由Washburn等式描述的纤维状介质芯吸被视为等同于根据达西定律的毛细压力的作用下的流动。为排汗的特性实验测试使用的碳和亚麻纤维加固进行。准单向织物然后通过一个张力的手段来确定沿光纤方向的形态和润湿参数测试。该过程被证明是有前途的，当织物的形态是毛细管芯吸过程中保持不变。在碳织物的情况下，该毛细管压力可以计算出来。亚麻纤维对水分的吸附敏感，并在水中溶胀。这种现象，必须考虑以评估润湿参数。一世n阶使纤维吸水较不敏感，热处理于亚麻增援进行。这种治疗方法增强纤维的形态稳定性和在水中的防止肿胀。结果表明，处理过的织物具有类似于在碳织物发现，允许毛细管压力的确定的线性芯吸的趋势。

与张力为碳和未处理的和处理过的亚麻织物芯吸得到期间增重的曲线示于图2和3。所有曲线的外部弯液面的两个权重的减法后示出由于样品保持器和过滤纸和被移位到零。 有可能从图2的曲线，与正己烷和水两者，公式1与实验芯吸的线性拟合是公实现，如果织物中的样品架正确插入到观察?...

Watch this Scientific Journal Video about Wicking Tests for Unidirectional Fabrics: Measurements of Capillary Parameters to Evaluate Capillary Pressure in Liquid Composite Molding Processes at JoVE.co

Wicking Tests for Unidirectional Fabrics: Measurements of Capillary Parameters to Evaluate Capillary Pressure in Liquid Composite Molding Processes

实验方法测量几何参数和说明毛细血管单向合成和天然面料吸湿排汗，提出了推进表观接触角。这些参数是强制性的，必须考虑到对液体复合成型（LCM）应用的毛细压力的确定。

吸湿排汗试验单向织物:毛细管参数的标准评价在液体复合成型工艺毛细管压力

During impregnation of a fibrous reinforcement in liquid composite molding (LCM) processes, capillary effects have to be understood in order to identify ...

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Civil Engineering

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Unit 1

Fluid Properties

SCIENTISTS IN ACTION

8.7K 次观看.  Mines Saint-Étienne. 实验方法测量几何参数和说明毛细血管单向合成和天然面料吸湿排汗，提出了推进表观接触角。这些参数是强制性的，必须考虑到对液体复合成型（LCM）应用的毛细压力的确定。 

视频: Wicking Tests for Unidirectional Fabrics: Measurements of Capillary Parameters to Evaluate Capillary Pressure in Liquid Composite Molding Processes

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with sub-nanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.

We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.

在液体中使用液体池透射电子显微镜揭示材料的动态过程

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted ...

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工程学

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

在极端的压力和温度的合成和Microdiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

Fabrication and Visualization of Capillary Bridges in Slit Pore Geometry

A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. High aspect ratio hydrophobic pillars are fabricated and functionalized to render their top surfaces hydrophilic. The combination of a physical feature (the pillar) with a chemical boundary (the hydrophilic film on the top of the pillar) provides both a physical and chemical heterogeneity that pins the triple contact line, a necessary feature to create stable long but narrow capillary bridges. The substrates with the pillars are attached to glass slides and secured into custom holders. The holders are then mounted onto four axis microstages and positioned such that the pillars are parallel and facing each other. The capillary bridges are formed by introducing a fluid in the gap between the two substrates once the separation between the facing pillars has been reduced to a few hundred micrometers. The custom microstage is then employed to vary the height of the capillary bridge. A CCD camera is positioned to image either the length or the width of the capillary bridge to characterize the morphology of the fluid interface. Pillars with widths down to 250 &#181;m and lengths up to 70 mm were fabricated with this method, leading to capillary bridges with aspect ratios (length/width) of over 1001.

A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. The creation of capillary bridges relies on the formation of pillars to provide a directional physical and chemical heterogeneity to pin the fluid. Capillary bridges are formed and manipulated using microstages and visualized using a CCD camera.

狭缝孔几何中毛细金香桥的制造和可视化

A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. High aspect ratio hydrophobic pillars are fabricated and ...

Single Plane Illumination Module and Micro-capillary Approach for a Wide-field Microscope

A module for light sheet or single plane illumination microscopy (SPIM) is described which is easily adapted to an inverted wide-field microscope and optimized for 3-dimensional cell cultures, e.g., multi-cellular tumor spheroids (MCTS). The SPIM excitation module shapes and deflects the light such that the sample is illuminated by a light sheet perpendicular to the detection path of the microscope. The system is characterized by use of a rectangular capillary for holding (and in an advanced version also by a micro-capillary approach for rotating) the samples, by synchronous adjustment of the illuminating light sheet and the objective lens used for fluorescence detection as well as by adaptation of a microfluidic system for application of fluorescent dyes, pharmaceutical agents or drugs in small quantities. A protocol for working with this system is given, and some technical details are reported. Representative results include (1) measurements of the uptake of a cytostatic drug (doxorubicin) and its partial conversion to a degradation product, (2) redox measurements by use of a genetically encoded glutathione sensor upon addition of an oxidizing agent, and (3) initiation and labeling of cell necrosis upon inhibition of the mitochondrial respiratory chain. Differences and advantages of the present SPIM module in comparison with existing systems are discussed.

A module for single plane illumination microscopy (SPIM) is described which is easily adapted to an inverted wide-field microscope and optimized for 3-dimensional cell cultures. The sample is located within a rectangular capillary, and via a microfluidic system fluorescent dyes, pharmaceutical agents or drugs can be applied in small quantities.

单一平面照明模块和一个宽场显微镜微毛细管法

A module for light sheet or single plane illumination microscopy (SPIM) is described which is easily adapted to an inverted wide-field microscope and ...

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal microfluidic device. W/O microdroplets have recently been used in powerful methods that enable miniaturized chemical experiments. Therefore, developing a versatile method to yield monodisperse W/O microdroplets is needed. We have developed a method for generating monodisperse W/O microdroplets based on a capillary-based centrifugal axisymmetric co-flowing microfluidic device. We succeeded in controlling the size of microdroplets by adjusting the capillary orifice. Our method requires equipment that is easier-to-use than with other microfluidic techniques, requires only a small volume (0.1-1 &#181;l) of sample solution for encapsulation, and enables the production of hundreds of thousands number of W/O microdroplets per second. We expect this method will assist biological studies that require precious biological samples by conserving the volume of the samples for rapid quantitative analysis biochemical and biological studies.

Here, we demonstrate a simple production method for size-controllable, monodisperse, water-in-oil (W/O) microdroplets using a capillary-based centrifugal microfluidic device. This method requires only a small sample volume and enables high-yield production. We expect this method will be useful for rapid biochemical and cellular analyses.

基于毛细管的离心微流体装置单分散微滴的大小可控的形成

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal ...

Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature

The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion batteries for use in devices operating at elevated temperatures require thermally stable and non-flammable electrolytes. Ionic liquids (ILs), which are non-flammable, non-volatile, thermally stable molten salts, are an ideal replacement for flammable and low boiling point organic solvent electrolytes currently used today. We herein describe the procedures to: 1) synthesize mono- and di-phosphonium ionic liquids paired with chloride or bis(trifluoromethane)sulfonimide (TFSI) anions; 2) measure the thermal properties and stability of these ionic liquids by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA); 3) measure the electrochemical properties of the ionic liquids by cyclic voltammetry (CV); 4) prepare electrolytes containing lithium bis(trifluoromethane)sulfonamide; 5) measure the conductivity of the electrolytes as a function of temperature; 6) assemble a coin cell battery with two of the electrolytes along with a Li metal anode and LiCoO2 cathode; and 7) evaluate battery performance at 100 &#176;C. We additionally describe the challenges in execution as well as the insights gained from performing these experiments.

Here, we describe protocols to prepare phosphonium-based ionic liquid and lithium bis(trifluoromethane)sulfonimide salt electrolytes, and assemble a non-flammable and high temperature functioning lithium-ion coin cell battery.

离子液体基电解质的合成，装配锂离子电池，并在高温性能的测量

The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion ...

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline.

This protocol describes the operation of a liquid flow specimen holder for scanning transmission electron microscopy of AuNPs in water, as used for the observation of nanoscale dynamic processes.

使用扫描透射电子显微镜研究纳米大小的物体的动态过程中的液体

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a ...

Magnet Assisted Composite Manufacturing: A Flexible New Technique for Achieving High Consolidation Pressure in Vacuum Bag/Lay-Up Processes

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed magnet assisted composite manufacturing (MACM) technique. In this technique, permanent magnets are utilized to apply a sufficiently high consolidation pressure during the curing stage. To enhance the intensity of the magnetic field, and thus, to increase the magnetic compaction pressure, the magnets are placed on a magnetic top plate. First, the entire procedure of preparing the composite lay-up on a magnetic bottom steel plate using the conventional wet lay-up vacuum bag process is described. Second, placement of a set of Neodymium-Iron-Boron permanent magnets, arranged in alternating polarity, on the vacuum bag is illustrated. Next, the experimental procedures to measure the magnetic compaction pressure and volume fractions of the composite constituents are presented. Finally, methods used to characterize microstructure and mechanical properties of composite laminates are discussed in detail. The results prove the effectiveness of the MACM method in improving the quality of wet lay-up vacuum bag laminates. This method does not require large capital investment for tooling or equipment and can also be used to consolidate geometrically complex composite parts by placing the magnets on a matching top mold positioned on the vacuum bag.

A new technique for applying consolidation pressure on the vacuum bag lay-up to fabricate composite laminates is described. The goal of this protocol is to develop a simple, cost-effective technique to improve the quality of laminates fabricated by the wet lay-up vacuum bag method.

磁铁辅助复合制造: 真空袋/糊化过程中实现高固结压力的一种柔性新技术

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

柔性单向复合层压板的切割程序、拉伸测试和老化

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

Calibration of Vector Network Analyzer for Measurements in Radio Frequency Propagation Channels

In situ measurements of radio frequency (RF) spectrum activity provide insight into the physics of radio frequency wave propagation and validate existing and new spectrum propagation models. Both of these parameters are essential to supporting and preserving interference-free spectrum sharing, as spectrum use continues to increase. It is vital that such propagation measurements are accurate, reproducible, and free of artifacts and bias. Characterizing the gains and losses of components used in these measurements is vital to their accuracy. A vector network analyzer (VNA) is a well-established, highly accurate, and versatile piece of equipment that measures both magnitude and phase of signals, if properly calibrated. This article details the best practices for calibrating a VNA. Once calibrated, it can be used to accurately measure components of a correctly configured propagation measurement (or channel sounding) system or can be used as a measurement system itself.

This protocol describes best practices for calibrating a vector network analyzer prior to use as an accurate instrument, intended to measure components of a radio frequency propagation measurement test system.

射频传播通道测量矢量网络分析仪的校准

In situ measurements of radio frequency (RF) spectrum activity provide insight into the physics of radio frequency wave propagation and validate existing ...