Name: measuring spray droplet size from agricultural nozzles using laser diffraction
Uploaded: 2016-09-16T14:00:00.000+00:00
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Description: Watch this Scientific Journal Video about Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction at JoVE.com

This study was supported in part by a grant from the Deployed War-Fighter Protection (DWFP) Research Program, funded by the U.S. Department of Defense through the Armed Forces Pest Management Board (AFPMB). Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity employer.

1.初步设置和校准<ol><li>之前的任何测试，对齐按照制造商提供的准则的激光衍射系统组件，以确保系统的正常功能和数据质量。 </li><li>按照与使用IIIa级的激光，避免眼睛直接暴露相关的适当的安全防范措施。如果正在使用活性成分化学喷雾解决方案，使用适当的个人防护设备。 </li></ol> 2.地面喷嘴雾滴大小调整<ol><li>通过加入47.5毫升制备"活性空白"（反映0.25％体积/体积的混合率）为90％的非离子表面活性剂的19升水中并充分混合以电钻使用搅拌棒。根据测试的要完成的量，可能需要更大的活性坯料卷。 </li><li>倒"活性空白"喷雾混合物放入不锈钢压力罐，密封所述罐和连接所述输入空气压力软管和传出液软管供给喷嘴。 </li><li>确认该喷嘴出口与该测量区之间的距离是使用卷尺30.5厘米（12）。如果是，则继续。如果不是这样，通过移动或激光衍射系统或喷嘴调整。 </li><li>与附连到横动系统的喷嘴体上的第05孔（注意到作为XRC11005喷嘴）安装一个标准的110度平面风扇喷嘴。调整喷嘴的取向，使得扁平扇形喷嘴的长轴在隧道垂直取向，但无论是旋转的单向阀安装环内，或通过改变单向阀的位置，如果在喷嘴不能转动到喷嘴正确的位置。 </li><li>打开风洞，通过调整风扇速度，并使用热线风速计确认在隧道内的空速空速设定至6.7米/秒。 </li><li>通过使用内联压力单组调整进入空气压力设定喷射压力至276千帕（40磅）荡器。确认使用喷雾喷嘴上游立即安装的电子压力计的压力。 </li><li>通过激活和运行线性横动到之前开始测定过程中的最上面的位置在通道的顶部的喷嘴的位置。 </li><li>确保所有的实验参数（喷嘴，压力，溶液等 ）适当地通过确认记录在用户参数界面窗口中的参数相匹配的检测条件记录在激光衍射系统数据记录的软件。 注:此数据参数记录屏幕可以通过激光衍射仪有所不同。 </li><li>通过在操作软件选择所述参考测量图标以考虑任何灰尘或背景颗粒发起参考测量。 </li><li>开始测量周期的开始。根据激光衍射系统上使用，在几秒钟，通常需要着重之前initi传感器和使用本测量过程。 </li><li>一旦系统表明它已准备好开始测量过程中，激活通过在压力罐打开液体供给阀的喷雾。一旦喷雾开始时，使用横动机构，直到整个喷雾缕已经穿过测量区域通过降低通过激光束的喷嘴。通过关闭液体供给阀停用喷雾。 注:在由作者使用的激光衍射系统，实际的测量过程不启动，直到通过该测量区的喷雾达到0.5％的光学浓度，并继续进行，直到10-12秒的经过时间是否已经过去。这些设置将通过激光衍射系统和用户设置而异。 </li><li>重复步骤2.7 - 2.11最少3次重复。确定是否通过计算对于D V0.1，D V0.5的平均值和标准偏差所需的额外重复，和三次重复的d- V0.9并确保标准偏差为10％或更小的平均的，。执行需要满足条件的其他重复。 </li><li>将喷雾压力为414千帕（60磅），并重复步骤2.7 - 2.12。 </li><li>重复步骤2.6 - 2.12为每个感兴趣的附加喷嘴和压力的组合。 </li><li>出口和使用操作软件中提供的方法保存液滴尺寸的数据。 </li></ol> 3.空中喷嘴雾滴大小调整<ol><li>准备了"活性空白"，加入47.5毫升90％的非离子表面活性剂的19升水中并充分混合以电钻使用搅拌棒。 注:根据测试需要做的量，可能需要更大的积极空白卷。 </li><li>倒"活性空白"喷雾混合物放入不锈钢压力罐，密封所述罐和连接所述输入空气压力软管和流出液体软管供给喷嘴。 </li><li>确认距离Between喷嘴出口和所述测量区是使用卷尺45.7厘米（18）。如果是，则继续。如果不是这样，通过从喷嘴移动激光衍射系统所需的距离调整。 </li><li>在止回阀和喷嘴主体上的风洞出口处的悬臂横截面＃15孔（标注为2015年喷嘴）安装一个标准的20度扇形喷嘴。确保喷嘴正确定位以水平和定向成平行于气流的喷嘴主体。 </li><li>打开风洞风机，并在隧道出口处的空速设为53.6米/秒（120英里），并使用连接到一个空速表皮托管的速度确认。 </li><li>通过调整使用内联压力调节器的进气压力设定喷射压力至207千帕（30磅）。 </li><li>喷嘴在之前启动测量过程中导线的上方位置的位置。 </li><li>确保所有实验参数（喷嘴，压力，溶液等 ），通过确认记录在用户参数界面窗口中的参数相匹配的检测条件被正确记录在激光衍射系统数据记录的软件。 注:此数据参数记录屏幕可以通过激光衍射仪有所不同。 </li><li>通过在操作软件选择所述参考测量图标以考虑任何灰尘或背景颗粒发起参考测量。 </li><li>开始测量周期的开始。根据激光衍射系统上使用，在几秒钟，通常需要对传感器聚焦开始测定处理之前。 </li><li>一旦系统表明它已准备好开始测量过程中，激活通过在压力罐打开液体供给阀的喷雾。一旦喷雾开始时，使用横动机构，直到整个喷雾缕已经穿过测量区域通过降低通过激光束的喷嘴。德通过关闭液体供给阀激活喷雾。 注:在由作者使用的激光衍射系统，实际的测量过程不启动，直到通过该测量区的喷雾达到0.5％的光学浓度，并继续进行，直到5-7秒的经过时间是否已经过去。这些设置将通过激光衍射系统和用户设置而异。 </li><li>重复步骤3.7 - 3.11最少3次重复。确定是否通过计算平均值和标准差为对D V0.1，D V0.5和三次重复的d- V0.9和确保标准偏差所需的额外重复为10％，或更小，平均的。执行需要满足条件的其他重复。 </li><li>每增加喷嘴，压力喷嘴方向和兴趣结合空速3.12 - 重复步骤3.4。 </li><li>使用操作左右的时间内提供的方法导出并保存液滴尺寸数据ftware。 </li></ol>

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The authors have nothing to disclose.

有若干关键的步骤应该应用此方法时执行。与两个空中和地面喷嘴评价，从喷嘴向测量线的出口的距离应之前的任何测量验证。在该距离的任何变化可能对结果的显著影响。同样地，在地面吸嘴测试中使用的并发空速应验证和调整，以推荐的6.7米/秒。从推荐的空速差异将显著影响结果，由于在较低的空速抽样偏差的问题，并且在较高的空速潜在地增加二次破碎。此外，激光衍射系统组件的正确对准是为了保证系统关键在由制造商认证的准确度和精度规范运行。相对于并发气流正确安装和喷嘴对准是确保质量数据的关键，因为即使是轻微的在喷嘴定位几度未对准可能导致在所得到的微滴大小数据显著影响。 提出的方法可以应用于任何喷嘴配置或喷雾溶液为地面和天线系统。与地面喷雾器，喷雾液滴大小的变化通常是喷嘴类型和尺寸，喷雾压力，喷雾液类型的功能。与天线喷雾器在空速和改变喷嘴到周围气流的方向的附加作用是向所得微滴大小是至关重要的。此方法可用于评价这些因素对最终液滴尺寸的综合效应。然而有些时候需要一些修改建议的方法罕见的情况。具体地，喷雾溶液或需要从喷嘴喷雾的完整解体成离散颗粒进一步的距离的喷嘴将需要调整喷嘴和测量POIN之间的距离吨。迄今为止，航拍时，应用程序测试条件下测定的那些需要这种调整的唯一喷嘴/喷雾液治疗已经直流喷嘴在所有操作设置和窄角扁平扇形喷嘴喷雾添加剂增加了解决方案粘度。激光衍射系统仍然将在喷雾云不完全解体的情况下返回的液滴尺寸的数据，但所得到的数据将典型地朝向由系统被测量更大的液滴尺寸喷雾韧带的结果有偏差。虽然这些韧带没有肉眼显而易见的，它们的存在通常会在视觉上的分布图作为液滴尺寸比例（ 图3）的较大端的次级峰出现。虽然谨慎在假定该二次峰是韧带的存在的结果，如外部的振动或用激光衍射系统其他干扰可能会造成宜类似的反应。作为用户的经验水平增加，使得基于错误两者之间的区别变得更容易。在喷射雾化是不完整的情况下，我们已经发现，取样距离延伸到1.8米（用于空中喷雾喷嘴）解决了问题，并返回质量数据。这1.8米距离其实在此我们评估组航拍应用条件下的所有直流喷嘴的标准距离。当与地面喷雾器喷嘴工作时，​​有一类是使用一个双喷嘴设计的，扁平风扇孔口出口可能需要修改以喷嘴安装设置，以确保在整个喷雾缕穿过取样区不结垢激光衍射系统的透镜。 虽然这种方法被设计以最小化抽样偏差由于与激光衍射系统相关联的空间的偏见，但它不能完全消除它们，这意味着液滴尺寸值换货政...RN不能被视为"绝对"。激光衍射不提供测量装置，并调整，所得到的微滴大小的数据用于非均相墨滴速度在复合喷雾云的不同液滴尺寸之中。当实验室间的数据集进行比较，特别是相对于地面喷嘴此变得至关重要。目前接受的实验室之间标准化的结果，并允许进行比较的方法，使用一系列高度校准的参考喷嘴，其液滴尺寸数据被用于建立一组分类类别的。这些喷嘴的评价应该作为每一个墨滴大小评估的一部分进行。在喷嘴和分类定义的进一步细节可以在农业与生物工程师学会（ASABE）国际标准（ASAE / ANSI，2009年）"通过飞沫光谱喷头分类"的美国社会中找到。 如在以所讨论简介显示屏，有除了激光衍射等的液滴尺寸的系统。其中，激光衍射提供​​在整个喷雾缕液滴尺寸的复合量度，这些其它的方法集中在与喷雾云的小区域，采样只有整体喷雾云的一小部分。获得具有这些更为方法整个羽的代表性样品要求的喷雾缕的横截面面积的更加严格，且耗时的，多弦横动，造成了大量的必须被组合，以产生一个子样本的复合的结果。这需要比使用激光衍射显著更多的时间。 一旦此方法已成功集成到一个研究项目和技术的用户掌握了，接下来的挑战是进行旨在了解每个角色的影响因素相对于液滴尺寸的形成起结构良好的实验。这是一个比格呃挑战似乎比给由农业应用行业使用的喷嘴类型，喷嘴的设置和操作因素，空速和喷嘴位置（空中喷洒）和真实世界桶混看似无穷无尽的组合。即使是一个更大的挑战是找到一种方式，使其可用于涂抹此信息的格式很容易可用。本集团已取得了巨大成功使用的一种选择是一类实验设计称为响应面，使液滴大小预测模型的基础上，实验性治疗允许多个喷嘴和解决方案14的一种非常有效的评估数量有限的发展， 15，这种结构化的设计方法已被用于开发通过农业施用器所使用的最常用的天线11和接地喷嘴16的一系列小滴尺寸模型。

当作出任何农药喷雾应用中，主要关注的是要确保最大生物学功效，同时尽量减少任何脱靶运动和相关的对环境的不利影响，或其他非目标生物的危害。之一的主要因素设定任何喷雾器时要考虑的，应用程序之前，是液滴尺寸，这一直被认为是影响整体喷射沉积，有效性和漂移的主要参数之一。虽然有一些其他的因素可能影响喷射沉积和漂移，液滴尺寸是最简单的一个，以改变，以适应一给定的应用场景的需求。从任何农业喷嘴的液滴大小由许多因素的影响，包括但不限于，喷嘴类型，喷嘴孔口尺寸，喷雾压力，喷雾液的物理性质。与天线的应用，空气剪的附加影响从飞机和的空速得到的喷嘴的方向相对于airshear，导致离开喷嘴1的喷雾二次破碎。与所有的这些因素，施用器都面临着使合适的喷嘴的选择和操作的设置决定的困难任务，从而确保所有的农药产品标签被满足，而且得到的喷雾液滴尺寸是这样的，在靶沉积和生物效力被保持同时尽量减少脱靶运动。该方法的目标是提供对液滴大小从影响因素，以支持一个涂抹器的操作决定的各种组合产生的清晰，简明的信息。 虽然有许多可用于测量来自喷雾液滴尺寸的仪器，从农药喷雾喷嘴测量通常是激光衍射，图像，或基于2相多普勒。意象和相位多普勒为基础的方法是单粒子计数器方法，这意味着在喷雾云内更小的区域都集中在与单个颗粒被测量3。而激光衍射方法采取合奏测量，这意味着一组颗粒的分布迅速测定3。虽然这些方法在原则上不同，以适当的安装和使用，比较的结果可以得到4。激光衍射方法已被广泛的农业应用的社区，由于使用的方便性，能够迅速地测量高数量密度喷雾和大的动态测量范围通过。作为合奏测量时，通过测量线的喷雾羽流的单个横动是所有需要对整个喷雾的复合液滴尺寸。这允许从大量的喷嘴和操作参数的组合的微滴大小的有效评估。通过比较，单粒计数器的方法不一定集中在更小的区域机智为了欣喷雾云捕获单个颗粒，这意味着多个测量位置必须进行评估，并组合以返回一个复合结果。这需要显著更多的时间，精力和喷雾溶液来评估单个喷雾缕比基于激光衍射的方法。所需增加的喷雾体积如实际农药产品被作为增加所用材料的成本和处理成本的结果，测试可呈现显著的问题。然而，单个颗粒计数器的方法提供提供的时间样品的优点，在于它们测量每单位时间通过的样品体积的液滴的数量，而激光衍射提供​​一个空间样品作为测量正比液滴的数量内给定体积5。被给定的范围内的所有液滴的速度喷相同，该方法将提供相同的结果。然而，对于大多数的喷雾系统的液滴速度是相关的液滴尺寸，导致与空间抽样方法6偏压。 通过适当的测试方法克服由激光衍射测量该空间偏差是从农业喷雾喷嘴4评估喷雾液滴尺寸的一个重要组成部分。 13米/秒的并发气流并与位于从喷嘴适当距离的测量位置的测试喷嘴时，由于这两个参数的结果中的均质液滴速度在整个喷雾云4的组合的空间偏压减小。此外，空间偏差小（5％或更少），用于空中喷嘴检测由于评价7,8的高并发空速。为了确定最佳的测试方法，以减少与我们目前的低速和高速风洞设施的空间偏差，用于确定农业喷雾大小分类中9系列的参考喷嘴，墨滴大小ü评价既唱激光衍射和成像方法10。上浆评价是下并发空气流速和测量距离（从喷嘴出口到测量点的距离），代表的现有设施的运行范围的多种组合进行的。激光衍射测量进行比较，以图像的结果来确定潜在的空间偏差和测量距离的最佳组合和并发空速被选为标准操作程序。 30.5厘米的测量距离和用于地面喷雾喷嘴的评价6.7米/秒的低速风洞并发空速减少的空间偏压到5％或更少10。在高速隧道天线喷嘴评价获得的3％或以下的空间偏差，对于所有的空速进行测试，以45.7厘米×10的测量距离。使用这些标准方法，作者也能够证明，实验室，实验室variability可以被最小化，提供了一致的实验室间液滴尺寸数据11。 表现为这项工作的一部分，所有液滴尺寸测试是在美国农业部ARS-航空应用技术研究单位的喷射雾化研究机构进行的。激光衍射系统定位在协议部分中指定的距离的喷嘴的下游。对于地面喷嘴检测，激光衍射系统配置，按照制造商的说明，以具有18-3,500微米跨越31箱12上的动态大小范围。同样对于空中喷嘴测试系统配置了9至1750微米的动态范围的大小，也可以跨31箱12。根据空中喷嘴评价是高速空气中进行，以模拟空战应用条件。地面喷雾器喷嘴在一个更大的风洞部分进行了测试与单个并发空速，以尽量减少水疗中心从TiAl合金激光衍射的偏差。被测试的喷嘴被定位在协议部分给定的距离的激光衍射系统的上游。喷嘴被安装在一个线性横动允许对喷雾缕要垂直通过该测量区的给定测量周期内运行。地面喷嘴检测该协议描述了一个实验研究三种典型的喷嘴在两喷压力，同时天线喷嘴测试描述了一个实验的两个喷雾压力和三个空速检查两个典型的喷嘴。两个测试情景使用"有效的空白"喷雾溶液，而不是只有水，以模仿真实世界喷雾溶液的影响。

<table><tbody><tr><td>90% Non-ionic surfactant</td><td>Wilbur-Ellis</td><td>R11</td><td>R11 is the trade name of Wilbur-Ellis non-ionic surfactant.&amp;nbsp;</td></tr><tr><td>HELOS-VARIO/KR</td><td>Sympatec GmbH System-Partikel-Technik</td><td>HELOS-VARIO/KR</td><td>This system is available with several different lens options that change the effective measurement size range.&amp;nbsp;&amp;nbsp;</td></tr><tr><td>Wind Tunnel/Blower systems</td><td>Custom built</td><td></td><td>Airspeed range of Low speed system is 0-7 m/sec and high speed from 18-98 m/sec</td></tr><tr><td>Air Compressor</td><td></td><td></td><td>There is no specific air compressor needed to feed the system.&amp;nbsp; However, the larger the tank volume and the higher the working volumetric flow rating, the better it will keep up with the testing.</td></tr><tr><td>2015 and 4015 Aerial Nozzles</td><td>CP Products</td><td>CP11TT and CP05 swivel with 2015 and 4015 tips</td><td>These were the aerial nozzles detailed in the methods, however, any number of spray nozzles can be evaluated by this method.</td></tr><tr><td>11005, AI11005 and TTI11005 Ground Nozzles</td><td>Spraying Systems</td><td>XR11005, AI11005 and TTI11005</td><td>As with the aerial spray nozzles, these were the nozzles detailed in the Protocol, but this method is not limited to these nozzles</td></tr><tr><td>200 psi Stainless Steel pressure tank</td><td>Alloy Products Corp.</td><td>B501-0328-00-E-R</td><td>There are a number of suppliers with similar pressure vessels that can be used.&amp;nbsp; This suppliers had the highest pressure rated tanks on the market</td></tr><tr><td>Various plumbing and air fittings and hoses</td><td></td><td></td><td>Liquid and air plumbing fittings and hoses as needed to plumb the entire system</td></tr><tr><td>200 psi Pressure regulator</td><td>Coilhose Pneumatics</td><td>8803GH</td><td>Any pressure regulator will work, this one was size to meet the high pressure needs as well as the plumbing used</td></tr><tr><td>Pressure transducer</td><td>Omega&amp;nbsp;</td><td>PX419-150GV</td><td>This pressure transducer was selected to fit the higher pressure loads we use.&amp;nbsp; There are other pressure ranges available from the manufacturer</td></tr><tr><td>Airspeed Indicator</td><td>Aircraft Spruce</td><td>Skysports dual dial airspeed indicator 30-250 mph.</td><td>Any airspeed indicator can be used. This one was selected to fit the speed range of our high speed aerial nozzle testing tunnel.&amp;nbsp; &lt;br /&gt;&amp;nbsp; &lt;br /&gt;</td></tr><tr><td>Hot Wire anemometer</td><td>Extech</td><td>407119</td><td>There are also a variety of options for measureing the airspeed in the low speed wind tunnel used for testing ground nozzles.&amp;nbsp;</td></tr></tbody></table>

measuring spray droplet size from agricultural nozzles using laser diffraction

当作出任何作物保护材料的应用，如除草剂或杀虫剂，涂抹器采用了多种技术和信息，使得材料到达目标部位（即植物），以使一个应用程序。信息在这个过程中关键的是液滴大小的特定喷嘴，喷雾压力，喷雾液组合产生，如液滴大小极大地影响产品的功效，以及如何通过环境喷雾移动。研究人员和产品制造商通常使用激光衍射设备测量实验室风洞喷射液滴尺寸。这里提出的工作描述在使喷雾液滴尺寸的测量用激光衍射设备可以用于确保之间和内部实验室精度，同时尽量减少用激光衍射系统相关联的抽样偏差地面和空中施用方案中使用的方法。维护重要的测量迪立场和并发气流整个测试过程中的关键是这个精度。实时数据质量分析也防止在数据或过量变化无关包容错误数据的关键。此方法的一些限制，包括非典型的喷嘴，喷雾溶液或导致不完全讨论的测量距离内雾化喷雾流应用条件。这种方法的成功适应可以在各种操作设置为农业化学喷涂喷嘴的性能评价非常有效的方法。还讨论是可以被包括，以提高所收集的数据的功能，潜在的实验设计的考虑。

从这种方法得到的数据可以以各种格式来表示，这取决于用户的喜好和激光衍射系统的业务能力。通常该数据表示为体积加权液滴尺寸分布的曲线图（ 图1和2）或作为说明性液滴尺寸度量（ 表1和2）。然后，这些结果可以被用于检查改变在喷嘴或操作参数对得到的喷雾液滴尺寸的影响。 我们研究了两种不同的空中喷雾喷嘴，两者具有相同的孔尺寸，但具有不同的喷雾扇角。与这两个天线的喷嘴，我们还检查了喷射压力的影响，并空速​​上液滴尺寸。检查2015年喷嘴在207千帕的喷雾压力下操作，并比较所述量weig从相同的喷嘴产生hted分布在53.6米/秒被操作与71.5米/秒空速，它是立即明显的是，较高的空速导致在增量和累积分布朝向更小的液滴直径的巨大转变（ 图1和2）这是在较高的空速喷雾液滴的增加破裂的结果。虽然结果的图形表示提供的结果的一个非常视觉表示，从这些分布衍生定量值是更大的数据集更实用。在农业喷雾研究采用典型的液滴尺寸度量包括喷雾量的D- V0.1，D V0.5和D V0.9值，其对应于液滴直径，使得10，50和90（分别）％载在等于或较小直径的液滴。这些数据是一样的，在图形分布所示的那些，而是提供一个更方便的FO表达数据的rmat。数据同时为2015年和4015在两个压力喷雾喷嘴和所有三种空速比较，总的趋势可以观察（ 表1）。在4015扁平扇形喷嘴导致更小的液滴尺寸比2015年在相同压力和空速，由较小的体积加权粒径（D V0.1，D V0.5和D V0.9），并在增加所指示由100微米或更小的液滴的喷射的总体积。 ðV0.1，D V0.5和D V0.9是液滴的直径，使得10，50和90％，分别的总喷雾体积是由等于或较小直径的液滴。这是在增加喷射扇形角在液体扇形角的外边缘看到更大的分裂的结果。在相同的喷嘴类型，喷雾压力，所有的液滴尺寸的度量降低与提高的空速，如再次在解释第1条增加液滴破裂的结果- [R空速。随着空中喷雾喷嘴一个有趣的现象看喷射压力，每个喷嘴和空速组合中的作用时看到。其他保持平等的，当压力增加时，也是如此液滴尺寸11。这是通过在离开喷嘴的液体和周围气流之间的相对速度差的降低引起的，作为液体出口速度随着压力的增加（ 表1）13。 看着从测试地面喷嘴和喷射压力的结果，喷嘴型的对液滴大小的影响是导致液滴尺寸是一倍以上的TTI11003该XRC11003和AI11003液滴尺寸落在其它的中间显著两（ 表2）。内的每个喷嘴型，可以与液滴尺寸与增加喷射压力减小可观察的压力的影响。 图1 为一个20度扇形天线喷嘴与207千帕和53.6米/秒的空速操作的＃15孔增量液滴尺寸分布。蓝色曲线表示增量体积加权分布，它提供的百分比如由激光衍射系统测定包含在液滴与每个测量仓的范围落入总喷雾体积。红色曲线是相同的数据，但表示为累积的数据。累计数据允许特定于总喷雾体积的一定比例的待确定的体积加权直径。如该图所示，为了得到对D V0.5体积直径，定位累积曲线和相关的液滴直径的50％点表明总喷雾体积的50％被包含在喷dropl直径为551 ETS微米或更小。 <a href="http://ecsource.jove.com/files/ftp_upload/54533/54533fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54533/54533fig2.jpg" /> 图2. 为一个40度的扇形天线喷嘴与207千帕和71.5米/秒的空速操作的＃15孔增量液滴尺寸分布。如在图1中 ，蓝色曲线表示增量体积加权分布和红色曲线是累积分布。相比于图1所示的结果，增量分布显示朝向更小的液滴直径a显著转变为增加的空速的结果，因此，二次液滴破裂。确定为D V0.5体积直径表明此喷雾体积的50％为c直径为350微米或更小的液滴ontained。 <a href="http://ecsource.jove.com/files/ftp_upload/54533/54533fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/54533/54533fig3.jpg" /> 图 假峰示例性绘图 3. 增量液滴尺寸分布。在右侧的二次，较小的峰，朝向液滴尺寸比例的较大端典型地是振动或系统中的其他噪声或韧带的关联的存在的结果与喷雾云内不完全雾化。作为典型的农业喷雾喷嘴和溶液的液滴尺寸分布，通常数正态分布，次级峰的分布中的存在可能是从非典型的喷雾溶液和/或喷嘴组合的有效的结果，但更可能的籼稻在测量过程中的一些混杂问题器。 <a href="http://ecsource.jove.com/files/ftp_upload/54533/54533fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td rowspan="2"> 喷嘴 </td><td rowspan="2"> 压力（千帕） </td><td rowspan="2"> 空速（米/秒） </td><td colspan="3"> 成交量加权直径（微米）平均值±圣开发。] </td><td rowspan="2"> ％的喷雾量小于100微米 </td></tr><tr><td> ðV0.1 </td><td> ðV0.5 </td><td> ðV0.9 </td></tr><tr><td rowspan="6"> 2015年</td><td rowspan="3"> 207 </td><td> 53.6 </td><td> 243.5±2.5 </td><td> 551.8±4.6 </td><td> 903.0±25.4 </td><td> 1.4±0.05 </td></tr><tr><td> 62.6 </td&gt; <td> 192.1±0.5 </td><td> 444.5±1.5 </td><td> 781.7±7.0 </td><td> 2.4±0.04 </td></tr><tr><td> 71.5 </td><td> 147.0±2.8 </td><td> 350.6±6.1 </td><td> 673.3±14.6 </td><td> 4.5±0.18 </td></tr><tr><td rowspan="3"> 414 </td><td> 53.6 </td><td> 289.1±3.1 </td><td> 655.6±2.1 </td><td> 1208.7±11.6 </td><td> 0.8±0.03 </td></tr><tr><td> 62.6 </td><td> 237.6±0.1 </td><td> 542.7±1.7 </td><td> 1072.5±13.7 </td><td> 1.3±0.01 </td></tr><tr><td> 71.5 </td><td> 170.8±1.1 </td><td> 400.6±3.3 </td><td> 732.1±6.4 </td><td> 3.2±0.05 </td></tr><tr><td rowspan="6"> 4015 </td><td rowspan="3"> 207 </td><td> 53.6 </td><td> 230.2±1.3 </td><td> 514.9±1.9 </td><td> 863.3±1.2 </td><td> 1.5±0.03 </td></tr><tr><td> 62.6 </td><td> 175.1±2.0 </td><td> 404.5±2.6 </td><td> 714.2±3。0 </td><td> 3.1±0.10 </td></tr><tr><td> 71.5 </td><td> 146.6±0.8 </td><td> 344.5±2.4 </td><td> 656.4±9.5 </td><td> 4.6±0.05 </td></tr><tr><td rowspan="3"> 414 </td><td> 53.6 </td><td> 255.2±2.4 </td><td> 557.3±2.3 </td><td> 994.9±8.1 </td><td> 1±0.04 </td></tr><tr><td> 62.6 </td><td> 200.1±2.6 </td><td> 449.4±7.0 </td><td> 774.9±10.7 </td><td> 2.1±0.06 </td></tr><tr><td> 71.5 </td><td> 165.5±1.4 </td><td> 383.5±2.6 </td><td> 696.8±4.9 </td><td> 3.4±0.08 </td></tr></tbody></table> 表1.成交量加权的直径（平均值±跨越三个重复测量标准偏差）在207和414千帕的压力喷操作2015年和4015平风扇式喷嘴，并在53.6，62.6 71.5米/秒的空速。 <table border="1" fo:keEP-together.within页="1"FO:保持与 - next.within页="总是"&gt; <tbody><tr><td rowspan="2"> 喷嘴 </td><td rowspan="2"> 压力（千帕） </td><td colspan="3"> 成交量加权直径（微米）平均值±圣开发。] </td><td rowspan="2"> ％的喷雾量小于100微米 </td></tr><tr><td> ðV0.1 </td><td> ðV0.5 </td><td> ðV0.9 </td></tr><tr><td rowspan="2"> XRC11005 </td><td> 276 </td><td> 115.1±2.1 </td><td> 268.2±5.6 </td><td> 451.0±18.0 </td><td> 7.2±0.28 </td></tr><tr><td> 414 </td><td> 101.0±0.0 </td><td> 244.2±0.7 </td><td> 424.3±4.3 </td><td> 9.8±0.01 </td></tr><tr><td rowspan="2"> AI11005 </td><td> 276 </td><td> 227.6±1.9 </td><td> 468.9±4.1 </td><td> 763.0±22.0 </td><td> 1.1±0.03 </td></tr><tr><td> 414 </td><td> 183.4＆＃177; 0.6 </td><td> 399.6±0.9 </td><td> 668.6±2.5 </td><td> 2.2±0.05 </td></tr><tr><td rowspan="2"> TTI11005 </td><td> 276 </td><td> 365.3±5.3 </td><td> 711.9±16.9 </td><td> 1013.8±26.1 </td><td> 0.1±0.00 </td></tr><tr><td> 414 </td><td> 311.5±4.0 </td><td> 645.7±12.3 </td><td> 992.7±24.7 </td><td> 0.2±0.01 </td></tr></tbody></table> 表2.成交量加权的直径（平均值±跨越三个重复测量标准偏差）三地喷雾器喷嘴（XRC11005，AI11005和TTI11005）在276和414千帕的压力喷操作。

Watch this Scientific Journal Video about Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction at JoVE.com

Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

我们提出在喷雾液滴尺寸的从两个空中和地面基于农用化学应用中使用的农业喷嘴测量要使用的协议。提出这些方法被开发使用激光衍射系统时提供一致的和可重复的微滴大小的数据两者之间和内部实验室。

从农业喷嘴采用激光衍射测量喷雾的雾滴尺寸

When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to ...

measuring-spray-droplet-size-from-agricultural-nozzles-using-laser

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

16.9K 次观看.  USDA ARS. 我们提出在喷雾液滴尺寸的从两个空中和地面基于农用化学应用中使用的农业喷嘴测量要使用的协议。提出这些方法被开发使用激光衍射系统时提供一致的和可重复的微滴大小的数据两者之间和内部实验室。 

视频: Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

A Protocol for Conducting Rainfall Simulation to Study Soil Runoff

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24&#160;hr&#160;after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

A rainfall simulator was used to apply a consistent rate of uniform rainfall to packed soil boxes in a study of the fate and transport of urea, a nonpoint source environmental contaminant. Under uniform soil and rainfall conditions, antecedent soil moisture content exerted strong control over urea loss in surface runoff.

一个协议，用于开展降雨模拟研究土壤径流

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The ...

科研

环境科学

Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization

The sonication process is commonly used for de-agglomerating and dispersing nanomaterials in aqueous based media, necessary to improve homogeneity and stability of the suspension. In this study, a systematic step-wise approach is carried out to identify optimal sonication conditions in order to achieve a stable dispersion. This approach has been adopted and shown to be suitable for several nanomaterials (cerium oxide, zinc oxide, and carbon nanotubes) dispersed in deionized (DI) water. However, with any change in either the nanomaterial type or dispersing medium, there needs to be optimization of the basic protocol by adjusting various factors such as sonication time, power, and sonicator type as well as temperature rise during the process. The approach records the dispersion process in detail. This is necessary to identify the time points as well as other above-mentioned conditions during the sonication process in which there may be undesirable changes, such as damage to the particle surface thus affecting surface properties. Our goal is to offer a harmonized approach that can control the quality of the final, produced dispersion. Such a guideline is instrumental in ensuring dispersion quality repeatability in the nanoscience community, particularly in the field of nanotoxicology.

Here, we present a step-wise protocol for the dispersion of nanomaterials in aqueous media with real-time characterization to identify the optimal sonication conditions, intensity, and duration for improved stability and uniformity of nanoparticle dispersions without impacting the sample integrity.

纳米材料在水介质中的分散: 对协议优化的研究

The sonication process is commonly used for de-agglomerating and dispersing nanomaterials in aqueous based media, necessary to improve homogeneity and ...

Quantitative Locomotion Study of Freely Swimming Micro-organisms Using Laser Diffraction

Soil and aquatic microscopic organisms live and behave in a complex three-dimensional environment. Most studies of microscopic organism behavior, in contrast, have been conducted using microscope-based approaches, which limit the movement and behavior to a narrow, nearly two-dimensional focal field.1 We present a novel analytical approach that provides real-time analysis of freely swimming C. elegans in a cuvette without dependence on microscope-based equipment. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light through the cuvette. We measure oscillation frequencies for freely swimming nematodes.
Analysis of the far-field diffraction patterns reveals clues about the waveforms of the nematodes. Diffraction is the process of light bending around an object. In this case light is diffracted by the organisms. The light waves interfere and can form a diffraction pattern. A far-field, or Fraunhofer, diffraction pattern is formed if the screen-to-object distance is much larger than the diffracting object. In this case, the diffraction pattern can be calculated (modeled) using a Fourier transform.2
C. elegans are free-living soil-dwelling nematodes that navigate in three dimensions. They move both on a solid matrix like soil or agar in a sinusoidal locomotory pattern called crawling and in liquid in a different pattern called swimming.3 The roles played by sensory information provided by mechanosensory, chemosensory, and thermosensory cells that govern plastic changes in locomotory patterns and switches in patterns are only beginning to be elucidated.4 We describe an optical approach to measuring nematode locomotion in three dimensions that does not require a microscope and will enable us to begin to explore the complexities of nematode locomotion under different conditions.

Microscopic organisms like the free-swimming nematode C. elegans, live and behave in a complex three-dimensional environment. We report on a novel approach that provides analysis of C. elegans using diffraction patterns. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light through a cuvette.

使用激光衍射自由游泳微生物的定量步态研究

Soil and aquatic microscopic organisms live and behave in a complex three-dimensional environment. Most studies of microscopic organism behavior, in ...

生物工程

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this work, we use single particle tracking of fluorescently labeled PNIPAM microgels as a showcase for tuning microgel size by a rapid non-stirred precipitation polymerization procedure. This approach is well suited for prototyping new reaction compositions and conditions or for applications that do not require large amounts of product. Microgel synthesis, particle size and structure determination by dynamic and static light scattering are detailed in the protocol. It is shown that the addition of functional comonomers can have a large influence on the particle nucleation and structure. Single particle tracking by wide-field fluorescence microscopy allows for an investigation of the diffusion of labeled tracer microgels in a concentrated matrix of non-labeled microgels, a system not easily investigated by other methods such as dynamic light scattering.

Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels

Non-stirred precipitation polymerization provides a rapid, reproducible prototyping approach to the synthesis of stimuli-sensitive poly(N-isopropylacrylamide) microgels of narrow size distribution. In this protocol synthesis, light scattering characterization and single particle fluorescence tracking of these microgels in a wide-field microscopy setup are demonstrated.

可控合成和高度统一聚荧光追踪（<em&gt;ñ</em&gt; -isopropylacrylamide）微凝胶

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this ...

化学

Measurement of Particle Size Distribution in Turbid Solutions by Dynamic Light Scattering Microscopy

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a technique used to measure the size distribution of polymer solutions or colloidal particles. Although this technique is widely used for the assessment of polymer solutions, it is difficult to measure the particle size in concentrated solutions due to the multiple scattering effect or strong light absorption. Therefore, the concentrated solutions should be diluted before measurement. Implementation of the confocal optical component in a dynamic light scattering microscope1 helps to overcome this barrier. Using such a microscopic system, both transparent and turbid systems can be analyzed under the same experimental setup without a dilution. As a representative example, a size distribution measurement of a temperature-responsive polymer solution was performed. The sizes of the polymer chains in an aqueous solution were several tens of nanometers at a temperature below the lower critical solution temperature (LCST). In contrast, the sizes increased to more than 1.0 &#181;m when above the LCST. This result is consistent with the observation that the solution turned turbid above the LCST.

A protocol for the direct measurement of particle size distribution in concentrated solutions using dynamic light scattering microscopy is presented.

通过动态光散射显微镜混浊解决方案粒度分布的测定

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a ...

Film Control to Study Contributions of Waves to Droplet Impact Dynamics on Thin Flowing Liquid Films

Droplet impact is a very common phenomenon in nature and attracts attention due to its aesthetic fascination and wide-ranging applications. Previous studies on flowing liquid films have neglected the contributions of spatial structures of waves to the impact outcome, while this has recently been shown to have a significant influence on the drop impact dynamics. In this report, we outline a step-by-step procedure to investigate the effect of periodic inlet forcing of a flowing liquid film leading to the production of spatiotemporally regular wave structures on drop impact dynamics. A function generator in connection with a solenoid valve is used to excite these spatiotemporally regular wave structures on the film surface while the impact dynamics of uniform-sized droplets are captured using a high-speed camera. Three distinct regions are then studied; viz. the capillary wave region preceding the large wave peak, the flat film region, and the wave hump region. The effects of important dimensionless quantities such as film Reynolds, drop Weber and Ohnesorge numbers parameterized by the film flow rate, drop speed, and drop size are also examined. Our results show interesting, hitherto undiscovered dynamics brought about by this application of film inlet forcing of the flowing film for both low and high inertia drops.

A protocol to study the contributions of waves to droplet impact dynamics on flowing liquid films is presented.

薄膜控制研究波浪对液滴冲击动力学的影响薄流动液体薄膜

Droplet impact is a very common phenomenon in nature and attracts attention due to its aesthetic fascination and wide-ranging applications. Previous ...

工程学

Measuring the Interaction Force Between a Droplet and a Super-hydrophobic Substrate by the Optical Lever Method

The goal of this paper is to investigate the interaction force between droplets and super-hydrophobic substrates in the air. A measurement system based on an optical lever method is designed. A millimetric cantilever is used as a force sensitive component in the measurement system. Firstly, the force sensitivity of the optical lever is calibrated using electrostatic force, which is the critical step in measuring interaction force. Secondly, three super-hydrophobic substrates with different grid fractions are prepared with nanoparticles and copper grids. Finally, the interaction forces between droplets and super-hydrophobic substrates with different grid fractions are measured by the system. This method can be used to measure the force on the scale of sub-micronewton with a resolution on the scale of nanonewton. The in-depth study of the contact process of droplets and super-hydrophobic structures can help to improve the production efficiency in coating, film and printing. The force measurement system designed in this paper can also be used in other fields of microforce measurement.

The protocol aims to investigate the interaction between droplets and super-hydrophobic substrates in the air. This includes calibrating the measurement system and measuring the interaction force at super-hydrophobic substrates with different grid fractions.

用光学杠杆方法测量液滴和超疏水基板之间的相互作用力

The goal of this paper is to investigate the interaction force between droplets and super-hydrophobic substrates in the air. A measurement system based on ...

High Throughput Analysis of Liquid Droplet Impacts

Experimental studies of liquid drop impacts on surfaces are often restricted in their scope due to the large range of possible experimental parameters such as material properties, impact conditions, and experimental configurations. Compounding this, drop impacts are often studied using data-rich high-speed photography, so that it is difficult to analyze many experiments in a detailed and timely manner. The purpose of this method is to enable efficient study of droplet impacts with high-speed photography by using a systematic approach. Equipment is aligned and calibrated to produce videos that can be accurately processed by a custom image processing code. Moreover, the file structure setup and workflow described here ensure efficiency and clear organization of data processing, which is carried out while the researcher is still in the lab. The image processing method extracts the digitized outline of the impacting droplet in each frame of the video, and processed data are stored for further analysis as required. The protocol assumes that a droplet is released vertically under gravity, and impact is recorded by a camera viewing from side-on with the drop illuminated using shadowgraphy. Many similar experiments involving image analysis of high-speed events could be addressed with minor adjustment to the protocol and equipment used.

This protocol enables efficient collection of experimental high-speed images of liquid drop impacts, and speedy analysis of those data in batches. To streamline these processes, the method describes how to calibrate and set up apparatus, generate an appropriate data structure, and deploy an image analysis script.

液滴冲击的高通量分析

Experimental studies of liquid drop impacts on surfaces are often restricted in their scope due to the large range of possible experimental parameters ...

Fabrication and Characterization of Thickness Mode Piezoelectric Devices for Atomization and Acoustofluidics

We present a technique to fabricate simple thickness mode piezoelectric devices using lithium niobate (LN). Such devices have been shown to atomize liquid more efficiently, in terms of &#64258;ow rate per power input, than those that rely on Rayleigh waves and other modes of vibration in LN or lead zirconate titanate (PZT). The complete device is composed of a transducer, a transducer holder, and a &#64258;uid supply system. The fundamentals of acoustic liquid atomization are not well known, so techniques to characterize the devices and to study the phenomena are also described. Laser Doppler vibrometry (LDV) provides vibration information essential in comparing acoustic transducers and, in this case, indicates whether a device will perform well in thickness vibration. It can also be used to &#64257;nd the resonance frequency of the device, though this information is obtained more quickly via impedance analysis. Continuous &#64258;uid atomization, as an example application, requires careful &#64258;uid flow control, and we present such a method with high-speed imaging and droplet size distribution measurements via laser scattering.

Fabrication of piezoelectric thickness mode transducers via direct current sputtering of plate electrodes on lithium niobate is described. Additionally, reliable operation is achieved with a transducer holder and &#64258;uid supply system and characterization is demonstrated via impedance analysis, laser doppler vibrometry, high-speed imaging, and droplet size distribution using laser scattering.

用于原子化和抗波流体的厚度模式压电器件的制造和特性

We present a technique to fabricate simple thickness mode piezoelectric devices using lithium niobate (LN). Such devices have been shown to atomize liquid ...

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future combustion engine vehicle technology may emit large amounts of sub-23 nm particles. The Horizon 2020 funded project DownToTen (DTT) developed a sampling and measurement method to characterize particle emissions in this currently unregulated size range. A PN measurement system was developed based on an extensive review of the literature and laboratory experiments testing a variety of PN measurement and sampling approaches. The measurement system developed is characterized by high particle penetration and versatility, which enables the assessment of primary particles, delayed primary particles, and secondary aerosols, starting from a few nanometers in diameter. This paper provides instruction on how to install and operate this Portable Emission Measurement System (PEMS) for Real Drive Emissions (RDE) measurements and assess particle number emissions below the current legislative limit of 23 nm.

Presented here is the DownToTen (DTT) portable emission measurement system to assess real driving automotive emissions of sub-23 nm particles.

从农业喷嘴采用激光衍射测量喷雾的雾滴尺寸

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