Name: fabric moisture uniform control to study the influence of air impingement parameters on fabric drying characteristics
Uploaded: 2019-08-19T14:00:00
Description: Watch this Scientific Journal Video about Fabric Moisture Uniform Control to Study the Influence of Air Impingement Parameters on Fabric Drying Characteristics at JoVE.com

This work was supported by the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization (grant number U1609205) and National Natural Science Foundation of China (grant number 51605443), the Key Research and Development Project of Zhejiang Province (grant number 2018C01027), the 521 Talent Project of Zhejiang Sci-Tech University, and the Young Researchers Foundation of Zhejiang Provincial Top Key Academic Discipline of Mechanical Engineering of Zhejiang Sci-tech University (grant number ZSTUME02B13).

1. Experimental rig set-up
NOTE: See Figure 1.
<ol>
	<li>Hot air blower unit
	<ol>
		<li>Ensure that the hot air blower is connected to the air nozzle through a high temperature resistant silicone pipeline that is heat-insulated with asbestos material. Gradually adjust the air nozzle to the desirable incline angle to control the air flow direction. For this work, the incline angle, &#945;, varied between 60&#176; and 90&#176;.</li>
		<l...

<ol>
	<li>Wang, G., Deng, Y., Xu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+air+jet+impingement+drying+of+okara+using+response+surface+methodology.">Optimization of air jet impingement drying of okara using response surface methodology.</a> Food Control. 59, 743-749 (2016).</li><li>Etemoglu, A. B., Ulcay, Y., Can, M., Avci, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mathematical+modelling+of+combined+diffusion+of+heat+and+mass+transfer+through+fabrics.">Mathematical modelling of combined diffusion of heat and mass transfer through fabrics.</a> Fibers and Polymers. 10 (2), 252-259 (2009).</li><li>Di, M. P., Frigo, S., Gabbrielli, R., Pecchia, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mathematical+modelling+and+energy+performance+assessment+of+air+impingement+drying+systems+for+the+production+of+tissue+paper.">Mathematical modelling and energy performance assessment of air impingement drying systems for the production of tissue paper.</a> Energy. 114 (2), 201-213 (2016).</li><li>Xiao, H. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drying+kinetics+and+quality+of+Monukka+seedless+grapes+dried+in+an+air-impingement+jet+dryer.">Drying kinetics and quality of Monukka seedless grapes dried in an air-impingement jet dryer.</a> Biosystems Engineering. 105 (2), 233-240 (2010).</li><li>Gu, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+on+optimum+temperature+value+setting+for+the+heat-setting+process+based+on+PSO.">Study on optimum temperature value setting for the heat-setting process based on PSO.</a> 3rd International Conference on Advances in Energy, Environment and Chemical Engineering. 69, (2017).</li><li>Aihua, M., Yi, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Numerical+heat+transfer+coupled+with+multidimensional+liquid+moisture+diffusion+in+porous+textiles+with+a+measurable-parameterized+model.">Numerical heat transfer coupled with multidimensional liquid moisture diffusion in porous textiles with a measurable-parameterized model.</a> Numerical Heat Transfer Part A - Applications. 56 (3), 246-268 (2009).</li><li>Angelova, R. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+and+mass+transfer+through+outerwear+clothing+for+protection+from+cold:+influence+of+geometrical,+structural+and+mass+characteristics+of+the+textile+layers.">Heat and mass transfer through outerwear clothing for protection from cold: influence of geometrical, structural and mass characteristics of the textile layers.</a> Textile Research Journal. 87 (9), 1060-1070 (2017).</li><li>Wei, Y., Hua, J., Ding, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mathematical+model+for+simulating+heat+and+moisture+transfer+within+porous+cotton+fabric+drying+inside+the+domestic+air-vented+drum+dryer.">A mathematical model for simulating heat and moisture transfer within porous cotton fabric drying inside the domestic air-vented drum dryer.</a> The Journal of The Textile Institute. 108 (6), 1074-1084 (2016).</li><li>Cay, A., Gurlek, G., Oglakcioglu, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+and+modeling+of+drying+behavior+of+knitted+textile+materials.">Analysis and modeling of drying behavior of knitted textile materials.</a> Drying Technology. 35 (4), 509-521 (2017).</li><li>Neves, S. F., Campos, J. B. L. M., Mayor, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+determination+of+parameters+required+for+numerical+studies+of+heat+and+mass+transfer+through+textiles+-+Methodologies+and+experimental+procedures.">On the determination of parameters required for numerical studies of heat and mass transfer through textiles - Methodologies and experimental procedures.</a> International Journal of Heat and Mass Transfer. 81, 272-282 (2015).</li><li>Sousa, L. H. C. D., Motta Lima, O. C., Pereira, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+drying+kinetics+and+moisture+distribution+in+convective+textile+fabric+drying.">Analysis of drying kinetics and moisture distribution in convective textile fabric drying.</a> Drying Technology. 24 (4), 485-497 (2006).</li><li>Wang, X., Li, W., Xu, W., Wang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+on+the+Surface+Temperature+of+Fabric+in+the+Process+of+Dynamic+Moisture+Liberation.">Study on the Surface Temperature of Fabric in the Process of Dynamic Moisture Liberation.</a> Fibers and Polymers. 15 (11), 2437-2440 (2014).</li><li>Qian, M., Wang, J. H., Xiang, Z., Zhao, Z. W., Hu, X. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+and+moisture+transfer+performance+of+thin+cotton+fabric+under+impingement+drying.">Heat and moisture transfer performance of thin cotton fabric under impingement drying.</a> Textile Research Journal. , (2018).</li><li>Rafael, C. G., Richard, 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=.">.</a> Digital image processing. , (2007).</li></ol>

This section provides a few tips necessary to ensure reliable quantitative results. First, the fabric specimens must be kept completely dry to ensure the initial weights are correct. This is achievable through the drying process (i.e., using a suitable drying stove). If possible, an environment humidity that is kept constant benefits the experiment.
Secondly, the fabric specimens must be well-processed to ensure that the moisture at each region of the fabric is uniform. This can be done by man...

Impinging drying is a very effective drying method due to its high heat, mass transfer coefficient, and short drying time. It has attracted extensive attention due to its numerous applications including chemical industry, food1, textile, dyeing2, paper making3,4, etc. Now, impinging drying is widely used for its enhanced transport characteristics, especially for the drying of textiles in the heat setting process5.
Fabric is impinging dried by the nozzle array for the heat setting. Nozzle layout affects the uniformity of drying temperature, which has a significant influence on the fabric properties, drying efficiency, and on the fabric surface directly. Thus, it is necessary to understand temperature distribution on the textile surface to design a better nozzle array. There has been little investigation in this field at the present, though there has been plenty of research on heat and moisture transfer performance of the fabric drying process so far. Some research has mainly focused on the natural evaporation of a textile under a specified heat source, in which the impinging drying process was not involved in these studies6,7. Some have focused on heat and moisture transfer of the textile with hot air drying, but the textile moisture and temperature were assumed to be uniform in these studies8,9,10,11. Furthermore, a few of these studies attempted to obtain the temperature distribution variation with time for studying the heat and moisture transfer of the textile under impinging drying.
Etemoglu et al.2 developed an experimental set-up for obtaining temperature variation with the time of the fabric and total drying time, but this set-up is limited to single-point temperature measurements. The initial moisture content distribution in the fabric is also neglected in this type of research. Wang et al.12 intended to obtain temperature distribution on the fabric by pasting thermocouples on the textile surface at various points, but surface temperature distribution was not able to be accurately obtained with their method. Obtaining temperature distribution at the air impingement area on a fabric with even humidity distribution is important for industrial printing and dyeing production, and it will provide better guidance on the distribution and arrangement strategy for object drying with a multi-nozzle13. The following procedure provides details to study the heat and moisture transfer of a fabric during the impinging drying process. The initial moisture content is well-controlled to be evenly distributed, while the surface temperature at every point of the fabric is obtained via the experimental set-up.
The experimental set-up consists of a hot air blower unit, infrared thermograph unit, uniform padder system, and other auxiliary devices. The hot air blower unit supplies the hot air with a specified temperature and velocity in an adjustable direction according to the experimental requirements. The infrared thermograph unit records the temperature history of each impinging drying process; thus, the temperature at each pixel point of the recorded video can be extracted with a supporting post-processing tool. The uniform padder system controls the even distribution of moisture content at every point of the fabric. Finally, the influence of air impingement parameters on fabric drying characteristic with fabric moisture uniform control method are investigated. The process can be carried out in a reproducible fashion following the standard protocol described below.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Air Blower</td>
			<td>Zhejiang jiaxing hanglin electromechanical equipment co., Ltd.</td>
			<td>HLJT-3380-TX10A-0.55</td>
			<td>Air Volume: 900 m3/s;</td>
		</tr>
		<tr>
			<td>Anemometer</td>
			<td>KIMO</td>
			<td>MP210</td>
			<td>Measurement range: 0-40 m/s; Accuracy: &#177;0.1 m/s</td>
		</tr>
		<tr>
			<td>Drying stove</td>
			<td>Shanghai Shangyi Instrument Equipment Co., Ltd.</td>
			<td>DHG 101-0A</td>
			<td>precision: 1 &#176;C; Temperature control range:10-300 &#176;C</td>
		</tr>
		<tr>
			<td>Electronic Balance</td>
			<td>Hangzhou Wante Weighing Instrument Co., Ltd.</td>
			<td>WT1002</td>
			<td>Precision: 1 &#176;C; Range: 100 g</td>
		</tr>
		<tr>
			<td>Fabric Style Measuring Instrument</td>
			<td>SDL Atlas</td>
			<td>M293</td>
			<td></td>
		</tr>
		<tr>
			<td>Fabric Touch Tester</td>
			<td>SDLATLAS Ltd</td>
			<td></td>
			<td>Fabric thickness tester</td>
		</tr>
		<tr>
			<td>High thermal resistance board</td>
			<td>Baiqiang</td>
			<td></td>
			<td>Flame resistance, Heat resistance is greater than 200 &#176;C</td>
		</tr>
		<tr>
			<td>High-temperature resistant silicon pipeline</td>
			<td>Kamoer</td>
			<td>18#</td>
			<td>Temperature range: -60-200 &#176;C</td>
		</tr>
		<tr>
			<td>Infrared Thermogragh</td>
			<td>Hangzhou Meisheng Infrared 
			Optoelectronic Technology Co., Ltd.</td>
			<td>R60-1009</td>
			<td>Temperature measuring range: -20-410 &#176;C; Maximum measuring error: &#177;2 &#176;C</td>
		</tr>
		<tr>
			<td>Padder</td>
			<td>Yabo textile machinery co., Ltd.</td>
			<td></td>
			<td>Roller pressure: 0.03-0.8 MPa; Stable pressure; Easy adjustment</td>
		</tr>
		<tr>
			<td>Personal Computer</td>
			<td>Lenovo Group.</td>
			<td>L460</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature Sensor</td>
			<td>Taiwan TES electronic industry co., Ltd.</td>
			<td>1311A</td>
			<td>resolution: 1 &#176;C; Temperature measuring range: -50-1350 &#176;C</td>
		</tr>
	</tbody>
</table>

fabric moisture uniform control to study the influence of air impingement parameters on fabric drying characteristics

Impinging dryness is now a widely used and effective way for fabric drying due to its high heat and mass transfer coefficient. Previous studies on fabric drying have neglected the contributions of moisture uniformity and diffusion coefficient to the drying process; though, they have recently been shown to have a significant influence on drying characteristics. This report outlines a step-by-step procedure to investigate the effects of air impingement parameters on a fabric&#39;s drying characteristics by controlling the uniformity of its area moisture distribution. A hot air blower unit equipped with an angle adjustable nozzle is used to generate air flow with different velocities and temperatures while the drying process is recorded and analyzed using an infrared thermograph. In addition, a uniform padder is adapted to ensure the fabric&#39;s moisture uniformity. Impinging drying is studied under different initial conditions by changing the air flow temperature, velocity, and direction, then the applicability and suitability of the protocol are evaluated.

The data presented in Figure 2 are typical temperature contours for cotton fabric at different drying stages under the condition that air velocity and temperature at the nozzle outlet are 20.0 m/s and 120 &#176;C, respectively. It can be figured from Figure 2A,B,C,D that under the air impingement drying, temperature decays from the center to the periphery and forms sets of concentric circles. Meanwhile, temperatu...

Watch this Scientific Journal Video about Fabric Moisture Uniform Control to Study the Influence of Air Impingement Parameters on Fabric Drying Characteristics at JoVE.com

Fabric Moisture Uniform Control to Study the Influence of Air Impingement Parameters on Fabric Drying Characteristics

Presented here is a protocol that guarantees uniform distribution of initial moisture inside of a fabric and investigates the effects of hot-air thermodynamic parameters (velocity, temperature, and direction) and thickness on the fabric&#39;s drying characteristics (e.g., temperature variation) under the condition of air impingement.

Impinging dryness is now a widely used and effective way for fabric drying due to its high heat and mass transfer coefficient. Previous studies on fabric ...

This protocol provides a method for drying performance analysis based on surface temperature distribution instead of single-point temperature, which is the traditional way. As part of this, we developed a technique to obtain even moisture distribution in the fabric for investigating the drying performance of fabric and the air impingement. This method could provide insight into the drying of textiles in the heat inciting process, and it could be applied in the paper drying industry.To begin, start heating an oven to 120 degrees Celsius. Let it dry at that temperature for 30 minutes. Meanwhile, ensure that a hot air blower is connected to an air nozzle.Over the course of about 30 seconds, slowly move the air nozzle to between 60 and 90 degrees with respect to the sample position. Next, turn on the air blower fan, then supply power to the resistance wire of the heating element. Adjust the current until the desired air temperature is achieved.The nozzle and the air may be very hot. Don't touch the nozzle, and avoid directing the hot air blower directly on your body during the experiment. Next, hold an anemometer probe perpendicular to the air nozzle, and measure the air velocity.Adjust the rotation speed of the fan to reach the desired velocity. After that, cover the air nozzle with the heat insulation cover to shield the sample area during setup. Then, mount an infrared thermographic camera about a meter above the air nozzle.Connect the thermographic camera to a computer and open the instrument software. Then use a needle plate fixture to mount the standard fabric sample 30 millimeters above the air nozzle outlet. Focus the camera on the fabric.Then, set the temperature unit to degrees Celsius, the thermal radiance to 0.95, the ambient relative humidity to 50%the ambient temperature to 25 degrees Celsius, and the distance between the measured object and the camera to 1.5 meters. Next, confirm that the uniform padder system is connected to an air compressor. Start the compressor, and set its maximum output to 0.8 megapascals.Manually adjust the pressure regulators for the clamp cylinders to ensure that the pressure will be equal on both sides of the upper roller. Place a water-saturated, pre-weighed fabric sample on the upper roller and run the uniform padder. Turn off the padder afterwards, and confirm that the moisture content is even throughout the sample.Lastly, once the oven is dry, set it to the sample drying temperature. To begin preparing the fabric sample, cut a 400-millimeter-by-280-millimeter fabric square, and dry it in the oven for about three hours. Weigh the dry fabric, and then soak it in water for five minutes.Then turn on the padder and set the desired initial pressure. Lay the saturated fabric on the top roller of the uniform padder. Once the sample passes through the rollers, retrieve the sample and turn off the padder.Weigh the wet fabric sample and calculate the moisture content. If needed, dry the rollers with a paper towel, and run the fabric through the uniform padder again until the desired moisture content is achieved. Then confirm that the air blower temperature and velocity are set correctly, and that the nozzle is covered with the thermally-insulating board.Mount the sample in the needle plate fixture and start recording the sample temperature with the thermographic camera. Remove the heat-insulating cover so that the hot air impinges on the underside of the sample. Monitor the increasing fabric temperature on the computer.Once the temperature is approximately stable for at least 30 seconds, the fabric has dried to the target level. Stop recording the temperature, cover the nozzle with the heat-insulating cover, and remove the sample from the fixture. Set the target area in the video for analysis, and extract the temperature data.Navigate through the video, and save individual frames from notable points in time as pseudocolor images. Convert the saved frames to grayscale, and identify the intensity value for the fabric that is close to the hot air temperature. Binarize the grayscale images using that value as the threshold to display the dry regions.This cotton fabric showed a clear temperature decay from the center of the periphery under air-impingement drying. The center of the drying fabric reached a steady-state temperature after 20 seconds of heating. Minimal heating was observed at the edges of the impingement area.Increasing the temperature of the impinging air sped up the time to dryness, as did increasing the air velocity. The fabric thickness also significantly affected the drying time. Air impingement angles under 75 degrees substantially decreased the temperature at the drying center, and increased the time to dryness.Air impingement angles under 75 degrees also correspond to smaller impingement areas. Binarization analysis showed that a 70-degree impingement angle reduced the drying area by about 20%and a 65-degree angle reduced the area by about 40%relative to a 90-degree angle. The keys to obtaining the accurate drying performance of the seen fabric is the even distribution of the initial moisture content and the contiguous measurement of surface temperature.The research paves the way for future studies of the drying characteristics of sheet materials, such as fabric and paper.

fabric-moisture-uniform-control-to-study-influence-air-impingement

Research

JoVE Journal

Engineering

Encapsulation and Permeability Characteristics of Plasma Polymerized Hollow Particles

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma polymerization of isopropanol on various solid substrates, including silica and potassium chloride. This versatile technique is used to treat nanoparticles and nanopowders with sizes ranging from 37 nm to 1 micron, by depositing films whose thickness can be anywhere from 1 nm to upwards of 100 nm. Dissolution of the core allows us to study the rate of permeation through the film. In these experiments, we determine the diffusion coefficient of KCl through the barrier film by coating KCL nanocrystals and subsequently monitoring the ionic conductivity of the coated particles suspended in water. The primary interest in this process is the encapsulation and delayed release of solutes. The thickness of the shell is one of the independent variables by which we control the rate of release. It has a strong effect on the rate of release, which increases from a six-hour release (shell thickness is 20 nm) to a long-term release over 30 days (shell thickness is 95 nm). The release profile shows a characteristic behavior: a fast release (35% of the final materials) during the first five minutes after the beginning of the dissolution, and a slower release till all of the core materials come out.

We have used plasma enhanced chemical vapor deposition to deposit thin films ranging from a few nm to several 100 nm on nano-sized particles of various materials. We subsequently etch the core material to produce hollow nanoshells whose permeability is controlled by the thickness of the shell. We characterize the permeability of these coatings to small solutes and demonstrate that these barriers can provide sustained release of the core material over several days.

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma ...

Fabrication of VB2/Air Cells for Electrochemical Testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

Fabrication of VB2/Air Cells for Electrochemical Testing

A protocol is presented to study multi-electron metal/air battery systems by using previous technology developed for the zinc/air cell. Electrochemical testing is then performed on fabricated batteries to evaluate performance.

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for ...

Fabrication of Uniform Nanoscale Cavities via Silicon Direct Wafer Bonding

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned and bonded silicon wafers. Unlike confinements in porous materials often used for these types of experiments3, bonded wafers provide predesigned uniform spaces for confinement. The geometry of each cell is well known, which removes a large source of ambiguity in the interpretation of data.
Exceptionally flat, 5 cm diameter, 375 &#181;m thick Si wafers with about 1 &#181;m variation over the entire wafer can be obtained commercially (from Semiconductor Processing Company, for example). Thermal oxide is grown on the wafers to define the confinement dimension in the z-direction. A pattern is then etched in the oxide using lithographic techniques so as to create a desired enclosure upon bonding. A hole is drilled in one of the wafers (the top) to allow for the introduction of the liquid to be measured. The wafers are cleaned2 in RCA solutions and then put in a microclean chamber where they are rinsed with deionized water4. The wafers are bonded at RT and then annealed at ~1,100 &#176;C. This forms a strong and permanent bond. This process can be used to make uniform enclosures for measuring thermal and hydrodynamic properties of confined liquids from the nanometer to the micrometer scale.

A method for permanently bonding two silicon wafers so as to realize a uniform enclosure is described. This includes wafer preparation, cleaning, RT bonding, and annealing processes. The resulting bonded wafers (cells) have uniformity of enclosure ~1%1,2. The resulting geometry allows for measurements of confined liquids and gasses.

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned ...

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for detailed observation, scenarios that make it challenging to observe with conventional imaging systems. One of these is the drop impact of liquids, which usually happens within one tenth of millisecond. To tackle this challenge, a fast imaging technique is introduced that combines a high-speed camera (capable of up to one million frames per second) with a macro lens with long working distance to bring the spatial resolution of the image down to 10 &#181;m/pixel. The imaging technique enables precise measurement of relevant fluid dynamic quantities, such as the flow field, the spreading distance and the splashing speed, from analysis of the recorded video. To demonstrate the capabilities of this visualization system, the impact dynamics when droplets of non-Newtonian fluids impinge on a flat hard surface are characterized. Two situations are considered: for oxidized liquid metal droplets we focus on the spreading behavior, and for densely packed suspensions we determine the onset of splashing. More generally, the combination of high temporal and spatial imaging resolution introduced here offers advantages for studying fast dynamics across a wide range of microscale phenomena.

Drop impact of non-Newtonian fluids is a complex process since different physical parameters influence the dynamics over a very short time (less than one tenth of a millisecond). A fast imaging technique is introduced in order to characterize the impact behaviors of different non-Newtonian fluids.

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for ...

Effect of Bending on the Electrical Characteristics of Flexible Organic Single Crystal-based Field-effect Transistors

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling immensely. However, in soft electronics, in which organic semiconductors play a critical role, the devices will be bent or folded repeatedly. The effect of bending on the crystal packing and thus the charge transport is crucial to the performance of the device. In this manuscript, we describe the protocol to bend a single crystal of 5,7,12,16-tetrachloro-6,13-diazapentacene (TCDAP) in the field-effect transistor configuration and to obtain reproducible I-V characteristics upon bending the crystal. The results show that bending a field-effect transistor prepared on a flexible substrate results in nearly reversible yet opposite trends in charge mobility, depending on the bending direction. The mobility increases when the device is bent toward the top gate/dielectric layer (upward, compressive state) and decreases when bent toward the crystal/substrate side (downward, tensile state). The effect of bending curvature was also observed, with greater mobility change resulting from higher bending curvature. It is suggested that the intermolecular &#960;-&#960; distance changes upon bending, thereby influencing the electronic coupling and the subsequent carrier transport ability.

This manuscript describes the bending process of an organic single crystal-based field-effect transistor to maintain a functioning device for electronic property measurement. The results suggest that bending causes changes in the molecular spacing in the crystal and thus in the charge hopping rate, which is important in flexible electronics.

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling ...

Study of Siphon Breaker Experiment and Simulation for a Research Reactor

Under the design conditions of a research reactor, the siphon phenomenon induced by pipe rupture can cause continuous outward flow of water. To prevent this outflow, a control device is required. A siphon breaker is a type of safety device that can be utilized to control the loss of coolant water effectively.
To analyze the characteristics of siphon breaking, a real-scale experiment was conducted. From the results of the experiment, it was found that there are several design factors that affect the siphon breaking phenomenon. Therefore, there is a need to develop a theoretical model capable of predicting and analyzing the siphon breaking phenomenon under various design conditions. Using the experimental data, it was possible to formulate a theoretical model that accurately predicts the progress and the result of the siphon breaking phenomenon. The established theoretical model is based on fluid mechanics and incorporates the Chisholm model to analyze two-phase flow. From Bernoulli&#39;s equation, the velocity, quantity, undershooting height, water level, pressure, friction coefficient, and factors related to the two-phase flow could be obtained or calculated. Moreover, to utilize the model established in this study, a siphon breaker analysis and design program was developed. The simulation program operates on the theoretical model basis and returns the result as a graph. The user can confirm the possibility of the siphon breaking by checking the shape of the graph. Furthermore, saving the entire simulation result is possible and it can be used as a resource for analyzing the real siphon breaking system.
In conclusion, the user can confirm the status of the siphon breaking and design the siphon breaker system using the program developed in this study.

The siphon breaking phenomenon was investigated experimentally and a theoretical model was proposed. A simulation program based on the theoretical model was developed and the results of the simulation program were compared with experimental results. It was concluded that the results of the simulation program matched the experimental results well.

Under the design conditions of a research reactor, the siphon phenomenon induced by pipe rupture can cause continuous outward flow of water. To prevent ...

The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach their targets. In recent years, reliance upon robots in both daily life and industry has increased. The protocol proposed in this paper describes the design and production of a handling robot with an intelligent search algorithm and an autonomous identification function.
First, the various working modules are mechanically assembled to complete the construction of the work platform and the installation of the robotic manipulator. Then, we design a closed-loop control system and a four-quadrant motor control strategy, with the aid of debugging software, as well as set steering gear identity (ID), baud rate and other working parameters to ensure that the robot achieves the desired dynamic performance and low energy consumption. Next, we debug the sensor to achieve multi-sensor fusion to accurately acquire environmental information. Finally, we implement the relevant algorithm, which can recognize the success of the robot&#39;s function for a given application.
The advantage of this approach is its reliability and flexibility, as the users can develop a variety of hardware construction programs and utilize the comprehensive debugger to implement an intelligent control strategy. This allows users to set personalized requirements based on their needs with high efficiency and robustness.

We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design.

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach ...

Applicability Analysis of Assessment Methods for Morphological Parameters of Corroded Steel Bars

The irregular and uneven residual sections along the length of a corroded steel bar substantially change its mechanical properties and significantly dominate the safety and performance of an existing concrete structure. As a result, it is important to measure the geometry and amount of corrosion of a steel bar in a structure properly to assess the residual bearing capacity and service life of the structure. This paper introduces and compares five different methods for measuring the geometry and amount of corrosion of a steel bar. A single 500 mm long and 14 mm diameter steel bar is the specimen that is subjected to accelerated corrosion in this protocol. Its morphology and the amount of corrosion were carefully measured before and after using mass loss measurements, a Vernier caliper, drainage measurements, 3D scanning, and X-ray micro-computed tomography (XCT). The applicability and suitability of these different methods were then evaluated. The results show that the Vernier caliper is the best choice for measuring the morphology of a non-corroded bar, while 3D scanning is the most suitable for quantifying the morphology of a corroded bar.

This paper measures the geometry and the amount of corrosion of a steel bar using different methods: mass loss, calipers, drainage measurements, 3D scanning, and X-ray micro-computed tomography (XCT).

The irregular and uneven residual sections along the length of a corroded steel bar substantially change its mechanical properties and significantly ...

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.

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

O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression

Unlike macroscopic process variables, near-infrared spectroscopy provides process information at the molecular level and can significantly improve the prediction of the components in industrial processes. The ability to record spectra for solid and liquid samples without any pretreatment is advantageous and the method is widely used. However, the disadvantages of analyzing high-dimensional near-infrared spectral data include information redundancy and multicollinearity of the spectral data. Thus, we propose to use partial least squares regression method, which has traditionally been used to reduce the data dimensionality and eliminate the collinearity between the original features. We implement the method for predicting the o-cresol concentration during the production of polyphenylene ether. The proposed approach offers the following advantages over component regression prediction methods: 1) partial least squares regression solves the multicollinearity problem of the independent variables and effectively avoids overfitting, which occurs in a regression analysis due to the high correlation between the independent variables; 2) the use of the near-infrared spectra results in high accuracy because it is a non-destructive and non-polluting method to obtain information at microscopic and molecular scales.

The protocol describes a method of predicting o-cresol concentration during the production of polyphenylene ether using near-infrared spectroscopy and partial least squares regression. To describe the process more clearly and completely, an example of predicting the o-cresol concentration during the production of polyphenylene is used to clarify the steps.

Unlike macroscopic process variables, near-infrared spectroscopy provides process information at the molecular level and can significantly improve the ...