This study was supported by the Research Program funded by the SeoulTech (Seoul National University of Science and Technology).

1. Broker installation
NOTE: To monitor and record processing data via the Internet, a computer system that relays the data should be prepared. The system should be accessible from both the publishers and the subscribers as shown in Figure 2. Thus, it needs to have a public IP address that is known prior to any communication. An open MQTT broker called Eclipse Mosquitto is installed on the system13.
<ol>
	<li>Connect a computer to the Internet giving a public IP address. Give the address in the IP setting of the operating system.</li>
	<li>Install a broker software such as Eclipse Mosquitto on the computer. Download the installation file using a browser and execute it.</li>
	<li>Test the broker with a test program such as MQTT Lens. Download MQTT Lens using a browser and install it. Then, ensure published messages are subscribed.</li>
</ol>
2. Main publisher preparation
NOTE: This computer publishes the machine data via MQTT over TCP to the broker. Legacy data should be interpreted and repackaged to be sent out.This can be usually done by RS485 or Ethernet. The connection at the hardware level should be verified depending on the bus type. The extrusion machine sends out the data via Modbus through an Ethernet port.
<ol>
	<li>Physically place a computer in the machine site and set it up as the main publisher. 
	NOTE: Although not obligatory, an industrial computer was selected in this work.</li>
	<li>Install Python3 on the computer. Download the installer file using a browser and execute it.</li>
	<li>Install PyModbus16. Download the installer file using a browser and execute it.</li>
	<li>Examine the extrusion controller with HMI controlling the machine and connect the extrusion controller to the main publisher.</li>
	<li>Fully identify the data and the corresponding address in the Modbus protocol from the machine using a Modbus tool such as ModbusPoll or QModMaster. Ensure the sent machine data are shown in the corresponding cells of the Modbus tool.</li>
	<li>Write a Python code on the publisher PC that retrieves the data from the extrusion controller. 
	NOTE: Here is a code example: 
	from pyModbusTCP.client import ModbusClient 
	client = ModbusClient(host=&#34;192.168.1.***&#34;, port=***, unit_id=***) 
	client.open() 
	ExtrusionData = str(client.read_holding_registers(1000, 58))</li>
	<li>Merge additional data streams from other devices via PCIe, USB, RS232, and RS485. 
	NOTE: This is straightforward. Once an additional data string is obtained, simply add the data to the existing data stream, which is done by the following code: 
	ExtrusionData += AdditionalData</li>
	<li>Import the paho.mqtt.client after installing paho-mqtt by pip install paho-mqtt17.</li>
	<li>Implement the code to connect and publish data to the broker. 
	NOTE: Refer to the following code example: 
	url=&#34;117.xx.xxx.xx&#34;; port = 1883; username = &#34;****&#34;; password = &#34;xxxxx&#34;; topic = &#34;Extruder&#34; 
	mqttc = mqtt.Client() 
	mqttc.username_pw_set(username,password) 
	mqttc.connect(host=url, port=port) 
	mqttc.loop_start() 
	ExtrusionData = str(client.read_holding_registers(1000, 58)) 
	Pub1= mqttc.publish(topic, ExtrusionData)) 
	Pub1.wait_for_publish()</li>
</ol>
3. Additional publisher preparation
NOTE: This computer also publishes the machine data via MQTT over TCP to the broker. Sometimes, additional measurement that cannot be done on the main publisher is required. Internet of Things (IoT) devices such as Raspberry Pi and Arduino can take the role. In this work, Raspberry Pi was employed for temperature data and illuminance data. The procedure is similar to protocol section 2.
<ol>
	<li>Place a Raspberry Pi near the sensor location. 
	NOTE: Since the wiring distance is limited, the Raspberry Pi cannot be placed very far from the measurement location. However, as the vicinity of the extruder is very hot, the device needs to be placed at least 1 m away from the measurement location.</li>
	<li>Install Python3 on the Raspberry Pi by the following commands in the command line: 
	sudo apt update 
	sudo apt install Python3 idle3</li>
	<li>Implement the code to acquire the sensor data. The sensor data can be transmitted via I2C or GPIO. 
	NOTE: Refer to the following code example for additional temperature data via GPIO: 
	from max6675 import MAX6675 
	cs_pin1 = 24; clock_pin1 = 25; data_pin1 = 18 
	cs_pin2 = 9; clock_pin2 = 11; data_pin2 = 19 
	units = &#34;C&#34; 
	thermocouple1 = MAX6675(cs_pin1, clock_pin1, data_pin1, units) 
	thermocouple2 = MAX6675(cs_pin2, clock_pin2, data_pin2, units) 
	T1 = thermocouple1.get() 
	T2 = thermocouple2.get()</li>
	<li>Import paho.mqtt.client.</li>
	<li>Reuse the code in section 2 to connect and publish data to the broker.</li>
</ol>
4. Subscriber&#39;s setup
NOTE: Any devices on Internet may receive the processing data via the broker. The data is processed and visualized also by a Python code. In case the development is difficult, available applications such as MQTT Client in Google Play and MQT Tool in the App Store can be employed. Since the implementation of the user interface is quite lengthy, the details are not described here. Also note that existing applications such as MQT Tool in App Store can receive the data.
<ol>
	<li>Engage a device for subscription to the Internet. Ensure a physical cable connection and then execute a ping to the broker IP on the command line (e.g., ping 117.xx.xxx.xx).</li>
	<li>Install a suitable Python environment depending on the device and the OS. For example, install Pydroid3 on an android device instead of Python3 from the Google Play.</li>
	<li>Import both paho.mqtt.client and paho.mqtt.subscribe to connect to and receive data from the broker. 
	NOTE: Refer to the following code example: 
	import paho.mqtt.client as mqtt 
	import paho.mqtt.subscribe as subscribe 
	url=&#34;117.xx.xxx.xx&#34;; port = 1883; username = &#34;****&#34;; password = &#34;xxxxx&#34;; topic = &#34;Extruder&#34; 
	mqttc.username_pw_set(username, password) 
	mqttc.connect(host=url, port=port) 
	mqttc.subscribe(topic, 0) 
	mqttc.loop_start() 
	Sub1 = subscribe.simple(topic, hostname=url) 
	ExtruderData = Sub1.payload.decode(&#34;utf-8&#34;)</li>
	<li>Build a user interface as required using PyQT5. 
	NOTE: This part is very lengthy and focuses on graphical representation of the received data rather than communication. The corresponding code is provided as supplementary data.</li>
	<li>Display the incoming data on the GUI by executing the built code.</li>
</ol>
5. Data logging
NOTE: The processing data can be written in a database while monitoring. In this work, a lab-scale database was chosen. The data are connected onto a Microsoft Access file to easily write and retrieve from a user computer. In addition, a table can be instantly built by a query to analyze data in a spreadsheet such as Microsoft Excel.
<ol>
	<li>Select a subscriber device to record the data.</li>
	<li>Import pyodbc by executing &#34;pip install pyodbc&#34; on the command line for the Python code to access the database as shown in Figure 318.</li>
	<li>Send a query to the database by the Python code for recording the processing data. Refer to the Python code in Figure 3 for the method.</li>
	<li>Send a query to the database for retrieval of the recorded data. 
	NOTE: A code example for data retrieval is given below: 
	import pyodbc 
	x for x in pyodbc.drivers() if x.startswith(&#39;Microsoft Access Driver&#39;)] 
	conn_str = ( 
	r&#39;DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};&#39; 
	r&#39;DBQ=C:\Users\data_analysis\db1.accdb;&#39; 
	) 
	cnxn = pyodbc.connect(conn_str) 
	crsr = cnxn.cursor() 
	for table_info in crsr.tables(tableType=&#39;TABLE&#39;): 
	print(table_info.table_name) 
	sql = &#34;&#34;&#34;\ 
	SELECT * FROM Process_Condition 
	&#34;&#34;&#34; 
	crsr = cnxn.execute(sql) 
	for row in crsr: 
	RetrievedData = pd.read_sql(sql, cnxn) 
	crsr.close() 
	cnxn.close()</li>
</ol>
6. Deployment
NOTE: If all the devices can be connected to the Internet, the setup is simple. However, to secure the machine side data, the publishers can be in the intranet only. In this case, the broker can be a gateway to the Internet. To be so, the broker should be equipped with two ethernet adaptors, one of which must have a public IP address. After all the items are developed, the codes should be deployed onto each device as shown in Figure 4. The mode of connection, wired or wireless, is not important, but it has to be secured so that each device should be able to access the broker. This means the broker can act as a gateway on the border between the intranet and the Internet for security purposes. Of course, even if all the devices are exposed to the Internet, there is no problem from a communication point of view.
<ol>
	<li>Connect the extrusion controller, the main publisher, and the additional publishers to the Intranet port via ethernet.</li>
	<li>Connect one ethernet port of the broker to the intranet and the other to the Internet.</li>
	<li>Connect subscribers to the Internet by repeating step 4.1 for all of them.</li>
</ol>
7. Execution
NOTE: To test the whole system, we started the extrusion line and ran all the Python codes and Mosquitto.
<ol>
	<li>Start the extrusion process. On the HMI of the machine, set the temperatures and turn on the heater by touching the button on the HMI screen. Once the required temperature is reached, start the screw rotation to extrude the polymer melt.</li>
	<li>Turn on all the computers, start the broker software on the broker device by the command &#34;net start mosquitto&#34;, and then run the Python codes to monitor and record the processing data as needed. 
	NOTE: The order of step 7.1 and step 7.2 can be reversed. The Python codes can be executed simply by typing &#34;python3 xxxxx.py&#34; on the command line followed by pressing Enter. Add this command to the start-up programs to avoid typing the command every time the device reboots.</li>
</ol>

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The authors declare no conflicts of interest.

By following the protocol presented, the processing data can be monitored and recorded without expensive IT solutions such as the MES. The IoT technologies can make it easier to acquire and deliver data from conventional machines. It has been shown that the message-based protocol, MQTT, successfully serves as a platform for data communication for polymer processing lines. Moreover, additional data can be flexibly measured and transmitted together. The additional publishers employed in this work were the Raspberry Pis. No...

In the wave of the 4th industrial revolution, the acquisition and monitoring of various processing data have become important tasks1. In particular, improving the manufacturing process using process data and establishing efficient operation plans will be an important goal of all manufacturing facilities2,3. Downtime can be greatly reduced if an alarm can be sent out of the factory or if predictive maintenance can be performed in time4. Recently, many efforts have been made for data analyses in polymer processes5,6. However, it is not easy to conduct these tasks due to the difficulties in acquiring such data from the existing systems7. The hierarchical structure of the control and instrumentation makes the data acquisition and communication difficult.
First of all, it is not possible to obtain data from different machines with different manufacturing dates. It is difficult to realize communication between different machines since this requires interoperability between different fieldbuses in proprietary formats. In this way, communication methods and data formats are kept private. This helps one easily maintain data security but keeps users dependent on the machine builder for the services and future developments. The recent control computers including human-machine interface (HMI) attached to polymer processing machines are mostly Windows-based these days but are loaded with software created in a proprietary development environment. It is possible to use programmable logic controllers (PLCs) from different companies to communicate with the sensors or actuators, but in many cases, the upper supervisory control and data acquisition (SCADA) system is dependent on the control computers8. This practice has caused numerous protocols, fieldbuses, and control systems to compete in the market. Although this complexity has been alleviated little by little over time, many types of fieldbuses and protocols are still in active use.
On the other hand, communication between control devices and SCADA has been standardized by the Open Platform Communications United Architecture (OPCUA)9. Moreover, communication between SCADA and the Manufacturing Execution System (MES) has also been mainly made through OPCUA. In such a tight hierarchical structure, it is not easy to freely extract data for process monitoring and analysis. Usually, data has to be extracted out of the SCADA or MES10. As mentioned earlier, these systems are vendor-specific, and the data formats are rarely open. As a result, the data extraction requires substantial support from the original information technology/operational technology (IT/OT) solution vendors. This can hinder data acquisition for monitoring and analysis.
In a film extrusion line, the control PC is supervised by a SCADA system11. The SCADA system is operated by a computer program that cannot be easily modified. The computer program might be editable, but the editing is quite expensive and time-consuming. To easily monitor and analyze the processing data, the data should be accessible from any location. To monitor the processing data away from the site, the computer program should be capable of streaming the processing data to the Internet12. Moreover, an open free method reduces the expenses for the data acquisition13. This approach allows data analysis to be performed even in small factories that cannot afford to invest in commercial IT solutions14.
In this study, a message protocol based on the publisher-subscriber model is employed. The Message Queuing Telemetry Transport (MQTT) is an open and standard protocol that enables messaging between multiple data providers and consumers15. Here, we propose a system that acquires, transmits, and monitors data using MQTT for existing manufacturing facilities. The system is tested in a film extrusion line to verify the performance. The data from the original controller are transmitted to an edge device via the Modbus protocol. Then, the data is published to the broker. In the meantime, two Raspberry Pis publish the measured temperatures and illuminance to the same broker. Then, any device on the Internet can subscribe to the data, followed by monitoring and recording it as shown in Figure 1. The protocol in this work shows how the whole procedure can be done.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Edge Device</td>
			<td>Adavantech</td>
			<td>UNO 420</td>
			<td>Intel Atom E3815 Fanless</td>
		</tr>
		<tr>
			<td>Film Extrusion Machine</td>
			<td>EM Korea</td>
			<td>Not Available</td>
			<td>For production of 450 mm film</td>
		</tr>
		<tr>
			<td>Pydroid</td>
			<td>IIEC</td>
			<td>Not Available</td>
			<td>Android Devices</td>
		</tr>
		<tr>
			<td>Python3</td>
			<td>Python Software Foundataion</td>
			<td>Not Available</td>
			<td>Windows, Linux</td>
		</tr>
		<tr>
			<td>Raspberry Pi 4</td>
			<td>CanaKit</td>
			<td>Not Available</td>
			<td>Standard Kit</td>
		</tr>
	</tbody>
</table>

data communication based on mqtt in a polymer extrusion process

This work aims at building a flexible data communication structure for a polymer processing machine by employing a publisher-subscriber based protocol called Message Queuing Telemetry Transport (MQTT), which is operated over TCP/IP. Even when using conventional equipment, processing data can be measured and recorded by various devices anywhere through an Internet communication. A message-based protocol allows flexible communication that overcomes the shortcomings of the existing server-client protocol. Multiple devices can subscribe to the processing data published by source devices. The proposed method facilitates data communication between multiple publishers and subscribers. This work has implemented a system that publishes data from the equipment and additional sensors to a message broker. The subscribers can monitor and store the process data relayed by the broker. The system has been deployed and run for a film extrusion line to demonstrate the effectiveness.

It has been found that the data shown in the HMI and measured by the Raspberry Pis were monitored and recorded in the subscribers as shown in Figure 5. As presented in the video, the processing data are logged into the database.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63717/63717fig01.jpg" /> 
Figure 1: Outline of the data transmission using the MQTT protocol.<...

Watch this Scientific Journal Video about Data Communication Based on MQTT in a Polymer Extrusion Process at JoVE.com

Data Communication Based on MQTT in a Polymer Extrusion Process

This work proposes a flexible method for data communication between a film extrusion system and monitoring devices based on a message protocol called Message Queuing Telemetry Transport (MQTT).

This work aims at building a flexible data communication structure for a polymer processing machine by employing a publisher-subscriber based protocol ...

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3.4K Views.  Seoul National University of Science and Technology (SeoulTech). This work proposes a flexible method for data communication between a film extrusion system and monitoring devices based on a message protocol called Message Queuing Telemetry Transport (MQTT). 

Video: Data Communication Based on MQTT in a Polymer Extrusion Process

Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications2,3. Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials4. For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form5,6. One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes.
A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers4, polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures7. The fabricated microstructures of conducting polymers have been used as humidity8, chemical8, and glucose sensors9. Combined microstructures of Al and conducting polymers have been employed to fabricate capacitors and various heterojunctions9,10,11. The "cutting" operation was also applied to generate submicron-patterns, such as 100- and 500-nm-wide PPy lines as well as 100-nm-wide Au wires. The "drawing" operation was employed for two applications: (i) produce Au sidewall patterns on high density polyethylene (HDPE) channels which could be used for building 3D microsystems12,13,14, and (ii) fabricate polydimethylsiloxane (PDMS) micropillars on HDPE substrates to increase the contact angle of the channel15.

A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Morphology Control for Fully Printable Organic&#8211;Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting material. However, fullerene derivatives are air-sensitive; therefore, air-stable material is needed as an alternative. In the present study, we propose and describe the properties of Ti-alkoxide as an alternative electron-accepting material to fullerene derivatives to create highly air-stable BHJ solar cells. It is well-known that controlling the morphology in the photoactive layer, which is constructed with fullerene derivatives as the electron acceptor, is important for obtaining a high overall efficiency through the solvent method. The conventional solvent method is useful for high-solubility materials, such as fullerene derivatives. However, for Ti-alkoxides, the conventional solvent method is insufficient, because they only dissolve in specific solvents. Here, we demonstrate a new approach to morphology control that uses the molecular bulkiness of Ti-alkoxides without the conventional solvent method. That is, this method is one approach to obtain highly efficient, air-stable, organic-inorganic bulk-heterojunction solar cells.

A method for fully printable, fullerene-free, highly air-stable, bulk-heterojunction solar cells based on Ti alkoxides as the electron acceptor and the electron-donating polymer fabrication is described here. Moreover, a method for controlling the morphology of the photoactive layer through the molecular bulkiness of the Ti-alkoxide units is reported.

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...

A Polymer-based Piezoelectric Vibration Energy Harvester with a 3D Meshed-Core Structure

In this study, we fabricated a flexible 3D mesh structure with periodic voids by using a 3D lithography method and applying it to a vibration energy harvester to lower resonance frequency and increase output power. The fabrication process is mainly divided into two parts: three-dimensional photolithography for processing a 3D mesh structure, and a bonding process of piezoelectric films and the mesh structure. With the fabricated flexible mesh structure, we achieved the reduction of resonance frequency and improvement of output power, simultaneously. From the results of the vibration tests, the meshed-core-type vibration energy harvester (VEH) exhibited 42.6% higher output voltage than the solid-core-type VEH. In addition, the meshed-core-type VEH yielded 18.7 Hz of resonance frequency, 15.8% lower than the solid-core-type VEH, and 24.6 &#956;W of output power, 68.5% higher than the solid-core-type VEH. The advantage of the proposed method is that a complex and flexible structure with voids in three dimensions can be relatively easily fabricated in a short time by the inclined exposure method. As it is possible to lower the resonance frequency of the VEH by the mesh structure, use in low-frequency applications, such as wearable devices and house appliances, can be expected in the future.

In this study, we fabricated a flexible 3D mesh structure and applied it to the elastic layer of a bimorph cantilever-type vibration energy harvester for the purpose of lowering resonance frequency and increasing output power.

In this study, we fabricated a flexible 3D mesh structure with periodic voids by using a 3D lithography method and applying it to a vibration energy ...

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 ...

Data Communication Based on MQTT in a Polymer Extrusion Process

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