This work was supported by the National Natural Science Foundation of China under Grant 62103308, Grant 62173255, Grant 62073247, and Grant 61773144.

In this work, three separate visualized examples are provided to enhance teaching and learning and research, which can be accessed via the Networked Control System Laboratory (NCSLab&#160;https://www.powersim.whu.edu.cn/react).
1. Example 1: First-order system using circuit-based experimentation protocol
<ol>
	<li>Access the NCSLab system.
	<ol>
		<li>Open a mainstream web browser and enter the URL&#160;https://www.powersim.whu.edu.cn/react.</li>
		<li>Click on the Start Experiment button on the left side of the main page to log in to the system. User name: whutest; password: whutest. 
		NOTE: This step also suits for other two examples (Example&#160;2 and Example 3).</li>
		<li>Enter the WHULab in the left side sub-laboratory list and choose WHUtypicalLinks for experimentation. 
		NOTE: Six sub-interfaces are designed and implemented for different purposes to support simulation and real-time experimentation.</li>
		<li>Enter the Algorithm Design sub-interface. 
		NOTE: The user can choose a public algorithm model designed and shared by other authorized users or create a new model.</li>
		<li>Choose and click on the Create New Model button and enter the web-based algorithm interface. Build a circuit diagram using the provided blocks, as shown in Figure 1. 
		NOTE: Another operational amplifier (op-amp) (Op-Amp2 in Figure 1) is used to cancel the 180&#176; phase shift. To ensure that the input, the resistors, and the capacitor are tunable, one variable capacitor and two variable resistors in the ELECTRIC ELEMENTS library and four constant blocks from the SOURCES library are selected from the left-side block library panel.</li>
		<li>Double click the corresponding blocks to set parameters as listed in Table 1. Set the X-axis range of the chart to 8 s. 
		NOTE: A popup window will be triggered after a double click to the block, which includes the descriptions of the block and can be used for setting the parameter. An example of the Resistor (R3) is illustrated in Figure 1.</li>
		<li>Click on the Start Simulation button; the simulation result will be provided in the interface, as included in Figure 1. 
		NOTE: This step also suits the two other examples with other test rigs. The simulation results can provide information for users to recheck the designed circuit-based system to avoid a wrong circuit. However, a faulty circuit will cause no harm to the users or the system, so the users do not have to worry about the consequences.</li>
		<li>Click on the Start Compilation button. Wait until the designed block diagram is generated into an executable control algorithm that can be downloaded and executed into the remote controller deployed at the test rig side to implement control algorithms. 
		NOTE: This step also suits the following experiments with other test rigs.</li>
		<li>Conduct real-time experiments using the generated control algorithm. Click on the Request Control button to apply for control of the circuit system. 
		NOTE: &#34;Request control&#34; is the scheduling mechanism for the system. Once a user is granted the control privilege, the user can conduct experiments with the corresponding test rig. Only one user can occupy the test rig at a time for physical test rigs, and the queue scheduling mechanism has been implemented to schedule other potential users based on the First Come First Served rule11. For virtual test rigs, a massive number of users can be concurrently supported. 500 concurrent user experimentation has been tested effectively. For the circuit-based system, 50 users can access the system at a time.</li>
		<li>Click on the Return button to the Algorithm Design sub-interface. Find the executable control algorithm under the Private Algorithm Models panel. 
		NOTE: The executable control algorithm can also be found in the My Algorithm panel in the Control Algorithm sub-interface.</li>
		<li>Click on the Conduct An Experiment button to download the designed control algorithm to a remote controller.</li>
		<li>Enter the Configuration sub-interface and click on the Create New Monitor button to configure a monitoring interface, as shown in Figure 2. Four textboxes for parameter tuning and one curve chart for signal monitoring are included. 
		NOTE: The chart on the right in Figure 2 is the same chart as the one in the left, which was added to demonstrate the data using the Suspend button.</li>
		<li>Link the signals and parameters with the selected widgets. 
		NOTE: Parameter/ Input, Parameter/ R0, Parameter/ R1, and Parameter/ C for four textboxes, respectively, and Parameter/ Input and Signal/ Output for the curve chart.</li>
		<li>Click on the Start button to start the experiment. 
		NOTE: This step also suits the following experiments with other test rigs. Users can save the configuration for future use.</li>
		<li>Set the input voltage to 0 V, tune the capacitor C to 5 &#181;F (0.000005 in Figure 2), and then set the input voltage to 1 V; the dynamic process of the output voltage is illustrated in Figure 2.</li>
	</ol>
	</li>
	<li>Calculate the corresponding parameters K and T. 
	&#8203;NOTE: The time constant can be calculated when the output reaches 63.2% of the final value K after t = T, which is 0.63212. From Figure 2, it can be seen that the time duration is 1 s, thus, T = 1, which is consistent with the theory in which, T = R1C = 200000*0.000005 = 1, and K = R1/R0 = 200000 / 200000 = 1 (which equals the final value)12. Thus, the first-order system can be specified as: <img alt="Equation 1" src="/files/ftp_upload/63342/63342eq01.jpg" />.</li>
</ol>
2. Example 2: Interactive and visualized virtual experimentation protocol
<ol>
	<li>Use the NCSLab system to conduct simulation and real-time experimentation.
	<ol>
		<li>Log in to the NCSLab system. Enter the ProcessControl sub-laboratory and choose the dualTank test rig, and then enter the Algorithm Design sub-interface.</li>
		<li>Design a proportional-integral-derivative (PID) control algorithm using the web interface provided by NCSLab following the steps described in Example 1. Figure 3 is an algorithm example for the dual tank system.</li>
		<li>Double click on the PID controller, and tune the parameters for Proportional (P), Integral (I) and Derivative (D) terms. Set P = 1.12, I = 0.008 and D = 6.6, respectively. 
		NOTE: The P, I, and D terms should be tuned combined with the simulation result.</li>
		<li>Click on the Start Simulation button; the simulation result will pop up, which is included on the right side of Figure 3. 
		NOTE: It can be seen that the control performance is good, and the control algorithm is ready for real-time experimentation.</li>
		<li>Generate the executable control algorithm following the previously mentioned steps.</li>
		<li>Download the control algorithm to the remote controller and configure a monitoring interface with four textboxes for Set_point, P, I, and D, respectively.</li>
		<li>Include a chart for monitoring the water level and the corresponding Set_point. Choose a 3-D widget, which can provide all angles of the test rigs and animations of water level connected with the real-time data.</li>
		<li>Click on the Start button; then, the monitoring interface will be activated as shown in Figure 4, which provides a visualized virtual experiment.</li>
		<li>Set the Set_point from 10 cm to 5 cm, and then set I = 0.1 when the height of the water level in the controlled tank reaches and stabilizes at 5 cm. Reset the set-point from 5 cm to 15 cm; it can be seen from Figure 4 that there is an overshoot.</li>
		<li>Tune I from 0.1 to 0.01 and reset the set-point from 15 cm to 25 cm. It can be seen that the overshoot has been eliminated, and the water level can quickly stabilize at the set-point value of 25 cm.</li>
	</ol>
	</li>
</ol>
3. Example 3: Research with remote and virtual laboratories protocol
<ol>
	<li>Conduct a real-time experiment in NCSLab.
	<ol>
		<li>Log into the NCSLab system and choose Fan Speed Control&#160;in the Remote Laboratory&#160;sub-laboratory.</li>
		<li>Enter the Algorithm Design sub-interface. Drag the blocks to construct the internal model control (IMC) control algorithm diagram, as shown in Figure 5. 
		NOTE: The F(s) and Gm(s)-1 is designed as shown in Figure 5, in which the designed control algorithm using NCSLab is illustrated to control a fan speed control system in a remote and virtual laboratory mode.</li>
		<li>Generate the executable control algorithm and employ the fan speed control system to verify the designed IMC algorithm.</li>
		<li>Configure a monitoring interface. Link two textboxes with two parameters, namely, the Set_point and lambda (for&#160;&#955; which is the filter time constant) for tuning, and a real-time chart with the Set_point and Speed for monitoring. Select the 3-D model widget of the fan and the camera widget for monitoring.</li>
		<li>Click on the Start button to activate real-time experimentation. Reset the Set_point from 2,000 rpm to 1,500 rpm, and then reset it from 1,500 rpm to 2,500 rpm, the result of which is shown in Figure 6. 
		NOTE: It can be concluded that when&#160;&#955; = 1 the system can be stabilized to a step reference.</li>
	</ol>
	</li>
</ol>

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The authors have nothing to disclose.

The presented protocol&#160;describes a hybrid online laboratory system that integrates physical test rigs for remote experimentation and 3-D virtual test rigs for virtual experimentation. Several different block libraries are provided for the algorithm design process, such as the electrical elements for circuit-based design. Users from control backgrounds can focus on learning without programming skills. The proper design of a control algorithm that can be applied to a suitable test rig should be considered. It is also ...

Laboratories are vital infrastructure for research and education. When conventional laboratories are not available and/or accessible due to different causes, for example, unaffordable purchases and maintenance cost, safety considerations, and crises such as the coronavirus disease 2019 (COVID-19) pandemic, online laboratories can offer alternatives1,2,3. Like conventional laboratories, significant progress such as interactive features4 and customizable experiments5 have been achieved in the online laboratories. Before and during the COVID-19 pandemic, online laboratories are providing experimental services to users throughout the world6,7.
Among online laboratories, remote laboratories can provide users with an experience similar to hands-on experiments with the support of physical test rigs and cameras8. With the advancement of the Internet, communication, computer graphics, and rendering technologies, virtual laboratories also provide alternatives to conventional laboratories1. The effectiveness of remote and virtual laboratories to support research and education has been validated in related literature1,9,10.
Providing visualized experiments is crucial for online laboratories, and visualization in online experimentation has become a trend. Different visualization techniques are achieved in online laboratories, for example, curve charts, two-dimensional (2-D) test rigs, and three-dimensional (3-D) test rigs11. In control education, numerous theories, concepts, and formulas are obscure to comprehend; thus, visualized experiments are vital to enhancing teaching, student learning, and research. The involved visualizing can be concluded into the following three categories: (1) Visualizing theories, concepts, and formulas with web-based algorithm design and implementation, with which simulation and experimentation can be conducted; (2) Visualizing the experimental process with 3-D virtual test rigs; (3) Visualizing control and monitoring using widgets such as a chart and a camera widget.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Fan speed control system</td>
			<td>/</td>
			<td>/</td>
			<td>Made by our team</td>
		</tr>
		<tr>
			<td>https://www.powersim.whu.edu.cn/react</td>
			<td></td>
			<td></td>
			<td>Made by our team</td>
		</tr>
	</tbody>
</table>

interactive and visualized online experimentation system for engineering education and research

Experimentation is crucial in engineering education. This work explores visualized experiments in online laboratories for teaching and learning and also research. Interactive and visualizing features, including theory-guided algorithm implementation, web-based algorithm design, customizable monitoring interface, and three-dimensional (3-D) virtual test rigs are discussed. To illustrate the features and functionalities of the proposed laboratories, three examples, including the first-order system exploration using a circuit-based system with electrical elements, web-based control algorithm design for virtual and remote experimentation, are provided. Using user-designed control algorithms, not only can simulations be conducted, but real-time experiments can also be conducted once the designed control algorithms have been compiled into executable control algorithms. The proposed online laboratory also provides a customizable monitoring interface, with which users can customize their user interface using provided widgets such as the textbox, chart, 3-D, and camera widget. Teachers can use the system for online demonstration in the classroom, students for after-class experimentation, and researchers to verify control strategies.

The proposed laboratory system has been used in several different disciples at Wuhan University, such as the Automation, Power and Energy Engineering, Mechanical Engineering, and other universities, such as Henan Agricultural University6.
Teachers/students/researchers are provided with great flexibility to explore the system using different virtual and/or physical test rigs, define their control algorithms, and customize their monitoring interface; thus, users at differ...

Watch this Scientific Journal Video about Interactive and Visualized Online Experimentation System for Engineering Education and Research at JoVE.com

Interactive and Visualized Online Experimentation System for Engineering Education and Research

This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras.

Experimentation is crucial in engineering education. This work explores visualized experiments in online laboratories for teaching and learning and also ...

interactive-visualized-online-experimentation-system-for-engineering

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2.3K Views.  Wuhan University. Ons protocol realiseert externe en virtuele experimenten in online laboratoria voor lesgeven, leren en ook onderzoek. Theoretische kennis en experimenteerpraktijk worden gecombineerd om het lesgeven en leren via ons protocol te verbeteren. Het biedt een uniform raamwerk dat theoriegestuurde implementatie, webgebaseerd algoritmeontwerp, aanpasbare bewakingsinterface en driedimensionale virtuele en externe experimenten mogelijk maakt.Zijie Wie en Shengwang Ye zullen helpen om de procedur...

Video: Interactive and Visualized Online Experimentation System for Engineering Education and Research

Novel 3D/VR Interactive Environment for MD Simulations, Visualization and Analysis

The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced.

A new computational system featuring GPU-accelerated molecular dynamics simulation and 3D/VR visualization, analysis and manipulation of nanostructures has been implemented, representing a novel approach to advance materials research and promote innovative investigation and alternative methods to learn about material structures with dimensions invisible to the human eye.

The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials ...

Research and Development of High-performance Explosives

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of Photonic Doppler Velocimetry (PDV) for the measurement of detonation pressure will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products.

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. This paper will share typical development tests associated with the measurement of detonation velocity and detonation pressure.

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance ...

3D Printing of Biomolecular Models for Research and Pedagogy

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

Physical models of biomolecules can facilitate an understanding of their structure-function for the researcher, aid in communication between researchers, and serve as an educational tool in pedagogical endeavors. Here, we provide detailed guidance for the 3D printing of accurate models of biomolecules using fused filament fabrication desktop 3D printers.

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (&#60;0.02 &#176;C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Isolating electrical and thermal effects on electrically assisted deformation (EAD) is very difficult using macroscopic samples. Metallic sample micro- and nanostructures together with a custom test procedure have been developed to evaluate the impact of applied current on the formation without joule heating and evolution of dislocations on these samples.

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

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 ...

Processing of Bulk Nanocrystalline Metals at the US Army Research Laboratory

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued development of nanocrystalline metals. Despite these efforts, the transition of these materials from the lab bench to actual applications has been blocked by the inability to produce large scale parts that retain the desired nanocrystalline microstructures. Following the development of a method proven to stabilize the nanosized grain structure to temperatures approaching that of the melting point for the given metal, the US Army Research Laboratory (ARL) has progressed to the next stage in the development of these materials - namely the production of large scale parts suitable for testing and evaluation in a range of relevant test environments. This report provides a broad overview of the ongoing efforts in the processing, characterization, and consolidation of these materials at ARL. In particular, focus is placed on the methodology used for producing the nanocrystalline metal powders, in both small and large-scale amounts, that are at the center of ongoing research efforts.

This paper provides a brief overview of the ongoing efforts at the Army Research Laboratory on the processing of bulk nanocrystalline metals with an emphasis on the methodologies used for the production of the novel metal powders.

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued ...

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 ...

A Rapid Method for Modeling a Variable Cycle Engine

The variable cycle engines (VCE) that combine the advantages of turbofan and turbojet engines, are widely considered to be the next generation aircraft engines. However, developing VCE requires high costs. Thus, it is essential to build a mathematical model when developing an aircraft engine, which may avoid a large number of real tests and reduce the cost dramatically. Modeling is also crucial in control law development. In this article, based on a graphical simulation environment, a rapid method for modeling a double bypass variable cycle engine using object-oriented modeling technology and modular hierarchical architecture is described. Firstly, the mathematical model of each component is built based on the thermodynamic calculation. Then, a hierarchical engine model is built via the combination of each component mathematical model and the N-R solver module. Finally, the static and dynamic simulations are carried out in the model and the simulation results prove the effectiveness of the modeling method. The VCE model built through this method has the advantages of clear structure and real-time observation.

Here, we present a protocol to build a component-level mathematical model for a variable cycle engine.

The variable cycle engines (VCE) that combine the advantages of turbofan and turbojet engines, are widely considered to be the next generation aircraft ...

Scattering And Absorption of Light in Planetary Regoliths

Theoretical, numerical, and experimental methods are presented for multiple scattering of light in macroscopic discrete random media of densely-packed microscopic particles. The theoretical and numerical methods constitute a framework of Radiative Transfer with Reciprocal Transactions (R2T2). The R2T2 framework entails Monte Carlo order-of-scattering tracing of interactions in the frequency space, assuming that the fundamental scatterers and absorbers are wavelength-scale volume elements composed of large numbers of randomly distributed particles. The discrete random media are fully packed with the volume elements. For spherical and nonspherical particles, the interactions within the volume elements are computed exactly using the Superposition T-Matrix Method (STMM) and the Volume Integral Equation Method (VIEM), respectively. For both particle types, the interactions between different volume elements are computed exactly using the STMM. As the tracing takes place within the discrete random media, incoherent electromagnetic fields are utilized, that is, the coherent field of the volume elements is removed from the interactions. The experimental methods are based on acoustic levitation of the samples for non-contact, non-destructive scattering measurements. The levitation entails full ultrasonic control of the sample position and orientation, that is, six degrees of freedom. The light source is a laser-driven white-light source with a monochromator and polarizer. The detector is a mini-photomultiplier tube on a rotating wheel, equipped with polarizers. The R2T2 is validated using measurements for a mm-scale spherical sample of densely-packed spherical silica particles. After validation, the methods are applied to interpret astronomical observations for asteroid (4) Vesta and comet 67P/Churyumov-Gerasimenko (Figure 1) recently visited by the NASA Dawn mission and the ESA Rosetta mission, respectively.

Numerical and experimental methods are presented for multiple scattering of light in discrete random media of densely-packed particles. The methods are utilized to interpret the observations of asteroid (4) Vesta and comet 67P/Churyumov-Gerasimenko.

Theoretical, numerical, and experimental methods are presented for multiple scattering of light in macroscopic discrete random media of densely-packed ...

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

In this work, an easy, low-cost, and widely applicable method was developed to improve the compatibility between the ceramic fillers and the polymer matrix by adding 3-aminopropyltriethoxysilane (KH550) as a coupling agent during the fabrication process of BaTiO3-P(VDF-CTFE) nanocomposites through solution casting. Results show that the use of KH550 can modify the surface of ceramic nanofillers; therefore, good wettability on the ceramic-polymer interface was achieved, and the enhanced energy storage performances were obtained by a suitable amount of the coupling agent. This method can be used to prepare flexible composites, which is highly desirable for the production of high-performance film capacitors. If an excessive amount of coupling agent is used in the process, the non-attached coupling agent can participate in complex reactions, which leads to a decrease in dielectric constant and an increase in dielectric loss.

Here, we demonstrate a simple and low-cost solution-casting process to improve the compatibility between the filler and the matrix of polymer-based nanocomposites using surface modified BaTiO3 fillers, which can effectively enhance the energy density of the composites.

In this work, an easy, low-cost, and widely applicable method was developed to improve the compatibility between the ceramic fillers and the polymer ...

Interactive and Visualized Online Experimentation System for Engineering Education and Research

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