ZOOM WEBINAR PRESENTATION

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Abstract:  Thin film systems are everywhere: in modern electronics, solar cells, functional and protective coatings, sensors and many more. To develop those complex devices it is necessary to accurately characterize key properties of thin films such as their thickness, density, homogeneity or roughness. In this talk, I will introduce spectroscopic ellipsometry (SE) which is an optical, non-destructive technique that uses reflection of polarized light to study thin films. I will focus, in particular, on how we can use SE to learn about the behavior of ultra-thin polymer films when exposed to various fluids – a topic vital for the development of industrial membranes used for molecular separations (e.g. air separations, natural gas purification or hydrogen production).

Biography:  Wojciech Ogieglo is Research Scientist in the group of Prof. Ingo Pinnau at King Abdullah University of Science and Technology in Kingdom of Saudi Arabia. He received his PhD degree (cum laude) from the University of Twente in the Netherlands in 2014 followed by two postdoctoral fellowships at the University of Twente and DWI Leibniz Institute for Interactive Materials in Germany. He has co-authored over 40 peer-reviewed articles in the field of chemical engineering, physics of thin polymer films, and membrane science and technology. His current research activities deal with thin and ultra-thin composite membranes comprising amorphous microporous materials, such as polymers of intrinsic microporosity and carbon molecular sieves.

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• CONTACTLinda J. Sapolu
• EMAILLinda.Sapolu@kaust.edu.sa

​Abstract:

The mechanics play a crucial role in outlining, determining, and analyzing the structures/schemes for various state-of-the-art technologies including flexible, wearable and stretchable electronic devices. Moreover, it essentially allows us to explore novel paradigms of advanced manufacturing capabilities for electronic materials, especially for inorganic-based. These electronic devices, among others, include the sensors, actuators, energy storage, and harvesting components i.e. piezoelectrics, Li-ion batteries. For tangible and portable electronic products, one of the most challenging tasks is to establish a compliant battery system that would provide the required input energy. This presentation demonstrates how the understanding of pertinent mechanics helps to achieve the high-performance island/interconnect-based stretchable electronic & healthcare devices, as well as energy storage & harvesting devices. The benefits of utilizing the principals of mechanics to explore various materials, propose novel topologies and methods averting mechanical failure during the functioning of these devices will be presented. The numerical calculations using the FEM tool were conducted to understand their working mechanism followed by the fabrication and testing of electronic devices. Lastly, the future outlook in terms of integration and packaging of the above-mentioned devices will be briefly discussed that potentially could help to get the cheap and scalable integrated devices.

Bio:

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• CONTACTEmmanuelle Sougrat

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• CONTACTProf. Tariq Alkhalifah

​Abstract:

Gas turbine engines are an efficient and flexible way of generating electrical power or propelling aircraft. More stringent regulations on pollutant emissions have been imposed to these engines throughout the years, especially in terms of nitrogen oxides (NOx). A very promising combustion technology to reduce NOx emissions and increase efficiency is the lean premixed combustion (LPC). The main drawback of LPC is its intense flame dynamics. Thermoacoustic instabilities, lean blow-off and lean instabilities are examples of such dynamical phenomena that can seriously damage or even lead to failure of gas turbines.

This work investigates the response of lean premixed swirl flames to acoustic perturbations at atmospheric and elevated pressures, for different values of equivalence ratio and various fuels. Understanding this response is a prerequisite for solving problems of thermoacoustic instabilities. For analyzing the flame response to acoustic fluctuations, the flame transfer functions are obtained from the heat release and velocity fluctuations measurements. Moreover, the flow and flame dynamics are analyzed for relevant conditions using phase-locked particle imaging velocimetry, images of the flame chemiluminescence, and planar laser-induced fluorescence of OH radicals. Furthermore, the effects of non-thermal plasma discharges on the lean blow-off and stability limits of premixed swirl flames are discussed at pressure up to 5 bar. To this end, electrical measurements of the plasma discharges and direct imaging of the flames are performed.

The results of these analyses show that the pressure has a strong effect on the flame response to acoustic fluctuations as well as on the flame-plasma interactions. Specifically, increasing the pressure, or changing equivalence ratio and fuel, affects mainly the flame vortex roll-up that is the dominant mechanism controlling the response of swirl flames to acoustic perturbations. Regarding the flame-plasma interactions, it is observed that the non-thermal plasma discharges can efficiently extend the lean blow-off and stability limits to lower equivalence ratios even at elevated pressures, underlining the potential applicability of plasma discharges at conditions relevant for gas turbines.

Link to join Webinar:

https://kaust.zoom.us/j/517528517

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• CONTACTEmmanuelle Sougrat

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• EMAILProfessor Volker Vahrenkamp

​Abstract: Ion transport is ubiquitous in aqueous environments in biological, geological, chemical and environmental systems. Electrokinetics plays a very important and key role in some special cases where pore size is comparable to the screening length of electrical double layer. The applications include tight oil/gas exploration and development, radiative waste disposal, high-quality water purification, and even ion channels in cells. This talk will present (1) electrokinetic and interface theories for ion transport in micro/nanoporous media; (2) a mesoscopic numerical framework for predictions and the validations by comparisons with theories and experimental data; (3) multiscale analysis in both spacial and temporal scales for special applications.

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• CONTACTProf. Shuyu Sun