ILTPC Newsletter 13
3 May 2021
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Table of Contents
- Call for contributions
- Images
- Invited LTP perspectives
- Leaders of the LTP Community
- General interest announcements
- Meetings and online seminars
- Community initiatives and special issues
- Research highlights and breakthroughs
- New resources
- Career opportunities
- Collaborative opportunities
Call for Contributions
Please submit content for the next issue of the Newsletter. Please send your contributions to iltpc-central@umich.edu by May 30, 2021. Please send contributions as MS-Word files if possible – and avoid sending contributions as PDF files.
In particular, please send Research Highlights and Breakthroughs using this template. The highlight consists of an image and up to 200 words of text; please also send your image as a separate file (the recommended image format is JPG or PNG; the minimum file width is 800 px). The topic can be anything you want - a recently published work, a new unpublished result, a proposed new area of research, company successes, anything LTP-related. Please see the Research highlights and breakthroughs for examples.
Images to Excite and Inspire!
Thank you for submitting your images, some of which are shown here. Those images already submitted will appear in later Newsletters. Please do send your images (with a short description or source) to iltpc-central@umich.edu. The recommended image format is JPG or PNG; the minimum file width is 800 px.
(Click the image to enlarge.)
Prof. John E. Foster and Dr. Yao Kovach, University of Michigan, jefoster@umich.edu, yaok@umich.edu. https://iopscience.iop.org/article/10.1088/1361-6595/abc815/meta.
Invited LTP Perspectives: Policy, Opportunities, Challenges
Contributing to Change in the Low Temperature Plasma Community
What motivates you to study plasmas? Perhaps you are passionate about solving global energy problems and think that LTPs provide solutions through materials synthesis, or catalysis? Perhaps you see the immense promise of plasma-liquid/air/surface interactions for purification and sterilization? No matter the reason, the best way to discover, innovate, and create global change is to leverage the intellect and creativity of the most talented individuals you have access to.
By now, you probably know that this means including people from every possible background and identity - increasing diversity means accessing a broader range of perspectives, raising the potential for groundbreaking discoveries. This is why increasing diversity in the LTP research community is so important. And it’s also why it cannot be left to other people alone to increase diversity or improve equity and inclusion (DEI) in our community – you have a stake in this endeavor. You don’t have to dedicate your whole career to DEI. Just making a few – or even one – small contribution can have ripple effects that work to everyone’s benefit. Consider trying one or two of the following suggestions:
- Speak to young people: When planning your outreach and education efforts, include events at high schools or for first- and second-year college students. As education level goes up, participation from women, students of color, and other sectors of diversity declines. As LTPs are fascinating and engaging, outreach at pre-graduate school levels can help entrain individuals from these groups to join the field.
- Become an ally: Speak up when you see or hear inappropriate behaviors or comments, even if you aren’t the target. Maybe it’s a joke uttered at an informal gathering, maybe it’s a comment at a faculty meeting, or maybe it’s gendered language in the notes of a computational code. These little moments have a big impact on whether people feel welcome in a community.
- Be a sponsor: When considering nominations for awards or recognition, make sure you consider colleagues and students from underrepresented groups. They may not have the spotlight as much as individuals from better-represented sectors, but their contributions are just as valuable, so help them share some of that spotlight.
- Welcome newcomers: At meetings and conferences, be as welcoming as possible by focusing on the science, not on the person. When asking a question, be kind. You probably remember your first research conference and how terrifying the Q&A can be. Remember that feeling when you pose your own questions.
- Honor codes of conduct: Develop, implement, and remind people of codes of conduct at meetings and events. Many larger-scale conferences already have codes of conduct, but they can be implemented at faculty meetings and in courses, too. Simply referring to these codes at the start of a meeting can influence behaviors that make it more welcoming.
Prof. Rebecca Anthony Michigan State University, USA, ranthony@msu.edu Prof. Scott Baalrud University of Michigan, USA, baalrud@umich.edu
Leaders of the LTP Community: Career Profiles
Professor Kunihide Tachibana – From Swarms and Microplasmas to Societal Leader
Professor Kunihide Tachibana, who is now Professor Emeritus of Kyoto University (KU) and Osaka Electro-Communication University (OECU), has given us a career rich in research activities and educational experiences. The footprints of his impact are evident not only at KU and OEUC but also at the Kyoto Institute of Technology and Ehime University. Among our international colleagues, he is recognized as an intellectual leader from his participation and leadership of a number of international conferences and societies. This is especially true of the International Plasma Chemistry Society (IPCS), where he served as a president and established the archives of International Symposium on Plasma Chemistry (ISPC). Prof. Tachibana was also a co-founder of the International Workshop on Microplasmas (IWM), while also hosting the inaugural meeting (2003) in Japan. His service to the scientific community in Japan has been hugely impactful. Establishing the Division of Plasma Electronics in the Japan Society of Applied Physics in 1990 was one of Prof. Tachibana’s prominent achievements. In the latter part of his tenure as president of OECU, he devoted his efforts to developing a new educational methodology for realizing his concept of active learning through four steps: Opportunity → Experience → Capability → Utility.
At the beginning of his research activities in the 1970s and 1980s, Prof. Tachibana provided us with the fundamental parameters of electron-neutral collisions obtained by using electron swarm-experiments. He started in this field following collaborations with Prof. A. V. Phelps at his laboratory at JILA (Joint Institute for Laboratory Astrophysics) at the University of Colorado. Prof. Tachibana’s research area expanded to cover plasma chemistry to provide fundamental understanding of plasma material processing (PECVD, RIE, etc.). He and his colleagues and students developed techniques to measure reactive species in these systems utilizing in-situ optical (from the VUV to microwave) and mass spectroscopic diagnostics. Another notable achievement was his observation of Coulomb-crystal formation in dust-growing plasmas by Mie-scattering ellipsometry. For five years from 2003, Prof. Tachibana conducted a collaborative project in Japan (informally called the Tachibana School) to create the new field of micro-plasmas, i.e., small-scale low-temperature plasmas (LTPs) in high-pressure or high-density media.
Prof. Tachibana is an excellent experimentalist and could often be found performing experiments in his laboratories with his students. (Tachibana-sensei is well known as being a very good teacher in experimental techniques). As a lifelong experimentalist, he continued to perform experiments into his 70’s with his own handmade apparatuses. After his full retirement, he continues to apply his experimental expertise to vegetable farming and new methods of preparing those vegetables. Another astonishing fact for us is his excellent memory of his fruitful interactions with his many friends and acquaintances in LTP society. When we return to meetings after the pandemic, we encourage you to seek out Prof. Tachibana, a lifelong experimentalist, to discuss your research and learn of the impact of his many contributions.
Prof. Osamu Sakai University of Shiga Prefecture, Japan, sakai.o@e.usp.ac.jp Prof. Keiichiro Urabe Kyoto University, Japan, urabe.keiichiro.3x@kyoto-u.ac.jp
General Interest Announcements
Plasma Hack Week Organized by the PlasmaPy Project
PlasmaPy is a collection of computational tools and functionality commonly used and shared between plasma physicists and researchers globally, running within and leveraging the open source scientific Python ecosystem. As part of the outreach for the PlasmaPy Project, we announce the Plasma Hack Week.
The inaugural Plasma Hack Week will be held remotely from June 28 – July 2, 2021. A hack week is a mixture of a hackathon (where coders meet and work on programming together for an extended period) and a summer school. Tutorials will be held on topics such as Python, git & GitHub, contributing to an open source project, and writing clean scientific software.
The Plasma Hack Week itself will have both structured learning activities such as tutorials as well as unstructured project time. This week will be a chance to:
- Learn how to contribute to an open source project
- Learn new software development skills with peers
- Network with fellow plasma students and researchers who are engaging in software development
- Meet fellow students and scientists who are engaging in programming
- Collaborate on adding a new feature to an existing software project
- Add tests and/or documentation to an existing package; and/or
- Write use cases and user stories to support software projects
Please see https://hack.plasmapy.org to learn more about the PlasmaPy project, Plasma Hack Week and to register for the free event!
Contact: Prof. David Schaffner Bryn Mawr College, USA dschaffner@brynmawr.edu
National Science Foundation Engineering Research Visioning Alliance
The U.S. National Science Foundation (NSF) announces the launch of the Engineering Research Visioning Alliance (ERVA), a new organization that will convene the engineering community to identify important engineering research challenges and opportunities. “Engineering has the power to transform people’s lives, especially when it brings to bear a diversity of knowledge, perspectives, and experience to solve important problems,” says NSF Assistant Director for Engineering Dawn Tilbury. “With NSF’s support, the Engineering Research Visioning Alliance will enable the engineering community to mobilize and make a difference in our country’s future.”
ERVA will obtain and integrate input on nascent opportunities and priorities in fundamental engineering research. ERVA will engage the engineering research community, including people and organizations in academia, government and industry, as well as professional organizations and the interested public. Building on community ideas, ERVA will share compelling visions for future engineering research to address national needs and societal challenges, leading to positive impacts on people’s lives.
The engineering community can get involved with ERVA and learn about its upcoming visioning activities at https://www.ervacommunity.org/.
Meetings and Online Seminars
Online LTP Seminar (OLTP)
The Online Low Temperature Plasma (OLTP) Seminar series schedule for January – June 2021 has been updated. The next seminars will be presented by Dr. Gerjan Hagelaar (May 11, 2021); Dr. Jean-Paul Booth (May 25, 2021); and Prof. David Graves and Dr. Malcolm Carroll (June 8, 2021).
International Online Plasma Seminar (IOPS)
The International Online Plasma Seminar (IOPS) is a non-profit international seminar on low temperature plasma science with bi-weekly sessions via Zoom. The main purpose of the seminar is to make high quality research results in low temperature plasma science available to our community to foster scientific discussion. Based on the speaker’s written consent, presentations will be recorded and will be made available for on-demand download. IOPS speakers can be nominated by anybody and are selected by the IOPS committee. The program for IOPS is available here. Nominations for speakers for the July – December 2021 can also be made from this page.
The next seminars will be given by Dr. Dirk Hegemann (May 6, 2021); Brayden Myers and Tat Loon Chng (May 20, 2021); and Dr. Matt Hopkins (June 6, 2021).
To attend IOPS, use this Zoom link.
Community Initiatives and Special Issues
Submit your announcement for Community Initiatives and Special Issues to iltpc-central@umich.edu.
Research Highlights and Breakthroughs
Interim Report on Plasma Catalysis: Footprints in the Past and Blueprints for the Future
Interactions at the interface of the plasma and catalyst surface have the potential to open new chemical pathways that have never been realized with conventional plasma alone or catalyst-only processes. Plasma catalysis is now facing a rapid growth phase after a long, gradual period of growth over several decades. This interim report aims to analyze the progress of plasma catalysis over the last two decades and provide future challenges.
The first part of the report addresses five important matching issues for plasma and one for catalyst. We collectively present experimental evidence in the literature that underpins the interaction of plasma with a catalyst. We also emphasize synergy, which is sometimes not appreciated by neglecting the heating that occurs with high energy input. In the second part, we discuss recent achievements. A review of the historical development of plasma reactors from a packed-bed to a honeycomb discharge, which are suitable for large-scale applications, is provided.
In the final part, blueprints for future challenges are presented based on the experimentally observed evidence from macro- to nano- and atomic-scale measurements. Developing effective catalysts capable of utilizing vibrationally excited hot molecules will be key for forthcoming innovations in plasma catalysis. We also underline the importance of implementing new sets of materials by introducing recent notable examples in conventional catalysis.
Contact: Dr. Hyun-Ha Kim National Institute of Advanced Industrial Science and Technology (AIST), Japan hyun-ha.kim@aist.go.jp
Source: Int. J. Plasma Environ. Sci. Technol. 15, e01004 (2021).
The Effect of Packing Material Properties on Tars Removal by Plasma Catalysis
Plasma catalysis has been utilized in many environmental applications for removal of various hydrocarbons including tars. The aim of this work was to study the tars removal process by atmospheric pressure DBD non-thermal plasma generated in combination with packing materials of various composition and catalytic activity (TiO2, Pt/Al2O3, BaTiO3, Al2O3, ZrO2, glass beads), dielectric constant (5–4000), shape (spherical and cylindrical pellets and beads), size (3–5 mm in diameter, 3–8 mm in length), and specific surface area (37–150 m2/g). Naphthalene was chosen as a model tar compound. The experiments were performed at a temperature of 100°C and a naphthalene initial concentration of approx. 3000 ppm, i.e., under conditions that are usually less favorable to achieve high removal efficiencies. For a given specific input energy of 320 J/L, naphthalene removal efficiency followed a sequence: TiO2 > Pt/Al2O3 > ZrO2 > Al2O3 > glass beads > Ba-TiO3 > plasma only. The efficiency increased with the increasing specific surface area of a given packing material, while its shape and size were also found to be important. By-products of naphthalene decomposition were analyzed by means of FTIR spectrometry and surface of packing materials by SEM analysis.
Contact: Dr. Karol Hensel Comenius University, Slovakia hensel@fmph.uniba.sk
Source: Catalysts 10 (12), 1476 (2020).
Oxidative Damage to Hyaluronan–CD44 Interactions as an Underlying Mechanism of Action of Oxidative Stress-inducing Cancer Therapy
Multiple cancer therapies, including non-thermal plasma (NTP), rely on oxidative stress to damage cancer cells. In this study, we investigated the biological and molecular effects of oxidative stress on the interaction between the cell adhesion receptor CD44 and hyaluronan (HA), as interrupting their binding can hinder cancer progression.
Our experiments demonstrated that following NTP treatment, HA oxidized and decreased its recognition by CD44. This effect was further enhanced when both CD44 and HA were oxidized. The reduction of CD44–HA binding negatively affected the proliferative state of three cancer cell lines (U87-MG, A375 and HT29).
Our multi-level atomistic simulations revealed that the binding free energy of HA to CD44 decreased upon oxidation by NTP treatment. The effect of HA and CD44 oxidation on CD44–HA binding was similar, but when both HA and CD44 were oxidized, the effect was much larger, in agreement with our experiments. Our experiments and computations support our hypothesis on the role of oxidation (such as produced by NTP) in the disturbance of CD44–HA interaction, which can lead to the inhibition of proliferative signaling pathways inside the tumor cell to induce cell death.
Contacts: Dr. Angela Privat-Maldonado Universiteit Antwerpen, Belgium angela.privatmaldonado@uantwerpen.be Dr. Maksudbek Yusupov Universiteit Antwerpen, Belgium maksudbek.yusupov@uantwerpen.be
Source: Redox Biol. 43, 101968 (2021).
Absolute OH Radical Density Measurements in a Plasma-filled Vapor Bubble in Liquid Water
Electrical discharges in bubbles in liquid water have been extensively investigated for many applications including water treatment. Often the OH radical is as-sumed to be a key enabler of many applications alt-hough direct measurements of OH radicals in bubbles remained elusive.
Researchers at the University of Minnesota used laser induced fluorescence (LIF) to measure OH radical densities and gas temperatures in a microsecond pulsed discharge generated in a water vapor bubble in a Hele-Shaw cell. The millimeter sized plasma-filled vapor bubble enabled probing by a laser beam and flu-orescence signal could be collected during a signifi-cant part of the discharge period and coinciding bubble dynamics.
The high collisional conditions and strong collisional quenching of the laser-pumped level made the abso-lute calibration and gas temperature measurement ex-ceptionally challenging. A rotational level resolved LIF model, capturing the highly non-equilibrium rota-tional population distributions of the laser excited rota-tional manifold enabled us to analyze the LIF data and obtain accurate gas temperatures and OH densities. The results show that the gas temperature in the bubble has a maximum value of 4900 ± 800 K and the abso-lute OH density reaches a value of 3.2 ± 0.5×1017 cm-3 corresponding to an OH mole fraction of more than 20%. The obtained OH radical densities are consistent with a thermal dissociation model of H2O in the vapor bubble.
Contact: Prof. Peter Bruggeman University of Minnesota, USA pbruggem@umn.edu
New Resources
Submit your announcement for New Resources to iltpc-central@umich.edu.
Career Opportunities
PhD Position, Methane Upgrading by Ultra-Fast Plasma Pyrolysis, Maastricht University (The Netherlands)
We seek PhD candidates to work on methane upgrading using fast-pulsed microwave generated plasma. The research will be primarily by experimental – the candidate will perform product gas analysis combined with state-of-the art laser diagnostics to develop a comprehensive understanding of the underlying physical and chemical processes occurring in the plasma.
Project description:
The chemical industry urgently needs to cut its CO2 emissions. Electrification will reduce emissions from processes by powering them with renewable electricity in place of fossil fuels. Circular processes will reuse valuable resources (e. g. plastics), and in doing so will cut end-of-life emissions and reduce resource depletion rates. We research novel plasma technologies to facilitate both electrification and circular processes for the chemical industry. In future, industry expects to have an environmentally sustainable source of methane, which can be most effectively valorised via upgrading to ethylene; a crucial feedstock in the production of plastics. However, methane-to-ethylene conversion is notoriously difficult, as it a strongly endothermic reaction with highly complex chemistry. Thermal plasma technology is a promising approach for methane to ethylene conversion as it allows the possibility for high efficiency, excellent reactant conversion, and refined product selectivity.
In this project, we use microwave generated plasma to induce ultra-fast heating and quenching of methane and its reaction products, at rates around 106 – 108 K/s. With such ultra-fast heating and quenching, we can induce thermal decomposition of methane and freeze the reaction products before further chemistry has time to occur. There is a short window of opportunity where highly selective conversion of methane to ethylene should be possible. In this project we will evaluate this window of opportunity – this requires temporally and spatially resolved in-situ measurements, a task which is ideally suited to laser diagnostics. We will assess the chemistry occurring within the plasma, from which we will determine – is it possible to selectively produce ethylene by ultra-fast thermal plasma processing of methane?
The PhD position will mainly focus on engineering and studying on-chip micro-plasmas by fast imaging methods, spectroscopy techniques and modelling. The student will work in close cooperation with world leading team of Photonics from Ghent University. We are looking for candidates with a MSc degree in electrical engineering or applied physics. A good background in photonics or plasma physics, spectroscopy, or good experimental skills are desirable. The PhD student will be able to gain experience in areas such as chip design, clean room processing, plasma physics, plasma generation, optical imaging, and UV spectroscopy.
For more information and to apply for the position, contact: Prof. Tom Butterworth t.butterworth@maastrichtuniversity.nl Prof. Gerard van Rooij g.vanrooij@maastrichtuniversity.nl Maastricht University, The Netherlands
Research Associate, Modeling and Simulation of the Impedance Probe in Technical Plasmas, University of Applied Science (Soest, Germany)
The South Westphalia University of Applied Science offers a Research Associate position for the project “The impedance probe: a possible industry compatible diagnostic tool in metallic depositing plasmas“ in the department of Electrical Power Engineering at the campus in Soest, Germany to be filled as soon as possible.
Typical tasks:
- Research and coordination of the project on the Impedance Probe
- Modeling and simulation of the interaction between the impedance probe and the plasma
- Support in project acquisition and proposals
- Publication of results in journal paper and conference contributions
- Documentation of the project via reports
Essential characteristics:
- Above-average completed university degree, especially in the fields of computational engineer-ing or science, electrical engineering, plasma science physics, mathematics, or similar.
- Very good knowledge in plasma physics and/or technical plasmas as well as simulation of electromagnetic fields (ideally in CST).
- Programming experience in at least one language (C/C++, Python, or similar) is expected, knowledge in parallelization is an advantage.
- A high level of proficiency in English language (written and spoken) and a structured and self-organized way of working is expected. Knowledge of German is an asset.
- Further knowledge in kinetic theory, functional analytic methods, and/or solving of large linear systems of equations is an advantage.
Contract conditions:
The full-time position in salary group EG TV-L 13 (100%) is offered for a period of three years. The opportunity for further personal qualification (PhD) is available.
Please apply with the usual documents and a research motivation of 2 pages DIN A4 letter with the keyword 18/2021 only via the online application page until May 31, 2021.
For information and application details, contact: Prof. Dr.-Ing. Jens Oberrath oberrath.jens@fh-swf.de
Collaborative Opportunities
Please submit your notices for collaborative opportunities to iltpc-central@umich.edu.
Disclaimer
The content of this Newsletter comes from the contributions of members of the ILTPC. The Newsletter editors are attempting to provide as inclusive a communication as possible. However, inclusion of items in the Newsletter should not be interpreted as an endorsement by the editors nor as advertisement for commercial purposes. The content of this newsletter should also not be interpreted as an endorsement by our sponsors – the US National Science Foundation, the US Department of Energy, or the University of Michigan. The Newsletter editors may do some light editing of the original submissions, to maintain a consistent tone and style.