Timothy Lieuwen has been appointed interim executive vice president for Research (EVPR) by Georgia Tech President Ángel Cabrera, effective September 10. 

Lieuwen is a Regents’ Professor, the David S. Lewis, Jr. Chair in the Daniel Guggenheim School of Aerospace Engineering, and executive director of the Strategic Energy Institute. His research interests range from clean energy and propulsion systems to energy policy, national security, and regional economic development. He works closely with industry and government to address fundamental problems and identify solutions in the development of clean energy systems and alternative fuels. 

A proud Georgia Tech alumnus, Lieuwen (M.S. ME 1997, Ph.D. ME 1999) has had a remarkable academic career. He is a member of the National Academy of Engineering and is a fellow of the American Society of Mechanical Engineers, the American Institute of Aeronautics and Astronautics, the American Physical Society, the Combustion Institute, and the Indian National Academy of Engineering (foreign fellow). He has received numerous awards, including the ASME George Westinghouse Gold Medal and the AIAA Pendray Award. He serves on governing or advisory boards of three Department of Energy national labs: Oak Ridge National Laboratory, Pacific Northwest National Laboratory, and the National Renewable Energy Laboratory and was appointed by the U.S. Secretary of Energy to the National Petroleum Council. 

Lieuwen has authored or edited four books on combustion and over 400 scientific publications. He also holds nine patents, several of which are licensed to industry, and is founder of an energy analytics company, Turbine Logic, where he acts as chief technology officer.

In Lieuwen’s appointment announcement, President Cabrera said, “Tim’s extensive experience and knowledge of Georgia Tech makes him uniquely suited to lead our research enterprise as we search for a permanent EVPR. I am grateful for his willingness to serve the Institute during this period of remarkable growth, and I look forward to working with him and the rest of the team.”

From keeping warm in the winter to doing laundry, heat is crucial to daily life. But as the world grapples with climate change, buildings’ increasing energy consumption is a critical problem. Currently, heat is produced by burning fossil fuels like coal, oil, and gas, but that will need to change as the world shifts to clean energy. 

Georgia Tech researchers in the George W. Woodruff School of Mechanical Engineering (ME) are developing more efficient heating systems that don’t rely on fossil fuels. They demonstrated that combining two commonly found salts could help store clean energy as heat; this can be used for heating buildings or integrated with a heat pump for cooling buildings.

The researchers presented their research in “Thermochemical Energy Storage Using Salt Mixtures With Improved Hydration Kinetics and Cycling Stability,” in the Journal of Energy Storage.

Reaction Redux 

The fundamental mechanics of heat storage are simple and can be achieved through many methods. A basic reversible chemical reaction is the foundation for their approach: A forward reaction absorbs heat and then stores it, while a reverse reaction releases the heat, enabling a building to use it.

ME Assistant Professor Akanksha Menon has been interested in thermal energy storage since she began working on her Ph.D.  When she arrived at Georgia Tech and started the Water-Energy Research Lab (WERL), she became involved in not only developing storage technology and materials but also figuring out how to integrate them within a building. She thought understanding the fundamental material challenges could translate into creating better storage.

“I realized there are so many things that we don't understand, at a scientific level, about how these thermo-chemical materials work between the forward and reverse reactions,” she said.

The Superior Salt

The reactions Menon works with use salt. Each salt molecule can hold a certain number of water molecules within its structure. To instigate the chemical reaction, the researchers dehydrate the salt with heat, so it expels water vapor as a gas. To reverse the reaction, they hydrate the salt with water, forcing the salt structure’s expansion to accommodate those water molecules. 

It sounds like a simple process, but as this expansion/contraction process happens, the salt gets more stressed and will eventually mechanically fail, the same way lithium-ion batteries only have so many charge-discharge cycles. 

“You can start with something that's a nice spherical particle, but after it goes through a few of these dehydration-hydration cycles, it just breaks apart into tiny particles and completely pulverizes or it overhydrates and agglomerates into a block,” Menon explained. 

These changes aren’t necessarily catastrophic, but they do make the salt ineffective for long-term heat storage as the storage capacity decreases over time. 

Menon and her student, Erik Barbosa, a Ph.D. student in ME, began combining salts that react with water in different ways. After testing six salts over two years, they found two that complemented each other well. Magnesium chloride often fails because it absorbs too much water, whereas strontium chloride is very slow to hydrate. Together, their respective limitations can mutually benefit each other and lead to improved heat storage.

“We didn't plan to mix salts; it was just one of the experiments we tried,” Menon said. “Then we saw this interactive behavior and spent a whole year trying to understand why this was happening and if it was something we could generalize to use for thermal energy storage.”

The Energy Storage of the Future

Menon is just beginning with this research, which was supported by a National Science Foundation (NSF) CAREER Award. Her next step is developing the structures capable of containing these salts for heat storage, which is the focus of an Energy Earthshots project funded by the U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences.

A system-level demonstration is also planned, where one solution is filling a drum with salts in a packed bed reactor. Then hot air would flow across the salts, dehydrating them and effectively charging the drum like a battery. To release that stored energy, humid air would be blown over the salts to rehydrate the crystals. The subsequently released heat can be used in a building instead of fossil fuels. While initiating the reaction needs electricity, this could come from off-peak (excess renewable electricity) and the stored thermal energy could be deployed at peak times. This is the focus of another ongoing project in the lab that is funded by the DOE’s  Building Technologies Office.

Ultimately, this technology could lead to climate-friendly energy solutions. Plus, unlike many alternatives like lithium batteries, salt is a widely available and cost-effective material, meaning its implementation could be swift. Salt-based thermal energy storage can help reduce carbon emissions, a vital strategy in the fight against climate change.

“Our research spans the range from fundamental science to applied engineering thanks to funding from the NSF and DOE,” Menon said. “This positions Georgia Tech to make a significant impact toward decarbonizing heat and enabling a renewable future.”

This partnership in the advancement of AI and mathematical optimization to address pressing energy transformations in Latin America and the U.S. has formed between the NSF Artificial Intelligence (AI) Research Institute for Advances in Optimization (AI4OPT) at Georgia Tech and PSR, Inc. - Energy Consulting and Analytics. 

PSR is a global leader in analytical solutions for the energy sector, providing innovative technical consultancy services and state-of-the-art power systems planning software. Their tools are used for detailed modeling of entire countries or regions and are utilized in over 70 countries. Together with AI4OPT, they aim to leverage advancements in AI and mathematical optimization to address pressing energy transformations in Latin America and the U.S.

Latin America boasts abundant renewable energy resources, especially hydropower, leading to one of the largest shares of renewables in its energy mix. However, expanding renewable energy capacity in Latin America and the U.S. to meet decarbonization goals will require system operational advances and new technologies that can adapt to current needs.

One focus of this collaboration will be studying how to efficiently incorporate pumped storage into the resource mix as a solution for long-duration storage. These plants act as large batteries, pumping water to higher reservoirs during low demand periods and generating electricity during high demand with minimal energy loss over time. This technology supports both short-term and long-term energy storage, making it crucial for managing the variability of intermittent renewables like solar and wind.

The complex and large-scale nature of the expansion problem, exacerbated by inherent uncertainty and time-coupled decisions, traditionally requires sophisticated optimization techniques. AI innovations now provide faster solutions and better representations of non-linear dynamics, leading to more cost-effective operations and optimized energy mix selection for the energy transition.

This collaboration plans to use machine learning to enhance power system operators' ability to perform faster security checks and screenings. As renewable energy sources introduce more variability, traditional methods struggle with the increasing number of scenarios needed for grid stability. Machine learning offers a solution by expediting these analyses, supporting the integration of more renewable energy into the system.

About PSR

PSR is a global provider of analytical solutions for the energy sector, spanning from insightful and innovative technical consultancy services to state-of-the-art specialized power systems planning software applied to the detailed modelling of entire countries or regions. Having its products applied in over 70 countries, PSR contributes to the research and development of optimization and data analytics’ tools for guaranteeing a reliable and least-cost operation of power systems, helping the countries achieve their decarbonization targets.

About AI4OPT

The Artificial Intelligence (AI) Research Institute for Advances in Optimization, or AI4OPT, aims to deliver a paradigm shift in automated decision-making at massive scales by fusing AI and Mathematical Optimization (MO) to achieve breakthroughs that neither field can achieve independently. The Institute is driven by societal challenges in energy, logistics and supply chains, resilience and sustainability, and circuit design and control. To address the widening gap in job opportunities, the Institute delivers an innovative longitudinal education and workforce development program.

Georgia Tech will lead a consortium of 12 universities and 12 national labs as part of a $25 million U.S. Department of Energy National Nuclear Security Administration (NNSA) award. This is the second time Georgia Tech has won this award and led research and development efforts to aid NNSA’s nonproliferation, nuclear science, and security endeavors.

The Consortium for Enabling Technologies and Innovation (ETI) 2.0 will leverage the strong foundation of interdisciplinary, collaboration-driven technological innovation developed in the ETI Consortium funded in 2019. The technical mission of the ETI 2.0 team is to advance technologies across three core disciplines: data science and digital technologies in nuclear security and nonproliferation, precision environmental analysis for enhanced nuclear nonproliferation vigilance and emergency response, and emerging technologies. They will be advanced by research projects in novel radiation detectors, algorithms, testbeds, and digital twins.

“What we're trying to do is bring those emergent technologies that are not implemented right now to fruition,” said Anna Erickson, Woodruff Professor and associate chair for research in the George W. Woodruff School of Mechanical Engineering, who leads both grants. “We want to understand what's ahead in the future for both the technology and the threats, which will help us determine how we can address it today.” 

While half the original collaborators remain, Erickson sought new institutional partners for their research expertise, including Abilene Christian University, University of Alaska Fairbanks, Stony Brook University, Rensselaer Polytechnic Institute, and Virginia Commonwealth University. Other university collaborators include the Colorado School of Mines, the Massachusetts Institute of Technology, Ohio State University, Texas A&M University, the University of Texas at Austin, and the University of Wisconsin–Madison.  

National lab partners are the Argonne National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Nevada National Security Site, Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Princeton Plasma Physics Laboratory, Sandia National Laboratories, and Savannah River National Laboratory.

The partners, along with the other NNSA Consortia, gathered at Texas A&M in June to present the new results of the research — NNSA DNN R&D University Program Review — and the kickoff will be hosted in Atlanta in February 2025. More than 300 collaborators, including 150 students, met for four days to share their research and develop new partnerships. 

Engaging students in research in the nuclear nonproliferation field is a key part of the award. The plan is to train over 50 graduate students, provide internships for graduate and undergraduate students, and offer faculty-student lab visit fellowships. This pipeline aims to develop well-rounded professionals equipped with the expertise to tackle future nonproliferation challenges.

“Because nuclear proliferation is a multifaceted problem, we try to bring together people from outside nuclear engineering to have a conversation about the problems and solutions,” Erickson said.

“One of the biggest accomplishments of ETI 1.0 is this incredible relationship that our university PIs have been able to forge with national labs,” she said. “Over five years, we've supported over 70 student internships at national labs, and we have already transitioned a number of Ph.D. students to careers at national labs.” 

As the consortium efforts continue, the team looks forward to the next phase of engagement with government, university, and national lab partners.

“With a united team and a focus on cutting-edge technologies, the ETI 2.0 consortium is poised to break new ground in nuclear nonproliferation,” Erickson said. “Collaboration is the fuel, and innovation is the engine.”

Nine early-career professors will pursue cutting-edge climate mitigation research during the upcoming year as part of the Seed Grant Challenge for Climate Solutions created by the Strategic Energy Institute (SEI) and the Brook Byers Institute for Sustainable Systems (BBISS). 

Launched in April during the Frontiers in Science: Climate Action Conference and Symposium, the Challenge “provides seed funding for climate mitigation and adaptation research led by ambitious early-career faculty eager to work across disciplines,” explains Beril Toktay, Regents’ Professor and interim executive director of BBISS. 

One goal of the Challenge is to facilitate research collaboration across the Institute. “Transitioning to a sustainable, clean energy system requires concerted collaboration across diverse disciplines,” says Tim Lieuwen, Regents’ Professor, David S. Lewis, Jr. Chair, and executive director of SEI. “Initiatives like this are instrumental in paving the way for such groundbreaking interdisciplinary work.” 

The four selected proposals include researchers from five different schools and two centers, and will investigate biodiversity, coral reef resilience, lithium-ion battery recycling, and coastal resilience. “I am pleased with the range of proposals submitted by our assistant professors,” adds Susan Lozier, dean of the College of Sciences and Betsy Middleton and John Clark Sutherland Chair and professor in the School of Earth and Atmospheric Sciences. “Each proposal represents an opportunity to combine expertise from across the Institute to deepen our understanding of climate challenges and uncover possible solutions.”

Each of the following projects will receive a $15,000 seed grant to be used during the 2025 fiscal year:

Climate Solutions in the Most Biodiverse Regions on Earth: Testing Whether Warming Temperatures have set in Motion an “Escalator to Survival” in Tropical Rainforests

• Benjamin Freeman, assistant professor in the School of Biological Sciences
• James Stroud, assistant professor in the School of Biological Sciences
• Saad Bhamla, assistant professor in the School of Chemical and Biomolecular Engineering
• Amirali Aghazadeh, assistant professor in the School of Electrical and Computer Engineering

The research team seeks to test the “escalator to survival” concept, which theorizes that lowland tropical species will only be able to persist in the face of rising temperatures if they are able to shift their ranges to nearby foothills and mountains, where temperatures remain cooler. 

Macro- and Microscale Drivers of Coral Reef Resilience in a Changing Climate

• Isaiah W. Bolden, assistant professor in the School of Earth and Atmospheric Sciences
• Lauren Speare, assistant professor in the School of Biological Sciences and the Center for Microbial Dynamics and Infection

The research team will develop transformative tools to evaluate reef health and resilience; detect impending compositional changes; determine the capacity for reef regeneration; and elevate mitigation strategies that preserve reef diversity and ecosystem services.

A Workforce and Community-Engaged Team Building Approach for Lithium-Ion Battery Recycling in the U.S. Southeast: Addressing Social and Ecological Implications 

• Joe F. Bozeman III, assistant professor in the School of Civil and Environmental Engineering and the School of Public Policy
• Jennifer Hirsch, senior director of the Center for Sustainable Communities Research and Education

This project will build a transdisciplinary team to determine how to effectively unite community stakeholders, industry, social scientists, and engineers when applying for external grants to establish a U.S. southeastern hub for EV-battery lithium recycling.

Building Coastal Resilience: Science-based Adaptive Solutions to Mitigate Hurricane-Induced Compound Flooding in the Southeast U.S.

• Ali Sarhadi, assistant professor in the School of Earth and Atmospheric Sciences

This project will quantify the risks associated with hurricane-induced compound flooding in a warming climate by developing physics-based hydrodynamic and AI models. The project aims to investigate factors related to geography in climate resilience and develop science-based, cost-effective adaptation strategies through active community engagement in Savannah, Georgia and Jacksonville, Florida.

Chaouki Abdallah, Georgia Tech's executive vice president for Research (EVPR), has been named the new president of the Lebanese American University in Beirut.  

Abdallah, MSECE 1982, Ph.D. ECE 1988, has served as EVPR since 2018; in this role, he led extraordinary growth in Georgia Tech's research enterprise. Through the work of the Georgia Tech Research Institute, 10 interdisciplinary research institutes (IRIs), and a broad portfolio of faculty research, Georgia Tech now stands at No. 17 in the nation in research expenditures — and No. 1 among institutions without a medical school.  

Additionally, Abdallah has also overseen Tech's economic development activities through the Enterprise Innovation Institute and such groundbreaking entrepreneurship programs as CREATE-X, VentureLab, and the Advanced Technology Development Center. 

Under Abdallah's strategic, thoughtful leadership, Georgia Tech strengthened its research partnerships with historically Black colleges and universities, launched the New York Climate Exchange with a focus on accelerating climate change solutions, established an AI Hub to boost research and commercialization in artificial intelligence, advanced biomedical research (including three research awards from ARPA-H), and elevated the Institute's annual impact on Georgia's economy to a record $4.5 billion.  

Prior to Georgia Tech, Abdallah served as the 22nd president of the University of New Mexico (UNM), where he also had been provost, executive vice president of academic affairs, and chair of the electrical and computer engineering department. At UNM, he oversaw long-range academic planning, student success initiatives, and improvements in retention and graduation rates. 

A national search will be conducted for Abdallah's replacement. In the coming weeks, President Ángel Cabrera will name an interim EVPR. 

Georgia’s saltwater marshes — living where the land meets the ocean — stretch along the state’s entire 100-mile coastline. These rich ecosystems are largely dominated by just one plant: grass.

Known as cordgrass, the plant is an ecosystem engineer, providing habitats for wildlife, naturally cleaning water as it moves from inland to the sea, and holding the shoreline together so it doesn’t collapse. Cordgrass even protects human communities from tidal surges.

Understanding how these plants stay healthy is of crucial ecological importance. For example, one known plant stressor prevalent in marsh soils is the dissolved sulfur compound, sulfide, which is produced and consumed by bacteria. But while the Georgia coastline boasts a rich tradition of ecological research, understanding the nuanced ways bacteria interact with plants in these ecosystems has been elusive. Thanks to recent advances in genomic technology, Georgia Tech biologists have begun to reveal never-before-seen ecological processes.

The team’s work was published in Nature Communications. 

Joel Kostka, the Tom and Marie Patton Distinguished Professor and associate chair for Research in the School of Biological Sciences, and Jose Luis Rolando, a postdoctoral fellow, set out to investigate the relationship between the cordgrass Spartina alterniflora and the microbial communities that inhabit their roots, identifying the bacteria and their roles.

“Just like humans have gut microbes that keep us healthy, plants depend on microbes in their tissues for health, immunity, metabolism, and nutrient uptake,” Kostka said. “While we’ve known about the reactions that drive nutrient and carbon cycling in the marsh for a long time, there’s not as much data on the role of microbes in ecosystem functioning.”

Out in the Marsh

A major way that plants get their nutrients is through nitrogen fixation, a process in which bacteria convert nitrogen into a form that plants can use. In marshes, this role has mostly been attributed to heterotrophs, or bacteria that grow and get their energy from organic carbon. Bacteria that consume the plant toxin sulfide are chemoautotrophs, using energy from sulfide oxidation to fuel the uptake of carbon dioxide to make their own organic carbon for growth.

“Through previous work, we knew that Spartina alterniflora has sulfur bacteria in its roots and that there are two types: sulfur-oxidizing bacteria, which use sulfide as an energy source, and sulfate reducers, which respire sulfate and produce sulfide, a known toxin for plants,” Rolando said. “We wanted to know more about the role these different sulfur bacteria play in the nitrogen cycle.”

Kostka and Rolando headed to Sapelo Island, Georgia, where they have regularly conducted fieldwork in the salt marshes. Wading into the marsh, shovels and buckets in hand, the researchers and their students collected cordgrass along with the muddy sediment samples that cling to their roots. Back at the field lab, the team gathered around a basin filled with creek water and carefully washed the grass, gently separating the plant roots.

Next, they used a special technique involving heavier versions of chemical elements that occur in nature as tracers to track the microbial processes. They also analyzed the DNA and RNA of the microbes living in different compartments of the plants.

Using a sequencing technology known as shotgun metagenomics, they were able to retrieve the DNA from the whole microbial community and reconstruct genomes from newly discovered organisms. Similarly, untargeted RNA sequencing of the microbial community allowed them to assess which microbial species and specific functions were active in close association with plant roots.

Using this combination of techniques, they found that chemoautotrophic sulfur-oxidizing bacteria were also involved in nitrogen fixation. Not only did these bacteria help plants by detoxifying the root zone, but they also played a crucial role in providing nitrogen to the plants. This dual role of the bacteria in sulfur cycling and nitrogen fixation highlights their importance in coastal ecosystems and their contribution to plant health and growth.

"Plants growing in areas with high levels of sulfide accumulation tend to be smaller and less healthy," said Rolando. "However, we found that the microbial communities within Spartina roots help to detoxify the sulfide, enhancing plant health and resilience."

Local to Global Significance

Cordgrasses aren’t just the main player in Georgia marshes; they also dominate marsh landscapes across the entire Southeast, including the Carolinas and the Gulf Coast. Moreover, the researchers found that the same bacteria are associated with cordgrass, mangrove, and seagrass roots in coastal ecosystems across the planet.

"Much of the shoreline in tropical and temperate climates is covered by coastal wetlands,” Rolando said. “These areas likely harbor similar microbial symbioses, which means that these interactions impact ecosystem functioning on a global scale."  

Looking ahead, the researchers plan to further explore the details of how marsh plants and microbes exchange nitrogen and carbon, using state-of-the-art microscopy techniques coupled with ultra-high-resolution mass spectrometry to confirm their findings at the single-cell level.

"Science follows technology, and we were excited to use the latest genomic methods to see which types of bacteria were there and active,” Kostka said. “There's still much to learn about the intricate relationships between plants and microbes in coastal ecosystems, and we are beginning to uncover the extent of the microbial complexity that keeps marshes healthy.”

 

Citation: Rolando, J.L., Kolton, M., Song, T. et al. Sulfur oxidation and reduction are coupled to nitrogen fixation in the roots of the salt marsh foundation plant Spartina alterniflora. Nat Commun 15, 3607 (2024).

DOI: https://doi.org/10.1038/s41467-024-47646-1

Funding: This work was supported in part by an institutional grant (NA18OAR4170084) to the Georgia Sea Grant College Program from the National Sea Grant Office, National Oceanic and Atmospheric Administration, US Department of Commerce, and by a grant from the National Science Foundation (DEB 1754756).