Recent Submissions

  • A coupled phase-field and reactive-transport framework for fracture propagation in poroelastic media

    Addassi, Mouadh (2022-11-08) [Poster]
    We present a novel approach to model hydro-chemo-mechanical responses in rock formations subject to fracture propagation within chemically active rock formations.
  • Anatomy of 2D materials based memristors: the role of each type of defect

    Shen, Yaqing (2022-11-07) [Poster]
    In the race of fabricating solid-state nano/micro-electronic devices using two-dimensional (2D) layered materials (LMs), achieving high yield and low device-to-device variability are the two main challenges. Electronic devices that drive currents in-plane along the 2D-LMs (i.e. transistors, memtransistors) are strongly affected by local defects (i.e. grain boundaries, wrinkles, thickness fluctuations, polymer residues), as they create inhomogeneities and increase the device-to-device variability, resulting in a poor performance at the circuit level. Here we show that memristors are insensitive to most types of defects in 2D-LMs, even when fabricated in academic laboratories that do not meet industrial standards. The reason is that the currents produced in these devices, which flow out-of-plane across the 2D-LM, are always driven locally by the most conductive locations. Consequently, we conclude that it is much easier to fabricate 2D-LMs based solid-state nano/micro-electronic circuits using memristors than transistors or memtransistors, not only due to the inherent simpler fabrication process (i.e. less lithography steps), but also because the local defects do not degrade the yield and variability of memristors considerably.
  • Defect-Free Metal Deposition on 2D Materials via Inkjet Printing Technology

    Zheng, Wenwen (2022-11-07) [Poster]
    2D materials have many outstanding properties that make them attractive for the fabrication of electronic devices, such as high conductivity, flexibility, and transparency. However, integrating 2D materials in commercial devices and circuits is challenging because their structure and properties can be damaged during the fabrication process. Recent studies have demonstrated that standard metal deposition techniques (like electron beam evaporation and sputtering) significantly damage the atomic structure of 2D materials. Here it is shown that the deposition of metal via inkjet printing technology does not produce any observable damage in the atomic structure of ultrathin 2D materials, and it can keep a sharp interface. These conclusions are supported by abundant data obtained via atomistic simulations, transmission electron microscopy, nanochemical metrology, and device characterization in a probe station. The results are important for the understanding of inkjet printing technology applied to 2D materials, and they could contribute to the better design and optimization of electronic devices and circuits.
  • Linked nickel oxide/perovskite interface passivation for high-performance textured monolithic tandem solar cells

    Zhumagali, Shynggys (2022-11-07) [Poster]
    Sputtered nickel oxide (NiOx) is an attractive hole-transport layer for efficient, stable, and large-area p-i-n metal-halide perovskite solar cells (PSCs). However, surface traps and undesirable chemical reactions at the NiOx/perovskite interface are limiting the performance of NiOx-based PSCs. To address these issues simultaneously, an efficient NiOx/perovskite interface passivation strategy by using an organometallic dye molecule (N719) is reported. This molecule concurrently passivates NiOx and perovskite surface traps, and facilitates charge transport. Notably, the N719 molecule self-anchors and conformally covers NiOx films deposited on complex surfaces. This enables highly efficient textured monolithic p-i-n perovskite/silicon tandem solar cells. The N719 layer also forms a barrier that prevents undesirable chemical reactions at the NiOx/perovskite interface, significantly improving device stability. These findings provide critical insights for improved passivation of the NiOx/perovskite interface, and the fabrication of highly efficient, robust, and large-area perovskite-based optoelectronic devices.
  • COMPUTATIONAL STUDIES ON COMBUSTION MODELS AND FLAME SPEEDS TOWARDS PREDICTIVE PRE-CHAMBER ENGINE MODELING

    Silva, Mickael (2022-11-07) [Poster]
    High-fidelity pre-chamber combustion engine modeling is known to be susceptible to the choice of combustion model and associated laminar (𝑆_𝐿) and turbulent (𝑆_𝑇) flame speed correlations. 𝑆_𝐿 correlations are mostly semi-empirical, for which the ultralean values are unknown and rely on extrapolation for engine-relevant conditions, where high uncertainty may reside. Furthermore, the necessity of high Karlovitz correction on 𝑆_𝑇 remains debatable. Ultimately, the suitable combustion model to predict the correct physics of pre-chamber engine needs to be determined and, if needed, calibrated.
  • LCA of PEM Fuel Cell Vehicles Powered by Grey and Blue Hydrogen: A Case Study in Saudi Arabia

    Zhao, Chengcheng (2022-11-07) [Poster]
    Decarbonizing the transportation sector is essential to achieving climate stabilization and reaching net zero greenhouse gas emissions by 2050. Hydrogen proton-exchange membrane (PEM) fuel cell vehicles (FCVs) is a promising novel solution to reach this target. There are three primary forms of hydrogen to power the PEM fuel cell vehicle: “grey”, “blue”, and “green”, produced from steam methane reforming (SMR), SMR with carbon capture and storage (CCS), and water electrolysis powered by zero/ low carbon energy sources, respectively. In this study, the focus is on grey and blue hydrogen due to their cost-competitiveness and technological availability. Saudi Arabia heavily relies on fossil fuels such as crude oil and natural gas as its main energy provider. As the sixth largest natural gas reserve, it has tremendous potential for natural gas development. Therefore, grey and blue hydrogen sources are considered to be more accessible and feasible for PEM fuel cell vehicle development in Saudi Arabia. Literature studies on the life cycle assessment (LCA) of heavy-duty vehicles are limited. A research gap exists in the environmental assessment of the application of battery electric (BE) and PEM fuel cell buses in Saudi Arabia, as well as the energy consumption and emissions. Furthermore, the complete LCA can be divided into two parts: fuel cycle and vehicle cycle, and only a few studies have focused on both. This study bridged these research gaps and explored the global warming potential (GWP), abiotic depletion potential (ADP), and acidification potential (AP) of using grey and blue hydrogen in PEM fuel cell vehicles operating in Makkah in Saudi Arabia. It compares the life-cycle emissions of 20 internal combustion engine (ICE) vehicles, 20 battery electric (BE) vehicles, and PEM fuel cell vehicles for heavy-duty transportation with a lifetime of 254,040 km. The emissions and energy use of refueling infrastructure for 3 types of vehicles for 5 years were also determined, as well as the emissions and energy use of hydrogen transportation from eastern Saudi Arabia to Makkah. The emissions from upstream fuel production and delivery (or well-to-pump) are the most critical for the hydrogen PEM vehicles. This is due to the fact that the emissions in the usage phase are almost zero. Hydrogen can be produced and used inside Saudi Arabia employing gas tube trailers for fuel transport and has a potential to reduce the emissions at this stage. Blue hydrogen has most of its production emissions captured, hence it delivers lower total emissions compared to grey hydrogen. The LCA study highlights the importance of developing PEM fuel cell vehicles and provides guidelines to governments and companies for developing hydrogen PEM fuel cell vehicles in Saudi Arabia.
  • Deep Imaging Group: the intersection of Physics, Mathematics, Machine Learning and HPC

    Luiken, Nick (2022-11-07) [Poster]
    At the Deep Imaging Group (DIG) we aim to merge the traditional principles of physics with modern developments in mathematics, machine learning and HPC. In this poster we show two of our ongoing research projects that embody this principle. The first is seismic deblending, where the aim is to separate overlapping recorded signals. We combine the physics of signal blending with a powerful self-supervised denoiser based on UNet to obtain an algorithm that outperforms the state-of-the-art methods. in the second projects, we show how we create high-quality estimates of subsurface properties to characterize reservoirs for monitoring or CO2 sequestration, by adapting a novel algorithm introduced in the mathematical community to the seismic post-stack inversion problem.
  • Reactive transport modeling of CO2-water-rock interaction and mineralization in basalt

    Omar, Abdirizak (2022-11-07) [Poster]
    The continuously increasing CO2 concentration in the atmosphere has been a major global concern over the past few decades. Subsurface CO2 storage in various geological media has been proven to be one of the large-scale options to mitigate emissions, and provide a secure way to sequester CO2 for long time periods. The sequestration of CO2 in the subsurface depends on different trapping mechanisms which must be carefully evaluated in order to ensure safe storage and accurate predictions of storage potential. One of these trapping mechanisms, mineralization, has been shown to be one of the most secure over geologic time scales. Mineralization of CO2 is directly dependent on the interaction between CO2, in-situ brine, and the rock. In this study, we use reactive transport modeling to study the CO2-water-rock interactions and also investigate the mineralization potential of CO2 in reactive volcanic rocks such as basalts.
  • Wireless Strain Sensor for Structural Health Monitoring (SHM) Applications

    Mahmoud, Hassan (2022-11-07) [Poster]
    Based on the RFID sensing technology, A flexible strain sensor has been developed based on the LC circuit where the capacitance is considered as a sensing unit. To increase the sensor sensitivity, nano cracks have been introduced to the electrodes to create a piezoresistive effect that leads to a transmission line behavior of the capacitance. The unconventional change in capacitance of the LC oscillator reflects a sensitive shifting in resonance frequency of the flexible circuit, producing a sensitive wireless strain sensor with a Gauge factor of 50 for less than 1% strain.
  • Co-optimization of CO2 storage and enhanced gas recovery using carbonated water and supercritical CO2

    Omar, Abdirizak (2022-11-07) [Poster]
    CO2-based enhanced gas recovery (EGR) is an appealing method with the dual benefit of improving recovery from mature gas reservoirs and storing CO2 in the subsurface, thereby reducing net emissions. However, CO2 injection for EGR has the drawback of excessive mixing with the methane gas, therefore, reducing the quality of gas produced and leading to an early breakthrough of CO2. Although this issue has been identified as a major obstacle in CO2-based EGR, few strategies have been suggested to mitigate this problem. We propose a novel hybrid EGR method that involves the injection of a slug of carbonated water before beginning CO2 injection. While still ensuring CO2 storage, carbonated water hinders CO2-methane mixing and reduces CO2 mobility, therefore delaying breakthrough. We use reservoir simulation to assess the feasibility and benefit of the proposed method. Through a structured design of experiments (DoE) frame-work, we perform sensitivity analysis, uncertainty assessment, and optimization to identify the ideal operation and transition conditions. Results show that the proposed method only requires a small amount of carbonated water injected up to 3% pore volumes. This EGR scheme is mainly influenced by the heterogeneity of the reservoir, slug volume injected, and production rates. Through Monte Carlo simulations, we demonstrate that high recovery factors and storage ratios can be achieved while keeping recycled CO2 ratios low.
  • Three-dimensional Structural and Compositional Inhomogeneity in Zeolites Unraveled by Low-dose 4D-STEM Ptychography

    Li, Guanxing (2022-11-07) [Poster]
    To characterize electron-beam sensitive materials like zeolites, MOFs at sub-atomic resolution still faces challenges, dut to various of experimental limitations and obstacles. Electron ptychography is a potential candidate to solve these challenges and even break the resolution limitation of conventional transmission electron microscopy. In this work, we introduce 4D-STEM based ptychography to the beam-sensitive materials' characterization at sub-angstrom resolution, taking a zeolite, ZSM-5, as an example. After the systematic exploration on experimental parameters and optimization of reconstruction algrithms, we acquire the highest lateral resolution of this material and even in the zeolites family. Besides, the multi-slice reconstruction method enables us to obtain the electron-beam direction resolution. Based on these superiority of 4D-STEM ptychography, we are able to analyse the detailed structural and compositional inhomogeneity of ZSM-5 in three dimensions (3D), e.g., the 3D distribution of oxygen vacancies and the interface of MFI and MEL phases are investigated. 4D-STEM ptychography may open a new ero for high-resolution characterization of beam-sensitive materials under low dose.
  • Crustal Deformation and InSAR Group

    Fittipaldi, Margherita (2022-11-07) [Poster]
    We are a research group in geophysics at King Abdullah University of Science and Technology (KAUST) that focuses on the use of satellite geodesy, bathymetry, and fieldwork to measure ground deformation on the Earth's surface due to a variety of geophysical processes. We are interested in everything that moves the ground, e.g. earthquakes, magma accumulation under volcanoes, and pressure changes in reservoirs.
  • Deep-Wave

    Brandolin, Francesco (2022-11-07) [Poster]

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