Engineering Commons^™

Coupling Nitrate Capture With Ammonia Production Through Bifunctional Redox-Electrodes, Kwiyong Kim, Alexandra Zagalskaya, Jing Lian Ng, Jaeyoung Hong, Vitaly Alexandrov, Tuan Anh Pham, Xiao Su

Department of Chemical and Biomolecular Engineering: Faculty Publications

Nitrate is a ubiquitous aqueous pollutant from agricultural and industrial activities. At the same time, conversion of nitrate to ammonia provides an attractive solution for the coupled environmental and energy challenge underlying the nitrogen cycle, by valorizing a pollutant to a carbon-free energy carrier and essential chemical feedstock. Mass transport limitations are a key obstacle to the efficient conversion of nitrate to ammonia from water streams, due to the dilute concentration of nitrate. Here, we develop bifunctional electrodes that couple a nitrate-selective redox-electrosorbent (polyaniline) with an electrocatalyst (cobalt oxide) for nitrate to ammonium conversion. We demonstrate the synergistic reactive separation …

Direct Synthesis Of Ethylene And Hydrogen From Co2 And Ethane Over A Bifunctional Structured Cao/Cr2o3-V2o5/Zsm-5 Adsorbent/Catalyst Monolith, Khaled Baamran, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study, we synthesized bifunctional adsorbent/catalyst materials (BFMs) consisting of a C_aO adsorbent admixed with Cr₂O₃-V₂O₅/ZSM-5 catalysts. The obtained BFMs were further formulated, processed, and shaped through additive manufacturing (3D printing) method. The physical and chemical properties of structured C_aO/Cr₂O₃-V₂O₅/ZSM-5 adsorbent/catalyst monoliths were thoroughly characterized and evaluated. The effects of operating conditions including reaction temperature, ethane composition, and space velocity on single-bed CO₂ capture and selective formation of ethylene and hydrogen were systematically investigated. The adsorption-reaction experiments revealed …

Development Opportunities And Technical Challenges Of Industrialization For Hydrogen Production From Bio-Ethanol Reforming, Xue Han, Hong He, Guojun Yue, Hailong Lin, Jinsong Liu, Bin Yu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Bio-ethanol reforming for hydrogen production, using renewable raw materials and adopting mature and efficient chemical processes, is an important source of green hydrogen supply to achieve the goals of carbon peaking and carbon neutrality. Bio-ethanol is a widely used substitute for fossil fuels. With the continuous progress of cellulosic ethanol technology in recent years, bio-ethanol will gradually break through the constraints of starch-based raw material supply. Based on the industrialization achievements of hydrogen production and bio-ethanol, bio-ethanol reforming can realize a rapid linkage with the existing hydrogen energy industry. However, the existence of a carbon-carbon signal bond in ethanol poses …

Adsorptive Properties And On-Demand Magnetic Response Of Lignin@Fe3o4 Nanoparticles At Castor Oil–Water Interfaces, Mohammad J. Hasan, Emily Westphal, Peng Chen, Abishek Saini, I-Wei Chu, Sarah J. Watzman, Esteban E. Ureña-Benavides, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

Lignin@Fe3O4 nanoparticles adsorb at oil–water interfaces, form Pickering emulsions, induce on-demand magnetic responses to break emulsions, and can sequester oil from water. Lignin@Fe3O4 nanoparticles were prepared using a pH-induced precipitation method and were fully characterized. These were used to prepare Pickering emulsions with castor oil/Sudan red G dye and water at various oil/water volume ratios and nanoparticle concentrations. The stability and demulsification of the emulsions under different magnetic fields generated with permanent magnets (0–540 mT) were investigated using microscopy images and by visual inspection over time. The results showed that the Pickering emulsions were more stable at the castor oil/water …

Development Of Battery Materials To Function As Corrosion Protection On Car Body Plates, Tubagus Noor Rohmannudin, Sulistijono Sulistijono, Noval Adrinanda, Faridz Wira Dharma, Samuel Areliano

Journal of Materials Exploration and Findings

Most car bodies made for mass production are made from steel or aluminum. Both are strong metals, but steel is cheaper than aluminum and is more commonly used in lower-end cars for a broader consumer range. The weakness of steel compared to aluminum is that it is susceptible to corrosion under certain conditions, and thus it may deteriorate over time without proper care. To prevent corrosion, modern cars are coated with paint to prevent direct contact with the environment. As a second line of protection, a car battery can be connected to the body to create an impressed current cathodic …

Potential Of Biduri Fiber (Calotropis Gigantea) As Material For Oil Spill Absorbent, Anne Sukmawati, Wulan Septiani

Journal of Materials Exploration and Findings

Biduri fiber (Calotropis gigantea) is a natural hollow fiber with hydrophobic and oleophilic properties potentially used as oil spilled sorbent from seawater. This study aims to determine the absorption capacity and efficiency of the Biduri fiber and membrane to fuel oil. Measurement of oil absorption to seawater was carried out at various fiber weights (0.5-1.5 g), fiber composition (50-95%), contact time (10-90 minutes), temperature (30 and 50°C), and compared with commercial products. The results showed that the fiber weight variation of 0.5-1.5 g has an average absorption efficiency of 96.67%, and the highest absorption was obtained in a weight of …

Residual Trapping Of Co2 And Enhanced Oil Recovery In Oil-Wet Sandstone Core – A Three-Phase Pore-Scale Analysis Using Nmr, Auby Baban, Alireza Keshavarz, Robert Amin, Stefan Iglauer

Research outputs 2022 to 2026

Hypothesis: Combining Carbon Geo-sequestration (CGS) with Enhanced Oil Recovery (EOR) in three-phase flow oil reservoirs is an effective and economically attractive technology to mitigate global warming caused by emission of anthropologic CO2 from fossil fuel combustion, as it offsets some of the costs of CO2 extraction. The targeted oil reservoirs display oil-wet characteristics, primarily because of the strong affinity of polar molecules present in oil; a mixture of a large number of chemical compounds to the rock's surface; and oil-wet surfaces that drastically reduce storage capacity of geological trapping mechanisms and increase the vertical migration of CO2. Thus, it is …

Liquid-Liquid Equilibria Of Water + Ethanol + Castor Oil And The Effect Of Cellulose Nanocrystal/Fe3o4 And Lignin/Fe3o4 Nanoparticles, Mohammad J. Hasan, Fariba Yehaneh, Amy Ciric, Peng Chen, Erick S. Vasquez, Esteban E. Ureña-Benavides

Chemical and Materials Engineering Faculty Publications

Castor oil has been proposed as a renewable solvent for the liquid extraction of ethanol from water as an alternative to more traditional energy intensive distillation-based methods. The liquid–liquid equilibrium (LLE) of the ternary system water + ethanol + castor oil was determined at 295.15 K using high performance liquid chromatography (HPLC). Castor oil was herein treated as a pseudo-component with the molecular weight of the triglyceride of ricinoleic acid. The experimental data was fitted to the UNIQUAC and NRTL models to obtain parameters for castor oil, and binary interaction parameters for castor oil/ethanol and castor oil/water pairs. The separation …

Computational Study Of C-C Coupling Reactions On Heterogeneous Catalysts, Md Saeedur Rahman

LSU Doctoral Dissertations

The utilization of carbon dioxide (CO₂) in chemical production has attracted global research interest. Reacting CO₂ with methane (CH₄) removes these greenhouse gases from the atmosphere and turns both compounds into building blocks for organic compound synthesis. A commonly explored pathway involves dry reforming of methane (DRM), which reacts CH₄ and CO₂ to form syngas, a mixture of H₂ and CO. Syngas is a widely used feedstock for synthesizing chemicals ranging from methanol to fuels via the Fischer-Tropsch (FT) process. However, DRM has a large positive ΔGº, which requires the …

Influence Of Synthesis Conditions On The Physicochemical And Electrocatalytic Properties Of Non-Stoichiometric Ba2sr2la2ti4o12 Perovskites, Ofeliya Kostadinova, Iliyan Popov, Simeon M. Stankov, Hristo Kolev, Tamara Petkov

Karbala International Journal of Modern Science

Present work studies the influence of the pretreatment milling media (deionized water (BLTOS-H) and isopropanol (BLTOS-i)) on the surface characteristics, structure, chemical composition and catalytic activity of non-stoichiometric Ba2Sr2La2Ti4O12 perovskites. The IR spectroscopy and XRD analyses shows a difference in the structure and phase composition of the two materials. X-ray photoelectron spectroscopy detects a Ba2+- and La3+-enriched and Sr2+-depleted surface. The BLTOS-i sample appears to exhibit higher specific surface area (SSA) and pore volume in comparison to BLTOS-H. The electrochemical tests showed that BLTOS-H sample have similar behavior to platinum at current densi-ties up to 10 mA cm-2, while BLTOS-i …

Enhancing Sustainable Process Designs Through Strategic Material Utilization And Waste Minimization Approaches, John David Chea

Theses and Dissertations

Sustainability is a growing concern as resources are continually depleted for various applications without adequate renewal plans. The resulting impacts on the ecosystem, health, and resource circularity are often overlooked. This research analyzes improvement opportunities at each major stage in a product's life cycle. Raw material acquisition, product synthesis, process waste management, and the fate of a material in the end-of-life phases were examined. The viability of utilizing renewable resources has been demonstrated in this work by extracting bio-based chemicals from underutilized renewable resources at a commercial scale and transforming the extracted resources into polymeric materials. The optimization of raw …

Poly(Pro-Curcumin) Materials Exhibit Dual Release Rates And Prolonged Antioxidant Activity As Thin Films And Self-Assembled Particles, Ruiwen Chen, Jessica L. Funnell, Geraldine B. Quinones, Marvin Bentley, Jeffrey R. Capadona, Ryan J. Gilbert, Edmund F. Palermo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Curcumin is a natural polyphenol that exhibits remarkable antioxidant and anti-inflammatory activities; however, its clinical application is limited in part by its physiological instability. Here, we report the synthesis of curcumin-derived polyesters that release curcumin upon hydrolytic degradation to improve curcumin stability and solubility in physiological conditions. Curcumin was incorporated in the polymer backbone by a one-pot condensation polymerization in the presence of sebacoyl chloride and polyethylene glycol (PEG, Mn = 1 kDa). The thermal and mechanical properties, surface wettability, self-assembly behavior, and drug-release kinetics all depend sensitively on the mole percentage of curcumin incorporated in these statistical copolymers. Curcumin …

Figure Data From "Electrochemical Identification Of Metal Chlorides In Eutectic Licl-Kcl Without Prior Knowledge Of Analyte Identities", Tyler Williams, Jason Torrie, Mark Schvaneveldt, Ranon Fuller, Greg Chipman, Devin Rappleye

ScholarsArchive Data

This is the data associated with figures found in a publication by the authors with the name of "Electrochemical Identification of Metal Chlorides in Eutectic LiCl-KCl Without Prior Knowledge of Analyte Identities".

Some of the data saved here is raw data collected by an Autolab potentiostat, while other data was derived from this raw data. Please reach out to the corresponding author for further questions.

Deep Transfer Learning For Approximate Model Predictive Control, Samuel Arce Munoz, Junho Park, Cristina M. Stewart, Adam M. Martin, John Hedengren

Faculty Publications

Transfer learning is a machine learning technique that takes a pre-trained model that has already been trained on a related task, and adapts it for use on a new, related task. This is particularly useful in the context of model predictive control (MPC), where deep transfer learning is used to improve the training of the MPC by leveraging the knowledge gained from related controllers. One way in which transfer learning is applied in the context of MPC is by using a pre-trained deep learning model of the MPC, and then fine-tuning the controller training for a new process automation task. …

Nafion Modified Titanium Nitride Ph Sensor For Future Biomedical Applications, Shimrith Paul Shylendra, Magdalena Wajrak, Kamal Alameh, James Jin Kang

Research outputs 2022 to 2026

pH sensors are increasingly being utilized in the biomedical field and have been implicated in health applications that aim to improve the monitoring and treatment of patients. In this work, a previously developed Titanium Nitride (TiN) solid-state pH sensor is further enhanced, with the potential to be used for pH regulation inside the human body and for other biomedical, industrial, and environmental applications. One of the main limitations of existing solid-state pH sensors is their reduced performance in high redox mediums. The potential shift E⁰ value of the previously developed TiN pH electrode in the presence of oxidizing or …

Engineering At-Home Dilution And Filtration Methods To Enable Paper-Based Colorimetric Biosensing In Human Blood With Cell-Free Protein Synthesis, Tyler J. Free, Ryan W. Tucker, Katelyn M. Simonson, Sydney A. Smith, Caleb M. Lindgren, William G. Pitt, Bradley C. Bundy

Faculty Publications

Diagnostic blood tests can guide the administration of healthcare to save and improve lives. Most clinical biosensing blood tests require a trained technician and specialized equipment to process samples and interpret results, which greatly limits test accessibility. Colorimetric paper-based diagnostics have an equipment-free readout, but raw blood obscures a colorimetric response which has motivated diverse efforts to develop blood sample processing techniques. This work uses inexpensive readily-available materials to engineer user-friendly dilution and filtration methods for blood sample collection and processing to enable a proof-of-concept colorimetric biosensor that is responsive to glutamine in 50 µL blood drop samples in less …

The Effect Of Process Parameters On The Properties Of Elastic Melt Blown Nonwovens: Air Pressure And Dcd, Li Change, Yanfen Zhou, Stephen Jerrams, Jianwei Ma, Shaojuan Chen

Articles

An elastic masterbatch and elastic melt blown nonwovens are prepared based successively on styrene-ethylene/butylene-styrene (SEBS) and polypropylene (PP) blend. The phase separation morphology, rheological properties and crystal structure of the elastic masterbatch are investigated. The results show that a compatible and stable structure is obtained in molten SEBS and PP blend with excellent mobility in the temperature range of 210–230C. The crystallization of PP slows down resulting in a finer structure due to the restriction of the SEBS network structure with rarely change of crystalline structure. The relationship between process parameters and properties of the elastic nonwoven is also studied …

Using Computational Fluid Dynamics And Optical Sensor Technology To Scale Cell Culture Platforms, Mandar Makwana

KGI Theses and Dissertations

Different cell culture vessels ranging from micro scale to laboratory scale to commercial scale play critical role in upstream process development for biologics manufacturing. Based on the mode of operation, cell culture vessels have different hydrodynamic environments, making it challenging to scale. Integrated approaches using computational tools supported by experimental studies can overcome these challenges. Computational Fluid Dynamics (CFD) is one such tool that can simulate hydrodynamics within the cell culture vessels and can provide insights at macro and micro-scale. Accuracy of a CFD model significantly depends on the fluid model and assumptions. Traditionally, simple two-equation fluid models were developed …

Concentration Field Based Micropore Flow Rate Measurements, Matia P. Edwards, Samuel F. D. J. Gómez, Michael S. H. Boutilier

Chemical and Biochemical Engineering Publications

Demand is growing for a larger catalogue of experimental techniques to measure flow rates through micro-/nanoscale systems for both fundamental research and device development. Flow emerging from a hole in a plane wall is a common system of interest in such work for its relevance to membrane separation. In this paper, we consider the possibility of measuring volume flow rates through small scale orifice plates from images of dye dispersions downstream. Based on approximate analytical solutions to the advection–diffusion equation, we show that, at low Reynolds numbers, the concentration in the nearly hemispherical plume that forms increases linearly with inverse …

Experimental Study: Investigating The Anions And Cations' Effects On The Elasticity Of The Anionic And Cationic High Viscosity Friction Reducers, Xiaojing Ge, Ghith Biheri, Abdulmohsin Imqam, Baojun Bai, Yuwei Zhang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

High viscosity friction reducers (HVFRs) are widely used as friction-reducing agents and proppant carriers during hydraulic fracturing. The reuse of produced water has gained popularity due to environmental and economic benefits. Currently, the field's most commonly used friction reducers are anionic and cationic HVFRs. Anionic HVFRs are typically pumped with freshwater, while cationic HVFRs are used with high Total Dissolved Solids (TDS) produced water. Cationic friction reducers are believed to have better TDS tolerance, friction reduction performance, and proppant transport capabilities compared to anionic friction reducers under high TDS conditions due to their superior viscoelastic properties. In addition, the impact …

Finite Line Relief Well System Design For Dams And Levees, Andrew M. Keffer, Erich D. Guy, Katherine R. Grote

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

An Analytical Method is Commonly Used to Design Relief Well Systems by Assuming the Well Line Extends an Infinite Distance Parallel to the Dam or Levee. This Assumption May Be Met in Some Cases, But When a Well Line is of Finite Length, This Can Severely Underestimate Excess Heads. Although These Consequences Have Been Historically Recognized, a Practical Graph-Based Analytical Approach for Finite Well Line Design Has Not Been Developed. Finite Well Lines Exist and Continue to Be Installed at Many Locations, So This Study Developed a Practical Design Method for Such Systems. Analytical Solutions and Numerical Models Were Used …

Oil Recovery Performance And Asphaltene Deposition Evaluation Of Miscible And Immiscible Carbon Dioxide Or Nitrogen Huff-N-Puff Processes In Shale Reservoirs, Mukhtar Elturki, Abdulmohsin Imqam, Shari Dunn-Norman, Hasan Shaglouf, Ahmed Kablan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The utilization of gas enhanced oil recovery to extract oil from unconventional reservoirs has become a widely discussed topic, as it has proven to be effective in significantly boosting oil recovery rates. Among various enhanced oil recovery methods, Gas Enhanced Oil Recovery (GEOR) is a frequently implemented approach. However, a significant challenge encountered during the process of injecting Carbon Dioxide (CO₂) or Nitrogen (N₂) to displace oil is the occurrence of asphaltene precipitation and deposition, which can impede production. This work is an experimental study to examine the effects of cyclic (huff-n-puff) CO₂ or N …

The Taphonomic Character, Occurrence, And Persistence Of Upper Permian–Lower Triassic Plant Assemblages In The Mid-Paleolatitudes, Bogda Mountains, Western China, Robert A. Gastaldo, Mingli Wan, Wan Yang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Bogda Mountains, Xianjiang Uygur Autonomous Region, Western China, Expose an Uppermost Permian–Lower Triassic Succession of Fully Continental Strata Deposited Across Three Graben (Half Graben) Structures in the Mid-Paleolatitudes of Pangea. a Cyclostratigraphy Scheme Developed for the Succession is Subdivided into Three Low-Order Cycles (Wutonggou, Jiucaiyuan, Shaofanggou). Low-Order Cycles Are Partitioned into 1838 High-Order Cycles based on Repetitive Environmental Changes, and their Plant Taphonomic Character is Assessed in . 4700 M of High-Resolution, Measured Sections Distributed Across ~ 100 Km. Four Taphonomic Assemblages Are Represented By: Permineralized Wood (Both Autochthonous and Allochthonous), Megafloral Adpressions (?parautochthonous and Allochthonous) Identifiable to Systematic …

Comparing Weathering Effects Of Ultraviolet And Xenon Arc Accelerated Aging On Polyvinyl Chloride, Collin Mcinnes

Williams Honors College, Honors Research Projects

As the ubiquitousness of polymers increases and begins seeing use in outdoor settings, the need to fully understand how these materials degrade is also necessary. This study aims to compare two known accelerated aging methods, namely an ultraviolet light chamber and a xenon arc light chamber, to understand what differences, if any, manifest in the mechanical, chemical, and cosmetic deterioration of polyvinyl chloride (PVC) after long-term exposure. The study utilizes Fourier-transform infrared spectroscopy, dynamic mechanical analysis, thermogravimetric analysis, and colorimetry analysis to determine the extent of degradation and potential discrepancies between the aging methods.

3d Cfd Simulation Of A Bubble Column With Internals: Validation Of Interfacial Forces And Internal Effects For Local Gas Holdup Predictions, Hayder Al-Naseri, Joshua P. Schlegel, Muthanna H. Al-Dahhan

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

CFD Models (Turbulent Models and Interfacial Forces) Incorporated with the Population Balance Model (PBM) Have Been Validated, Azimuthally, with the Gamma-Ray-Computed Tomography (CT) Results to Address the Effect of the Presence of Internals with Different Arrangements and Diameters. the Superficial Gas Velocity Applied Was Varied from 0.05 to 0.45 M/s. the Results Exhibit the Capability to Predict the Hydrodynamics of the Bubble Column, Further Incorporating the Population Balance Model and Promoting the Prediction of Simulation in High Superficial Gas Velocity. the Effect of Internals Revealed that the Gas Holdup Was Significantly Enhanced in the Bubble Column's Wall Region, While the …

Prediction Of Single Proppant Terminal Settling Velocity In High Viscosity Friction Reducers By Using Artificial Neural Networks And Xgboost, Xiaojing Ge, Rong Lu, Ghith Biheri, Abdulmohsin Imqam, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

High viscosity friction reducers (HVFRs) have been recently gaining more attention and increasing in use, not only as friction-reducing agents but also as proppant carriers. The settling velocity of the proppant is one of the key outputs to describe their proppant transport capability. However, it is influenced by many factors such as fluid properties, proppant properties, and fracture properties. Many empirical/physics-based models and correlations to predict particle settling velocity have been developed. However, they are usually based on certain assumptions and have applicable limits. In contrast, machine learning models can be considered as a black box. The objective of this …

Recovery Of Valuable Metals From Electronic Waste Using A Novel Ammonia-Based Hydrometallurgical Process, Peijia Lin

Theses and Dissertations--Mining Engineering

The growing quantity of waste electrical and electronic equipment (WEEE), also known as electronic waste (E-waste), has been an area of growing public concern. The abundance of valuable metals contained in waste printed circuit boards (WPCBs) has made it a promising secondary resource, especially for Cu and Au. Although the recovery of metals from WPCBs via hydrometallurgical routes has been studied extensively over the past 20 years, most of the research has been limited in the laboratory. In current hydrometallurgical processes, strong acids and expensive oxidizers are often used to ensure a high recovery of metals without considering the sustainability …

A Process Intensification Approach To Improve Volatile Fatty Acids Production, Extraction, And Valorization, Can Liu

Theses and Dissertations--Biosystems and Agricultural Engineering

Anaerobic digestion (AD) is a widely used biowaste conversion method. Recent studies have explored arrested methanogenesis as an alternative approach to leverage existing AD facilities and produce volatile fatty acids (VFAs) instead of biogas. VFAs have been recognized as precursors for a range of value-added chemicals and bioproducts. Arrested methanogenesis involves inducing acidic fermentation by halting the AD process before methanogenesis. It has been found that higher organic loading and thermophilic conditions enhance VFA accumulation and stabilize the acidic fermentation (AF) system.

Brewer's spent grain (BSG), a significant by-product of the brewing industry, was employed as the feedstock for VFA …

Magnetic Inversion Approach For Modeling Data Acquired Across Faults: Various Environmental Cases Studies, Khalid S. Essa, Eid R. Abo-Ezz, Neil Lennart Anderson, Omar A. Gomaa, Mahmoud Elhussein

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

An effective extension to the particle swarm optimizer scheme has been developed to visualize and modelize robustly magnetic data acquired across vertical or dipping faults. This method can be applied to magnetic data sets that support various investigations, including mining, fault hazards assessment, and hydrocarbon exploration. The inversion algorithm is established depending on the second horizontal derivative technique and the particle swarm optimizer algorithm and was utilized for multi-source models. Herein, the inversion method is applied to three synthetic models (a dipping fault model contaminated without and with different Gaussian noises levels, a dipping fault model affected by regional anomaly, …

The Influence Of Tropical Atlantic Sea-Surface Temperatures And The North Atlantic Subtropical High During The Maya Droughts, Derek K. Gibson, Jonathan Obrist-Farner, Brooke A. Birkett, Jason H. Curtis, Melissa A. Berke, Peter M.J. Douglas, Prudence M. Rice, Jeremy Maurer

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The frequency and duration of Late-Holocene hydrologic extremes in northern Guatemala were investigated using multiple sedimentological and geochemical proxies preserved in a sediment core collected from Lake Petén Itzá. A general trend of increasing aridity in the Maya Lowlands during the past 2000 years was punctuated by several multidecadal- to centennial-scale drought events recorded in the Petén Itzá sediments. In particular, the period spanning the Maya Terminal Classic Period and the Medieval Climate Anomaly (MCA), between 800 and 1300 CE, was marked by several extreme droughts and included the driest conditions of the past 2000 years between 950 and 1100 …