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Hourly Simulated Power Production Data with No Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2021
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2021. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2021_PV_existing_site_metadata.csv file for individual site metadata
Thermal prospecting for lunar water with a percussive hot cone penetrometer
No full textWater is a resource that is critical for establishing a sustained presence on the moon and beyond. With the orbital discovery of water deposits in the polar permanently shadowed regions of the moon, it is proposed that water and other resources can be extracted and refined on the lunar surface rather than having to transport them from earth, a concept known as in-situ resource utilization. However, the spatial distribution, quantity, and composition of these resource deposits are largely unknown and require ground truth measurements for confirmation. Multiple instruments have been developed to quantify and map lunar resources, but many of them are mechanically complex and have considerable depth limitations. To address these issues, the Planetary Surface Technology Development Lab at Michigan Technological University has developed the Percussive Hot Cone Penetrometer (PHCP), a low mass, mechanically simple, and robust instrument for quantifying the vertical and lateral distribution of geotechnical properties and volatile content of regolith up to a 1 m depth. The PHCP uses a thermal volatile detection system to characterize the frozen volatiles present in volatile-bearing regolith. To assess the sensitivity of the PHCP\u27s thermal volatile detection system, it was tested under thermal vacuum using granular icy regolith mixtures with ice concentrations ranging from 1.5 – 10 wt% water ice. Statistical analysis of the resulting thermal data revealed that the PHCP can quantify the water content of regolith within ± 1 wt% if the bulk density of the surrounding regolith is known within ± 0.05 g/cm3
Data supporting the paper Evaluating the collision-coalescence process in idealized cloud convection using large-eddy simulations with Lagrangian microphysics
No full textDrizzle initiation through the collision and coalescence of cloud droplets plays a crucial role in warm cloud precipitation. Recent theoretical studies suggest that the influence of collisional growth on the droplet size distribution can be quantified by a non-dimensional drizzle number (Dz). Here, large-eddy simulations with Lagrangian microphysics are employed to evaluate the theory by simulating a tall convection-cloud chamber under various conditions. Results show that the smaller the Dz, the larger the impact of collisions on the right tail of the droplet size distribution, consistent with the theory. The simulations confirm that the collision rate can be estimated from the droplet size distribution interacting only with cloud droplets of the same size at the mode radius. This suggests that the idealized theory can be a useful tool to design a cloud chamber for drizzle investigation, as well as to represent drizzle formation in models of real atmospheric clouds
Catalytic Mechanism of the Bacterial Non-Heme Fe(II) and 2-Oxoglutarate Dependent Enzyme AlkB with Single-Stranded DNA Containing Complex Guanine Adducts
No full textThe bacterial nonheme Fe(II)/2-oxoglutarate (2OG)-dependent enzyme AlkB repairs alkylation damages in single-stranded DNA (ss-DNA) nucleotide bases. This study examines for the first time the reaction mechanism of the AlkB-catalyzed repair of alkylated and exocyclic guanine adducts (GAs) in single-stranded DNA induced by everyday chemical exposures associated with cancers and other genetic disorders. The studied substrates include N2-furfurylguanine (FF-dG), N2-tetrahydrofuran-2-yl-methylguanine (HF-dG), 3-(2\u27-deoxy-β-D-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2-α]purin-10(3H)-one (α-OH-PdG), 3-(2\u27-deoxy-β-D-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-α]purin-10(3H)-one (γ-OH-PdG), and 3-(2\u27-deoxy-β-D-erythro-pentofuranosyl) pyrimido[1,2-α]purin-10(3H)-one (MdG). Using molecular dynamics-based combined quantum mechanics/molecular mechanics (QM/MM) and QM calculations, we provide unique mechanistic insights into AlkB\u27s catalytic reaction pathways with ss-DNA containing complex alkylated/exocyclic GAs in strong correlation to experimental studies. While HF-dG, FF-dG, α-OH-PdG, and γ-OH-PdG are repaired through C-H hydroxylation, MdG follows epoxidation. The study elucidated that the repair mechanism favors the open tautomer of γ-OH-PdG and the closed tautomer of α-OH-PdG, respectively, in agreement with experimental studies, due to the preferable SCS interactions and the catalytic domain\u27s loop L1 and L4 dynamics. Our study also elucidated that the posthydroxylation/postepoxidation steps proceed in water rather than the enzyme. The results reveal the unique catalytic mechanism of AlkB with ss-DNA containing complex GAs, which can be used in drug design and metalloenzyme redesign
Systematic review on the technology’s role in supporting lung cancer patients in the treatment journey
No full textThis systematic review examines the role of technology-based interventions in supporting lung cancer patients during their treatment. It identifies (1) the different technologies utilized, (2) their functions and benefits, and (3) the barriers encountered by patients. The authors searched six databases for literature examining the use of technology to support treatment among lung cancer patients. Twenty-three papers were included. We mapped each technology, telehealth platforms, online portals, and mobile apps, to specific treatment phases (pre-treatment, active treatment, post-treatment) and symptom domains (symptom management (N = 17), emotional distress (N = 12), and patient–provider communication (N = 7)). Our results demonstrate that technology can effectively alleviate treatment-related symptoms, reduce emotional burden, and enhance communication. Key barriers included low digital literacy and limited device access. By explicitly linking intervention types to treatment stages and patient needs, this review provides a practical framework for designing and implementing tailored digital support strategies in lung cancer care
Deployable and load-bearing kirigami plates
No full textThis work develops an integrated framework for the design, simulation, and optimization of a kirigami-inspired deployable plate capable of covering arbitrarily large surfaces and locking into load-bearing configurations. Traditional origami-based systems face limitations in achieving uniform panel thickness, single-degree-of-freedom (SDOF) deployment, and planar tessellation simultaneously. To address these challenges, this work adopts a kirigami approach to build a deployable plate by connecting uniformly thick panels via simple butt hinges. To enable load-bearing capability after deployment, latch locks are integrated into the folding hinges. This design offers advantages in load-bearing performance and manufacturability. We developed a lumped parameter mechanical simulation to capture the deployment kinematics and load-bearing capacity. We showed that the simulation can capture the deployment kinematics accurately by comparing the simulation results with analytical solutions for different kirigami plates. Mechanical properties required for the load-bearing simulation are derived from four-point bending experiments on the locking hinges. A case study is presented to show that the model can predict the strength and stiffness of the kirigami plates. An optimization platform is then introduced to identify the most effective latch lock placements for maximizing structural stiffness. Finally, experimental studies are conducted to validate the accuracy of the simulation and optimization framework, confirming the proposed system\u27s effectiveness for deployable and load-bearing applications
Three-Sided Skyline Counting Queries
No full textA two-dimensional point p=(p.x,p.y) dominates another point p\u27=(p\u27.x,p\u27.y) if p.x ≥ p\u27.x and p.y\u3ep\u27.y or p.x\u3ep\u27.x and p.y ≥ p\u27.y. The skyline of a point set P is a subset P\u27 ⊆ P such that every point in P\u27 is not dominated by any other point in P. An orthogonal skyline counting query Q on a set of points P asks for the number of points on the skyline of P ⋂ Q.
In this work we study data structures that support orthogonal skyline counting queries in the special case when the query range is bounded on three sides. First, we describe a linear space data structure that counts the points on the skyline of a top-open three-sided query range in O(log log n) time. We also consider a variation of the skyline problem where each of the points have some category, which we call color. An orthogonal color skyline query Q on a set of points P returns the distinct color of points on the skyline of P ⋂ Q. We achieve a solution for top-open three-sided color skyline counting query that requires O(log n/ log log n) time and linear space.
Additionally, we show the reduction of four-sided skyline query to a bottom-open three-sided skyline query establishing that solving the skyline problems in a bottom-open three-sided query range is as hard as solving it for a four-sided query range. In contrast, we show that top-open three-sided skyline counting queries can be solved in just O(log log n) time. This demonstrates that for orthogonal skyline queries, although the top-open and bottom-open three-sided query ranges may seem similar, their computational complexities differ significantly
ROTTEN THROUGH THE CORES: WHAT DECOMPOSITION CAN TELL US ABOUT CARBON CYCLING
No full textSequestration of carbon (C) in forests means that the C is stored in the ecosystem and not emitted to the atmosphere, thus slowing the accumulation of greenhouse gases and mitigating the acceleration of manmade climate change. Quantifying the pools and fluxes of C in forests is therefore of considerable interest to landowners, policy makers, and scientists.
Decomposition is an ecological process central to the movement of C through ecosystems. This dissertation uses several techniques to help determine the factors influencing the speed of decomposition and long-term fate of decomposed plant material. In Chapter Two, phospholipid fatty acid analysis was used to assess microorganism populations in soils from experimental forest plots heavily amended by simulated anthropogenic nitrogen (N) deposition. Decomposition rates in the forests were suppressed during active N loading due to the alteration of the soil microbial community (Propson et al. 2024). Measurements made after three years of recovery following cessation of N loading found gradual recovery of microorganisms and their associated ecosystem processes. Chapters Three and Four detail my work on the FACE Wood Decomposition Experiment (FWDE), a long-term project that measured decomposition of three log species placed in nine forest sites across the continental United States. Fungal communities in logs from one site were measured to look for patterns in fungal species distribution or assemblages. No significant differences were found in fungal communities by species or orientation of logs after eleven years of decomposition, indicating a possible stronger influence of physical location than wood chemistry at advanced stages of decay. I further examined the movement of log C into soil via a unique 13C signature present in the decomposing logs. Soil samples from beneath and beside the logs to a depth of 50 cm were taken. I found that decomposing coarse woody debris (CWD) contributes measurably to the overall soil C stocks with 0.5% to nearly 40% of log C residing in mineral soil after ten years, and that the patterns and residence time of C from wood depended upon climate, soil texture, and specific log attributes. Sites with higher mean annual temperature and precipitation had faster log decomposition, but also less C storage in soils. Colder and dryer sites showed more C retained in intact wood on the surface as well as in soils beneath the dead logs. Soils with a high percentage of sand retained less log C than those with more silt and clay. Horizontal logs contributed more C to the soil than upright snags, and larger logs naturally decayed more slowly than small ones, slowing their inputs to the soil. Together, this dissertation sheds light on the process of decomposition and the long-term influences of dead wood on soil C sequestration
Advances in computational design of van der Waals heterostructures for photocatalytic water splitting
No full textLight-driven photocatalytic water splitting is a promising approach to renewable hydrogen production, driven by the increasing global energy demand. van der Waals (vdW) heterostructures have recently emerged as leading materials for next-generation photocatalysts, offering tunable electronic properties and band alignments. This review examines recent progress in vdW heterostructures fabricated from graphitic carbon nitride, transition metal dichalcogenides, black phosphorus, M-Xenes, and layered double hydroxides. We highlight their potential for high solar-to-hydrogen efficiency, facilitated by superior charge separation, enhanced light absorption, and improved carrier utilization. Compared to the type-II mechanism, the direct Z-scheme mechanism in these heterostructures promotes effective electron-hole pair separation, reducing recombination rates and enhancing photocatalytic performance. We also discuss the impact of band gap tunability, stacking patterns, rotational angles, interlayer interactions, and defects in enhancing the efficiency of these heterostructures as photocatalysts. Furthermore, we explore strategies for improving their photocatalytic performance through surface engineering, including doping and co-doping methods. Finally, we examine the potential of machine learning to accelerate the discovery of these heterostructures and propose future research directions for vdW heterostructures in photocatalytic water splitting
Revealing the catalytic mechanism of the Fe(II)/2-oxoglutarate-dependent human epigenetic modifying enzyme ALKBH5
No full textALKBH5 is one of only two known human non-heme Fe(II)/2-oxoglutarate-dependent oxygenases that catalyze the demethylation of N6-methyladenine (m6A) in single-stranded mRNA, underscoring its role in diverse cancers. Unlike its homolog, the fat mass and obesity-associated protein (FTO), which oxidizes m6A to a stable N6-hydroxymethyladenine (hm6A) intermediate, ALKBH5 demethylates m6A, yielding adenine and formaldehyde as products. Here, we integrate molecular dynamics simulations and quantum mechanics/molecular mechanics methods to elucidate ALKBH5’s complete catalytic mechanism. Two post-hydroxylation pathways were evaluated: a proton transfer pathway and a Schiff base formation pathway, with the former emerging as the favored mechanism. We identify second-sphere residues Lys132 and Tyr139 as essential contributors to catalysis and demonstrate how Val191 and Tyr133 modulate activity. Dynamic analyses reveal that correlated motions of structural elements such as nucleotide recognition lids NRL1 and NRL2 and increased flexibility of the NRL2 loop in the hm6A intermediate may be critical for efficient demethylation