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Effect of Precipitation on Runoff: Theory and Case Studies
No full textTo investigate the effect of changing precipitation on water and pollution runoff under climate change conditions, theory using the National Resources Conservation Service\u27s Curve Number Method and modeling of real watersheds with the Environmental Protection Agency\u27s Pollutant Load Estimation Tool (PLET) were performed showing that runoff was linearly proportional to precipitation with a nearly 1:1 slope, thereby highlighting the importance of water managers allocating more funds towards mitigation in the future
The Museum Guide Robot: Enhancing Visitor Experience Through Autonomous Robotics
No full textThis paper presents the design, implementation, and evaluation of the Museum Guide Robot (MGR), an autonomous robotic system aimed at enhancing visitor experiences in museum environments. Driven by advancements in artificial intelligence (AI) and robotics, the MGR integrates sophisticated navigation and interaction technologies to facilitate personalized museum tours. Employing a combination of mechanical design features, including a lightweight chassis and Mecanum wheels for omnidirectional movement, the robot effectively navigates crowded spaces while maintaining stability and performance. Its electronic architecture incorporates motor drivers, cameras, LiDAR sensors to ensure precise navigation, obstacle avoidance, and screen with a real-time interface to interact with visitors. The system operates on the Robot Operating System (ROS), which supports modular development, enabling efficient integration of various functionalities, such as path planning and natural language processing. Simulation results demonstrate the MGR\u27s high navigation accuracy and effective user interaction, while real-world testing highlights its potential to enrich the museum experience
Application of QuEchERs extraction method for optimization of organic matters in oil sand by ultrahigh fourier transform infrared orbitrap-mass spectrometry
Get PDFThis work focuses on the performance of composite solvents using the QuEchERs extraction (quick, easy, cheap, effective, rugged, and safe) method in bitumen recovery and determination of organic matters present in the oil sands of the Okitipupa area of southwestern Nigeria. Different correlated parameters, such as extraction time (h), stirring time (r/ min), change in temperature (°C), and type of solvent (heptane—toluene and dichloromethane—toluene), solvent ratios (2: 8, 3: 7, 5: 5, 7: 3, and 8: 2) were used to optimize dissolved organic matters from the oil sands using QuEchERs extraction method. Ratios 1 g/2.5 ml for each solvent mix were considered for each composite solvent. To our understanding, an integrated approach to the use of QuEChERS for the determination of organic matters in oil soil has not been established beforehand. Optimum values were observed at a ratio of 8: 2 for D/T and H/T after consideration of all the parameters for optimum yield, with the highest at D/T, respectively. Compositional analysis of dissolved organic matter was carried out using Fourier transform Orbitrap-mass spectrometry. The mass Formula Assignment (MFAssignR) method was employed to determine the molecular formulas of the detected compounds. The results of the count formula and the sum of experimental mass determination showed that over 50 molecular formulas were assigned in Okitipupa bituminous oil sand. The complex consists more of CHO, an aliphatic compound, and CHOS, a sulfonated aromatic compound, than the rest of the compounds. The overall study shows that the use of a composite solvent (dichloromethane—toluene) at a ratio of 8: 2, with a mechanism based on QuEchER techniques conceptualization on the composite solvent extraction process, would advance the knowledge base for bitumen recovery and serve as future engineering applications processing methods and performance of extracted bitumen for highest yields from oil sands
Reconstructing the geological and geomorphological history of Morella Crater, Mars
No full textAncient impact craters on Mars provide insights into the geological events and are time markers for studying global processes like colossal volcanism and fluvial activities. Among these craters, the 77 km diameter Morella Crater serves as a representative, capable of demonstrating diverse processes that acted on Martian terrain, and hence, the geological and geomorphological history of this crater is studied in detail. Despite its infilling, Morella hosts Ganges Cavus, a significant collapse structure, and Elaver Vallis, an outflow channel. We hypothesize the development of the crater through five stages, from its origin to its current denuded state, exhibiting diverse processes that determine the fate of Martian craters. Crater size-frequency distribution suggests a formation age of 3.8−0.03+0.03 Ga for the plateau hosting Morella Crater and 3.6−0.01+0.06Ga for Morella Plains, the vast expansive plains within the crater. The occurrence of pyroxene and olivine in Morella Plains, identified through hyperspectral data, indicates impact-induced volcanism. The heat source associated with faulting and dike intrusion in the adjoining Ophir Catenae Structural Complex might have ruptured the confined cryosphere, resulting in the formation of Ganges Cavus and eventual filling of Morella with water, which subsequently breached to form Elaver Vallis at3.4−0.10+0.07 Ga. Hydraulic modelling reveals a floodwater volume of 3.27 × 1012 m3 and an estimated peak discharge of 3 × 107 m s−1 associated with this event. Morella witnessed additional fluvial activity at 3.3−0.4+0.1 Ga that created the dark-toned channels. The extensive range of geological and geomorphological processes makes Morella Crater a promising location for future Mars missions
Turbulence numerical simulation of flow characteristics of Laval nozzle top blow jet
Get PDFThe turbulent characteristics of the top-blown Laval nozzle and the influence of pressure and Mach number were studied through numerical simulation. With 2.72% error between the results and the empirical formula, the results are reliable. Nozzle fluid is influenced by pipe structure, causing pressure and density to drop as speed increases. Differences in pressure and velocity between the jet and surrounding gas lead to jet velocity attenuation, flow expansion, deflection, and eddy currents. The optimal top blowing pressure is 0.6 MPa, and the center velocity and width of the jet are 345 m/s and 0.124 m, respectively, at 20De (De is the nozzle exit diameter). It achieves a maximum jet velocity of 456 m/s. The optimal nozzle Mach number is 1.75, with a maximum jet velocity of 451 m/s. At 20De, the jet center velocity is 338 m/s, with a width of 0.12 m
NEAR-INFRARED FLUORESCENT CYANINE PROBES FOR MONITORING NAD(P)H DYNAMICS IN LIVING CELLS AND DROSOPHILA LARVAE
Get PDFNicotinamide adenine dinucleotide (NAD+/NADH) plays a critical role in cellular metabolism, with abnormally elevated NADH levels linked to disrupted metabolic processes and cancer. In this study, we developed near-infrared fluorescent probes to selectively measure NADH concentrations. We present five cyanine-based probes, which were optimized by modifying the connection bridges to fine tune electronics. Two NAD(P)H-biosensing probes consisting of 1,3,3-trimethyl-3H-indolium and 3-quinolinium acceptors, linked by thiophene, A, and 3,4-ethylenedioxythiophene, B, bridges are detailed. They exhibit near-infrared fluorescence at 742.1 nm and 727.2 nm for probes A and B, respectively, and generate absorbance signals at 690.6 nm and 685.9 nm. Probe A was proven to effectively detect NADH levels in A549 cells and D. melanogaster larvae, confirming sensing capabilities in a whole organism. Furthermore, we monitored NADH production during cellular respiration and in response to anticancer drug treatments. These probes show promise for advancing medical research and monitoring therapeutic interventions
Criticality-Aware Instruction-Centric Bandwidth Partitioning for Data Center Applications
No full textTo reduce operational costs, modern data centers co-locate high-priority latency-critical (LC) tasks and low-priority best-effort (BE) tasks on the same physical node to increase resource utilization. However, such co-location leads to contention for memory bandwidth, resulting in priority inversion, where BE tasks severely slow down LC tasks. This priority inversion often leads to violations of the quality of service (QoS) requirements for LC tasks, defeating the purpose of co-location. Prior approaches to this issue either fail to enforce the QoS requirements for LC tasks or underutilize memory bandwidth.We present Pivot, a novel bandwidth partitioning system that overcomes the limitations of prior approaches based on two key insights. First, memory accesses from LC tasks must be prioritized across all the components on the memory path rather than a single component, as done in prior work. Second, only the scheduling of a selective portion of performance-critical loads (i.e., those causing a long stall on the re-order buffer), instead of all memory accesses from LC tasks, should be prioritized. To leverage these insights, Pivot overcomes the key challenge of accurately identifying performance-critical loads while incurring minimal runtime overhead by proposing a two-phase profiling technique. Our extensive evaluation shows that Pivot improves effective machine utilization by up to {3 4. 5%} while increasing the throughput of the BE applications by up to 2.76 × compared to state-of-the-art approaches
Multi-scale insights into the adhesion of steel slag-asphalt interface influenced by hydration process
No full textSteel slag, a byproduct of the steelmaking process, exhibits poor volumetric stability in its freshly produced or untreated state, which significantly restricts its application in pavement engineering. Currently, weathering is the predominant process for treating steel slag. A multi-scale approach was employed to investigate the mechanism of hydration reactions on the adhesion properties of the steel slag-asphalt interface during the weathering process in this study. The effects of hydration on adhesion properties were evaluated through modified boiling tests and surface free energy (SFE). The surface morphology of unhydrated and hydrated steel slag was compared using scanning electron microscopy (SEM) and optical profilometry. The adhesion properties of asphalt at the interfaces with unhydrated steel slag (C3S and C2S), hydrated steel slag (CaCO3), and basalt (SiO2) were systematically analyzed using molecular dynamics (MD) simulations, incorporating static, pull-off, and novel dynamic water scouring models to simulate diverse environmental conditions. The results indicated that the mass loss rate (MLR) and peeling rate (PR) of hydrated steel slag after a 10-minute boiling test were 1.3 and 2.2 times higher than those of unhydrated steel slag, respectively. Meanwhile, hydration treatment reduced the adhesion work between steel slag and asphalt by 2.0 % and increased the peeling work by 33.5 %. SEM images and 3D surface topography analyses showed that hydration transformed the rough-textured structure on the steel slag surface into a loose honeycomb structure, resulting in an increase of 6.42 % in arithmetic average roughness (Ra) and 8.84 % in root mean square roughness (Rq). MD simulations demonstrated that the mean square displacement (MSD), diffusion coefficient (DC), and z-value of relative concentration (RC) peaks of asphalt on the CaCO3 surface were greater than those on C3S and C2S, while the interface interaction energy, adhesion work, and cohesion ratio (CR) were lower. Under water molecule scouring, the simulated peeling rate (SPR) of asphalt on the CaCO3 surface increased by 34.5 % compared to C3S but decreased by 7.7 % compared to C2S. Furthermore, there was a strong correlation (r \u3e 0.8) between the experimental and simulation data
Surface Characteristics of Selected Wood Species after Treatment with Tannin and Ammonia Vapor
No full textEffects of ammonia vapor and tannin treatments were studied relative to the properties of wood. The color change, surface roughness, and surface hydrophobicity of Persian oak (Quercus persica), Persian walnut (Juglans regia L.), Oriental beech (Fagus orientalis Lipsky), and Siberian pine (Pinus sibirica) were evaluated after treatments for 8 and 24 h. The color difference (ΔE*) values increased with prolonged exposure, with the highest changes observed in tannin-treated samples exposed to ammonia vapor for 24 h. Pronounced color changes were observed in Siberian pine samples, while beech and oak showed moderate color shifts. Walnut exhibited a more complex response, with an initial increase in yellowness followed by stabilization. Surface roughness measurements demonstrated a significant increase, particularly in maximum height (Rz), indicating substantial modifications to the wood surface. The most significant increase in roughness was observed in the samples treated with ammonia vapor and tannin after 24 hours of exposure, regardless of species type, although oak and walnut showed more controlled alterations. The surface hydrophobicity of the samples was increased after treatment, with the highest contact angle values after treatment for 24 h. This study highlights the potential of tannin and ammonia vapor treatments for improving the aesthetical and surface properties of wood
QUANTIFYING SO₂ EMISSIONS FROM EXPLOSIVE EVENTS OF THE 2021 LA SOUFRIÈRE ERUPTION USING DSCOVR/EPIC
Get PDFVolcanic eruptions release large quantities of gases, including sulfur dioxide (SO₂), aerosol precursors, and ash into the atmosphere. Quantifying the emission fluxes and temporal variability of SO₂ is crucial for understanding volcanic processes and assessing their impacts on air quality, climate, and aviation safety. Episodic vulcanian to sub-Plinian explosive eruptions are a common feature of many arc volcanoes, but the underlying causes of such episodic behavior remain poorly understood. The 2021 La Soufrière eruption (St. Vincent) featured up to 40 discrete eruptive events between April 9 and April 22, presenting a rare opportunity to analyze time-resolved volcanic SO₂ emissions during a period of episodic explosive volcanism. In this study, we use ultraviolet (UV) satellite observations from the Earth Polychromatic Imaging Camera (EPIC) aboard the Deep Space Climate Observatory (DSCOVR) to track and quantify SO₂ emissions from individual explosions during the 2021 La Soufrière eruption. High-cadence EPIC imagery captures short-lived SO₂ plumes, complementing spatially detailed but temporally limited observations from the TROPOspheric Monitoring Instrument (TROPOMI) on the polar-orbiting Sentinel-5P satellite. SO₂ plumes observed by EPIC are further analyzed using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. By combining forward and backward trajectory simulations with satellite data, we estimate plume injection heights ranging from 15 to 21 km and confirm the volcanic origin of each detection and stratospheric injection of volcanic SO2. Pixel-level SO₂ mass estimates derived from EPIC and TROPOMI reveal substantial variability across events and highlight the sensitivity of mass retrievals to assumed plume height. TROPOMI-derived mass values (~380–840 kt) exceed those published by Esse et al. (2023) for the same days, reflecting differences in spatial coverage and retrieval methodology. EPIC SO2 measurements provide constraints on waning SO2 emissions during the later stages of the La Soufrière eruption (April 11-13) that were unavailable from TROPOMI. This study demonstrates the value of multi-sensor integration and trajectory modeling in capturing the dynamics and strength of explosive SO₂ emissions, with implications for hazard monitoring and atmospheric impact assessments