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Assessment of Whole-body Vibration Exposures Among Dumper Operators in Iron Ore Mines: A Comparative Investigation of Haul Truck Activity
No full textThis study aimed to fill the research gap on whole-body vibration (WBV) exposure of dumper operators in India, conducting a comprehensive investigation into specific phases of dumper operations. Results indicated that 59% of operators exceeded lower limits, with 90.8% exposed to vibration levels surpassing the lower limit for A(8) and VDV(8) values. Frequency analysis identified peaks aligning with crucial body parts, corroborating epidemiological findings. Statistical analysis (ANOVA) demonstrated significant differences in WBV exposure across activity groups (p \u3c 0.001), dumper speeds (p \u3c 0.001), and haul road conditions (p \u3c 0.001). Optimising driver speed, improving haul road surfaces, and regular vehicle maintenance are some recommendations to reduce WBV exposure among dumper operators
Rhodamine-derived ratiometric fluorescent probes for high-sensitivity detection and real-time imaging of mitochondrial pH and viscosity in HeLa cells and Drosophila melanogaster
No full textThe spirolactam on/off switch attached to rhodamine dye is known to be a highly selective and sensitive fluorescent probe, yet few studies have explored extending the π-conjugation system within its skeleton for pH detection in live cells. An extended π-conjugated rhodamine section should enable ratiometric pH detection in the near-infrared region. In this study, we synthesized probes A and B by coupling a rhodamine derivative with 7-nitrobenzofurazan and 7-(diethylamino)-2-oxo-3,8a-dihydro-2H-chromene-3-carbaldehyde sections, respectively. Probe A exhibits emission via a Förster resonance energy transfer (FRET) mechanism. Under excitation at 370 nm, the conjugated 7-nitrobenzofurazan in probe A exhibits fluorescence at 465 nm in the ring-closed state, while fluorescence at 660 nm appears in the ring-open state due to increased conjugation in the rhodamine moiety. Excitation of probe B at 325 nm resulted in reduced emission around 350 nm and a significantly enhanced response at 525 nm. Probe A was evaluated for mitochondrial pH detection through ratiometric fluorescence emission measurements. Additional tests in living HeLa cells, including responses to stimuli such as carbonyl cyanide-4(trifluoromethoxy)phenylhydrazone (FCCP), hydrogen peroxide (H2O2), N-acetyl cysteine (NAC), mitophagy induced by nutrient deprivation, and hypoxia triggered by cobalt chloride (CoCl2) treatment, as well as pH changes in fruit fly larvae, further validated its applicability for ratiometric measurement of mitochondrial pH variations. Probe A\u27s emission was dependent on the pH level under basic conditions, but under acidic conditions, the change in conformation upon ring opening resulted in the emission also being affected by viscosity
The Feasibility of Using Lidar-Derived Digital Elevation Models for Gravity Data Reduction
No full textGravity data require submeter elevation accuracy for data processing, and differential global navigation satellite system (dGNSS) equipment is commonly used to acquire three-dimensional positional data to achieve such accuracy. However, lidar (light detection and ranging) data are commonly used to develop digital elevation models (DEMs) of Earth’s surface. Therefore, using elevations from lidar-derived DEMs for gravity-data acquisition and reduction may improve field efficiency and reduce cost. This study examines the feasibility of using DEMs for gravity-data reduction by comparing dGNSS elevation data from 435 gravity stations in Michigan, Wyoming, and Colorado with their respective DEM elevations. The results show that the average difference between DEM and dGNSS elevations is 13 centimeters (cm) and that 93 percent of those differences are less than 50 cm, even in areas with steep terrain. Because an elevation discrepancy of 50 cm corresponds to an error of roughly 0.1 milligals (mGal) in the simple Bouguer gravity anomaly, the results suggest that lidar-derived DEMs are a viable source for acquiring the elevation data needed to process gravity data, thus improving both the cost and efficiency of data collection for regional surveys where an accuracy of less than 1.0 mGal is desired
Using LLMs, Knowledge Space Representations and Worked Examples to Support Adaptive Cybertraining in Construction Education
No full textConstruction education faces a number of challenges as the industry moves to embracing high-technology systems such as building information modeling, robotics, digital twins, AR/VR, and other systems. These systems usually need specific training to take advantage of, but the construction industry often relies on on-the-job or trade schools where there is limited expertise among instructors and limited resources to access technology. We describe a new pilot program for improving cyber-instruction in construction education that aims to improve access and support for students both at the university level and in non-traditional education and on-the-job training contexts. It explores using LLMs and chatbot to help learners explore new materials; knowledge-space representations to understand the necessary prerequisite knowledge (and move past information already mastered), and worked examples to improve student mastery of complex procedural skill. In this paper, we describe the approach of our ongoing project and illustrate some of the advances made
HAGMN-UQ: Hyper association graph matching network with uncertainty quantification for coronary artery semantic labeling
No full textCoronary artery disease (CAD) is one of the leading causes of death worldwide. Accurate extraction of individual arterial branches from invasive coronary angiograms (ICA) is critical for CAD diagnosis and detection of stenosis. Generating semantic segmentation for coronary arteries through deep learning-based models presents challenges due to the morphological similarity among different types of coronary arteries, making it difficult to maintain high accuracy while keeping low computational complexity. To address this challenge, we propose an innovative approach using the hyper association graph-matching neural network with uncertainty quantification (HAGMN-UQ) for coronary artery semantic labeling on ICAs. The graph-matching procedure maps the arterial branches between two individual graphs, so that the unlabeled arterial segments are classified by the labeled segments, and the coronary artery semantic labeling is achieved. Leveraging hypergraphs not only extends representation capabilities beyond pairwise relationships, but also improves the robustness and accuracy of the graph matching by enabling the modeling of higher-order associations. In addition, employing the uncertainty quantification to determine the trustworthiness of graph matching reduces the required number of comparisons, so as to accelerate the inference speed. Consequently, our model achieved an accuracy of 0.9211 for coronary artery semantic labeling with a fast inference speed, leading to an effective and efficient prediction in real-time clinical decision-making scenarios
Circular Economy and Mining
No full textAs world population and per capita income grows at an unprecedented rate, it has created stress on the availability of resources and the environment of the earth (UN, 2022, Kharas & Seidel, 2018). Growing population and income require ever larger amounts of goods and services that necessitate larger amounts of resources. This process has created concerns about the adverse impacts on the environment, climate, and availability of resources that have been growing in tandem with population and income. Properly addressing these concerns requires a different way of looking at how society produces and use products. The traditional market view by society is a linear one. (UNITAD, 2018) We extract the resources we need, produce goods with them, use the goods, and then discard the waste from extraction and the products that are no longer wanted. Recycling of waste and used products only occurs when its direct monetary costs are less than those from using new resources. This approach ignores the limitations that exists within the production system and assumes that this process can go on forever at an increasing rate. In reality, there are limits to our ability to produce and discard products based on the availability of resources and the impact on the environment. Another way of approaching this cycle of production and use is needed to better address the increasing negative impacts caused by the linear approach. One such approach is known as the circular economy. (Ellen MacArthur Foundation (2022). This approach incorporates three basic principles in production and consumption: eliminate waste and negative environmental impacts as much as possible in products, keep products and their materials in use as long as possible, and give nature the opportunity to regenerate
Supporting Human Exploration of Mars: Experimental Evaluation of Thermal Drilling for Water Extraction from Martian Glacier Ice
No full textMartian subterranean glacier ice is a valuable resource that could provide the water required for in situ life support and rocket fuel production. Rodriguez Well technology has been proposed as a means to access and extract this glacial ice. To investigate the energy requirements and efficiency of a thermal drill for Martian Rodriguez Well borehole creation, a scaled-down, simplified version of a Rodriguez Well melting drill bit was developed and tested in Martian atmospheric conditions. The small thermal probe was drilled into clear ice with two different actuation methods: gravity-driven actuation and motor-driven actuation. Thermal energy analysis of the resulting data shows that the average minimum specific energy for effective thermal drilling is 0.48±0.09 Wh/cm3 in Martian conditions, which is over an order of magnitude greater than mechanical drilling energy expenditure in similar conditions. However, maintaining a borehole pressure above Martian atmospheric pressure (\u3e9 torr) halves the energy expenditure of the thermal drilling process, which could be used to improve the performance and energy efficiency of thermal drilling on Mars
Coupling of chemical deconstruction and pyrolysis to upcycle metallized multilayer plastic films
No full textMultilayer metallized plastic films are popular packaging materials that are not currently recycled due to their complex multi-material make-up. In this study, a sequential pathway combining chemical, thermal and biological techniques was introduced to recycle military multilayer packaging made up of Polyethylene Terephthalate (PET), Polyethylene (PE), and aluminum. Chemical deconstruction using 10 wt% aqueous ammonia was able to selectively depolymerize the PET layer at a conversion close to 100 %. Aluminum and other metals were not detected in the deconstructed PET product, which contained Terephthalic Acid (TPA), terephthalic acid monoamide, terephthalamide, and ethylene glycol monomers that serve as the substrate for biological conversion. A natural microbial community was able to grow on the deconstructed multilayer at monomer concentrations of 5 g/L, producing a single cell protein product that could be used for food or animal feeds. The polyethylene and aluminum layers, which are inert during chemical deconstruction, were then pyrolyzed to breakdown the residual polyethylene into oil and wax hydrocarbons, leaving the aluminum unreacted. Elemental and gas chromatography-mass spectrometry analyses confirmed that the chemical deconstruction pretreatment step significantly improved the pyrolysis product quality by removing oxygen. The presented proof-of-concept technology represents an intriguing method to control contamination when processing complex waste plastic
Impact of soil particle size on lead distribution, geochemical speciation, and bioaccessibility in lead paint-contaminated residential soils
No full textDeteriorating lead (Pb)-based paint is a major source of Pb contamination in urban areas. Lead contamination in homes poses significant health risks, especially to children. Children ingest Pb-contaminated soil through their hand-to-mouth activity. The Bioaccessibility Research Group of Europe (BARGE) recommends using the \u3c 250 μm soil fraction for oral bioaccessibility assessment, while the USEPA suggests the \u3c 150 μm fraction for Human Health Risk Assessment (HHRA). However, these practices may underestimate risk, as smaller soil particles are more likely to adhere to children’s hands and be ingested; moreover, real-world exposure often involves a mix of particle sizes. Research on Pb speciation and bioaccessibility across soil sizes in residential soils is crucial for accurate risk assessment. This study examined the total Pb, geochemical fractionation, and bioaccessibility of Pb in different size fractions in Pb paint-contaminated residential soils in Detroit, Michigan, to identify the optimal particle size for health risk assessments. Lead-contaminated soil was collected from 10 homes known to have Pb-based paint contamination and separated into 3 size fractions, i.e., \u3c 250 μm, \u3c 150 μm, and \u3c 63 μm. Total Pb concentrations in the soils ranged from approximately 36–650 mg/kg across the size fractions, with the highest concentrations observed in the \u3c 63 μm fraction. Each fraction was analyzed for total and bioaccessible Pb concentrations, and geochemical speciation of Pb was performed. Results showed that overall, the highest Pb fraction was organic matter-bound (47.5%). However, Pb was mainly in the exchangeable form in the \u3c 63 μm fraction (33.1%) and contained higher total and bioaccessible Pb (22%) compared to the \u3c 250 μm (13%) and \u3c 150 μm (17%) size fractions. The study suggests that including \u3c 63 μm fractions in risk assessment may improve health risk prediction; however, comprehensive assessments should consider contributions from multiple particle size fractions to better reflect real-world exposure
Hourly Simulated Power Production Data with No Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Fixed-Tilt Systems in the U.S. Eastern Interconnection for Weather Year 2020
No full textUsing 2020 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory’s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be 30-degree, fixed tilt systems. Sites’ latitudes and longitudes were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadata