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Empowering rubidium-based halide PSCs: A deep dive into ETL material performance
No full textThis study uses the SCAPS-1D simulation system to investigate the feasibility of different ETL (Electron Transport Layer) candidates in rubidium-based halide perovskite solar cells (RbGeBr3). Various ETLs, including TiO2, SnO2, IGZO, WS2, SnS2 and ZnMgO, are evaluated in terms of their effect on the energy band alignment, charge transport properties, and efficiency metrics. Simulation results indicate that WS2 exhibits the highest performance with an efficiency of 33.43 %, followed by SnO2 (32.7 %), ZnMgO (32.5 %), TiO2 (31.74 %), IGZO (29.58 %) and SnS2 (27.17 %). The superior performance of WS2 is attributed to its excellent electron mobility (∼100 cm2/Vs) and low conduction band offset, which enhances charge extraction and reduces recombination losses. The results demonstrate that WS2 is the most promising ETL for Rb–PSCs, offering superior efficiency and charge transport characteristics. Further, the study expands to obtain the performance parameters w.r.t to thickness, defect density, temperature etc to validate the selected ETL material. This offers significant details regarding how ETLs are contributing to boosting the stability as well as efficiency of rubidium-based PSCs, contributing to the advancement of next-generation perovskite photovoltaics
Hillslope flow paths in snowmelt and rainfall seasons in permafrost-underlain areas, Northeastern Tibetan Plateau: Investigation based on hydrochemical tracers and end-member mixing analysis
Get PDFStudy area: The Binggou and adjacent Yakou catchments in the northeastern Tibetan Plateau. Study focus: Hillslope flow paths were studied using hydrochemical data of various water types in the spring snowmelt and summer rainfall periods based on hydrochemical tracers and end-member mixing analysis. New hydrological insights for the study region: End-member mixing analysis confirmed the dominance of surface and near-surface runoff during the spring snowmelt. Specifically, the spring Binggou stream water had 61 % surface runoff, 22 % shallow groundwater, and 17 % near-surface runoff. The spring Yakou stream water had 64 % snowmelt, 25.5 % near-surface runoff, and 10.5 % riparian saturated soil water at a depth of 20 cm. The application of end-member mixing analysis failed in the summer rainfall period, and shallow subsurface flow contributed the most to the streamflow (∼ 100 %). The average acid-neutralizing capacity of the spring Yakou stream water was 611 μeq/L, increasing to 841 μeq/L in the summer, and for the Binggou stream water, the values were 747 μeq/L and 1084 μeq/L, respectively, indicating that the thawed soil layers had a significant buffering effect on stream water chemistry. This study revealed seasonal shifts in flow paths and stream sources, with a transition from surface to subsurface flow influenced by meteorological conditions and the active layer thickness. Future climate change may enhance subsurface flow recharge, leading to less diluted streamflow and stronger water-soil interactions
On-Road Investigation of Energy Saving Opportunity for Autonomous Light-Duty Vehicles through Automated Vehicle-Following in Safe Distance Scenarios
No full textReducing aerodynamic drag through Vehicle-Following is one of the energy reduction methods for connected and automated vehicles with advanced perception systems. This paper presents the results of an investigation aimed at assessing energy reduction in light-duty vehicles through on-road tests of reducing the aerodynamic drag by Vehicle-Following. This study provides insights into the effects of lateral positioning in addition to intervehicle distance and vehicle speed, and the profile of the lead vehicle. A series of tests were conducted to analyze the impact of these factors, conducted under realistic driving conditions. The research encompasses various light-duty vehicle models and configurations, with advanced instrumentation and data collection techniques employed to quantify energy-saving potential. The study featured two sets of L4 capable light duty vehicles, including the Stellantis Pacifica PHEV minivan and Stellantis RAM Truck, examined in various lead and following vehicle configurations at different speeds with cruise control enabled. Energy savings per km in the range of 9-17% were observed in Pacifica and savings up to 25% were obtained in RAM within 1-2 seconds following gap for speeds of 55-75 mph. It was also observed that the lateral positioning has a significant impact on energy saving overall. The results are also compared to the previous studies on drag reduction in two-vehicle platoons. This investigation contributes valuable knowledge to the vehicle-following to reduce the aerodynamic drag and thus to reduce the overall energy consumption in the highway driving scenarios. This can also be used in advanced vehicle positioning controls in autonomous vehicles where advanced sensing of the relative positions can be estimated accurately. The results give insights into optimizing energy efficiency, with a focus on the role of Vehicle-Following, aerodynamic drag reduction, and lateral positioning strategies for sustainable and environmentally conscious road transportation
Photovoltaic Module Temperature Prediction Model Incorporating Wind Direction and Precipitation Effects
No full textThis study presents an innovativeapproach to estimate the operating temperature of photovoltaic modules by incorporating underexplored climatic factors, such as wind direction and precipitation, in addition to commonly analyzed variables, such as ambient temperature, wind speed, solar irradiance, and relative humidity. The research addresses a gap in the literature, improving the predictive accuracy of photovoltaic module temperature estimation models. The developed methodology is designed to integrate measurement data from any location and was validated using data collected from over two years of measurements, demonstrating that the resulting prediction model is both valid and precise. The methodology employs multiple linear regression to derive the predictive model, ensuring adaptability and accuracy across different environmental contexts. Results indicate a significant improvement in prediction performance compared to other models. This advancement supports better design and operation of distributed photovoltaic systems globally
Functionalized Jute Fabric Integrated With Recycled PET Nanomat for Packaging Applications
No full textThe transition from conventional plastics to eco-friendly materials has become essential to preserve the environment and advancing human well-being. Conventional packaging materials negatively impact both environment and living beings. Furthermore, consumption of polyethylene-based bottles is increasing which is needed to be recycled. This work uses jute fabric with recycled polyethylene terephthalate (PET) nanomat with silver nitrate solution for antimicrobial packaging applications. This study developed a hybrid packaging option combining PET\u27s excellent barrier properties and jute\u27s biodegradability through electrospinning. The characterization process involved the evaluation of tensile, thermal conductivity, radiative heat resistance, morphological and moisture management properties. Compared to jute fabric (JF) alone, the jute-PET nano coated (JPC) samples showed reduced thermal conductivity, enhanced radiative heat resistance and improved tensile strength. It showed antibacterial activity against S. aureus and E. coli. Therefore, favourable properties like an improved tensile, radiative barrier, antibacterial and moisture offer a workable and sustainable substitute for contemporary packaging
Microbially induced calcite precipitation in fine-grained soils through mechanical mixing
No full textMicrobially induced calcite precipitation (MICP), recognized as an eco-friendly method, has gained considerable attention in recent years. However, a primary obstacle to its widespread use is its application in fine-grained soils such as clays due to their very small pore sizes and low permeability. The small pore size and low permeability prevent the efficient delivery of bacteria, along with their required nutrients and also calcium sources, for calcium carbonate in the soil. This study aims to address these challenges by investigating a mechanical mixing method where the fine-grained soil is blended with bacteria and nutrients/calcium sources. The proposed method can be used in the Deep Soil Mixing method to reduce the use of cement grout. In this study, clayey samples were prepared, and solutions containing bacteria suspension and substrate solution were incorporated into the soil using the proposed mechanical mixing method. The precipitated carbonate content was measured using the Calcium Carbonate Content Chamber (ASTM D4373). Furthermore, Scanning Electron Microscopy (SEM) tests were conducted to examine the precipitated carbonates. Finally, soil strength changes were evaluated through Unconfined Compressive Strength (UCS) Tests. A comprehensive discussion of the results, the observed challenges during the lab experiments, and their implications for possible future field applications are presented
Electrospun ZnO/CoMoO4/ZnCo2O4 composite nanofibers for highly selective sub-ppm n-butanol sensing
No full textThis study reports the synthesis and gas sensing performance of electrospun ZnO/CoMoO4/ZnCo2O4 composite nanofibers for highly selective sub-ppm detection of n-butanol. The nanofibers were fabricated via electrospinning and calcination, incorporating Mo doping to optimize the structural and electronic properties. Pure p-type spinel ZnCo2O4, n-ZnO/p-ZnCo2O4 nanofibers, and Mo-incorporated composites with varying metal atomic ratios (5 %, 10 %, and 15 %) were synthesized, characterized, and tested for gas sensing performance. All materials exhibited p-type sensing behavior. The introduction of ZnO (n-type) into (p-type) ZnCo2O4 formed p-n heterojunctions, enhancing charge carrier modulation. Additionally, CoMoO4 contributed to increased oxygen vacancies and catalytic activity, further improving gas-sensing performance. The optimized 10 % Mo-doped ZnO/CoMoO4/ZnCo2O4 nanofibers demonstrated superior selectivity and response to n-butanol at 250 °C, detecting concentrations as low as 250 ppb with a calculated detection limit of 29 ppb. The enhanced sensitivity is attributed to the oxygen vacancy-induced adsorption sites and p-n heterojunction charge transfer effects. These findings highlight the potential of engineered p-type metal oxide composites for VOC sensing applications
Short-term erosion rate of impact craters using radar data: Implications for their morphology
No full textErosion poses several challenges for studying terrestrial impact craters, as it results in subdued morphology. Erosion not only erases crater morphology but also leads to disagreements among geoscientists on morphological aspects. Ramgarh Crater, in the north-western India, is an example of such a crater with notable contentions pertaining to its type and morphology as a few studies point towards the denudation of the outer rim of a complex crater of 10 km apparent diameter. Meanwhile, the simple crater theory argues for a rim-to-rim diameter of ∼2.4 km. In this study, for the first time, an advanced radar data analysis, called the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR), is applied to quantitatively assess the short-term erosion rate of Ramgarh Crater, for the period between 2017 and 2022. PSInSAR is a microwave based remote sensing method that measures the rate and direction of ground surface movement. This method enabled a more robust analysis of erosion processes within and around the crater and facilitated a comprehensive understanding of its morphological features. Our study using PSInSAR could not identify any significant erosion in the elevated relict structure (considered as the rim of the simple crater) (mean velocity of −0.83 mm/yr) whereas other zones, including the 10 km apparent diameter, are characterized by similar erosion (mean velocity between −2.02 to −6.9 mm/yr) because of agricultural practice, badland topography and active river bed erosion. Additionally, field observations from multiple traverses and visual interpretation of high-resolution remotely sensed images across the 10 km apparent diameter did not yield any morphological evidences favouring a raised rim. Based on these findings, Ramgarh can be classified as a simple crater with the relict structure of 2.4 km rim-to-rim diameter, being the elevated rim. Thus, the implementation of PSInSAR has facilitated a comprehensive examination of the crater\u27s morphology and has conclusively resolved a significant debate surrounding Ramgarh Crater. As a result, the PSInSAR technique emerges as a valuable tool for resolving various geological conundrums, especially in the field of planetary science
Multiscale characterization of bio-based polyurethane modified asphalt: Macro-micro experiments and molecular dynamics simulations
No full textThis study conducted a multiscale investigation of bio-based polyurethane modified asphalt (Bio-PUMA) by combining macro–micro experiments with molecular dynamics simulations. Penetration, softening point, ductility, viscosity testing, temperature sweep test, bending beam rheometer (BBR) test, and cigar tube segregation test were conducted to evaluate the macro performance and storage stability of Bio-PUMA. Fourier-transform infrared spectroscopy (FTIR) and fluorescence microscopy (FM) were used to characterize the micro properties of Bio-PUMA. The study found that the difference in solubility parameter (λ) between Bio-PU and base asphalt at 120℃ is minimal, indicating the best compatibility at this temperature. The diffusion coefficient at 150 °C is 2.44 times higher than that of 120 °C, it is recommended to prepare Bio-PUMA at temperatures above 150 °C. Lower temperatures and higher Bio-PU content result in a more stable system. The compatibility problem of Bio-PUMA gradually emerges with the increase of Bio-PU content. Bio-PU enhances the high-temperature property and thermal stability of base asphalt, and it has a certain negative impact on the low-temperature performance of asphalt. It is recommended that the Bio-PU content should not exceed 9 %
Hourly Simulated Power Production Data with Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2020
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 2020. 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 2020_PV_existing_site_metadata.csv file for individual site metadata