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Publication Study of the D*(sJ)(2317)(+) and D-sJ(2460)(+) mesons in inclusive cc(-) production near root s=10.6 GeV(2006-01-01) John, MJJ; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, PK; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Pioppi, MPublication Publication Publication Dynamic Trajectory Planning for Automated Lane Changing Using the Quintic Polynomial Curve(2023-01-01) Li, Yang; Li, Linbo; Ni, DaihengAs one of the key algorithms in supporting AV (autonomous vehicle) to complete the LC (lane changing) maneuver, the LTP (LC trajectory planning) algorithm generates safe and efficient LC trajectory for the AV. This paper proposes a novel dynamic LTP algorithm based on the quintic polynomial curve. This algorithm is capable of adjusting LC trajectory according to the state changes of the surrounding driving environment. The formulation of our proposed algorithm mainly consists the underlying form of trajectory equation, the optimization objective function, the corresponding constrains, and the SQP (sequential quadratic programming) algorithm. For each planning step, the time-based quintic polynomial function is introduced to model the trajectory equation. The problem of solving the parameters of the corresponding equation is then transformed into an optimization problem, which takes driver’s safety, comfort, and efficiency into account. After that, the SQP algorithm is employed to solve this optimization problem. Finally, both numerical simulation and field-data validation are used to verify the effectiveness of our proposed algorithm. We anticipate that the research could provide certain valuable insights for developing more reliable LC algorithms for AVs.Publication Low-Flow (7-Day, 10-Year) Classical Statistical and Improved Machine Learning Estimation Methodologies(2023-01-01) DelSanto, Andrew; Bhuiyan, Md Abul Ehsan; Andreadis, Konstantinos M.; Palmer, Richard N.Water resource managers require accurate estimates of the 7-day, 10-year low flow (7Q10) of streams for many reasons, including protecting aquatic species, designing wastewater treatment plants, and calculating municipal water availability. StreamStats, a publicly available web application developed by the United States Geologic Survey that is commonly used by resource managers for estimating the 7Q10 in states where it is available, utilizes state-by-state, locally calibrated regression equations for estimation. This paper expands StreamStats’ methodology and improves 7Q10 estimation by developing a more regionally applicable and generalized methodology for 7Q10 estimation. In addition to classical methodologies, namely multiple linear regression (MLR) and multiple linear regression in log space (LTLR), three promising machine learning algorithms, random forest (RF) decision trees, neural networks (NN), and generalized additive models (GAM), are tested to determine if more advanced statistical methods offer improved estimation. For illustrative purposes, this methodology is applied to and verified for the full range of unimpaired, gaged basins in both the northeast and mid-Atlantic hydrologic regions of the United States (with basin sizes ranging from 2–1419 mi2) using leave-one-out cross-validation (LOOCV). Pearson’s correlation coefficient (R2), root mean square error (RMSE), Kling–Gupta Efficiency (KGE), and Nash–Sutcliffe Efficiency (NSE) are used to evaluate the performance of each method. Results suggest that each method provides varying results based on basin size, with RF displaying the smallest average RMSE (5.85) across all ranges of basin sizes.Publication Peace-Athabasca Delta water surface elevations and slopes mapped from AirSWOT Ka-band InSAR(2023-01-01) Gleason, Colin J.In late 2023 the Surface Water and Ocean Topography (SWOT) satellite mission will release unprecedented high-resolution measurements of water surface elevation (WSE) and water surface slope (WSS) globally. SWOT’s exciting Ka-band near-nadir wide-swath interferometric radar (InSAR) technology could transform studies of surface water hydrology, but remains highly experimental. We examine Airborne SWOT (AirSWOT) data acquired twice over Canada’s Peace-Athabasca Delta (PAD), a large, low-gradient, ecologically important riverine wetland complex. While noisy and susceptible to “dark water” (low-return) data losses, spatially averaged AirSWOT WSE observations reveal a broad-scale water-level decline of ~44 cmn (σ =271 cm) between 9 July and 13 August 2017, similar to a ~56 cm decline (σ=33 cm) recorded by four in situ gauging stations. River flow directions and WSS are correctly inferred following filtering and reach-averaging of AirSWOT data, but ~10 km reaches are essential to retrieve them. July AirSWOT observations suggest steeper WSS down an alternate flow course (Embarras River–Mamawi Creek distributary) of the Athabasca River, consistent with field surveys conducted the following year. This signifies potential for the Athabasca River to avulse northward into Mamawi Lake, with transformative impacts on flooding, sedimentation, ecology, and human activities in the PAD. Although AirSWOT differs from SWOT, we conclude SWOT Ka-band InSAR observations may detect water level changes and avulsion potentials in other low-gradient deltas globally.Publication On the Measurements of Individual Particle Properties Via Compression and Crushing(2021-01-01) Liu, Chunlong; Liu, Fengyin; Song, Jinliang; Ma, Fuli; Wang, Dongfang; Zhang, GuopingAn experimental study is presented to measure the elastic, yielding, and crushing properties of individual particles under compression using substrates made of aluminum alloy, stainless steel, and sapphire. Carefully selected, highly spherical individual Ottawa sand particles of 0.75-1.1 mm in nominal diameter were compressed between two smooth substrates, and the load-deformation curves were analyzed by Hertz elastic contact theory to derive their reduced modulus and Young's modulus as well as yielding and crushing strengths, which vary significantly with the type of substrate materials. Further analysis of the yielding and plastic deformation at the particle-substrate contact shows that the yield strength or hardness of the substrate materials dominates the local contact behavior and hence affects the measured apparent yielding and crushing strengths. The two softer substrates (aluminum alloy and stainless steel) actually lead to underestimated apparent shear yield strengths of quartz particles by 60.4% and 54.2%, respectively, which are actually the yielding of substrates, while the true particle yielding occurs in the sapphire-particle contact. Moreover, the two softer substrates cause much overestimated crushing strengths of the quartz particles by 50.4% and 36.4%, respectively. Selection of inappropriate substrate materials and inappropriate interpretation of the particle-substrate contact can lead to significant errors in the measured yielding and crushing strengths. It is recommended that single particle compression testing uses substrates with yield strength greater than that of the tested particles and result interpretation also considers the elastic and yielding behaviors of the substrates. (C) 2021 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.Publication Understanding the Catalytic Active Sites of Crystalline CoSbxOy for Electrochemical Chlorine Evolution(2023-01-01) Dong, Heng; Shao, Xiaohan; Hancox, Shane; McBeath, Sean T.; Tarpeh, William A.; Hoffmann, Michael R.The chlorine evolution reaction (CER) is a key reaction in electrochemical oxidation (EO) of water treatment. Conventional anodes based on platinum group metals can be prohibitively expensive, which hinders further application of EO systems. Crystalline cobalt antimonate (CoSbxOy) was recently identified as a promising alternative to conventional anodes due to its high catalytic activity and stability in acidic media. However, its catalytic sites and reaction mechanism have not yet been elucidated. This study sheds light on the catalytically active sites in crystalline CoSbxOy anodes by using scanning electrochemical microscopy to compare the CER catalytic activities of a series of anode samples with different bulk Sb/Co ratios (from 1.43 to 2.80). The results showed that Sb sites served as more active catalytic sites than the Co sites. The varied Sb/Co ratios were also linked with slightly different electronic states of each element, leading to different CER selectivities in 30 mM chloride solutions under 10 mA cm–2 current density. The high activity of Sb sites toward the CER highlighted the significance of the electronic polarization that changed the oxidation states of Co and Sb.Publication In Vivo Evaluation of Oxygenic Photogranules’ Photosynthetic Capacity by Pulse Amplitude Modulation and Phototrophic–Irradiance Curves(2021-01-01) Gikonyo, Joseph G.; Keyser, Andrew; Tobiason, John; Jeong, Jeeyon; Park, ChulThe commingled microbial moiety of oxygenic photogranules (OPGs) facilitates aeration-free wastewater treatment. Embedded in an extracellular polymeric substances (EPS) matrix, microbial producers and consumers of oxygen occupying granular niches exchange substrates among themselves and with the bulk fluid. An assessment of the OPG's phototrophic potential or functional capacity may require combining different photoactivity signals. The photosynthetic capacity was evaluated using photosynthetic oxygen evolution (POE) and chlorophyll fluorescence (rapid light curves, RLC) measurements using OPGs grown at different light intensities.. A maximum oxygen generating capacity for optimal OPGs and reactor conditions was determined to be 284.4 mgO(2) gVSS(-1) h(-1) The OPGs exhibited photoelasticity, with higher photosynthetic capacity in high light (HL) compared to that in low light (LL) adapted samples. Saturation irradiances before the onset of photoinhibition for LL and HL samples were 1000 and 1200 mu mol m(-2) s(-1), respectively using POE signals, and 478 mu mol m(-2) s(-1) and 611 mu mol m(-2) s(-1) using RLC signals. Moreover, HL adapted samples had higher nonphotochemical quenching rates which allude to the OPG's photoelastic potential. The correlation coefficients (kappa) between POE and RLCs were lower than reported values for pure microbial cultures reflecting the enhanced contribution from different photosynthetic clades with a variety of light-harvesting pigments present in OPGs. In an OPG reactor, the photochemical activity can be influenced by the granular size, granular ecology, and reactor operation metrics related to irradiance interactions such as mixing, self-shading, light intensity, photoperiods, and reactor depth. This presents opportunities for design of intensive wastewater resource recovery using phototrophic granular biomass.Publication Hourly Surface Meltwater Routing for a Greenlandic Supraglacial Catchment Across Hillslopes and Through a Dense Topological Channel Network(2021-01-01) Gleason, Colin J.; Yang, Kang; Feng, Dongmei; Smith, Laurence C.; Liu, Kai; Pitcher, Lincoln H.; Chu, Vena W.; Cooper, Matthew G.; Overstreet, Brandon T.; Rennermalm, Asa K.Recent work has identified complex perennial supraglacial stream and river networks in areas of the Greenland Ice Sheet (GrIS) ablation zone. Current surface mass balance (SMB) models appear to overestimate meltwater runoff in these networks compared to in-channel measurements of supraglacial discharge. Here, we constrain SMB models using the hillslope river routing model (HRR), a spatially explicit flow routing model used in terrestrial hydrology, in a 63 km(2) supraglacial river catchment in southwest Greenland. HRR conserves water mass and momentum and explicitly accounts for hillslope routing (i.e., flow over ice and/or firn on the GrIS), and we produce hourly flows for nearly 10 000 channels given inputs of an ice surface digital elevation model (DEM), a remotely sensed supraglacial channel network, SMB-modeled runoff, and an in situ discharge dataset used for calibration. Model calibration yields a Nash-Sutcliffe efficiency as high as 0.92 and physically realistic parameters. We confirm earlier assertions that SMB runoff exceeds the conserved mass of water measured in this catchment (by 12 %-59 %) and that large channels do not de-water overnight despite a diurnal shutdown of SMB runoff production. We further test hillslope routing and network density controls on channel discharge and conclude that explicitly including hillslope flow and routing runoff through a realistic fine-channel network (as opposed to excluding hillslope flow and using a coarse-channel network) produces the most accurate results. Modeling complex surface water processes is thus both possible and necessary to accurately simulate the timing and magnitude of supraglacial channel flows, and we highlight a need for additional in situ discharge datasets to better calibrate and apply this method elsewhere on the ice sheet.Publication Estimation of Suspended Sediment Concentration from Remote Sensing and In Situ Measurement over Lake Tana, Ethiopia(2021-01-01) Womber, Zelalem R.; Zimale, Fasikaw A.; Kebedew, Mebrahtom G.; Asers, Bekalu W.; DeLuca, Nikole M.; Guzman, Christian D.; Tilahun, Seifu A.; Zaitchik, Benjamin F.Discharge from basins joining a lake is the main factor determining the lake volume and sediment inflow to the lake. Suspended sediment is an important parameter for describing the water quality of aquatic ecosystems. Lake Tana is an important and the largest lake in Ethiopia for the local ecological system. However, environmental change and anthropogenic activities in the area threaten its water quality. The conventional methods of suspended sediment concentration (SSC) observation are unable to determine and compare spatial and temporal SSC patterns for the lake over a period of years. Remote sensing methods have made it possible to map SSC. The objective of this study is to characterize the spatial and temporal distribution of suspended sediment of Lake Tana using in situ measurement and remote sensing applications and specifically to develop a relationship between in situ and remote sensing observation to retrieve suspended sediment concentration and map the spatal distribution of SSC. This study used MODIS-Terra and in situ data to characterize the spatial and temporal distribution of SSC in the rainy season. Four sampling campaigns (20 samples per campaign) were carried out on Lake Tana, and the first three sampled campaigns on May 11-13, 2018, June 08-10, 2018, and July 15-17, 2018, were used for calibration of regression models. MODIS-Terra reflectance in NIR was found best related to in situ water quality data and varies linearly with SSC (r(2) = 0.81) and turbidity (r(2) = 0.85). Secchi disc depth (SDD) found the best fit for a power relation with NIR band reflectance (r(2) = 0.74). The MODIS-Terra reflectance in red was found to be poorly related to in situ measurements. The relation in NIR reflectance was validated using the LOOCV (leave-one-out-cross-validation) technique and the fourth sampled data set collected on August 12-14, 2018. Developed models are validated with RMSE of 42.96 mg/l, 14.6 NTU, and 0.17 m, ARE of 23.3%, 27.6%, and 12.4%, and RRMSE of 25.1%, 44.5%, and 29.6% for SSC, turbidity, and SDD, respectively, using LOOCV. The equation was also validated using August 2018 collected data sets with RMSE of 87.6 mg/l, 11.7 NTU, 0.08 m, ARE of 20.8%, 25.9%, and 28.8%, and RRMSE of 17.8%, 20.5%, and 27.9% for SSC, turbidity, and SDD, respectively. Applying the developed regression model, a 10-year time series of SSC from 2008-2017 for May-August was estimated and the trend was tested using the Mann-Kendall trend test. It was found that an increasing trend was observed from the period 2008 to 2017. The result shows that satellite data like the MODIS-Terra imagery could be used to monitor and obtain past records of SSC with the developed equation. The increasing SSC can be reduced by implementing selected management practices in the surrounding watersheds of the lake to reduce nutrient and sediment inflow.Publication Activity-based epidemic propagation and contact network scaling in auto-depending metropolitan areas(2021-01-01) Kumar, Nishant; Oke, Jimi; Nahimias-Biran, Bat-henWe build on recent work to develop a fully mechanistic, activity-based and highly spatio-temporally resolved epidemiological model which leverages person-trajectories obtained from an activity-based model calibrated for two full-scale prototype cities, consisting of representative synthetic populations and mobility networks for two contrasting auto-dependent city typologies. We simulate the propagation of the COVID-19 epidemic in both cities to analyze spreading patterns in urban networks across various activity types. Investigating the impact of the transit network, we find that its removal dampens disease propagation significantly, suggesting that transit restriction is more critical for mitigating post-peak disease spreading in transit dense cities. In the latter stages of disease spread, we find that the greatest share of infections occur at work locations. A statistical analysis of the resulting activity-based contact networks indicates that transit contacts are scale-free, work contacts are Weibull distributed, and shopping or leisure contacts are exponentially distributed. We validate our simulation results against existing case and mortality data across multiple cities in their respective typologies. Our framework demonstrates the potential for tracking epidemic propagation in urban networks, analyzing socio-demographic impacts and assessing activity- and mobility-specific implications of both non-pharmaceutical and pharmaceutical intervention strategies.Publication Probabilistic Evaluation of Drought in CMIP6 Simulations(2021-01-01) Papalexiou, Simon Michael; Rajulapati, Chandra Rupa; Andreadis, Konstantinos M.; Foufoula-Georgiou, Efi; Clark, Martyn P.; Trenberth, Kevin E.As droughts have widespread social and ecological impacts, it is critical to develop long-term adaptation and mitigation strategies to reduce drought vulnerability. Climate models are important in quantifying drought changes. Here, we assess the ability of 285 CMIP6 historical simulations, from 17 models, to reproduce drought duration and severity in three observational data sets using the Standardized Precipitation Index (SPI). We used summary statistics beyond the mean and standard deviation, and devised a novel probabilistic framework, based on the Hellinger distance, to quantify the difference between observed and simulated drought characteristics. Results show that many simulations have less than error in reproducing the observed drought summary statistics. The hypothesis that simulations and observations are described by the same distribution cannot be rejected for more than of the grids based on our distance framework. No single model stood out as demonstrating consistently better performance over large regions of the globe. The variance in drought statistics among the simulations is higher in the tropics compared to other latitudinal zones. Though the models capture the characteristics of dry spells well, there is considerable bias in low precipitation values. Good model performance in terms of SPI does not imply good performance in simulating low precipitation. Our study emphasizes the need to probabilistically evaluate climate model simulations in order to both pinpoint model weaknesses and identify a subset of best-performing models that are useful for impact assessments.Publication A multi-variable equation for relationship between limiting void ratios of uniform sands and morphological characteristics of their particles(2018-01-01) Chang, Ching S.; Deng, Yibing; Meidani, MehrashkThe limiting void ratios (i.e., the minimum and the maximum void ratios) are two important index properties, which are related to the compressibility, shear strength, and permeability of granular soils. Experimental studies have shown that the limiting void ratios are correlated to morphological properties of soil particles (i.e. particle size and particle shape). However, empirical equations available in literature for the limiting void ratios are generally single-variable functions of either particle size, or particle shape. In this study, we propose multi-variable equations, in which the limiting void ratios are functions of both particle size and particle shape. The coupled effects of particle size and particle shape on the limiting void ratios are illustrated. Advantages of the proposed multi-variable equations over the existing single-variable equations are shown by comparing the calculated void ratios with the experimental data on a large number of uniform sand samples. The proposed multi-variable equations can be applied to predict the limiting void ratios of uniform sands encountered in geotechnical engineering projects in order to properly support heavy loads.Publication Recent changes to Arctic river discharge(2021-01-01) Feng, Dongmei; Gleason, Colin J.; Lin, Peirong; Yang, Xiao; Pan, Ming; Ishitsuka, YutaArctic rivers drain ~15% of the global land surface and significantly influence local communities and economies, freshwater and marine ecosystems, and global climate. However, trusted and public knowledge of pan-Arctic rivers is inadequate, especially for small rivers and across Eurasia, inhibiting understanding of the Arctic response to climate change. Here, we calculate daily streamflow in 486,493 pan-Arctic river reaches from 1984-2018 by assimilating 9.18 million river discharge estimates made from 155,710 satellite images into hydrologic model simulations. We reveal larger and more heterogenous total water export (3-17% greater) and water export acceleration (factor of 1.2-3.3 larger) than previously reported, with substantial differences across basins, ecoregions, stream orders, human regulation, and permafrost regimes. We also find significant changes in the spring freshet and summer stream intermittency. Ultimately, our results represent an updated, publicly available, and more accurate daily understanding of Arctic rivers uniquely enabled by recent advances in hydrologic modeling and remote sensing.Publication Modeling of minimum void ratio for sand–silt mixtures(2015-01-01) Chang, Ching S.; Wang, Jia-Yi; Ge, LouisMinimum void ratio or maximum packing density is an important soil property in geotechnical engineering. It correlates to the volume change tendency, the pore fluid conductivity, and the shear strength of the soil. In geotechnical engineering, it often requires to estimate the minimum void ratio for a sand–silt mixture with any amount of fines content, based only on few laboratory test results. The minimum void ratio for soil mixtures is usually estimated by methods based on, to some extent, an empirical approach, for example, the AASHTO coarse particle correction method. In this paper, based on a more fundamental approach using the concept of dominant particle network, we aim to develop a mathematical model that can predict the minimum void ratio for sand–silt mixtures with any amount of fines content. The developed model only requires two parameters for the prediction of minimum void ratios of soil mixtures with various fines contents. The developed model is evaluated by the experimental results on 33 types of soil mixtures available in the literature, including mixtures of sands (Ottawa sand, Nevada sand, Toyoura sand, Hokksund sand, etc), and silts (ATC silt, Nevada fines, crushed silica fines, grind Toyoura fines, etc). Comparisons of the results are discussed.Publication Packing potential index for binary mixtures of granular soil(2020-01-01) Chang, Ching S.; Deng, YibingPacking procedure is the mechanical process of forming a packing of soil particles, such as funnel pouring, tamping, rodding, pluviation, compaction, vibration, compression, etc. For a sand-silt mixture, packing procedure and particle shape have significant effects on the density of the binary mixture. However, these two factors have not been considered in most of the existing particle packing density models. Thus, the existing particle packing density models are not applicable to sand-silt mixtures. In this paper, we aim to study the packing procedure and particle shape effects on density of binary mixtures. We firstly define a packing potential index, which is a measure of volume reduction potential due to mixing of two components of a binary mixture system under a packing procedure. To understand the nature of packing potential index, we compare the packing potential indices of 24 different types of mixtures collected from the literature; the 24 types of mixtures were formed by two different types of packing procedure (i.e., for achieving minimum and maximum void ratios). It is found that the packing potential index is nearly independent of packing procedure but significantly dependent on the compound particle shapes of a mixture. Then, we mathematically link the packing potential index to the particle interaction parameters used in the particle packing density models. And we analyze the data to discuss the effect of packing procedure on the void ratios of sand-silt mixtures. We then propose an approach within the framework of particle packing density model to predict the void ratios of sand-silt mixtures under different packing procedures with the consideration of particle shape effect.Publication Strength–dilatancy and critical state behaviours of binary mixtures of graded sands influenced by particle size ratio and fines content(2021-01-01) Yilmaz, Yuksel; Deng, Yibing; Chang, Ching S.; Gokce, AydinBinary granular soil mixtures, as common heterogeneous soils, are ubiquitous in nature and man-made deposits. Fines content and particle size ratio are two important gradation parameters for a binary mixture, which have potential influences on mechanical behaviours. However, experimental studies on drained shear behaviour considering the whole range of fines content and different particle size ratios are scarce in the literature. For this purpose, a series of drained triaxial compression tests was performed on dense binary silica sand mixtures with four different particle size ratios to investigate systematically the effects of fines content and particle size ratio on the drained shear behaviours. Based on these tests, the strength-dilation behaviour and critical state behaviour were examined. It was observed that both fines content and particle size ratio have significant influence on the stress–strain response, the critical state void ratio, the critical state friction angle, the maximum dilation angle, the peak friction angle and the stress–dilatancy relation. The underlying mechanism for the effects of fines content and particle size ratio was discussed from the perspective of the kinematic movements at particle level.