bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental investigation of bio-enhancer drilling fluid additive: Can palm tree leaves be utilized as a supportive eco-friendly additive in water-based drilling fluid system?
Authors: Al-Hameedi Abo Taleb T. , Alkinani Husam H. , Dunn-Norman Shari , Al-Alwani Mustafa A. , Al-Bazzaz Waleed H. , Alshammari Abdullah F. , Albazzaz Hussien W. , Mutar Rusul A. 
Published: August 2019

AbstractSerious problems will be presented due to using conventional chemical additives to regulate the drilling mud properties, as they have health, safety, and environmental side effects. Thus, there is a considerable necessity for alternative multifunctional bio-enhancer drilling mud additives, which can assist in optimizing the drilling fluid specifications and enhance its effectiveness with the least effects on the environment and the drilling personnel safety. The effects of adding two concentrations of palm tree leaves powder (PTLP) to water-based mud were conducted under fresh and aged conditions using standard API drilling fluids testing methods such as rheometer/viscometer, pH meter and temperature, and filter press. All tests results were minutely recorded to understand the influence of PTLP additives on the drilling mud properties. The results indicated that PTLP as an effective material to be used as pH reducer, viscosity reducer, and as an excellent filtration loss control agent under the surface and sub-surface conditions. Thus, PTLP has excellent feasibility to be utilized as biodegradable drilling mud additive replacing or at least supporting other conventional chemical additives, which have usually been used for the same purposes such as lignosulphonate, chrome-lignite, and Resinex. Finally, this work can serve as a practical guide for minimizing the cost of the drilling fluid and reducing the amount of non-biodegradable waste disposed to the environment.
East‐West Differential Underthrusting of the Indian Lithospheric Plate Beneath Central Tibet Revealed by Imaging VP/VS
Authors: Si Shaokun , Gao Rui , Tian Xiaobo 
Published: August 2019

AbstractAlthough numerous research studies have already provided basic information on deeper lithospheric structure under Tibet, the northernmost edge and the geometry of the northward underthrusting of the Indian mantle lithosphere are yet to be understood. The P wave to S wave velocity ratio (VP/VS) can provide more insight into the mantle physical state than either VP or VS alone, owing to their different sensitivities to partial melting, temperature, and composition. High VP/VS usually indicates that partial melting exists in the upper mantle, while anomalously low VP/VS in the upper mantle reflects the enrichment of orthopyroxene in the subduction zone mantle wedge. Using teleseismic records of 164 broadband stations deployed in central Tibet, we obtained a high‐resolution velocity ratio image of the upper mantle. A striking difference is seen between western and eastern Tibet. A distinct high VP/VS zone exists at relatively a shallow depth (<200 km) to the west of the Yadong‐Gulu Rift, while the eastern part exhibits a shallow region (south of the Bangong‐Nujiang suture in the depth range of 120–160 km) with abnormally low VP/VS. Moreover, there are high VP/VS areas existing below 270‐km depth, and it appears further east at depth of 340 km than that at depth of 270 km. We propose that this difference reflects different geometries of the underthrusting Indian mantle lithosphere from west to east. Slab tearing under eastern Tibet and lithospheric delamination under western Tibet are likely good candidates to explain the observation.
Assessing the Role of High‐Frequency Winds and Sea Ice Loss on Arctic Phytoplankton Blooms in an Ice‐Ocean‐Biogeochemical Model
Authors: Castro de la Guardia L. , Garcia‐Quintana Y. , Claret M. , Hu X. , Galbraith E. D. , Myers P. G. 
Published: August 2019

AbstractThe long‐term trend of increasing phytoplankton net primary production (NPP) in the Arctic correlates with increasing light penetration due to sea ice loss. However, recent studies suggest that enhanced stormy wind mixing may also play a significant role enhancing NPP. Here, we isolate the role of sea ice and stormy winds (hereafter high‐frequency winds) using an eddy‐permitting ice‐ocean‐biogeochemical model configured for the North Atlantic and the Arctic. In the model, the presence of high‐frequency winds stimulates nutrient upwelling by producing an earlier and longer autumn‐winter mixing period with deeper mixing layer. The early onset of autumn mixing results in nutrients being brought‐up to near‐surface waters before the light becomes the dominant limiting factor, which leads to the autumn bloom. The enhanced mixing results in higher nutrient concentrations in spring and thus a large spring bloom. The model also shows significant iron limitation in the Labrador Sea, which is intensified by high‐frequency winds. The effect of sea ice loss on NPP was found to be regionally dependent on the presence of high‐frequency winds. This numerical study suggests high‐frequency winds play significant role increasing NPP in the Arctic and sub‐Arctic by alleviating phytoplankton nutrient limitation and that the isolated effect of sea ice loss on light plays a comparatively minor role.
Innovations in (U–Th)/He, Fission Track, and Trapped Charge Thermochronometry with Applications to Earthquakes, Weathering, Surface‐Mantle Connections, and the Growth and Decay of Mountains
Authors: Ault Alexis K. , Gautheron Cécile , King Georgina E. 
Published: August 2019

AbstractA transformative advance in Earth science is the development of low‐temperature thermochronometry to date Earth surface processes or quantify the thermal evolution of rocks through time.Grand challengesand new directions in low‐temperature thermochronometry involve pushing the boundaries of these techniques to decipher thermal histories operative over seconds to hundreds of millions of years, in recent or deep geologic time and from the perspective of atoms to mountain belts. Here we highlight innovation in bedrock and detrital fission track, (U–Th)/He, and trapped charge thermochronometry, as well as thermal history modeling that enable fresh perspectives on Earth science problems. These developments connect low‐temperature thermochronometry tools with new users across Earth science disciplines to enable transdisciplinary research. Method advances include radiation damage and crystal chemistry influences on fission track and (U–Th)/He systematics, atomistic calculations of He diffusion, measurement protocols and numerical modeling routines in trapped charge systematics, development of4He/3He and new (U–Th)/He thermochronometers, and multimethod approaches. New applications leverage method developments and include quantifying landscape evolution at variable temporal scales, changes to Earth's surface in deep geologic time and connections to mantle processes, the spectrum of fault processes from paleoearthquakes to slow slip and fluid flow, and paleoclimate and past critical zone evolution. These research avenues have societal implications for modern climate change, groundwater flow paths, mineral resource and petroleum systems science, and earthquake hazards.
Multicore Parallel Tempering Bayeslands for Basin and Landscape Evolution
Authors: Chandra Rohitash , Müller R. Dietmar , Azam Danial , Deo Ratneel , Butterworth Nathaniel , Salles Tristan , Cripps Sally 
Published: August 2019

AbstractThe Bayesian paradigm is becoming an increasingly popular framework for estimation and uncertainty quantification of unknown parameters in geophysical inversion problems. Badlands is a landscape evolution model for simulating topography evolution at a broad range of spatial and temporal scales. Our previous work presented Bayeslands that used the Bayesian inference for estimating unknown parameters in the Badlands model using Markov chain Monte Carlo sampling. Bayeslands faced challenges in terms of computational issues and convergence due to multimodal posterior distributions. Parallel tempering is an advanced Markov chain Monte Carlo method suited for irregular and multimodal posterior distributions. In this paper, we extend Bayeslands using parallel tempering with high‐performance computing to address previous limitations in Bayeslands. Our results show that parallel tempering Bayeslands not only reduces the computation time‚ but also provides an improvement in sampling multimodal posterior distributions, which motivates future application to continental scale landscape evolution models.
Global Alfvén Wave Power in the Auroral Zone in Relation to the AE Index
Authors: Keiling Andreas , Thaller Scott , Wygant John , Dombeck John 
Published: August 2019

AbstractThe importance of Alfvén waves in energy transport inside the magnetosphere has been demonstrated over the last two decades. Generated in various magnetospheric regions, much of their energy carried to the auroral zone is deposited inside the auroral acceleration region (AAR) via particle acceleration. In this report, we present the integrated contributions of Alfvén wave power to the nightside auroral zone during different levels of auroral activity, as measured by the auroral electrojet (AE) index. Data were collected from an ideal vantage point, namely, above the nominal AAR, over a 6‐year period of Polar satellite operation. We provide functional forms for the total inflowing and outflowing Alfvén wave powers, both of which are linear—at least up to an AE index of 700 nT. For all AE values the power inflow is significantly larger than the power outflow; therefore, the estimated net wave power flowing into the AAR is sufficient to account for the integrated precipitating Alfvénic electron power in the nightside auroral zone below the AAR. The estimated global Alfvén wave absorption (by electrons) and reflection are, respectively, 56% and 33% (upper limit), while an excess wave power of 11% (lower limit) is available for other energy conversion processes, such as Joule heating and Alfvénic ion outflow.
Late Oligocene to Pliocene Extension in the Maltese Islands and Implications for Geodynamics of the Pantelleria Rift and Pelagian Platform
Authors: Martinelli Mattia , Bistacchi Andrea , Balsamo Fabrizio , Meda Marco 
Published: August 2019

AbstractThe tectonic and geodynamic evolution of the Pelagian platform and of the Pantelleria Rift System, located in the foreland of the Apennine‐Sicilian‐Maghrebian Belt, from the Late Oligocene onward, is still debated. Here we present a new interpretation based on structural data collected in the Malta and Gozo islands. With a tectonic back‐stripping approach, we recognized two main extensional events separated by a period of tectonic quiescence: (D1) Early Miocene WNW‐ESE extension and (D2) Late Miocene to Pliocene N‐S extension that led to the opening of the Pantelleria Rift System. During both extensional events the Maltese Islands and the Pelagian Platform were located in the foreland of the Apennine‐Sicilian‐Maghrebian Belt (Western Mediterranean Arc), in a period of slab rollback. We suggest that both tectonic events are an evidence of the extensional regime imposed on the foreland area by the rollback of the subducting slab. The switch in the main extension axis between D1 and D2 (WNW‐ESE vs. N‐S) can be interpreted as a result of the varying orientation and distance of the trench due to the progressive development of the Western Mediterranean Arc and provides an independent tool to “monitor” the slab rollback. Results obtained in this study allowed, for the first time, to bind the tectonic evolution of the area with the geodynamic evolution of the Western and Central Mediterranean.
Canopy Adjustment and Improved Cloud Detection for Remotely Sensed Snow Cover Mapping
Authors: Rittger Karl , Raleigh Mark S. , Dozier Jeff , Hill Alice F. , Lutz James A. , Painter Thomas H. 
Published: August 2019

AbstractMaps of snow cover serve as early indicators for hydrologic forecasts and as inputs to hydrologic models that inform water management strategies. Advances in snow cover mapping have led to increasing accuracy, but unsatisfactory treatment of vegetation's interference when mapping snow has led to maps that have limited utility for water forecasting. Vegetation affects snow mapping because ground surfaces not visible to the satellite produce uncertainty as to whether the ground is snow covered. At nadir, the forest canopy obscures the satellite view below the canopy. At oblique viewing angles, the forest floor is obscured by both the canopy and the projection of tree profiles onto the forest floor. We present a canopy correction method based on Moderate Resolution Imaging Spectroradiometer satellite imagery validated with field observations that mitigates geometric and georegistration issues associated with changing satellite acquisition angles in forested areas. The largest effect from a variable viewing zenith angle on the viewable gap fraction in forested areas occurs in moderately forested areas with 30–40% tree canopy coverage. Cloud cover frequently causes errors in snow identification, with some clouds identified as snow and some snow identified as cloud. A snow‐cloud identification method utilizes a time series of fractional vegetation and rock land‐surface data to flag snow‐cloud identification errors and improve snow‐map accuracy reducing bias by 20% over previous methods. Together, these contributions to snow‐mapping techniques could advance hydrologic forecasting in forested, snow‐dominated basins that comprise an estimated one fifth of Northern Hemisphere snow‐covered areas.
Characterizing Biases in Mountain Snow Accumulation From Global Data Sets
Authors: Wrzesien Melissa L. , Pavelsky Tamlin M. , Durand Michael T. , Dozier Jeff , Lundquist Jessica D. 
Published: August 2019

AbstractMountain snow has a fundamental role in regional water budgets through its seasonal accumulation, storage, and melt. However, characterizing snow accumulation over large regions remains difficult because of limited observational networks and the inability of available satellite instruments to remotely sense snow depth or water equivalent in mountains. Models offer some ability to estimate snow water storage (SWS) on mountain range to continental scales. Here we compare four commonly used global data sets to understand whether there is a consensus regarding mountain SWS estimates among them. The data sets—European Centre for Medium‐Range Weather Forecasts Reanalysis‐Interim, Global Land Data Assimilation System, Modern‐Era Retrospective Analysis for Research and Applications version 2, and Variable Infiltration Capacity—agree to within ±36% of the four–data set average for total global SWS. When mountain areas are extracted using a new seasonal mountain snow classification data set, the four data products have more agreement, where all are within ±21% of the seasonal SWS for mountain regions. However, when compared to high‐resolution (9 km) simulations of SWS from the Weather Research and Forecasting (WRF) regional model, the four global products differ from WRF‐estimated North American mountain snow accumulation by 40–66%, with a negative bias up to 651 km3, comparable to the annual streamflow of the Mississippi River. If we extend the North America SWS bias to global mountains, the global data sets may miss as much as 1,500 km3 of SWS, equivalent to 4% of the flow in all the world's rivers. The potential difference of SWS suggests more work must be done to characterize water resources in snow‐dominated regions, particularly in mountains.
Comparing Discharge Estimates Made via the BAM Algorithm in High‐Order Arctic Rivers Derived Solely From Optical CubeSat, Landsat, and Sentinel‐2 Data
Authors: Feng Dongmei , Gleason Colin J. , Yang Xiao , Pavelsky Tamlin M. 
Published: August 2019

AbstractConventional satellite platforms are limited in their ability to monitor rivers at fine spatial and temporal scales: suffering from unavoidable trade‐offs between spatial and temporal resolutions. CubeSat constellations, however, can provide global data at high spatial and temporal resolutions, albeit with reduced spectral information. This study provides a first assessment of using CubeSat data for river discharge estimation in both gauged and ungauged settings. Discharge was estimated for 11 Arctic rivers with sizes ranging from 16 to >1,000 m wide using the Bayesian at‐many‐stations hydraulic geometry‐Manning algorithm (BAM). BAM‐at‐many‐stations hydraulic geometry solves for hydraulic geometry parameters to estimate flow and requires only river widths as input. Widths were retrieved from Landsat 8 and Sentinel‐2 data sets and a CubeSat (the Planet company) data set, as well as their fusions. Results show satellite data fusion improves discharge estimation for both large (>100 m wide) and medium (40–100 m wide) rivers by increasing the number of days with a discharge estimation by a factor of 2–6 without reducing accuracy. Narrow rivers (<40 m wide) are too small for Landsat and Sentinel‐2 data sets, and their discharge is also not well estimated using CubeSat data alone, likely because the four‐band sensor cannot resolve water surfaces accurately enough. BAM technique outperforms space‐based rating curves when gauge data are available, and its accuracy is acceptable when no gauge data are present (instead relying on global reanalysis for discharge priors). Ultimately, we conclude that the data fusion presented here is a viable approach toward improving discharge estimates in the Arctic, even in ungauged basins.
Scaling down of cobalt quantum‐dots by colloidal route for non‐volatile memory device application
Authors: Yadav Manoj , Velampati Ravi Shankar R. , Mandal Debaprasad 
Published: August 2019

The present work details the synthesis of cobalt quantum‐dots (Co QDs) with size downscaling to 1–2 nm and their applications in non‐volatile memory (NVM) devices. The process of colloidal synthesis is simple and provides the control over a wide range of QDs size. The scaled‐down colloidal Co QDs are applied for the NVM device fabrication. Colloidal synthesised Co QDs are spin‐coated over silicon dioxide wafer for the fabrication of floating‐gate NVM devices. Capacitance–voltage (C –V) and capacitance–time (C –t) measurements of the fabricated NVM device indicate a low voltage operation of device. A sweep voltages as small as 1.2–4 V lead to a flat band voltage shift of 0.35–1.5 V, evidencing the low operating voltage and low power NVM applications. Further, retention characteristics show a robust retention by fabricated NVM device. In addition, C –V measurements are done for the several samples in order to study the process repeatability. The work also is compared with the other processes for the floating gate memory device.
Recovery from Strenuous Downhill Running in Young and Older Physically Active Adults
Authors: Hayashi Koichiro , Leary Miriam E. , Roy Stephen J. , Laosiripisan Jitanan , Pasha Evan P. , Tanaka Hirofumi 
Published: August 2019

AbstractThere is a well-conceived notion that rate of recovery from strenuous exercise gets slower with age. However, it is unclear whether older adults who exercise habitually demonstrate slower rates of recovery. We determined whether older adults who are physically active demonstrate slower rates of recovery from unaccustomed strenuous exercise compared with younger peers. Healthy young sedentary (n=10, 28±2 years), young endurance-trained (n=15, 27±2 years), and older endurance-trained (n=14, 58±2 years) men and women were studied. Participants performed 45 min of downhill running at 65% of their maximal oxygen consumption. Visual analog pain scores of muscle groups increased at 24, 48, and 72 h in all three groups (p<0.05), and changes in the muscular pain scale of the legs was smaller in the older trained group than in the young trained group. Maximum isometric strengths at 90° decreased in all groups at 24 h, but the recovery rates were not different at 72 h among the groups. Plasma creatine kinase activity and myoglobin concentration increased at 24 h following downhill running and returned to baseline at 48 h in both the young and older trained groups. The present findings are not consistent with the prevailing notion that older trained adults have a slower rate of recovery from strenuous exercise.
Pacing characteristics of whole and part‐game players in professional rugby union
Authors: Tee Jason C. , Coopoo Yoga , Lambert Mike 
Published: August 2019

AbstractContemporary theories on players’ intensity distribution in team sports suggest that they regulate their outputs using pacing strategies. There is currently limited information on how movement patterns and pacing strategies of rugby union players in different position groups (forwards and backs) vary when exposed to different bout types (whole game, starter or finisher). Global positioning system (GPS) and accelerometer data were collected from 100 professional match participations to determine temporal effects on movement patterns. For forwards, finishers (players who entered the game as substitutes) demonstrated significantly greater high‐speed running distance (% difference, ± 90%CI; magnitude‐based inference and effect size) (↑ 55, ±17%; very likely large) and acceleration frequency (↑ 78, ±59%; very likely large) than whole game players. For backs, starters (players who started the game and were later substituted) displayed greater high‐speed running distance than whole game players (↑ 27, ±21%; ES = likely medium) but this difference did not achieve statistical significance (p = .07). Forwards displayed “slow‐positive” pacing strategies regardless of bout type, while backs displayed “flat” pacing strategies. Forwards and backs adopt different pacing strategies regardless of bout type, with forwards demonstrating progressively greater performance decrements over the course of the match. These findings reflect differing physical demands, notably contact and running loads, of players in different positions.
Climate change and future power systems: the importance of energy storage in reduced-hydropower systems in the American Southwest
Authors: Wadsack Karin , Acker Thomas L 
Published: August 2019

Abstract
Power systems are responding to climate change both through efforts to reduce greenhouse-gas emissions and through adaptive responses to the effects of climate change, such as changes in hydroelectric generation. These changes, experienced together, may cause new patterns in plant operations or pollutant emissions. Various scenarios representing future climate change mitigation and adaptation in the power sector were explored using the PLEXOS production-cost model, with a focus on plant utilization and behaviour, total system-operating costs and total CO2 emissions. Further, the effect of introducing widespread utility-scale energy storage into these scenarios was quantified in terms of these same parameters. Large increases in variable renewable penetration combined with extreme reduction of hydroelectric generation in the American Southwest (based on climate modelling in the Colorado River basin and actual drought experience in California) caused significant increases in thermal plant start-up/shutdown cycling. The introduction of storage significantly reduced this cycling, without a material increase in CO2 emissions. Storage introduced on even a modest scale can provide considerable flexibility under a range of future power-system circumstances that might be experienced due to climate change.