bluuebunny/crossref_metadata_2025_split huggingface dataset:
A matrix‐free approach for finite‐strain hyperelastic problems using geometric multigrid
Authors: Davydov Denis , Pelteret Jean‐Paul , Arndt Daniel , Kronbichler Martin , Steinmann Paul 
Published: February 2020

SummaryThis work investigates matrix‐free algorithms for problems in quasi‐static finite‐strain hyperelasticity. Iterative solvers with matrix‐free operator evaluation have emerged as an attractive alternative to sparse matrices in the fluid dynamics and wave propagation communities because they significantly reduce the memory traffic, the limiting factor in classical finite element solvers. Specifically, we study different matrix‐free realizations of the finite element tangent operator and determine whether generalized methods of incorporating complex constitutive behavior might be feasible. In order to improve the convergence behavior of iterative solvers, we also propose a method by which to construct level tangent operators and employ them to define a geometric multigrid preconditioner. The performance of the matrix‐free operator and the geometric multigrid preconditioner is compared to the matrix‐based implementation with an algebraic multigrid (AMG) preconditioner on a single node for a representative numerical example of a heterogeneous hyperelastic material in two and three dimensions. We find that matrix‐free methods for finite‐strain solid mechanics are very promising, outperforming linear matrix‐based schemes by two to five times, and that it is possible to develop numerically efficient implementations that are independent of the hyperelastic constitutive
law.
Randomized residual‐based error estimators for the proper generalized decomposition approximation of parametrized problems
Authors: Smetana Kathrin , Zahm Olivier 
Published: February 2020

SummaryThis article introduces a novel error estimator for the proper generalized decomposition (PGD) approximation of parametrized equations. The estimator is intrinsically random: it builds on concentration inequalities of Gaussian maps and an adjoint problem with random right‐hand side, which we approximate using the PGD. The effectivity of this randomized error estimator can be arbitrarily close to unity with high probability, allowing the estimation of the error with respect to any user‐defined norm as well as the error in some quantity of interest. The performance of the error estimator is demonstrated and compared with some existing error estimators for the PGD for a parametrized time‐harmonic elastodynamics problem and the parametrized equations of linear elasticity with a high‐dimensional parameter space.
Informal task‐sharing practices in inpatient newborn settings in a low‐income setting—A task analysis approach
Authors: Omondi Gregory B. , Murphy Georgina A. V. , Jackson Debra , Brownie Sharon , English Mike , Gathara David 
Published: February 2020

AbstractAimTo describe the complexity and criticality of neonatal nursing tasks and existing task‐sharing practices to identify tasks that might be safely shared in inpatient neonatal settings.DesignWe conducted a cross‐sectional study in a large geographically dispersed sample using the STROBE guidelines.MethodsWe used a task analysis approach to describe the complexity/criticality of neonatal nursing tasks and to explore the nature of task sharing using data from structured, self‐administered questionnaires. Data was collected between 26th April and 22nd August 2017.ResultsThirty‐two facilities were surveyed between 26th April and 22nd August, 2017. Nearly half (42%, 6/14) of the “moderately critical” and “not critical” (41%, 5/11) tasks were ranked as consuming most of the nurses' time and reported as shared with mothers respectively. Most tasks were reported as shared in the public sector than in the private‐not‐for‐profit facilities. This may largely be a response to inadequate nurse staffing, as such, there may be space for considering the future role of health care assistants.
Differential role of MAX2 and strigolactones in pathogen, ozone, and stomatal responses
Authors: Kalliola Maria , Jakobson Liina , Davidsson Pär , Pennanen Ville , Waszczak Cezary , Yarmolinsky Dmitry , Zamora Olena , Palva E. Tapio , Kariola Tarja , Kollist Hannes , Brosché Mikael 
Published: February 2020

AbstractStrigolactones are a group of phytohormones that control developmental processes including shoot branching and various plant–environment interactions in plants. We previously showed that the strigolactone perception mutant more axillary branches 2 (max2) has increased susceptibility to plant pathogenic bacteria. Here we show that both strigolactone biosynthesis (max3 and max4) and perception mutants (max2 and dwarf14) are significantly more sensitive to Pseudomonas syringae DC3000. Moreover, in response to P. syringae infection, high levels of SA accumulated in max2 and this mutant was ozone sensitive. Further analysis of gene expression revealed no major role for strigolactone in regulation of defense gene expression. In contrast, guard cell function was clearly impaired in max2 and depending on the assay used, also in max3, max4, and d14 mutants. We analyzed stomatal responses to stimuli that cause stomatal closure. While the response to abscisic acid (ABA) was not impaired in any of the mutants, the response to darkness and high CO2 was impaired in max2 and d14‐1 mutants, and to CO2 also in strigolactone synthesis (max3, max4) mutants. To position the role of MAX2 in the guard cell signaling network, max2 was crossed with mutants defective in ABA biosynthesis or signaling. This revealed that MAX2 acts in a signaling pathway that functions in parallel to the guard cell ABA signaling pathway. We propose that the impaired defense responses of max2 are related to higher stomatal conductance that allows increased entry of bacteria or air pollutants like ozone. Furthermore, as MAX2 appears to act in a specific branch of guard cell signaling (related to CO2 signaling), this protein could be one of the components that allow guard cells to distinguish between different environmental conditions.
Registration of CA 4007 cotton germplasm line for water‐limited production
Authors: Dever Jane , Kelly Carol , Ayele Addissu , Zwonitzer John , Payton Paxton , Jones Don 
Published: February 2020

AbstractIncreasing demands for irrigation and declining water availability are becoming critical issues in the Texas High Plains, the primary cotton (Gossypium hirsutum L.) growing area of the United States. Developing breeding lines suitable for water‐limited production is an important objective of the Texas A&M AgriLife Research cotton breeding program in Lubbock. CA 4007 cotton germplasm (Reg. no. GP‐1062, PI 691459) was derived from a 1993 cross of Verhalen V83‐116 with CA 2159, informal historical releases developed by cotton breeding programs at Oklahoma State University and Texas A&M AgriLife Research in Lubbock, respectively. Performance testing for yield, fiber quality, and other related agronomic properties was conducted in rainfed and irrigated conditions during the 2007, 2008, and 2009 growing seasons. Based on yield performance and other agronomic properties, CA 4007 was included in experiments to evaluate cotton genotypes’ response to moisture stress and its impact on yield, fiber quality, and other agronomic traits. Results indicate that CA 4007 germplasm developed from lines released in two southwestern United States public breeding programs produced good yield and fiber quality under water‐limited production across several growing seasons when compared to commercial production check cultivars in the Texas High Plains.
Experimental observations that simulated active‐layer deepening drives deeper rock fracture
Authors: Maji Vikram , Murton Julian B. 
Published: February 2020

AbstractThe impact of changes in active‐layer thickness on the depth of pervasive macrofracturing (brecciation) in frost‐susceptible bedrock is unclear but important to understanding its physical properties and geohazard potential. Here we report results from a laboratory experiment to test the hypothesis that active‐layer deepening drives an increase in the depth of brecciation. The experiment simulated active‐layer deepening in 300 mm cubic blocks of limestone (chalk) and sandstone. Temperature, surface heave and strain at depth were measured during 16 freeze–thaw cycles. Macrocracks photographed at intervals were digitally analyzed to visualize crack growth and to quantify crack inclination and length. In chalk, an upper horizon of macrocracks developed first at about 100 mm depth in a shallow active layer during cycles 1–8, followed by a lower horizon at about 175–225 mm depth in a deeper active layer during cycles 9–16. The longest cracks (>35 mm) were most common at inclinations of 0–30° from the horizontal, and numerous cracks <5 to 15 mm long developed at inclinations of 40–50°, with some longer vertical to subvertical cracks linking the two brecciated horizons. Overall, the observations support the hypothesis that a thickening active layer drives deeper rock fracture by ice segregation.
A Whole Explosive Dispersion Process Prediction Model for Fuel Clouds
Authors: Chen Xing , Wang Zhongqi , Liu Yun 
Published: February 2020

AbstractThe study of the liquids and granular materials dispersed by high explosions is of great significance in the fuel‐air‐explosion and petrochemical fields. However, there is minimal dynamic dispersal research at high speed. Therefore, the numerical calculation methods of explosive dispersion have become a priority. A model is proposed that can predict the characteristics of the explosive dispersal for fuel both in the near‐field and the far‐field. Then, the basic laws of the fuel cloud formed during explosive dispersal are derived. The model is constructed by six parts of different processes, with the characteristics obtained by tracking the fuel droplets or particles and calculating their velocity, displacement, mass, and particle size. This model is validated using two sets of experimental data consisting of dynamic fuel dispersion and static fuel dispersion that fit the model well.
Zinc, lead, and cadmium tolerance and accumulation in Cistus libanotis, Cistus albidus, and Cistus salviifolius: Perspectives on phytoremediation
Authors: El Mamoun Ibtihaj , Mouna Fahr , Mohammed Abourouh , Najib Bendaou , Zine‐El Abidine Triqui , Abdelkarim Guedira , Didier Bogusz , Laurent Laplaze , Abdelaziz Smouni 
Published: February 2020

AbstractHeavy metal contamination is of particular concern for human health and the environment. Phytoremediation is an emerging cost‐effective strategy to remediate heavy metal contaminated soil. However, this technique is limited by the small number of plants that are tolerant to heavy metals and are also accumulators. This study assayed zinc, lead, and cadmium tolerance and accumulation in Cistus libanotis, Cistus albidus, and Cistus salviifolius. The plants were cultivated in hydroponic conditions and exposed to different concentrations of Pb(NO3)2 (100 and 200 µM), ZnSO4 (100 and 200 µM), or CdCl2 (10 and 20 µM) for 3 weeks. Plant biomass and metal accumulation in roots and aboveground parts varied greatly among the species. All three species appeared to be sensitive to Zn. However, C. albidus displayed strong tolerance to Pb and accumulated large quantities of Pb and Cd in its roots. C. libanotis accumulated large quantities of Pb and Cd in its aboveground parts. C. libanotis can thus be classified as a Pb and Cd accumulator species. The study results show that C. albidus is suitable for phytostabilization of Pb‐contaminated soils, while C. libanotis can be used for phytoextraction of both Pb and Cd.
Carbon isotope forensics for methane source identification
Authors: Coffin Richard , Mueller James 
Published: February 2020

AbstractMethane (CH4) in ecosystems originates from ancient petroleum formed deep within the earth and/or via microbial fermentation of organic carbon and subsequent reduction of carbon dioxide (CO2). Given the complexity of different ecosystems, origins of CH4 present can be difficult to determine. This issue was realized in a situation where an antimethanogenic in situ chemical reduction (ISCR) remedial amendment containing organic carbon plus zero‐valent iron was applied to treat chlorinated solvents in groundwater at a former dry cleaner facility. The technology rapidly and effectively reduced the concentration of tetrachloroethene in groundwater thus meeting project goals without the stoichiometric accumulation of catabolites such as trichloroethene (TCE), cis‐1,2‐dichloroethene, or vinyl chloride and without excessive methanogenesis (e.g., <2 mg/L) in the treated area. However, approximately 9 months after treatment, increased levels of CH4 (from 5 to 10 mg/L) were observed downgradient from the treated area. The applied remedial amendment contained approximately 60% (weight basis) fermentation organic carbon and was therefore a potential source of this CH4. However, there was <500 mg/L total organic carbon in groundwater emanating from the upgradient treatment area which was unlikely sufficient to produce that much CH4. Moreover, the soil gas also contained benzene, toluene, ethylbenzene, and xylenes and other gasoline constituents. These data suggested that the presence of three gasoline/diesel underground storage tanks that were previously closed in place with no active remediation performed could be the source of elevated CH4. Thirdly, there were sewer lines, utilities, multiple gasoline stations, and industrial activities in the immediate area. With an initial assumption that CH4 source(s) could include the ISCR amendment over stimulation of production, gasoline sourced CH4 from nearby leaking lines, or sewage from local fractured pipes, carbon isotope analyses—radiocarbon (Δ14C) and stable carbon (δ13C)—were coupled with CH4 and CO2 concentration data from groundwater samples to determine the origin of respired carbon. The δ13C range for carbon sources respired in the process would be approximately −26.5‰ to −33.0‰ for the ISCR amendment and total petroleum hydrocarbons (TPH) residuals, respectively. Δ14C is approximately 0‰ and −999‰ for the ISCR amendment (young carbon) and TPH (old carbon), respectively. The isotopic signature of respired gasses confirmed that elevated CH4 downgradient of the treated area originated primarily from sewer gasses (or fermentation of liquids released from sewer lines). This study provides an overview of the capability to apply carbon isotope geochemistry to confirmation of remedial protocols and sources of anthropogenic carbon pools that conclusively identify the origin of CH4 in a complex ecosystem undergoing a remedial action.
In situ treatment of a dilute chlorinated solvent plume in an acidic aerobic aquifer
Authors: Alexander Matthew 
Published: February 2020

AbstractIn situ bioremediation was selected in the Record of Decision (ROD) as the remedial technology for a 29‐acre dilute, acidic and aerobic, chlorinated solvent plume (principally trichloroethylene [TCE] and 1,1‐dichloroethylene) for a Superfund site located in central New Jersey. Implementation of the remedy at full‐scale began in late 2010, using reductive dechlorination and bioaugmentation, and treatment has continued steadily over the last 9 years. The amendments injected include electron donor and alkaline (bicarbonate) buffer solution and, once anaerobic aquifer conditions became established, a bioaugmentation culture. Amendment injections occurred in multilevel injection wells (IWs), to maintain control over the vertical interval of amendment delivery. The areal coverage of the plume has been reduced by 59% based on the 10 µg/L TCE isocontour and the contaminant mass has been reduced by 79% through the 9 years of treatment. Lessons learned from this project include the need for bioaugmentation in the acidic aquifer and an efficient and effective manner of well construction and amendment injection using multiscreen single casing IWs and packer systems. Additional lessons learned include differences in longevity of the electron donor amendment versus the bicarbonate neutralization additive, and the need for varied amendment delivery techniques (IWs, direct injection, horizontal well installation) in selected lower permeable zones to attain treatment.
Novel shoreline cap for controlling sheen and dissolved‐phase constituent discharge
Authors: Gentry Jeff L. , Salter‐Blanc Alexandra , Sheets Keith , Sharma Bhawana , Tochko Laura , Martin Scott 
Published: February 2020

AbstractA novel, multilayered shoreline cap was designed and installed to mitigate the release of petroleum light nonaqueous phase liquid (LNAPL) and dissolved‐phase groundwater constituents to the Willamette River in Portland, OR. Releases of LNAPL related to upland impacts caused occasional sheens on a portion of the river within the Portland Harbor Superfund Site. The frequency and volume of sheens decreased following the installation of an upland sheet pile barrier wall, but occasional sheens related to LNAPL impacts stranded downgradient of the wall continued–prompting the design of a shoreline remedy. Because the site is located within the Portland Harbor Superfund Site, the cap was designed to mitigate sheen and to meet the objectives specified in the Portland Harbor Record of Decision including limiting the discharge of certain dissolved‐phase constituents of interest. The cap design was the first instance of combining an oleophilic bio‐barrier to mitigate sheen and an activated carbon layer to capture dissolved‐phase constituents. No sheens have been visually observed since cap installation.
The Synergetic Effect of LiMg0.5Mn1.5O4 Coating and Mg2+ Doping on Improving Electrochemical Performances of High‐Voltage LiNi0.5Mn1.5O4 by Sol‐Gel Self‐Combustion Method
Authors: Li Xuan , Zhang Yanhua , Li Wanpeng , Qiao Yingjun , Shang Huimin , Ge Wujie , Qu Meizhen , Fan Weifeng , Xie Zhengwei 
Published: February 2020

AbstractThe composites of LiNi0.5Mn1.5O4 (LNMO) modified with LiMg0.5Mn1.5O4 (LMgMO) named LNMO@LMgMO as cathode materials for lithium ion battery that can withstand high voltage and high temperature were prepared by a sol‐gel self‐combustion method. The results of physical characterization show that the LMgMO layer was effectively coated on the surface of LNMO, and the Mg2+ was also doped into the lattice of LNMO. Electrochemical tests reveal that the LNMO@LMgMO composites deliver excellent electrochemical performance, especially for LNMO@LMgMO‐1%, including great capacity retention (91.4% for 500 cycles at 25 °C and 90.4% for 100 cycles at 55 °C at 2 C in the 3.5‐5.2 V) and superior rate capability (95.6 mAh g−1 under 10 C). Moreover, the synergetic effect of LMgMO coating and Mg2+ doping could alleviate the impedance rise.
Effect of the Drying Temperature on Color, Antioxidant Activity and In Vitro Digestibility of Green Pea (Pisum sativum L.) Flour
Authors: Gonzalez Manolo , Alvarez‐Ramirez Jose , Vernon‐Carter E. Jaime , Reyes Isabel , Alvarez‐Poblano Lurdes 
Published: February 2020

AbstractGreen peas (Pisum sativum, cv. Warindo) are dehydrated in a channel air flowing (15 m s−1) drier at 50, 60, and 70 °C. Dried peas are milled for obtaining flour, and some properties are assessed. Increasing drying temperatures produce a significant greenness reduction (quantified by chroma parameter a) and on the relative crystallinity (assessed by X‐ray diffraction analysis) from ≈23% at 50 °C to 19% at 70 °C. Contrarily, the in vitro digestibility of both starch and protein increased as drying temperature is higher. The rapidly digestible starch increases from 15.94% at 50 °C to 36.48% at 70 °C, the effect that is linked to the reduction of the relative crystallinity, while protein digestibility increases from 76.26% at 50 °C to 85.87% at 70 °C. The increase of protein digestibility is ascribed to denaturation effects as detected by reduced content of β‐sheet secondary structures detected by FTIR analysis. From the consumer point of view, a higher protein digestibility is deemed as desirable, but the opposite holds true regarding starch digestibility. Thus, this work provides insights about the effect of drying temperature on the digestibility of starch and protein of green pea flour.
Experimental and shear bearing capacity studies of the assembled composite wall with bolted connections
Authors: Huang Wei , Miao Xinwei , Hu Gaoxing , Fan Zhenhui , Zhang Jiarui , Ling Ke 
Published: February 2020

SummaryTo realize the dry connection of an assembled composite wall structure, a bolted connection based on the horizontal joint of an assembled composite wall is proposed. Five specimens were designed under monotonic loading. The failure modes, the seismic performance of the specimens, and the strains and slip of the connectors were studied. The plate thickness and the high‐strength bolts diameter are the key points of research. Moreover, the finite element model for experiment is also established, and the parameters are analyzed based on the numerical models. The results of the experiments and the simulations show that the bolted connection is feasible and the specimens have good deformation capacity. Increasing the plate thickness can improve the bearing capacity of the specimens. Finally, the formula for the shear bearing capacity of the specimen is obtained.
Reproductive morphophysiology of the male scorpion mud turtle (Kinosternon scorpioides Linnaeus, 1766) in captivity
Authors: Fernandes Araujo Chaves Lianne P. , Viana Diego C. , Chaves Elba P. , Miglino Maria A. , de Sousa Alana L. 
Published: February 2020

AbstractKinosternon scorpioides, popularly known as scorpion mud turtle (jurará in Brazil), is a fresh water species. There is little information about its reproduction and the present study aims to morphologically characterize the reproductive organs of male K.scorpioides bred in captivity in two seasons of the year. The reproductive tracts of adult animals under went macroscopic ultrastructural analysis of the lumen, as well as scanning electron and transmission microscopy. Macroscopically, the male genital organs consist of a pair of testicles, epididymis, the vas deferens and a penis. Testicles, epididymis and deferents ducts were characterized by reproductive activity during the rainy season and reproductive inactivity in the dry period. The morphometry regarding the tubular and luminal diameter and epithelial height of the testicles, epididymis and deferents ducts showed changes along the studied periods. The rainy season presented higher averages than the dry period. The penis did not show any changes during both periods. It was concluded that K. scorpioides exhibits reproductive seasonality.