bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Evolution of an Oceanic Intraplate Volcano From Seismic Reflection Data: A New Model for La Réunion, Indian Ocean
Authors: Lebas E. , Le Friant A. , Deplus C. , de Voogd B. 
Published: January 2018

AbstractHigh‐resolution seismic reflection profiles gathered in 2006 on La Réunion submarine flanks and surrounding abyssal plain, enabled characterization of the seismostratigraphy architecture of the volcaniclastic apron. Four seismic units are defined beyond the edifice base: (1) a basal unit, interpreted as pelagic sediment predating La Réunion volcanism; (2) a second unit showing low‐ to medium‐amplitude reflections, related to La Réunion emergence including the submarine explosive phase; (3) a high‐amplitude seismic unit, associated with subaerial volcanic activity (i.e., mature island stage); and (4) an acoustically transparent unit, ascribed to erosion that currently affects the volcanic complex. Two prominent horizons delineate the base of the units II and III marking, respectively, the onset of La Réunion seamount explosive activity and the Piton des Neiges volcanic activity. Related isopach maps demonstrate: (1) the existence of a large proto‐Piton des Neiges volcano during the first building phase of the volcanic complex, and (2) the central role of the Piton des Neiges volcano during the second phase. Shield growth stage of the Piton de la Fournaise volcano is also captured in the upper part of the volcaniclastic apron, attesting to its recent contribution. Seismic facies identified in the apron highlight a prevalence of sedimentary and reworking processes since the onset of the volcanism compared to catastrophic flank collapses. We present here a new model of evolution for La Réunion volcanic complex since the onset of the volcanism and argue that a major proto Piton des Neiges‐Piton des Neiges volcanic complex controls La Réunion present‐day morphology.
Pressure and Stress Prediction in the Nankai Accretionary Prism: A Critical State Soil Mechanics Porosity‐Based Approach
Authors: Flemings Peter B. , Saffer Demian M. 
Published: January 2018

AbstractWe predict pressure and stress from porosity in the Nankai accretionary prism with a critical state soil model that describes porosity as a function of mean stress and maximum shear stress, and assumes Coulomb failure within the wedge and uniaxial burial beneath it. At Ocean Drilling Program Sites 1174 and 808, we find that pore pressure in the prism supports 70% to 90% of the overburden (λu = 0.7 to 0.9), for a range of assumed friction angles (5–30°). The prism pore pressure is equal to or greater than that in the underthrust sediments even though the porosity is lower within the prism. The high pore pressures lead to a mechanically weak wedge that supports low maximum shear stress, and this in turn requires very low basal traction to remain consistent with the observed narrowly tapered wedge geometry. We estimate the décollement friction coefficient (μb) to be ~0.08–0.38 (ϕb′ = 4.6°–21°). Our approach defines a pathway to predict pressure in a wide range of environments from readily observed quantities (e.g., porosity and seismic velocity). Pressure and stress control the form of the Earth's collisional continental margins and play a key role in its greatest earthquakes. However, heretofore, there has been no systematic approach to relate material state (e.g., porosity), pore pressure, and stress in these systems.
Compressible Flow Phenomena at Inception of Lateral Density Currents Fed by Collapsing Gas‐Particle Mixtures
Authors: Valentine Greg A. , Sweeney Matthew R. 
Published: January 2018

AbstractMany geological flows are sourced by falling gas‐particle mixtures, such as during collapse of lava domes, and impulsive eruptive jets, and sustained columns, and rock falls. The transition from vertical to lateral flow is complex due to the range of coupling between particles of different sizes and densities and the carrier gas, and due to the potential for compressible flow phenomena. We use multiphase modeling to explore these dynamics. In mixtures with small particles, and with subsonic speeds, particles follow the gas such that outgoing lateral flows have similar particle concentration and speed as the vertical flows. Large particles concentrate immediately upon impact and move laterally away as granular flows overridden by a high‐speed jet of expelled gas. When a falling flow is supersonic, a bow shock develops above the impact zone, and this produces a zone of high pressure from which lateral flows emerge as overpressured wall jets. The jets form complex structures as the mixtures expand and accelerate and then recompress through a recompression zone that mimics a Mach disk shock in ideal gas jets. In mixtures with moderate to high ratios of fine to coarse particles, the latter tend to follow fine particles through the expansion‐recompression flow fields because of particle‐particle drag. Expansion within the flow fields can lead to locally reduced gas pressure that could enhance substrate erosion in natural flows. The recompression zones form at distances, and have peak pressures, that are roughly proportional to the Mach numbers of impacting flows.
Malleable Curie Temperatures of Natural Titanomagnetites: Occurrences, Modes, and Mechanisms
Authors: Jackson Mike , Bowles Julie 
Published: January 2018

AbstractIntermediate‐composition titanomagnetites have Curie temperatures (Tc) that depend not only on composition but also on thermal history, with increases of 100°C or more in Tc produced by moderate‐temperature (300–400°C) annealing in the laboratory or in slow natural cooling and comparable decreases produced by more rapid cooling (“quenching”) from higher temperatures. New samples spanning a range of titanomagnetite compositions exhibit reversible changes in Tc comparable to those previously documented for pyroclastic samples from Mt. St. Helens and Novarupta. Additional high‐ and low‐temperature measurements help to shed light on the nanoscale mechanisms responsible for the observed changes in Tc. High‐T hysteresis measurements exhibit a peak in high‐field slope khf(T) at the Curie temperature, and the peak magnitude decreases as Tc increases with annealing. Sharp changes in low‐T magnetic behavior are also strongly affected by prior annealing or quenching, suggesting that these treatments affect the intrasite cation distributions. We have examined the effects of oxidation state and nonstoichiometry on the magnitude of Tc changes produced by quenching/annealing in different atmospheres. Treatments in air generally cause large changes (ΔTc > 100°). In an inert atmosphere, the changes are similar in many samples but strongly diminished in others. When the samples are embedded in a reducing material, ΔTc becomes insignificant. These results strongly suggest that cation vacancies play an essential role in the cation rearrangements responsible for the observed changes in Tc. Some form of octahedral‐site chemical clustering or short‐range ordering appears to be the best way to explain the large observed changes in Tc.
No Correlation Between Atmospheric Dust and Surface Ocean Chlorophyll‐a in the Oligotrophic Gulf of Aqaba, Northern Red Sea
Authors: Torfstein A. , Kienast S. S. 
Published: January 2018

AbstractHigh‐resolution records of daily surface chlorophyll‐a (chl‐a) concentrations and hourly atmospheric dust concentrations in the Gulf of Aqaba, northern Red Sea, are compared between 2012 and 2016 in order to examine the interplay between atmospheric dust input and surface productivity in this subtropic, nutrient‐poor marine ecosystem. Given that lags of days to weeks may occur between the dust input and phytoplankton response, and because of potential biases associated with differences in the sampling resolution, temporal offsets of 1–10 days between the dust and chl‐a are examined using smoothing windows between 3 and 31 days. The results suggest that there is no significant positive (or negative) correlation between dust and chl‐a surface concentrations, even when allowing for temporal offsets between the two records. This observation pertains to the seasonal as well as the daily time scale (i.e., abrupt dust storms). It is concluded that the role of atmospheric dust as a control on productivity in the Gulf of Aqaba and possibly other oligotrophic regions may have been previously overestimated.
New adaptive statistical iterative reconstruction ASiR‐V: Assessment of noise performance in comparison to ASiR
Authors: De Marco Paolo , Origgi Daniela 
Published: January 2018

AbstractPurposeTo assess the noise characteristics of the new adaptive statistical iterative reconstruction (ASiR‐V) in comparison to ASiR.MethodsA water phantom was acquired with common clinical scanning parameters, at five different levels of CTDIvol. Images were reconstructed with different kernels (STD, SOFT, and BONE), different IR levels (40%, 60%, and 100%) and different slice thickness (ST) (0.625 and 2.5 mm), both for ASiR‐V and ASiR. Noise properties were investigated and noise power spectrum (NPS) was evaluated.ResultsASiR‐V significantly reduced noise relative to FBP: noise reduction was in the range 23%–60% for a 0.625 mm ST and 12%–64% for the 2.5 mm ST. Above 2 mGy, noise reduction for ASiR‐V had no dependence on dose. Noise reduction for ASIR‐V has dependence on ST, being greater for STD and SOFT kernels at 2.5 mm. For the STD kernel ASiR‐V has greater noise reduction for both ST, if compared to ASiR. For the SOFT kernel, results varies according to dose and ST, while for BONE kernel ASIR‐V shows less noise reduction. NPS for CT Revolution has dose dependent behavior at lower doses. NPS for ASIR‐V and ASiR is similar, showing a shift toward lower frequencies as the IR level increases for STD and SOFT kernels. The NPS is different between ASiR‐V and ASIR with BONE kernel. NPS for ASiR‐V appears to be ST dependent, having a shift toward lower frequencies for 2.5 mm ST.ConclusionsASiR‐V showed greater noise reduction than ASiR for STD and SOFT kernels, while keeping the same NPS. For the BONE kernel, ASiR‐V presents a completely different behavior, with less noise reduction and modified NPS. Noise properties of the ASiR‐V are dependent on reconstruction slice thickness. The noise properties of ASiR‐V suggest the need for further measurements and efforts to establish new CT protocols to optimize clinical imaging.
Iron Single Clusters Anchored on N‐Doped Porous Carbon as Superior Trace‐Metal Catalysts toward Oxygen Reduction
Authors: Xue Hui , He Ting , Chabu Johnny Muya , Liu Jingjing , Wu Huiqiong , Zheng Jun , Tan Minli , Ma Jing , Shen Rujuan , Deng Liu , Zhang Yi 
Published: January 2018

AbstractA new strategy to in situ immobilize iron (Fe) single clusters on N‐doped porous carbon under the confinement effect of N‐coordination supplied by porphyrins is demonstrated. During the pyrolysis reaction, the strong chelated interaction between Fe and N atoms serves as the pivotal role for achieving Fe single clusters via inhibiting the superabundant aggregation of Fe atoms. Compared to the Fe‐based nanoparticles and commercial Pt‐C, the synthesized single Fe cluster catalyst (C/TP‐Fe700) owns a superior catalytic performance in alkaline medium, which is confirmed by the more positive half‐wave potential (0.865 V, 28 mV higher than Pt‐C), high mass activity (0.60 A mg−1Fe, 10 times larger than Pt‐C), the excellent durability and remarkable methanol tolerance. Additionally, it likewise presents satisfactory oxygen reduction reaction activity in acidic medium compared with Pt‐C. This single metal cluster (metal cluster with subnanometer) catalyst with trace‐metal contents displays double advantages from metal and metal‐free oxygen reduction catalysts, such as high activity, ultralight mass, and environmental friendliness. Insight into this successful paradigm can provide a novel concept for constructing and understanding oxygen reduction catalysts at an approximate atomic scale.
Layered Molybdenum (Oxy) Pyrophosphate (MoO2)2P2O7 as a Cathode Material for Sodium‐Ion Batteries
Authors: Deng Wenwen , Feng Xuyong , Xiao Yao , Li Changming 
Published: January 2018

AbstractLayer‐structured (MoO2)2P2O7 was prepared through the decomposition of MoO2HPO4 and further used as a cathode material for sodium‐ion batteries. Results reveal that the capacity and cycling stability of the (MoO2)2P2O7/Na battery largely depends on the lower cutoff voltage. When cycling between 4.0 ‐1.5 V, (MoO2)2P2O7 delivers a capacity of 180 mAh g−1 in the first cycle, but it drops very fast owing to a phase decomposition of the crystal structure to an amorphous one. The cycling stability is still not good when cycling between 4.0 ‐1.7 V. However, when cycling between 4.0 ‐ 2.0 V, the performance can be significantly improved, which delivers 93 mAh g−1 in the first cycle and, after 50 cycles, the capacity can maintain 55 mAh g−1. This is mainly attributed to the stable crystal structure of the Na‐intercalated (MoO2)2P2O7 electrode. Ex situ X‐ray diffraction examination demonstrates that the volume change of the (MoO2)2P2O7 electrode during the first charging process is only 1 %.
Self‐Organized Porous Titanium‐Chitosan Hybrid Materials with Tunable Functions
Authors: Khoury Christine , Gazit Oz M. 
Published: January 2018

AbstractMultifunctional hybrid polymer‐based materials are shown to self‐organize into a patterned solid microstructure, specific enough to induce cooperative catalytic interactions between primary amine sites and grafted titanium (Ti) sites. We demonstrate this by a new procedure for the grafting of titanium sites onto the backbone of polyhydroxylated‐amine‐containing polymer (chitosan). The Ti grafting is shown to form an amorphous hybrid (Ti@CS) high surface area material (up to 130 m2 g−1), despite the strong thermodynamic tendency of CS to collapse into a compact structure held by hydrogen bonds. We find that the surface area of Ti@CS materials is stable even at 110 °C under high vacuum. Tuning of the grafting conditions and the post treatment conditions provide control over the functionalities of both the Ti sites and the primary amine sites. These can be tuned such that the nitro‐aldol condensation (Henry), used as probe reaction, is either (i) not catalyzed, (ii) catalyzed by amines promoted by Ti presence or (iii) catalyzed cooperatively by the primary amines and the Ti sites. Critical parameters related to the microstructure and chemical interactions between the organic and inorganic components are discussed in detail and cross‐referenced with catalytic results.
Ecohydrological functioning of an upland undergoing reclamation on post‐mining landscape of the Athabasca oil sands region, Canada
Authors: Gingras‐Hill Tristan , Nwaishi Felix C. , Macrae Merrin L. , Price Jonathan S. , Petrone Richard M. 
Published: January 2018

AbstractEcohydrological functioning of natural Boreal forest in Canada's Boreal Plains is a product of interactions between soil hydrophysical characteristics and hydrogeochemical processes. These interactions create a moisture–nutrient gradient within the surface soils, increasing along low‐relief transitions from upland to riparian zone, and in turn influence the distribution of vegetation communities. It is not yet known if/when analogous ecohydrological functions can be achieved in constructed uplands following industrial disturbance, such as that following oil sands development. Hence, to assess this, we studied interactions between hydrogeochemical processes and vegetation colonization in a constructed upland relative to hydrophysical properties of 2 reclamation cover substrates during a typical continental climate's growing season. Our results indicated that in 3 years of postconstruction, the establishment of a moisture–nutrient gradient that supports vegetation colonization along slope positions was still limited by heterogeneity of cover substrates. Portions of the upland under peat–mineral mix were characterized by lower nutrient availability, high moisture content, and establishment of planted shrubs and trees. In contrast, forest floor materials plots were characterized by poor soil quality, but higher nutrient availability and greater colonization of invasive grasses and native shrubs. We suggest that the colonization of underdeveloped soils by invasive grasses may facilitate pedogenic processes and thus should be accepted by reclamation managers as a successional milestone in the recovery of ecohydrological functioning of constructed uplands. Poor soil structure under forest floor materials could not support edaphic conditions required by plants to efficiently utilize fertilizer, making this practise futile at the early stage of soil development.
Effects of higher versus lower threat contexts on pain‐related attention biases: An eye‐tracking study
Authors: Jackson T. , Su L. , Wang Y. 
Published: January 2018

AbstractBackgroundThreat is hypothesized to affect the degree to which pain captures attention but little is known about its impact on dynamic courses of attention towards pain. In this eye‐tracking study, we evaluated pain‐related visual attention biases during image pair presentations in comparatively lower versus higher threat conditions.MethodsGaze biases of healthy adults (47 women, 35 men) were assessed during image presentation phases standardized across (1) a modified visual dot‐probe task featuring painful‐neutral (pain) and neutral–neutral contrast (neutral) image pair blocks (lower threat context); and (2) an impending pain task wherein the same image pair blocks, respectively, cued potentially painful postoffset somatosensory stimuli (higher threat context) and its absence.ResultsAcross tasks, participants were more often oriented towards, gazed longer at, and fixated more times on pain images in pain block trials, although trait fear of pain was not related to any gaze biases. Critically, however, participants reported more state fear and displayed significantly fewer initial fixations, longer first and overall gaze durations, and more unique fixations on pain images when image pairs signalled possible postoffset pain stimulation.ConclusionsResults underscored stronger overall attention maintenance on visual pain cues in a higher threat (impending pain) context.SignificanceThrough considering gaze parameters during image presentation phases of dot‐probe and impending pain tasks, possible effects of lower versus higher threat contexts on attention biases were elucidated. Participants reported more fear and gazed longer at painful than neutral images in the higher threat context whereby image pairs cued possible pain.
Analyse der Temperaturfahnenausbreitung kleiner Geothermiesondenanlagen
Authors: Wagner Isabel M. 
Published: January 2018

AbstractKleine oberflächennahe Geothermiesondenanlagen mit einer Heizleistung < 30 kW sind insbesondere im privaten Wohnsektor zu finden. Die Geothermiesonden erzeugen durch ihren Wärmeentzug Temperaturänderungen im Untergrund, deren Form sich in Abhängigkeit von den projektbezogenen Parametern, wie u. a. den geothermischen Untergrundeigenschaften, dem Betrieb der Sonde und der Grundwasserströmung, ausbildet. Im Rahmen des Genehmigungsprozesses werden vonseiten der Genehmigungsbehörde pauschale und nicht projektbezogene Grenzabstände für die Geothermiesonden gefordert, deren Einhaltung sich mit abnehmender Grundstücksgröße bisweilen schwierig gestaltet. Der Einsatz eines analytischen Ansatzes zur Abschätzung der Temperaturfahnenausbreitung wird präsentiert, um eine auf das Projekt abgestimmte Festlegung der Grenzabstände zu ermöglichen, die die Größe der Grundwasserströmung, die Betriebsweise und die Anzahl der Sonden kleiner oberflächennaher Geothermiesondenanlagen berücksichtigt.
N‐Palmitoyl Ethanol Amide Pharmacological Treatment in Patients With Nonsurgical Lumbar Radiculopathy
Authors: Chirchiglia Domenico , Paventi Saverio , Seminara Paolo , Cione Erika , Gallelli Luca 
Published: January 2018

AbstractPalmitoyl ethanol amide (PEA) is an endogenous substance that plays a role in neuropathic pain. In this article, we evaluated both the safety and the efficacy of ultramicronized PEA (um‐PEA) in the treatment of low back pain related to nonsurgical lumbar radiculopathy. In this prospective single‐blind study, patients with low back pain related to nonsurgical lumbar radiculopathy received the fixed combination acetaminophen/codeine (500 mg + 30 mg/d) for 7 days, and then it was stopped and changed to um‐PEA (1200 mg/d) for 30 days. Patients without an improvement in pain or disability started a second cycle of treatment with um‐PEA (600 mg/d in tablets) for 30 days and then acetaminophen/codeine for 30 days. A total of 155 patients were included in the analysis. After the first cycle of treatment we recorded an improvement of pain in all patients with mild pain (visual analog scale score from 3‐4 to 1) and in 75% of the patients with moderate pain (visual analog scale score from 5‐6 to 2). After the second cycle, we recorded an improvement of pain and disability in all patients with moderate pain (P < .01), but in 26% of patients with severe pain we did not record any improvement in disability (P > .05). In conclusion we evaluated the role of um‐PEA in patients with lumbar radiculopathy with a long‐term follow‐up (24 months) and put in evidence the effectiveness and the safety of this formulation in patients with mild and moderate pain.
Maturation periods for Coffea arabica cultivars and their implications for yield and quality in Brazil
Authors: de Oliveira Aparecido Lucas Eduardo , Rolim Glauco de Souza , Moraes José Reinaldo da Silva Cabral de , Valeriano Taynara Tuany Borges , Lense Guilherme Henrique Expedido 
Published: January 2018

AbstractBACKGROUNDClimatic conditions directly affect the maturation period of coffee plantations, affecting yield and beverage quality. The quality of coffee beverages is highly correlated with the length of fruit maturation, which is strongly influenced by meteorological elements. The objective was to estimate the probable times of graining and maturation of the main coffee varieties in Brazil and to quantify the influences of climate on coffee maturation. We used degree days to estimate flowering/graining periods (green fruit) and flowering/maturation periods (cherry fruit) for all cultivars. We evaluated the influence of climate on the time of maturity using Pearson correlation and nonlinear regression analysis and successfully mapped the influences of these elements.RESULTSArabica coffee matured up to 2–3 months earlier in São Paulo, where air temperatures (TAIR) were higher, than in Minas Gerais, which would allow earlier harvesting and the training of seedlings at the beginning of the rainy season. Catuaí‐Amarelo‐IAC‐62 cultivar needed 205–226 days between the end of flowering and maturation at locations with high TAIR and 375–396 days at locations with low TAIR.CONCLUSIONWater surplus and deficit were generally the most important variables for coffee maturation. Coffee matured faster in regions with high TAIR and evapotranspiration, moderate altitudes and deficits. Acaiá‐Cerrado‐MG‐1474 and Icatu‐Precoce‐Amarelo‐3282 were cultivars with an early cycle. © 2018 Society of Chemical Industry