bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magma Plumbing System at a Young Back‐Arc Spreading Center: The Marsili Volcano, Southern Tyrrhenian Sea
Authors: Trua T. , Marani M. P. , Gamberi F. 
Published: December 2017

AbstractAlthough spreading rate is commonly taken as a proxy for decompression mantle melting at mid‐ocean ridges (MORs), magmatism at back‐arc spreading centers (BASCs) is further influenced by the subduction‐related flux melting of the mantle. These regions consequently show a diversity of crustal structures, lava compositions, and morphologies not typically found in MORs. Here we investigate the crustal plumbing system of the small‐scale, Marsili back‐arc spreading center of the Southern Tyrrhenian Sea using plagioclase data from a wide spectrum of lavas (basalts to andesites) dredged from its summit and flanks. We employ petrological modeling to identify the plagioclase populations carried in the individual lavas, allocate them to plausible magmatic components present within the plumbing system, and trace the processes occurring during magma ascent to the surface. The properties of the system, such as mush porosity and abundance of the melt bodies, vary from one magma extraction zone to another along the BASC, evidencing the local variability of melt supply conditions. The plagioclase crystals document a range of relationships with the host lavas, indicating magma extraction from a composite, vertically extensive mush and melt‐lens system resembling that of MORs. At the same time, however, in small BASCs, such as in the case of the Marsili Basin, crustal accretion and resulting morphology are significantly influenced by the three‐dimensional setting of the basin margins. This is an important deviation from the conventional model based on the linear continuity and essentially two‐dimensional framework of MORs.
Seasonal and ENSO Influences on the Stable Isotopic Composition of Galápagos Precipitation
Authors: Martin N. J. , Conroy J. L. , Noone D. , Cobb K. M. , Konecky B. L. , Rea S. 
Published: December 2017

AbstractThe origin of stable isotopic variability in precipitation over time and space is critical to the interpretation of stable isotope‐based paleoclimate proxies. In the eastern equatorial Pacific, modern stable isotope measurements in precipitation (δ18Op and δDp) are sparse and largely unevaluated in the literature, although insights from such analyses would benefit the interpretations of several regional isotope‐based paleoclimate records. Here we present a new 3.5 year record of daily‐resolved δ18Op and δDp from Santa Cruz, Galápagos. With a prior 13 year record of monthly δ18Op and δDp from the island, these new data reveal controls on the stable isotopic composition of regional precipitation on event to interannual time scales. Overall, we find Galápagos δ18Op is significantly correlated with precipitation amount on daily and monthly time scales. The majority of Galápagos rain events are drizzle, or garúa, derived from local marine boundary layer vapor, with corresponding high δ18Op values due to the local source and increased evaporation and equilibration of smaller drops with boundary layer vapor. On monthly time scales, only precipitation in very strong, warm season El Niño months has substantially lower δ18Op values, as the sea surface temperature threshold for deep convection (28°C) is only surpassed at these times. The 2015/2016 El Niño event did not produce strong precipitation or δ18Op anomalies due to the short period of warm SST anomalies, which did not extend into the peak of the warm season. Eastern Pacific proxy isotope records may be biased toward periods of high rainfall during strong to very strong El Niño events.
MJO‐Related Intraseasonal Variation in the Stratosphere: Gravity Waves and Zonal Winds
Authors: Alexander M. J. , Grimsdell A. W. , Stephan C. C. , Hoffmann L. 
Published: December 2017

AbstractPrevious work has shown eastward migrating regions of enhanced temperature variance due to long‐vertical wavelength stratospheric gravity waves that are in sync with intraseasonal precipitation and tropopause wind anomalies associated with the Madden‐Julian Oscillation (MJO). Here the origin of these intraseasonal gravity wave variations is investigated with a set of idealized gravity wave‐resolving model experiments. The experiments specifically test whether tropopause winds act to control gravity wave propagation into the stratosphere by a critical level filtering mechanism or play a role in gravity wave generation through an obstacle source effect. All experiments use identical convective latent heating variability, but the large‐scale horizontal wind profile is varied to investigate relationships between stratospheric gravity waves and zonal winds at different levels. Results show that the observed long vertical wavelength gravity waves are primarily sensitive to stratospheric zonal wind variations, while tropopause wind variations have only a very small effect. Thus, neither the critical level filter mechanism nor the obstacle source play much of a role in the observed intraseasonal gravity wave variations. Instead, the results suggest that the stratospheric waves follow the MJO precipitation sources, and tropopause wind anomalies follow the same sources. We further find evidence of intraseasonal wave drag effects on the stratospheric circulation in reanalyzed winds. The results suggest that waves drive intraseasonal stratospheric zonal wind anomalies that descend in altitude with increasing MJO phases 3 through 7. Eastward anomalies descend farther than westward, suggesting that MJO‐related stratospheric waves cause larger eastward drag forces.
New Observations and Modeling of Jupiter's Quasi‐Quadrennial Oscillation
Authors: Cosentino Richard G. , Morales‐Juberías Raúl , Greathouse Thomas , Orton Glenn , Johnson Perianne , Fletcher Leigh N. , Simon Amy 
Published: December 2017

AbstractThe quasi‐quadrennial oscillation (QQO) and its ∼4 year period in Jupiter's atmosphere were first discovered in 7.8 μm infrared observations spanning the 1980s and 1990s from detecting semiregular variations in equatorial brightness temperatures near 10 hPa. New observations that probe between 0.1 and 30 hPa in Jupiter's atmosphere using the Texas Echelon Cross Echelle Spectrograph (TEXES), mounted on the NASA Infrared Telescope Facility, have characterized the vertical structure of the QQO during a complete cycle between January 2012 and April 2016. These new observations show the thermal oscillation previously detected at 10 hPa and that it extends over a pressure range of 2–17 hPa. We have incorporated a spectrum of wave drag parameterizations into the Explicit Planetary Isentropic Code general circulation model to simulate the observed Jovian QQO temperature signatures inferred from the TEXES observations as a function of latitude. A new stochastic wave drag parameterization explores vertical wind structure and offers insight into the spectra of waves that likely exist in Jupiter's atmosphere to force the QQO. High‐frequency gravity waves produced from convection likely contribute significantly to the QQO momentum budget. The model temperature outputs show strong correlations to equatorial and surrounding latitude temperature fields retrieved from the TEXES data sets at different epochs. Our results reproduce the QQO phenomenon as a zonal jet that descends over time in response to Jovian atmospheric forcing (e.g., gravity waves from convection).
McSnow: A Monte‐Carlo Particle Model for Riming and Aggregation of Ice Particles in a Multidimensional Microphysical Phase Space
Authors: Brdar S. , Seifert A. 
Published: December 2017

AbstractWe present a novel Monte‐Carlo ice microphysics model, McSnow, to simulate the evolution of ice particles due to deposition, aggregation, riming, and sedimentation. The model is an application and extension of the super‐droplet method of Shima et al. (2009) to the more complex problem of rimed ice particles and aggregates. For each individual super‐particle, the ice mass, rime mass, rime volume, and the number of monomers are predicted establishing a four‐dimensional particle‐size distribution. The sensitivity of the model to various assumptions is discussed based on box model and one‐dimensional simulations. We show that the Monte‐Carlo method provides a feasible approach to tackle this high‐dimensional problem. The largest uncertainty seems to be related to the treatment of the riming processes. This calls for additional field and laboratory measurements of partially rimed snowflakes.
Comparison of Sampling and Detection Methods for Chinook Salmon and Steelhead Naturally Infected with Myxobolus cerebralis
Authors: Chiaramonte Luciano V. , Burbank David , Scott Roberta , Trushenski Jesse T. 
Published: December 2017

Abstract
Myxobolus cerebralis (Mc) is a myxozoan parasite causing whirling disease in hatchery- and natural-origin salmonids. To minimize spread of this parasite and the incidence of its associated disease, fish health professionals routinely screen fish for Mc before stocking or moving the fish to Mc-free waters. Sample collection for Mc traditionally entails lethal sampling of cranial tissue followed by pepsin–trypsin digest (PTD) and screening of the sample for mature myxobolid myxospores (PTD method); however, nonlethal sampling methods would be advantageous in some circumstances, such as when dealing with rare or otherwise valuable fish. Accordingly, we compared Mc detections in cranial cartilage by using the PTD method with PCR assays of fin biopsies collected from juvenile Chinook Salmon Oncorhynchus tshawytscha and adult steelhead O. mykiss. Cranial samples were also analyzed using PCR methods for comparative purposes. Results indicated that Mc could be detected by PCR in fin clips, but the results generated by this approach differed significantly from those associated with PTD- and/or PCR-based analysis of cranial cartilage samples. Polymerase chain reaction-based analysis—of individual head samples and head digest pools in both species as well as fins in steelhead—yielded more positive detections than PTD analysis alone. The PCR-based analysis of head and fin tissues yielded different Mc detection rates in both species, but the nature of the detection disparity varied depending on the species and/or life stage of the fish. We conclude that for lethal cranial samples, neither PTD nor PCR should be used alone, but using these techniques in concert may provide the most complete and accurate estimation of Mc presence in a group of salmonids. If imperiled or highly valuable fish are in question, nonlethal fin samples may be used to generate some information regarding Mc status, with the understanding that parasite DNA detections do not necessarily signify mature infections or disease.
“Like No One Is Listening to Me”: A Qualitative Study of Patient–Provider Discordance Between Global Assessments of Disease Activity in Rheumatoid Arthritis
Authors: Kvrgic Zoran , Asiedu Gladys B. , Crowson Cynthia S. , Ridgeway Jennifer L. , Davis John M. 
Published: December 2017

ObjectiveTo explore the perspectives and experiences of patients with rheumatoid arthritis (RA) whose assessments of their disease differ from those of their rheumatology care provider.MethodsA total of 20 adult RA patients with patient‐provider discordance at their most recent rheumatology appointment (within 4 weeks) were recruited. Discordance was defined by an absolute difference of 25 or more between patient and provider global assessments on a visual analog scale (VAS) of disease activity. For descriptive purposes, participants completed the Health Assessment Questionnaire II, pain VAS, and Patient Health Questionnaire 9 depression scale. Interviews were conducted in person and individually with each patient with a semistructured interview guide. Topics ranged widely, including participants’ perspectives and experiences with living with RA, clinical disease assessments, patient‐provider communication, and psychosocial or other needs. Data from the interviews were analyzed using interpretive phenomenological analysis.ResultsSix major themes emerged from the patient interviews describing patient‐provider discordance and disease assessment: being misunderstood by others, limitations of provider assessments, discrepancy with provider findings, inadequate active listening on the part of health care providers, unmet psychosocial needs, and lack of patient empowerment.ConclusionPatients described discordance in terms of symptom assessment and understanding how RA affects everyday life. Typical clinical assessments did not capture their experience. The resulting conceptual framework should inform future interventional studies seeking to enhance concordance of patient‐physician communication and to optimize satisfaction with care and health‐related quality‐of‐life outcomes for patients with RA.
MOF‐Derived Bifunctional Cu3P Nanoparticles Coated by a N,P‐Codoped Carbon Shell for Hydrogen Evolution and Oxygen Reduction
Authors: Wang Rui , Dong Xi‐Yan , Du Jiao , Zhao Jin‐Yan , Zang Shuang‐Quan 
Published: December 2017

AbstractMetal–organic frameworks (MOFs) have recently emerged as a type of uniformly and periodically atom‐distributed precursor and efficient self‐sacrificial template to fabricate hierarchical porous‐carbon‐related nanostructured functional materials. For the first time, a Cu‐based MOF, i.e., Cu‐NPMOF is used, whose linkers contain nitrogen and phosphorus heteroatoms, as a single precursor and template to prepare novel Cu3P nanoparticles (NPs) coated by a N,P‐codoped carbon shell that is extended to a hierarchical porous carbon matrix with identical uniform N and P doping (termed Cu3P@NPPC) as an electrocatalyst. Cu3P@NPPC demonstrates outstanding activity for both the hydrogen evolution and oxygen reduction reaction, representing the first example of a Cu3P‐based bifunctional catalyst for energy‐conversion reactions. The high performances are ascribed to the high specific surface area, the synergistic effects of the Cu3P NPs with intrinsic activity, the protection of the carbon shell, and the hierarchical porous carbon matrix doped by multiheteroatoms. This strategy of using a diverse MOF as a structural and compositional material to create a new multifunctional composite/hybrid may expand the opportunities to explore highly efficient and robust non‐noble‐metal catalysts for energy‐conversion reactions.
Realizing Efficient Lead‐Free Formamidinium Tin Triiodide Perovskite Solar Cells via a Sequential Deposition Route
Authors: Zhu Zonglong , Chueh Chu‐Chen , Li Nan , Mao Chengyi , Jen Alex K.‐Y. 
Published: December 2017

AbstractRecently, the evolved intermediate phase based on iodoplumbate anions that mediates perovskite crystallization has been embodied as the Lewis acid–base adduct formed by metal halides (serve as Lewis acid) and polar aprotic solvents (serve as Lewis base). Based on this principle, it is proposed to constitute efficient Lewis acid–base adduct in the SnI2 deposition step to modulate its volume expansion and fast reaction with methylammonium iodide (MAI)/formamidinium iodide (FAI) (FAI is studied hereafter). Herein, trimethylamine (TMA) is employed as the additional Lewis base in the tin halide solution to form SnY2–TMA complexes (Y = I−, F−) in the first‐step deposition, followed by intercalating with FAI to convert into FASnI. It is shown that TMA can facilitate homogeneous film formation of a SnI2 (+SnF2) layer by effectively forming intermediate SnY2–TMA complexes. Meanwhile, its relatively larger size and weaker affinity with SnI2 than FA+ ions will facilitate the intramolecular exchange with FA+ ions, thereby enabling the formation of dense and compact FASnI3 film with large crystalline domain (>1 µm). As a result, high power conversion efficiencies of 4.34% and 7.09% with decent stability are successfully accomplished in both conventional and inverted perovskite solar cells, respectively.
Filtration‐Assisted Fabrication of Large‐Area Uniform and Long‐Term Stable Graphene Isolated Nano‐Ag Array Membrane as Surface Enhanced Raman Scattering Substrate
Authors: Ouyang Lei , Wang Yesheng , Zhu Lihua , Irudayaraj Joseph , Tang Heqing 
Published: December 2017

AbstractIn this research, a facile strategy to obtain graphene isolated uniform Ag array membrane that are stable for long‐term use as surface enhanced Raman scattering (SERS) substrates is demonstrated. The fabrication process consisted of three main steps: interfacial assembly of Ag nanoparticles (NPs) into an array, transferring the Ag array to a membrane, and tightly wrapping the Ag array with graphene. The fabricated Ag array and graphene layer structure is tightly packed with effective electromagnetic coupling and electron transferring as confirmed by X‐ray photoelectron spectroscopy, UV‐vis spectra and Raman analysis. Owing to the uniform and effective electromagnetic coupling between Ag NPs and chemical enhancement from tightly wrapped graphene, this hierarchical membrane exhibited excellent SERS enhancing ability (an enhancement factor of 7.3 × 108) and large area uniformity (with relative standard deviation less than 5.91% for 50 times of detection over an area up to 9 cm2). Due to the protection effect by graphene as both an isolation layer and an electron shuttle, this substrate showed out‐standing long‐term stability (stable more than 25 weeks). Specific functions of graphene in fluorescence quenching and photo‐bleaching inhibition further contributed to intrinsic Raman information access. The obtained flexible membrane based multi‐layer architecture is also easy of use for real application.
Thermoelectric Devices: A Review of Devices, Architectures, and Contact Optimization
Authors: He Ran , Schierning Gabi , Nielsch Kornelius 
Published: December 2017

AbstractIn recent years, the substantially improved performance of thermoelectric (TE) materials has attracted considerable interest in studying the potential applications of the TE technique. Serving as the bridge between TE materials and applicable TE products, TE devices must be properly designed, engineered, and assembled to meet the required performance of TE products for cooling (thermoelectric cooler) and power generation (thermoelectric generator). The principle feasibility of the TE technique has been demonstrated using a variety of different materials and processing technologies, and many different architectures of TE devices have been successfully realized. This review discusses the architectures of TE devices, including bulk and thin‐film TE devices, TE devices with flexible designs, pn‐junction‐based TE devices that provide robust solutions for high operation temperatures, and the meta‐material‐based transverse TE devices. In addition, the assembly of TE devices involves contact layers on which the reliability of TE devices depends. Thus solutions to contact issues, including bonding strength, contact resistance, and thermomechanical stress, are also reviewed.
Fracture Behavior of Nanoscale Notched Silicon Beams Investigated by the Theory of Critical Distances
Authors: Gallo Pasquale , Yan Yabin , Sumigawa Takashi , Kitamura Takayuki 
Published: December 2017

AbstractThis paper investigates the nanoscale fracture behavior of silicon using the Theory of Critical Distances (TCD) and demonstrates that TCD can correctly estimate the magnitude of the breakdown of continuum fracture mechanics. Moreover, it proposes the TCD as an alternative strategy for the determination of fracture toughness, KIC, at the nanoscale. More specifically, in situ micromechanical testing of notched nano‐cantilever beams has been carried out in a transmission electron microscope. The material characteristic length and fracture toughness are then evaluated. The average KIC value obtained is 0.98 MPa m0.5, which is in agreement with that reported in the literature for macro‐Si. The characteristic length L is in the range of 1.3–1.9 nm. It is found that within an atomistic interpretation of the fracture of silicon, these values are in agreement with the breakdown of continuum fracture mechanics.
Multiple Cases of Efficient Nonfullerene Ternary Organic Solar Cells Enabled by an Effective Morphology Control Method
Authors: Jiang Kui , Zhang Guangye , Yang Guofang , Zhang Jianquan , Li Zhengke , Ma Tingxuan , Hu Huawei , Ma Wei , Ade Harald , Yan He 
Published: December 2017

AbstractTernary organic solar cells (OSCs) have attracted much research attention, as they can maintain the simplicity of the single‐junction device architecture while broadening the absorption range of OSCs. However, one main challenge that limits the development of ternary OSCs is the difficulty in controlling the morphology of ternary OSCs. In this paper, an effective approach to control the morphology is presented that leads to multiple cases of efficient nonfullerene ternary OSCs with efficiencies of up to 11.2%. This approach is based on a donor polymer with strong temperature dependent aggregation properties processed from hot solutions without any solvent additives and a pair of small molecular acceptors (SMAs) that have similar surface tensions and thus low propensity to form discrete phases. Such a ternary blend exhibits a simplified bulk‐heterojunction morphology that is similar to the morphology of previously reported binary blends. As a result, an almost linear relationship between VOC and film composition is observed for all nonfullerene ternary devices. Meanwhile, by carefully designing a control system with a large interfacial tension, a different phase separation and VOC dependence is demonstrated. This morphology control approach can be applicable to more material systems and accelerates the development of the ternary OSC field.
Facile Metal Coordination of Active Site Imprinted Nitrogen Doped Carbons for the Conservative Preparation of Non‐Noble Metal Oxygen Reduction Electrocatalysts
Authors: Mehmood Asad , Pampel Jonas , Ali Ghulam , Ha Heung Yong , Ruiz‐Zepeda Francisco , Fellinger Tim‐Patrick 
Published: December 2017

AbstractIron‐ or cobalt‐coordinated heteroatom doped carbons are promising alternatives for Pt‐based cathode catalysts in polymer‐electrolyte fuel cells. Currently, these catalysts are obtained at high temperatures. The reaction conditions complicate the selective and concentrated formation of metal–nitrogen active sites. Herein a mild procedure is introduced, which is conservative toward the carbon support and leads to active‐site formation at low temperatures in a wet‐chemical metal‐coordination step. Active‐site imprinted nitrogen doped carbons are synthesized via ionothermal carbonization employing Lewis‐acidic Mg2+ salt. The obtained carbons with large tubular porosity and imprinted N4 sites lead to very active catalysts with a half‐wave potential (E1/2) of up to 0.76 V versus RHE in acidic electrolyte after coordination with iron. The catalyst shows 4e− selectivity and exceptional stability with a half‐wave potential shift of only 5 mV after 1000 cycles. The X‐ray absorption fine structure as well as the X‐ray absorption near edge structure profiles of the most active catalyst closely match that of iron(II)phthalocyanine, proving the formation of active and stable FeN4 sites at 80 °C. Metal‐coordination with other transition metals reveals that Zn–Nx sites are inactive, while cobalt gives rise to a strong performance increase even at very low concentrations.