bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling the Hydrothermal Ageing of a Fe‐Zeolite Catalyst for Automotive NH3‐SCR Applications
Authors: Ruggeri Maria Pia , Nova Isabella , Tronconi Enrico , Schmeißer Volker , Weibel Michel 
Published: April 2018

AbstractThe effects of duration and temperature of hydrothermal ageing treatments were investigated on a commercial Fe‐zeolite catalyst for NH3‐SCR addressing NH3 adsorption, NH3 oxidation, and NH3 reaction with NOx. Hydrothermal ageing affected primarily NH3 oxidation and standard SCR activities, as well as NH3 storage capacity. Deactivation was fast in the first few hours, eventually approaching asymptotic levels. There is potential to predict the effects of hydrothermal ageing on the SCR behavior of Fe‐zeolite catalysts as a function of just one parameter, i.e., the NH3 storage capacity.
Extraction of macauba kernel oil using supercritical carbon dioxide and compressed propane
Authors: Trentini Caroline Portilho , Cuco Roberta Pazinato , Cardozo‐Filho Lucio , Silva Camila da 
Published: April 2018

AbstractMacauba kernel oil (MKO) was extracted using supercritical CO2 and compressed propane as the solvent. The influence of temperature (313–353 K for CO2 and 303–333 K for propane) and pressure (18–22 MPa for CO2 and 8–12 MPa for propane) on oil yield was investigated, and the results were compared with conventional extraction. A characterization of oil and defatted meal was performed. Temperature and pressure, in the evaluated range, influenced oil yield with the use of CO2. For propane, the oil yield was not influenced by the experimental conditions. In the evaluated experimental range, the use of propane and CO2 provided 100 % and ∼93 % oil yield compared to conventional extraction, respectively. MKO showed a predominance of saturated fatty acids, among which lauric acid was the major constituent. CO2 presented greater efficiency in the removal of phytosteroids and tocopherols from the macauba kernel, however, the oil extracted with propane presented longer oxidative stability. Defatted meals presented modified physico‐chemical composition and potentiated technological characteristics due to oil removal.
Evolution of Graphene Oxide and Graphene: From Imagination to Industrialization
Authors: Tiwari Santosh K. , Mishra Raghvendra Kumar , Ha Sung Kyu , Huczko Andrzej 
Published: April 2018

AbstractDuring the past 32years, more than 103000 research articles with term graphene in the title or in manuscript have been recorded in the Scopus database. This exceptional reputation of graphene is due to numerous reasons; the most significant one appears to be its incomparable physical properties, resulting in real‐time application in many fields of science and technology. That's why it seems to be absolutely justified that “graphene possesses everything's what you want”. This article is a tribute to the researchers who contributed to the background of the current face of graphene. In this short paper we are presenting the contributions of initial research articles on graphite that are responsible for the present status of graphene and led the research interests of materials scientists toward the potential applications of graphene and its derivatives. The current progress in graphene research output of renowned scientists around the globe is also evaluated based on the Scopus and Web of Science databases. However, a particular emphasis is focused on the current technological innovations (2010–2017) based on graphene, as well as mostly prototype devices fabricated using graphene as a key material along with discussing the recent challenges in graphene nanotechnology, and a recommendation of the ways to advance the commercial readiness of the products based on graphene and their derivatives. In addition, we have also briefly discussed the limitations of graphene, future prospects and present global market trends of graphene‐based products.
Mechanochemistry in [6]Cycloparaphenylene: A Combined Raman Spectroscopy and Density Functional Theory Study
Authors: Qiu Lili , Peña‐Alvarez Miriam , Baonza Valentín G. , Taravillo Mercedes , Casado Juan , Kertesz Miklos 
Published: April 2018

AbstractRaman spectroscopy under high pressures up to 10 GPa and density functional computations up to 30 GPa are combined to obtain insights into the behavior of a prototypical nanohoop conjugated molecule, [6]cycloparaphenylene ([6]CPP). Upon increasing pressure, the nanohoop undergoes deformations, first reversible ovalization and then at even higher pressures aggregates are formed. This irreversible aggregation is caused by the formation of new intermolecular σ‐bonds. Frequencies and derivatives of the Raman frequency shifts as a function of pressure are well reproduced by the computations. The frequency behavior is tied to changes in aromatic/quinonoid character of the nanohoop. The modeling at moderate high pressures reveals the deformation of the [6]CPP molecules into oval‐like and peanut‐like shapes. Surprisingly the pressure derivatives of the observed Raman mode shifts undergo a sudden change around a pressure value that is common to all Raman modes, indicating an underlying geometrical change extended over the whole molecule that is interpreted by the computational modeling. Simulations predict that under even larger deformations caused by higher pressures, oligomerization reactions would be triggered. Our simulations demonstrate that these transformations would occur regardless of the solvent, however pressures at which they happen are influenced by solvent molecules encapsulated in the interior of the [6]CPP.
Fear Conditioning by Proxy: Social Transmission of Fear Between Interacting Conspecifics
Authors: Jones Carolyn E. , Agee Laura , Monfils Marie‐H. 
Published: April 2018

AbstractWe describe a method of social fear transmission to a discrete auditory cue in freely behaving rats. Extending beyond traditional observer/demonstrator paradigms, rats are allowed to physically interact and integrate cues from all sensory modalities. In the protocol described in this article, “observer” rats experience social fear conditioning through a proxy cage mate that serves as a “demonstrator” during retrieval of a cued fear memory. We find that a specific auditory cue can come to elicit fear expression in an animal with no foot shock experience simply by interacting with a conspecific expressing a conditioned response in the presence of an otherwise benign stimulus. In this “fear conditioning by proxy” paradigm, we have demonstrated that some, but not all, rats display conditioned responding (e.g., freezing) to a cue after interacting with a cage mate during fear memory retrieval. The amount of freezing exhibited by this fear conditioned “by proxy” rat 24 hr after learning critically depends on social influences, including social relationships and social interactions during learning. © 2018 by John Wiley & Sons, Inc.
Photooxidation of Fulvenes in a Continuous Flow Photoreactor using Carbon Dioxide as a Solvent
Authors: Wu Lingqiao , Lee Darren S. , Boufroura Hamza , Poliakoff Martyn , George Michael W. 
Published: April 2018

AbstractA range of 3‐substituted oxepinones have been synthesised by the photooxidation of fulvenes with photochemically generated singlet oxygen (1O2) using carbon dioxide (CO2) as a solvent and a CO2‐soluble porphyrin photosensitizer. The reactive intermediates generated in this reaction decompose to yield a range of useful and underutilized building blocks that are not easily accessible using more traditional reaction setups. Fulvenes containing an exocyclic allylic hydrogen are shown to form three products through potentially competing intramolecular pathways, which can be tuned to some extent by adjusting the conditions in the flow reactor. A range of substrates containing a variety of functional groups was examined; this led to lower yields of the desired lactones being observed in the case of compounds containing polar electron‐donating groups. We also demonstrate that one of the lactones can be further hydrogenated over a Pd/C catalyst to the unsaturated 7‐membered ring in high yield.
Self‐Assembled Metal Zinc Three‐Dimensional Microstructures at Room Temperature
Authors: Song Limin , liu Dan , Zhang Shujuan 
Published: April 2018

AbstractThree‐dimensional metal zinc (Zn) with the shapes of like‐flower, like‐grass, and like‐urchin are successfully prepared by a convenient method that replaced zinc cations (Zn2+) with metal magnesium (Mg) plate at room temperature. The as‐prepared microstructures are investigated by X‐ray diffraction and scanning electron microscopy. The morphology of Zn microstructures is affected by both solvents and anions. The conditions of the self‐assembly of variable shapes are clarified. The formation mechanism of various microstructures is also deduced in detail. The method herein is advantageous in convenience, low cost, and environmental benignity.
On the efficient simulation of electrical circuits with constant phase elements: The Warburg element as a test case
Authors: Athanasiou Vasileios , Konkoli Zoran 
Published: April 2018

SummaryThe constant phase Element (CPE) concept naturally emerges as a model for describing a range of electrical phenomena where ionic diffusion is involved. We suggest a new method for modelling the transient behavior of electrical circuits that contain CPE elements. Without loss of generality, we study the Warburg element to demonstrate the method, but the method can be easily extended to any CPE. Transient simulations of such elements require the numerical evaluation of a computationally expensive convolution integral that links the voltage drop across the element, with the current that passed through it. In our work we suggest a new method for reducing the computational cost of the numerical evaluation of the convolution integral. We show that the computational cost can be reduced by one order of magnitude.
Adaptive management of animal populations with significant unknowns and uncertainties: a case study
Authors: Gerber Brian D. , Kendall William L. 
Published: April 2018

AbstractConservation and management decision making in natural resources is challenging due to numerous uncertainties and unknowns, especially relating to understanding system dynamics. Adaptive resource management (ARM) is a formal process to making logical and transparent recurrent decisions when there are uncertainties about system dynamics. Despite wide recognition and calls for implementing adaptive natural resource management, applications remain limited. More common is a reactive approach to decision making, which ignores future system dynamics. This contrasts with ARM, which anticipates future dynamics of ecological process and management actions using a model‐based framework. Practitioners may be reluctant to adopt ARM because of the dearth of comparative evaluations between ARM and more common approaches to making decisions. We compared the probability of meeting management objectives when managing a population under both types of decision frameworks, specifically in relation to typical uncertainties and unknowns. We use a population of Sandhill Cranes as our case study. We evaluate each decision process under varying levels of monitoring and ecological uncertainty, where the true underlying population dynamics followed a stochastic age‐structured population model with environmentally driven vital rate density dependence. We found that the ARM framework outperformed the currently employed reactive decision framework to manage Sandhill Cranes in meeting the population objective across an array of scenarios. This was even the case when the candidate set of population models contained only naïve representations of the true population process. Under the reactive decision framework, we found little improvement in meeting the population objective even if monitoring uncertainty was eliminated. In contrast, if the population was monitored without error within the ARM framework, the population objective was always maintained, regardless of the population models considered. Contrary to expectation, we found that age‐specific optimal harvest decisions are not always necessary to meet a population objective when population dynamics are age structured. Population managers can decrease risks and gain transparency and flexibility in management by adopting an ARM framework. If population monitoring data has high sampling variation and/or limited empirical knowledge is available for constructing mechanistic population models, ARM model sets should consider a range of mechanistic, descriptive, and predictive model types.
Structure is more important than physiology for estimating intracanopy distributions of leaf temperatures
Authors: Woods H. Arthur , Saudreau Marc , Pincebourde Sylvain 
Published: April 2018

AbstractEstimating leaf temperature distributions (LTDs) in canopies is crucial in forest ecology. Leaf temperature affects the exchange of heat, water, and gases, and it alters the performance of leaf‐dwelling species such as arthropods, including pests and invaders. LTDs provide spatial variation that may allow arthropods to thermoregulate in the face of long‐term changes in mean temperature or incidence of extreme temperatures. Yet, recording LTDs for entire canopies remains challenging. Here, we use an energy‐exchange model (RATP) to examine the relative roles of climatic, structural, and physiological factors in influencing three‐dimensional LTDs in tree canopies. A Morris sensitivity analysis of 13 parameters showed, not surprisingly, that climatic factors had the greatest overall effect on LTDs. In addition, however, structural parameters had greater effects on LTDs than did leaf physiological parameters. Our results suggest that it is possible to infer forest canopy LTDs from the LTDs measured or simulated just at the surface of the canopy cover over a reasonable range of parameter values. This conclusion suggests that remote sensing data can be used to estimate 3D patterns of temperature variation from 2D images of vegetation surface temperatures. Synthesis and applications. Estimating the effects of LTDs on natural plant–insect communities will require extending canopy models beyond their current focus on individual species or crops. These models, however, contain many parameters, and applying the models to new species or to mixed natural canopies depends on identifying the parameters that matter most. Our results suggest that canopy structural parameters are more important determinants of LTDs than are the physiological parameters that tend to receive the most empirical attention.
Guano exposed: Impact of aerobic conditions on bat fecal microbiota
Authors: Fofanov Viacheslav Y. , Furstenau Tara N. , Sanchez Daniel , Hepp Crystal M. , Cocking Jill , Sobek Colin , Pagel Nicole , Walker Faith , Chambers Carol L. 
Published: April 2018

AbstractBats and their associated guano microbiota provide important terrestrial and subterranean ecosystem services and serve as a reservoir for a wide range of epizootic and zoonotic diseases. Unfortunately, large‐scale studies of bats and their guano microbiotas are limited by the time and cost of sample collection, which requires specially trained individuals to work at night to capture bats when they are most active. Indirectly surveying bat gut microbiota through guano deposits could be a more cost‐effective alternative, but it must first be established whether the postdefecation exposure to an aerobic environment has a large impact on the guano microbial community. A number of recent studies on mammalian feces have shown that the impact of aerobic exposure is highly species specific; therefore, it is difficult to predict how exposure will affect the bat guano microbiota without empirical data. In our study, we collected fresh guano samples from 24 individuals of 10 bat species that are common throughout the arid environments of the American southwest and subjected the samples to 0, 1, and 12 hr of exposure. The biodiversity decreased rapidly after the shift from an anaerobic to an aerobic environment—much faster than previously reported in mammalian species. However, the relative composition of the core guano microbiota remained stable and, using highly sensitive targeted PCR methods, we found that pathogens present in the original, non‐exposed samples could still be recovered after 12 hr of exposure. These results suggest that with careful sample analysis protocols, a more efficient passive collection strategy is feasible; for example, guano could be collected on tarps placed near the roost entrance. Such passive collection methods would greatly reduce the cost of sample collection by allowing more sites or roosts to be surveyed with a fraction of trained personnel, time, and effort investments needed.
Covariance between predation risk and nutritional preferences confounds interpretations of giving‐up density experiments
Authors: McMahon Jordan D. , Lashley Marcus A. , Brooks Christopher P. , Barton Brandon T. 
Published: April 2018

AbstractGiving‐up density (GUD) experiments have been a foundational method to evaluate perceived predation risk, but rely on the assumption that food preferences are absolute, so that areas with higher GUDs can be interpreted as having higher risk. However, nutritional preferences are context dependent and can change with risk. We used spiders and grasshoppers to test the hypothesis that covariance in nutritional preferences and risk may confound the interpretation of GUD experiments. We presented grasshoppers with carbohydrate‐rich and protein‐rich diets, in the presence and absence of spider predators. Predators reduced grasshopper preference for the protein‐rich food, but increased their preference for the carbohydrate‐rich food. We then measured GUDs with both food types under different levels of risk (spider density, 0–5). As expected, GUDs increased with spider density indicating increasing risk, but only when using protein‐rich food. With carbohydrate‐rich food, GUD was independent of predation risk. Our results demonstrate that predation risk and nutritional preferences covary and can confound interpretation of GUD experiments.
Attachment to groups: Relationships with group esteem, self‐esteem, and investment in ingroups
Authors: DeMarco Tina C. , Newheiser Anna‐Kaisa 
Published: April 2018

AbstractWe apply a model of interpersonal attachment style to the group domain, examining how attachment to ingroups relates to self‐views, group esteem, and ingroup investment. In Study 1 (N = 306), participants completed measures of self‐esteem, group esteem, group attachment insecurity, and investment. Study 2 (N = 316) implemented a within‐subjects experimental design in which participants completed the same measures as in Study 1 with regard to ingroups they held in high versus low esteem. In both studies, the negative relationship between group esteem and group attachment avoidance was stronger among participants with higher self‐esteem, and the negative relationship between self‐esteem and group attachment anxiety was stronger for more esteemed ingroups. Over and above group esteem, group attachment anxiety was positively and avoidance negatively related to investment in ingroups. We integrated frameworks spanning group dynamics and close relationships to contribute to a more comprehensive understanding of how individuals perceive their relationships with ingroups.
Square Wave‐Anodic Stripping Voltammetric Determination of Copper at a Bismuth Film/Glassy Carbon Electrode Using 3‐[(2‐Mercapto‐Vinyl)‐Hydrazono]‐ 1,3‐Dihydro‐Indol‐2‐One
Authors: Al‐Harbi Eman A. , El‐Shahawi Mohammad S. 
Published: April 2018

AbstractThis study reports a highly sensitive electrochemical sensor based on Bi film modified glassy carbon electrode (BiF/GCE) for total determination and speciation trace concentrations of copper(II) ions in environmental water samples. Square wave‐adsorptive anodic stripping voltammetric (SW‐ASV) experiment was performed for monitoring selective accumulation of copper(II) with reagent 3‐[(2‐mercapto‐vinyl)‐hydrazono]‐1,3‐dihydro‐indol‐2‐one (MHDI) at pH 9–10. The mechanism of the electrode reaction of Cu2+‐MHDI complex was safely assigned. The sensor exhibited a wide linear range (3.22×10−9–2.0×10−7 mol L−1) with lower limits of detection (LOD) and quantitation (LOQ) of 9.6×1−10 and 3.22×10−9 mol L−1, respectively (R2=0.9993). The proposed sensor exhibited interference from active metal ions e. g. Cd, Hg. The performance of the proposed method was compared successfully with most of the reported methods and comparable efficiencies were obtained. The analytical utility of the proposed SW‐ASV method has been successfully validated for trace analysis of copper(II) in environmental water samples. The method offers a precise, accurate approach with good reproducibility, robustness, ruggedness, and cost effectiveness.
Flexural behavior of fiber and nanoparticle reinforced concrete at high temperatures
Authors: Gao Danying , Zhao Liangping , Chen Gang 
Published: April 2018

SummaryIn this study, the flexural tests were conducted to investigate the effects of temperature, steel fiber, nano‐SiO2, and nano‐CaCO3 on flexural behavior of concrete at high temperatures. The load‐deflection curves of fiber and nanoparticle reinforced concrete (FNRC) were measured both at room and high temperatures. Test results show that the load‐deflection curves become flatter, and the flexural strength, peak deflection, and energy absorption capacity decrease seriously with the increase of temperature. Both steel fiber and nanoparticles could significantly improve the flexural behavior of the concrete at room and high temperatures. The energy absorption capacity of FNRC before the peak point increases with the increase of steel fiber volume fraction. The improvement of nano‐SiO2 on flexural strength of FNRC at high temperature is better than that at room temperature, but the enhancement on energy absorption capacity is reverse. Nano‐SiO2 is more effective than nano‐CaCO3 in improving flexural behavior of concrete both at room and high temperatures.
Consistency between S&P500 and VIX derivatives: Insights from model‐free VIX futures pricing
Authors: Hülsbusch Hendrik , Kraftschik Alexander 
Published: April 2018

AbstractThis paper studies the interdependencies between the VIX futures market and the S&P500 and VIX options markets using a model‐free pricing method for VIX futures. We show that the replication strategy for the VIX futures greatly deviates from observed prices. Limited strike ranges do not suffice to explain these deviations, whereas the options’ bid–ask spreads can explain most of it. After controlling for the spreads, we find a lead–lag structure between markets segmented by product, not by its underlying. If options markets imply higher volatility risks than VIX futures, options prices in both markets adjust and vice versa.