bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D Printed SnSe Thermoelectric Generators with High Figure of Merit
Authors: Burton Matthew R. , Mehraban Shahin , Beynon David , McGettrick James , Watson Trystan , Lavery Nicholas P. , Carnie Matthew J. 
Published: June 2019

AbstractSince the discovery of the record figure of merit (ZT) of 2.6 ± 0.3 in tin selenide (SnSe), the material has attracted much attention in the field of thermoelectrics. This paper reports a novel pseudo‐3D printing technique to fabricate bulk SnSe thermoelectric elements, allowing for the fabrication of standard configuration thermoelectric generators. In contrast to fabrication examples presented to date, this technique is potentially very low‐cost and allows for facile, scalable, and rapid fabrication. Bulk SnSe thermoelectric elements are produced and characterized over a wide range of temperatures. An element printed from an ink with 4% organic binder produces the highest performance, with a ZT value of 1.7 (±0.25) at 758 K. This is the highest ZT reported of any printed thermoelectric material, and the first bulk printed material to operate at this temperature. Finally, a proof‐of‐concept, all printed SnSe thermoelectric generator is presented, producing 20 µW at 772 K.
Oxalisseeds from the Cape Flora have a spectrum of germination strategies
Authors: Jooste Michelle , Midgley Guy F. , Oberlander Kenneth C. , Dreyer Léanne L. 
Published: June 2019

PremiseSeed germination strategy has profound ecological and evolutionary consequences, with transitions between germination strategies receiving renewed recent attention.Oxalisfrom the Cape Flora, South Africa, has seeds with two contrasting germination strategies: orthodox and recalcitrant. The morphological gulf between these strategies (and potential intermediate morphologies) has been poorly quantified, with questions regarding their ecological function and evolution. We reconsidered this binary classification, emphasizing potential intermediate states.MethodsSeed physiological traits were used to assign strategies to 64Oxalisspecies. We tested for morphological/phenological signal corresponding to defined strategies with cluster, principal component,K‐means clustering and discriminant analyses.ResultsWe showed that an intermediate germination strategy does exist among CapeOxalis, with two possible morphological groups within each strategy. These could reflect a continuum of germination states, where an ancestral orthodox strategy evolved toward a maximally recalcitrant peak, with a mosaic of intermediate states reflected in extant taxa.ConclusionsEnvironmental factors may affect germination strategy and distribution throughout the Cape because recalcitrant and intermediate species are confined to the winter rainfall region. They occupy specialized niches and may face adverse impacts under predicted climate change (hotter and drier winters), meriting focused future conservation.
Dermal Tattoo Biosensors for Colorimetric Metabolite Detection
Authors: Yetisen Ali K. , Moreddu Rosalia , Seifi Sarah , Jiang Nan , Vega Katia , Dong Xingchen , Dong Jie , Butt Haider , Jakobi Martin , Elsner Martin , Koch Alexander W. 
Published: June 2019

AbstractTattooing is a ubiquitous body modification involving the injection of ink and/or dye pigments into the dermis. Biosensors in the form of tattoos can be used to monitor metabolites in interstitial fluid. Here, minimally invasive, injectable dermal biosensors were developed for measuring pH, glucose, and albumin concentrations. The dermal pH sensor was based on methyl red, bromothymol blue, and phenolphthalein, which responded to a pH range from 5.0 to 9.0. The dermal glucose sensor consisted of glucose oxidase, 3,3′,5,5′‐tetramethylbenzidine, and peroxidase that detected concentrations up to 50.0 mmol L−1. The dermal albumin sensor consisted of 3′,3′′,5′,5′′‐tetrachlorophenol‐3,4,5,6‐tetrabromosulfophthalein to measure concentrations up to 5.0 g L−1. The sensors were multiplexed in ex vivo skin tissue and quantitative readouts were obtained using a smartphone camera. These sensors can be used to manage of acid–base homeostasis, diabetes, and liver failure in point‐of‐care settings.
Effect of carbon nanotube addition on structure and properties for extrudates of high‐density polyethylene
Authors: Nishikawa Riho , Yamaguchi Masayuki 
Published: June 2019

ABSTRACTWe investigated the structure and properties of strands of high‐density polyethylene (HDPE), containing multi‐walled carbon nanotubes (MWCNTs) extruded from a capillary rheometer. Surprisingly, we found that the MWCNTs enhanced the chain orientation of HDPE, and that in the absence of MWCNTs, orientation relaxation occurred in the HDPE immediately after passing through the die. Conventional differential scanning calorimetry measurements indicated that MWCNT acts as a nucleating agent and raises the crystallization temperature 2–4 °C under quiescent condition. In the flow field, oriented MWCNTs behave like polymeric chain extended crystals “shish” and greatly accelerate the flow‐induced crystallization of the HDPE “kebab.” Consequently, the modulus was significantly increased in the flow direction. These findings demonstrate that the addition of MWCNTs is an effective method of enhancing the rigidity of HDPE. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48010.
Influence of thermal treatment and aging time on the stability and swelling properties of nano/micron‐sized polymeric spheres for improved oil recovery application
Authors: Rosero Gustavo , Olmos Carol M. , Peñaherrera Ana , Vaca Andrea , Vizuete Karla , Debut Alexis , Cumbal Luis , Masiero Diana , Hernandez Maria I. , Lasorsa Carlos , Pérez Maximiliano S. , Lerner Betiana 
Published: June 2019

ABSTRACTUnderstanding the knowledge of swelling and stability properties of polymeric spheres are essential for improved oil recovery; these properties will allow guaranteeing an efficient block of high permeability channels and large pore throats. These properties of nano/micron‐sized polymeric spheres commercially available for improved oil recovery applications were investigated. The polymeric spheres emulsion was characterized by scanning electron microscopy (SEM). Data analysis reveals uniform and spherical structures with an average diameter of 47 ± 4.8 nm. After hydration, polymeric spheres can swell due to water absorption reaching an average particle diameter of 3.3 ± 0.2 μm. The effect of aging time, thermal treatment, the removal of the oil phase, and the dispersing stabilizer on the swelling and stability was studied. It has been found that polymeric spheres structure suffers deterioration with the progressive aging time, temperature increase, and with the removal of the oil phase and dispersing stabilizer. As a result, crosslinked polymer aggregates are formed which subsequently acquiring fibrillar morphologies. Further, this study provides an understanding of the stability and swelling behavior of polymeric microspheres using polydimethylsiloxane microdevices. The results evidenced that the behavior of the polymeric spheres can be beneficial to improve oil recovery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 48030.
Freshwater biodiversity conservation through source water protection: Quantifying the potential and addressing the challenges
Authors: Abell Robin , Vigerstol Kari , Higgins Jonathan , Kang Shiteng , Karres Nathan , Lehner Bernhard , Sridhar Aparna , Chapin Emily 
Published: June 2019

Abstract

Water insecurity is a defining feature of the Anthropocene, with degraded water quality and unreliable flows putting the well‐being of upstream and downstream communities, both human and aquatic, at risk. Within this context, the protection of drinking water at its source – ‘source water protection’ – is growing as a complementary water security solution to conventional built infrastructure, particularly but not only to address non‐point source pollution.
An assessment of the likely source catchments of 4000 cities, supplying water to as many as 1.7 billion city dwellers, found that 85% of the total area of the catchments overlaps with freshwater ecoregions of high biodiversity value. Source water protection could contribute to conserving important freshwater biodiversity elements in these catchments, through activities such as land protection, restoration, and agricultural and ranching best‐management practices.
Empirical evidence supporting the benefits of these types of activities to freshwater species and ecosystems is sparse, especially when considered at the scales required to achieve meaningful conservation objectives. This article explores the potential of source water protection to deliver freshwater conservation benefits, and solutions are proposed to address the challenges related to evidence gaps, trade‐offs, and financing.
The broader opportunity for leveraging water security investments for biodiversity conservation, and the overall efficiencies that may accrue from optimizing for multiple benefits simultaneously, are discussed in the context of global frameworks such as the Sustainable Development Goals.
Retracted: Traffic identification and traffic analysis based on support vector machine
Authors: Zhongsheng Wang , Jianguo Wang , Sen Yang , Jiaqiong Gao 
Published: June 2019

SummaryThe number of applications based on the Internet is increasing, which results the traffic becoming more and more complex. Therefore, how to improve the service quality and security of the network is becoming more and more important. This paper studies the application of SVM in traffic identification to classify network traffic. Through data collection and feature generation methods and network traffic feature screening methods, SVM is used as a classifier by using the generalization capability of SVM, and the parameters and kernel functions of the SVM are adjusted and selected based on cross comparison ideas and methods. Using the cross‐validation method to make the most reasonable statistics for the classification and recognition accuracy of the adjusted support vector machine avoids the situation that the classification accuracy of the support vector machine is unstable or the statistics are inaccurate. Finally, a traffic classification and identification system based on SVM is realized. The final recognition rate of encrypted traffic is up to 99.31%, which overcomes the disadvantages of traditional traffic identification and achieves a fairly reliable accuracy.
Single‐Atom Catalysis Using Chromium Embedded in Divacant Graphene for Conversion of Dinitrogen to Ammonia
Authors: Riyaz Mohd , Goel Neetu 
Published: June 2019

AbstractReduction of dinitrogen to ammonia under ambient conditions is a long‐standing challenge. The few metal‐based catalysts proposed have conspicuous disadvantages such as high cost, high energy consumption, and being hazardous to the environment. Single‐atom catalysis has emerged as a new frontier in heterogeneous catalysis and metal atoms atomically dispersed on supports receive more and more attention owing to rapid advances in synthetic methodologies and computational modeling. Herein, we propose metal atoms embedded in divacant graphene as a catalyst for N2 fixation based on density functional calculations. We systematically investigate the potential of using transition metal like Cr, Mn, Fe, Mo and Ru as catalysts and our study reveals that Cr embedded in graphene exhibit good catalytic activity for N2 fixation. The synergy between the metal atoms and graphene surface provides a stable support to the metal center that has a high spin density to promote adsorption of N2 and activation of its N≡N triple bond. Our study deciphers the mechanism of conversion of N2 to ammonia following two possible reaction pathways, distal and enzymatic routes, via sequential protonation and reduction of activated N2. The study provides a rational framework for conversion of dinitrogen to ammonia using single atom catalyst.
Direct Arylation Polycondensation (DAP) Synthesis of Alternating Quaterthiophene−Benzothiadiazole Copolymers for Organic Solar Cell Applications
Authors: Keller Tina , Gahlmann Tobias , Riedl Thomas , Scherf Ullrich 
Published: June 2019

AbstractPoly[(2,1,3‐benzothiadiazole‐4,7‐diyl)‐alt‐4′,3′′‐difluoro‐3,3′′′‐di(2‐octyldodecyl)‐2,2′;5′,2′′;5′′,2′′′‐quaterthiophene‐5,5′′′‐diyl)] (PBTff4T‐2OD) and poly[(5,6‐difluoro‐2,1,3‐benzothiadiazol‐4,7‐diyl)‐alt‐3,3′′′‐di(2‐octyldodecyl)‐2,2′;5′,2′′;5′′,2′′′‐quaterthiophene‐5,5′′′‐diyl)] (PffBT4T‐2OD) for use as the p‐donor component of high‐efficiency fullerene‐based organic solar cells are usually synthesized in established C−C cross‐coupling reactions, preferably using the Stille procedure. This report describes how PBTff4T‐2OD and PffBT4T‐2OD are generated in a direct arylation polycondensation (DAP) approach with molecular weights up to Mn=19.4 kDa and 21.1 kDa, respectively, and how structural defects in the copolymers (e. g., homocoupling defects) show a strong impact on the pre‐aggregation behavior. The optimized reaction conditions allow for a distinct reduction of the amount of such defects in the resulting copolymers. When the Stille‐type products are used in the active layer of organic solar cells (OCSs) together with fullerene acceptors, high power‐conversion efficiencies (PCEs) in the range of 8.6–10.8 % have been reported. The high PCEs are particularly related to the pre‐aggregation of the conjugated copolymers prior to film formation. Despite quite similar characterization data, non‐optimized OCSs with the DAP polymers as replacement for the Stille products afforded a relatively low power‐conversion efficiency of up to 2.4 %.
Spectral Variability in Phycocyanin Cryptophyte Antenna Complexes is Controlled by Changes in the α‐Polypeptide Chains
Authors: Corbella Marina , Cupellini Lorenzo , Lipparini Filippo , Scholes Gregory D. , Curutchet Carles 
Published: June 2019

AbstractQuantitative models of light harvesting in photosynthetic antenna complexes depend sensitively on the challenging determination of the relative site energies of the pigments. Herein we analyze the basis of the light harvesting properties of four antennae from cryptophyte algae, phycocyanines PC577, PC612, PC630 and PC645, by comparing two alternative theoretical strategies to derive the excitonic Hamiltonian. The first is based on molecular dynamics simulations and subsequent polarizable quantum/molecular mechanics (QM/MMPol) calculations, whereas the second is based on three‐layer QM/MMPol/ddCOSMO calculations performed on optimized geometries of the pigments, where the water solvent is described using the ddCOSMO continuum model. We find the latter approach to be remarkably accurate, suggesting that these four phycobiliproteins share a common energetic ordering PCB82 < PCB158 < DBV51/61 for pigments located in the highly‐conserved β chains, whereas bilins in the more divergent α chains cause their spectral differences. In addition, we predict a strong screening of the coupling among central dihydrobiliverdins (DBVs) in “open” form complexes PC577 and PC612 compared to “closed” form ones, which together with the increased interpigment separation explains the attenuation of coherence beatings observed for these complexes.
The Absorption Spectrum of Guanine Based Radicals: a Comparative Computational Analysis
Authors: Martínez Fernández Lara , Cerezo Javier , Asha Haritha , Santoro Fabrizio , Coriani Sonia , Improta Roberto 
Published: June 2019

AbstractThe excited states of three radical derivatives of guanine, i. e. guanine cation (G+) and its two main deprotonated derivatives (G−H1 and G−H2), have been characterized in the Franck‐Condon region by TD‐DFT, using different functionals, CASPT2, and EOM‐EE‐CCSD calculations. In the gas phase, all the methods provide a similar description of the main spectral features, the pictures provided by TD‐DFT, with long range corrected functionals, and EOM‐EE‐CCSD being very close. Solvent effects are then taken into account by a mixed discrete‐continuum approach, including five water molecules of the first solvation shell and the Polarizable Continuum Model (PCM). The vibronic absorption line‐width has finally been simulated at the TD‐M052X level by a time dependent method within the harmonic approximation. The resulting absorption spectra are in good agreement with their experimental counterparts, providing useful indications on the use of PCM/TD‐DFT based approaches to interpret the spectra of guanine based radicals within DNA.
Behavior out of control: Experimental evolution of resistance to host manipulation
Authors: Hafer‐Hahmann Nina 
Published: June 2019

AbstractMany parasites alter their host's phenotype in a manner that enhances their own fitness beyond the benefits they would gain from normal exploitation. Such host manipulation is rarely consistent with the host's best interests resulting in suboptimal and often fatal behavior from the host's perspective. In this case, hosts should evolve resistance to host manipulation. The cestodeSchistocephalus solidusmanipulates the behavior of its first intermediate copepod host to reduce its predation susceptibility and avoid fatal premature predation before the parasite is ready for transmission to its subsequent host. Thereafter,S. solidusincreases host activity to facilitate transmission. If successful, this host manipulation is necessarily fatal for the host. I selected the copepodMacrocyclops albidus, a first intermediate host ofS. solidus,for resistance or susceptibility to host manipulation to investigate their evolvability. Selection on the host indeed increased host manipulation in susceptible and reduced host manipulation in resistant selection lines. Interestingly, this seemed to be at least partly due to changes in the baseline levels of the modified trait (activity) rather than actual changes in resistance or susceptibility to host manipulation. Hence, hosts seem restricted in how rapidly and efficiently they can evolve resistance to host manipulation.
Trait‐mediated foraging drives patterns of selective predation by native and invasive coral‐reef fishes
Authors: Green Stephanie J. , Dilley Eric R. , Benkwitt Cassandra E. , Davis Alexandra C. D. , Ingeman Kurt E. , Kindinger Tye L. , Tuttle Lillian J. , Hixon Mark A. 
Published: June 2019

AbstractAs the geographic ranges of species are increasingly altered by forces such as biological invasion and climate change, when and where will strong biotic interactions arise within reassembling communities? Prey selectivity data are often of limited use for predicting future consumptive interactions because they are specific to the identity and relative abundance of species in past assemblages. Here, we investigate whether the strength of consumptive interactions can be predicted based on a priori knowledge of behavioral traits that are hypothesized to affect the predation process and recur across species. To test this approach, we conducted multi‐species foraging trials with coral‐reef fishes in the Bahamas, a diverse, trait‐rich fauna for which interactions are likely shifting rapidly due to the introduction of predatory Indo‐Pacific lionfish. We evaluated predictions about the combined effects of three behavioral traits—water column position of both predator and prey, anti‐predator aggregation behavior of prey, and hunting strategy of predators—on successive phases of the predation process and ultimately the strength of predator–prey interactions. Tracking predator and prey behaviors revealed that inter‐specific variation in traits mediated relative encounter, attack, and capture rates between different predators and prey. Behaviorally driven bottlenecks at different stages of the process underpinned selective consumption by each predator species, resulting in large differences in total mortality rates among prey species. Our analysis also suggests that unique behaviors exhibited by invasive lionfish, rather than naïve responses by prey, mediate their high foraging success relative to native predators. Our results illustrate how incorporating a priori knowledge about foraging and anti‐predator traits can improve predictions of the strength of emergent consumptive interactions caused by global change.
Long‐term trajectories of fractional component change in the Northern Great Basin, USA
Authors: Rigge Matthew , Shi Hua , Homer Collin , Danielson Patrick , Granneman Brian 
Published: June 2019

AbstractThe need to monitor change in sagebrush steppe is urgent due to the increasing impacts of climate change, shifting fire regimes, and management practices on ecosystem health. Remote sensing provides a cost‐effective and reliable method for monitoring change through time and attributing changes to drivers. We report an automated method of mapping rangeland fractional component cover over a large portion of the Northern Great Basin, USA, from 1986 to 2016 using a dense Landsat imagery time series. Our method improved upon the traditional change vector method by considering the legacy of change at each pixel. We evaluate cover trends stratified by climate bin and assess spatial and temporal relationships with climate variables. Finally, we statistically evaluate the minimum time density needed to accurately characterize temporal patterns and relationships with climate drivers. Over the 30‐yr period, shrub cover declined and bare ground increased. While few pixels had >10% cover change, a large majority had at least some change. All fractional components had significant spatial relationships with water year precipitation (WYPRCP), maximum temperature (WYTMAX), and minimum temperature (WYTMIN) in all years. Shrub and sagebrush cover in particular respond positively to warming WYTMIN, resulting from the largest increases in WYTMIN being in the coolest and wettest areas, and respond negatively to warming WYTMAX because the largest increases in WYTMAX are in the warmest and driest areas. The trade‐off of lowering temporal density against removing cloud‐contaminated years is justified as temporal density appears to have only a modest impact on trends and climate relationships until n ≤ 6, but multi‐year gaps are proportionally more influential. Gradual change analysis is likely to be less sensitive to n than abrupt change. These data can be used to answer critical questions regarding the influence of climate change and the suitability of management practices.