bluuebunny/crossref_metadata_2025_split huggingface dataset:
RESISTÊNCIA DE CULTIVARES DE BRÁSSICAS À HÉRNIA DAS CRUCÍFERAS
Authors: MAY DE MIO Louise Larissa , KOWATA Ligia Sayko , RUARO Lucimeris 
Published: January 2015

A hérnia das crucíferas causada por Plasmodiophora brassicae ocasiona sérios danos à cultura das brássicas. O presente trabalho teve como objetivo avaliar a resistência de cultivares de brássicas a hérnia das crucíferas. Foram utilizados 45 cultivares comercializadas de repolho, brócolos, couve-manteiga, couve-flor e couve-chinesa. A parcela experimental foi constituída de um vaso de alumínio com capacidade para três litros de solo contendo duas plantas, com quatro repetições. Em cada vaso foram aplicados dois gramas de galhas trituradas, na forma de rega. Aos 60 dias foram avaliadas a severidade da doença no sistema radicular e a massa fresca da parte aérea, verificando os efeitos sobre as cultivares de cada espécie avaliada. Utilizou-se o programa SASM-Agri e o teste Scott-Knott a 5% de probabilidade para a análise dos dados. A severidade de galhas foi menor nos ‘Híbrido Kukai 70’ e ‘65’ de couve-chinesa e ‘Bola de Neve‘ de couveflor. A massa fresca da parte aérea entre cultivares de mesma espécie foi maior para ‘Ramoso Piracicaba’; ‘Ramono Santana’; ‘Pirate’; ‘Vida Sul’; ‘Flórida’ e ‘Condor’ para brócolos, ‘Híbrido Kukai 70’ e ‘Híbrido Kukai 65’ para couve-chinesa e ‘HíbridoMatsukaze’ para repolho. Entre as cultivares testadas quanto à resistência ao isolado de P. brassicae, o ‘Híbrido Kukai 70’ e ‘65’ de couve-chinesa e ‘Bola de Neve‘ de couve-flor comportaram-se como os mais resistentes.
Swarm equatorial electric field chain: First results
Authors: Alken P. , Maus S. , Chulliat A. , Vigneron P. , Sirol O. , Hulot G. 
Published: January 2015

AbstractThe eastward equatorial electric field (EEF) in the E region ionosphere drives many important phenomena at low latitudes. We developed a method of estimating the EEF from magnetometer measurements of near‐polar orbiting satellites as they cross the magnetic equator, by recovering a clean signal of the equatorial electrojet current and modeling the observed current to determine the electric field present during the satellite pass. This algorithm is now implemented as an official Level‐2 Swarm product. Here we present first results of EEF estimates from nearly a year of Swarm data. We find excellent agreement with independent measurements from the ground‐based coherent scatter radar at Jicamarca, Peru, as well as horizontal field measurements from the West African Magnetometer Network magnetic observatory chain. We also calculate longitudinal gradients of EEF measurements made by the A and C lower satellite pair and find gradients up to about 0.05 mV/m/deg with significant longitudinal variability.
Daytime ionospheric equatorial vertical drifts during the 2008–2009 extreme solar minimum
Authors: Rodrigues F. S. , Smith J. M. , Milla M. , Stoneback R. A. 
Published: January 2015

AbstractOne of the most interesting observations made by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite mission was the detection of average equatorial ionospheric vertical drifts that largely differed from model predictions. C/NOFS measurements showed, in particular, downward drifts in the afternoon sector, and upward drifts around local midnight hours during the 2008 and 2009 extreme solar minimum. The unexpected behavior of the drifts has important implications for ionospheric modeling and suggests the necessity for a better understanding of the low‐latitude electrodynamics. We used ground‐based radar measurements to quantify the seasonal and solar flux variability of daytime equatorial drifts at lower altitudes (∼150 km) than those probed by C/NOFS (above ∼400 km). We found that average vertical drifts at 150 km altitude are in good agreement with model predictions of F region drifts and did not show the signatures of an enhanced semidiurnal pattern, as seen by C/NOFS. Comparison of the 150 km echo drifts with model predictions also shows that the increase (decrease) with height of the vertical drifts in the morning (afternoon) hours is a regular feature of the equatorial ionosphere. It occurred in all seasons and solar flux conditions between 2001 and 2011.
A data‐driven approach to develop physically sound predictors: Application to depth‐averaged velocities on flows through submerged arrays of rigid cylinders
Authors: Tinoco R. O. , Goldstein E. B. , Coco G. 
Published: January 2015

AbstractWe use a machine learning approach to seek an accurate, physically sound predictor, to estimate the mean velocity for open‐channel flow when submerged arrays of rigid cylinders (model vegetation) are present. A genetic programming routine is used to find a robust relationship between relevant properties of the model vegetation and flow parameters. We use published data from laboratory experiments covering a broad range of conditions to obtain an equation that matches the performance of other predictors from recent literature in terms of accuracy, while showing a less complex structure. We also investigate how different criteria for data selection, as well as the size of the data set used to train the algorithm, influences the accuracy of the resulting predictors. Our results show that a proper use of Machine‐Learning techniques does not only provide empirical correlations, but can yield physically sound models as representative of the physical processes involved. We provide a clear, thorough example of the application of GP, its advantages and shortcomings, to encourage the use of data‐driven techniques as part of the data analysis process, and to address common misconceptions of machine learning as simple correlation techniques or physically senseless statistical analysis.
Neue Ansätze zur direkten Verwendung elementaren Schwefels in der Synthese und Verarbeitung moderner Werkstoffe
Authors: Lim Jeewoo , Pyun Jeffrey , Char Kookheon 
Published: January 2015

AbstractElementarer Schwefel ist ein weitverbreitetes und preiswertes Material, das bei der Erdgas‐ und Erdöl‐Raffination als Nebenprodukt anfällt. Die Notwendigkeit, neue Energiespeichersysteme zu entwickeln, brachte vor kurzem das Potential von Schwefel als hochleistungsfähiges Kathodenmaterial in Sekundärbatterien ans Licht. Außerdem wurden die nützlichen optischen Eigenschaften schwefelhaltiger Materialien im Infrarotbereich entdeckt. Diese Entwicklungen gepaart mit den wachsenden ökologischen Bedenken im Zusammenhang mit der globalen Produktion von überschüssigem elementarem Schwefel führten zu einem großen Interesse an seiner Nutzung als Rohstoff in Werkstoffanwendungen. Dieser Kurzaufsatz konzentriert sich auf die jüngsten Entwicklungen physikalischer und chemischer Methoden für die direkte Verarbeitung von elementarem Schwefel in der Produktion funktionaler Verbundwerkstoffe und Polymere.
Biologisch inspirierte dynamische Materialsysteme
Authors: Studart André R. 
Published: January 2015

AbstractIn der Natur findet man zahlreiche Materialsysteme, die dynamisch mit ihrer Umgebung interagieren und sich an diese anpassen. Dazu gehören z. B. tierische, auf Haaren basierte Mechanorezeptoren, selbstformende Samenkapseln von Pflanzen oder die Remodellierung von Knochengewebe in Wirbeltieren. Inspiriert von diesen faszinierenden biologischen Strukturen wurde eine breite Palette von technischen Materialsystemen entwickelt, welche die Design‐Konzepte von dynamischen natürlichen Strukturen nachbilden. In diesem Aufsatz wird anhand von Beispielen biologischer Strukturen und ihrer künstlichen Pendants gezeigt, wie dynamische und adaptive Reaktionen entstehen können, indem Bausteine auf der Mikrometerebene eng mit intrinsischen Eigenschaften auf der Nanometerebene verknüpft werden. Mit Top‐down‐Photolithographieverfahren und Bottom‐up‐Herstellungsmethoden wurden biologisch inspirierte dynamische Materialsysteme (DynMatS) hergestellt, die 1) Flüssigkeitsströme mithilfe von haarähnlichen mikroelektromechanischen Systemen (MEMS) messen können, 2) aufgrund ihrer pflanzenartigen, heterogenen Architektur selbständig ihre Form ändern, 3) durch selbstregulierende adaptive Oberflächen homöostatisch die Umgebung beeinflussen und 4) chemische Spezies in synthetischen Mikrokammern räumlich konzentrieren. Die zunehmende Komplexität und die bemerkenswerten Funktionalitäten solcher synthetischer Systeme bieten eine vielversprechende Perspektive auf die breite Palette an dynamischen und adaptiven Eigenschaften, die potentiell in künstlichen Materialsystemen implementiert werden können.
“Heterogenität innerhalb von Ordnung” in Metall‐organischen Gerüsten
Authors: Furukawa Hiroyasu , Müller Ulrich , Yaghi Omar M. 
Published: January 2015

AbstractMetall‐organische Gerüste (MOFs) sind eine Klasse ausgedehnter Netzwerke, die aus anorganischen Knoten und organischen Molekülen als Linker aufgebaut sind. Die meisten MOFs sind hochgeordnete Strukturen, die in der Regel aus einer geringen Anzahl unterschiedlicher Bausteine bestehen; es gibt nur sehr wenige heterogene MOFs, die aus einer Vielzahl verschiedener Bausteinen aufgebaut sind. Während Heterogenität und Multiplizität fundamentale Merkmale biologischer Systeme sind, kennt man kaum synthetische Materialien, die diese Eigenschaften aufweisen, ohne ihre Kristallinität einzubüßen. Die Frage ist daher: Wie lassen sich gezielt heterogene MOFs realisieren, ohne ihre geordnete, kristalline Struktur zu verlieren? Dieser Aufsatz beschreibt, wie durch Variation der Bausteine sowohl in der MOF‐Primärstruktur als auch im Inneren der Poren Heterogenität eingeführt werden kann und welchen Einfluss sie auf die MOF‐Eigenschaften hat. Im zweiten Teil des Aufsatzes wird ein Update über die Industrialisierung der MOF‐Chemie gegeben.
A 36‐Fold Multiple Unit Cell and Switchable Anisotropic Dielectric Responses in an Ammonium Magnesium Formate Framework
Authors: Shang Ran , Wang Zhe‐Ming , Gao Song 
Published: January 2015

AbstractAn ammonium Mg formate framework, prepared by using di‐protonated 1,3‐propanediamine (pnH22+), has a rare three‐dimensional binodal (412⋅63)(49⋅66)3 Mg‐formate framework with elongated cavities accommodating pnH22+⋅⋅⋅H2O⋅⋅⋅pnH22+ assemblies. It displays a para‐electric to antiferroelectric phase transition at 275 K, with a 36‐fold multiple unit cell from the high‐temperature cell of 1703 Å3 to the low‐temperature one of 60 980 Å3. The change results from the disorder–order transition of the pnH22+ cations and H2O molecules. The motions of these components freeze in a stepwise fashion on going from the high‐temperature disorder state to the low‐temperature ordered state, triggering the switch from high to low dielectric constants, and the spatial limitation of such motions contributes the strong dielectric anisotropy.
A Bio‐Inspired Total Synthesis of Tetrahydrofuran Lignans
Authors: Albertson Anna K. F. , Lumb Jean‐Philip 
Published: January 2015

AbstractLignan natural products comprise a broad spectrum of biologically active secondary metabolites. Their structural diversity belies a common biosynthesis, which involves regio‐ and chemoselective oxidative coupling of propenyl phenols. Attempts to replicate this oxidative coupling have revealed significant challenges for controlling selectivity, and these challenges have thus far prevented the development of a unified biomimetic route to compounds of the lignan family. A practical solution is presented that hinges on oxidative ring opening of a diarylcyclobutane to intercept a putative biosynthetic intermediate. The effectiveness of this approach is demonstrated by the first total synthesis of tanegool in 4 steps starting from ferulic acid, as well as a concise synthesis of the prototypical furanolignan pinoresinol.
Recent Approaches for the Direct Use of Elemental Sulfur in the Synthesis and Processing of Advanced Materials
Authors: Lim Jeewoo , Pyun Jeffrey , Char Kookheon 
Published: January 2015

AbstractElemental sulfur is an abundant and inexpensive material obtained as a by‐product of natural‐gas and petroleum refining operations. Recently, the need for the development of new energy‐storage systems brought into light the potential of sulfur as a high‐capacity cathode material in secondary batteries. Sulfur‐containing materials were also shown to have useful IR optical properties. These developments coupled with growing environmental concerns related to the global production of excess elemental sulfur have led to a keen interest in its utilization as a feedstock in materials applications. This Minireview focuses on the recent developments on physical and chemical methods for directly processing elemental sulfur to produce functional composites and polymers.
Biologically Inspired Dynamic Material Systems
Authors: Studart André R. 
Published: January 2015

AbstractNumerous examples of material systems that dynamically interact with and adapt to the surrounding environment are found in nature, from hair‐based mechanoreceptors in animals to self‐shaping seed dispersal units in plants to remodeling bone in vertebrates. Inspired by such fascinating biological structures, a wide range of synthetic material systems have been created to replicate the design concepts of dynamic natural architectures. Examples of biological structures and their man‐made counterparts are herein revisited to illustrate how dynamic and adaptive responses emerge from the intimate microscale combination of building blocks with intrinsic nanoscale properties. By using top‐down photolithographic methods and bottom‐up assembly approaches, biologically inspired dynamic material systems have been created 1) to sense liquid flow with hair‐inspired microelectromechanical systems, 2) to autonomously change shape by utilizing plantlike heterogeneous architectures, 3) to homeostatically influence the surrounding environment through self‐regulating adaptive surfaces, and 4) to spatially concentrate chemical species by using synthetic microcompartments. The ever‐increasing complexity and remarkable functionalities of such synthetic systems offer an encouraging perspective to the rich set of dynamic and adaptive properties that can potentially be implemented in future man‐made material systems.
Anagostic Interactions under Pressure: Attractive or Repulsive?
Authors: Scherer Wolfgang , Dunbar Andrew C. , Barquera‐Lozada José E. , Schmitz Dominik , Eickerling Georg , Kratzert Daniel , Stalke Dietmar , Lanza Arianna , Macchi Piero , Casati Nicola P. M. , Ebad‐Allah Jihaan , Kuntscher Christine 
Published: January 2015

AbstractSquare‐planar d8‐ML4 complexes might display subtle but noticeable local Lewis acidic sites in axial direction in the valence shell of the metal atom. These sites of local charge depletion provide the electronic prerequisites to establish weakly attractive 3c–2e M⋅⋅⋅HC agostic interactions, in contrast to earlier assumptions. Furthermore, we show that the use of the sign of the 1H NMR shifts as major criterion to classify M⋅⋅⋅HC interactions as attractive (agostic) or repulsive (anagostic) can be dubious. We therefore suggest a new characterization method to probe the response of these M⋅⋅⋅HC interactions under pressure by combined high pressure IR and diffraction studies.
Scalable Template Synthesis of Resorcinol–Formaldehyde/Graphene Oxide Composite Aerogels with Tunable Densities and Mechanical Properties
Authors: Wang Xin , Lu Lei‐Lei , Yu Zhi‐Long , Xu Xue‐Wei , Zheng Ya‐Rong , Yu Shu‐Hong 
Published: January 2015

AbstractResorcinol–formaldehyde (RF) and graphene oxide (GO) aerogels have found a variety of applications owing to their excellent properties and remarkable flexibility. However, the macroscopic and controllable synthesis of their composite gels is still a great challenge. By using GO sheets as template skeletons and metal ions (Co2+, Ni2+, or Ca2+) as catalysts and linkers, the first low‐temperature scalable strategy for the synthesis of a new kind of RF–GO composite gel with tunable densities and mechanical properties was developed. The aerogels can tolerate a strain as high as 80 % and quickly recover their original morphology after the compression has been released. Owing to their high compressibility, the gels might find applications in various areas, for example, as adsorbents for the removal of dye pollutants and in oil‐spill cleanup.
Gas‐Separation Membranes Loaded with Porous Aromatic Frameworks that Improve with Age
Authors: Lau Cher Hon , Konstas Kristina , Thornton Aaron W. , Liu Amelia C. Y. , Mudie Stephen , Kennedy Danielle F. , Howard Shaun C. , Hill Anita J. , Hill Matthew R. 
Published: January 2015

AbstractPorosity loss, also known as physical aging, in glassy polymers hampers their long term use in gas separations. Unprecedented interactions of porous aromatic frameworks (PAFs) with these polymers offer the potential to control and exploit physical aging for drastically enhanced separation efficiency. PAF‐1 is used in the archetypal polymer of intrinsic microporosity (PIM), PIM‐1, to achieve three significant outcomes. 1) hydrogen permeability is drastically enhanced by 375 % to 5500 Barrer. 2) Physical aging is controlled causing the selectivity for H2 over N2 to increase from 4.5 to 13 over 400 days of aging. 3) The improvement with age of the membrane is exploited to recover up to 98 % of H2 from gas mixtures with N2. This process is critical for the use of ammonia as a H2 storage medium. The tethering of polymer side chains within PAF‐1 pores is responsible for maintaining H2 transport pathways, whilst the larger N2 pathways gradually collapse.
Organic Synthesis: March of the Machines
Authors: Ley Steven V. , Fitzpatrick Daniel E. , Ingham Richard. J. , Myers Rebecca M. 
Published: January 2015

AbstractOrganic synthesis is changing; in a world where budgets are constrained and the environmental impacts of practice are scrutinized, it is increasingly recognized that the efficient use of human resource is just as important as material use. New technologies and machines have found use as methods for transforming the way we work, addressing these issues encountered in research laboratories by enabling chemists to adopt a more holistic systems approach in their work. Modern developments in this area promote a multi‐disciplinary approach and work is more efficient as a result. This Review focuses on the concepts, procedures and methods that have far‐reaching implications in the chemistry world. Technologies have been grouped as topics of opportunity and their recent applications in innovative research laboratories are described.
Melt extrusion of polyethylene nanocomposites reinforced with nanofibrillated cellulose from cotton and wood sources
Authors: Farahbakhsh Nasim , Roodposhti Peiman Shahbeigi , Ayoub Ali , Venditti Richard A. , Jur Jesse S. 
Published: January 2015

ABSTRACTReplacing petroleum‐based materials with biodegradable materials that offer low environmental impact and safety risk is of increasing importance in sustainable materials processing. The objective of this study was to produce uniform nanofibrillated cotton from recycled waste cotton T‐shirts using microgrinding techniques and compare its performance as reinforcing agent in thermoplastic polymers constructs with wood‐originated materials. The effect of the microgrinding process on morphology, crystallinity, and thermal stability of materials was evaluated by transmission electron microscopy (TEM), scanning electron microscope (SEM), X‐ray diffraction (XRD), and thermogravimetry analysis (TGA). Nanofibrillated cotton resulted in higher crystallinity and thermal stability than fibrillated bleached and unbleached softwood. All the materials were extruded with low‐density polyethylene to fabricate nanocomposite films. Nanofibrillated cotton nanocomposites had a higher optical transparency than did the wood‐based composites. The mechanical properties of the nanofibrillated cotton nanocomposites were largely improved and showed 62.5% increase in strength over the wood‐based nanofibrillated containing composites, in agreement with the higher crystallinity of the nanosized cotton‐derived filler material. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41857.
Preparation and properties of crosslinked network coatings based on perfluoropolyether/poly(dimethyl siloxane)/acrylic polyols for marine fouling–release applications
Authors: Sun Xiaoying , Zhang Fan , Chen Yuanyuan , Cheng Zhang , Su Youquan , Hang Jianzhong , Jin Lujiang , Li Na , Shang Dan , Shi Liyi 
Published: January 2015

ABSTRACTα,ω‐Triethoxysilane terminated poly(dimethyl siloxane) (PDMS) oligomer, α,ω‐triethoxysilane terminated perfluoropolyether (PFPE) oligomer, and acrylic polyols were first synthesized via an addition reaction and free‐radical polymerization. Then, crosslinked network coatings based on PFPE/PDMS/acrylic polyols for marine fouling‐release applications were prepared by a condensation reaction. The structure of the crosslinked network coating was characterized by Fourier transform infrared spectroscopy. The chemical composition of the coating surface was characterized by X‐ray photoelectron spectroscopy. The thermal properties, surface energy, mechanical properties, adhesion, and antiseawater immersion performance of the coatings were systematically studied. The antibiofouling properties of the crosslinked network coating were evaluated by laboratory biofouling assays with the bacteria Escherichia coli and the fouling diatom Navicula. The results from the preliminary study suggested that this crosslinked network coating had good adhesion and promising antifouling properties that were comparable to a silicone standard. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41860.
Microstructure and characterization of electrospun poly(vinyl alcohol) nanofiber scaffolds filled with graphene nanosheets
Authors: Huang Chien‐Lin , Peng Sheng‐Yin , Wang Yu‐Jyun , Chen Wen‐Cheng , Lin Jia‐Horng 
Published: January 2015

ABSTRACTGraphene nanosheets (GNSs) have attracted significant scientific attention because of their remarkable features, including exceptional electron transport, excellent mechanical properties, high surface area, and antibacterial functions. Poly(vinyl alcohol) (PVA) solutions filled with GNSs were prepared for electrospinning, and their spinnability was correlated with their solution properties. The effects of GNS addition on solution rheology and conductivity were investigated. The as‐spun fibers were characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), wide‐angle X‐ray diffraction (WAXD), and differential scanning calorimetry (DSC). The results revealed the effects of GNS on the microstructure, morphology, and crystallization properties of PVA/GNS composite nanofibers. The addition of GNSs in PVA solution increased the viscosity and conductivity of the solution. The electrospun fiber diameter of the PVA/GNS composite nanofiber was smaller than that of neat PVA nanofiber. GNSs were not only embedded at the fibers but also formed protrusions on the fibers. In addition, the crystallinity of PVA/GNS fiber decreased with higher GNS content. The possible application of PVA/GNS fibers in tissue engineering was also evaluated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41891.