bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer and dissipation of energy during wave group propagation on a gentle beach slope
Authors: Padilla Enrique M. , Alsina José M. 
Published: August 2017

AbstractThe propagation of bichromatic wave groups over a constant 1:100 beach slope and the influence of the group modulation is presented. The modulation is controlled by varying the group frequency, fg, which is shown to remarkably affect the energy transfer to high and low frequency components. The growth of the high frequency (hf) wave skewness increases when fg decreases. This is explained by nonlinear coupling between the primary frequencies, which results in a larger growth of hf components as fg decreases, causing the hf waves to break earlier. Due to high spatial resolution, wave tracking has provided an accurate measurement of the varying breakpoint. These breaking locations are very well described (
) by the wave‐height to effective‐depth ratio (γ). However, for any given Iribarren number, this γ is shown to increase with fg. Therefore, a modified Iribarren number is proposed to include the grouping structure, leading to a considerable improvement in reproducing the measured γ‐values. Within the surf zone, the behavior of the Incident Long Wave also depends on the group modulation. For low fg conditions, the lf wave decays only slightly by transferring energy back to the hf wave components. However, for high fg wave conditions, strong dissipation of low frequency (lf) components occurs close to the shoreline associated with lf wave breaking. This mechanism is explained by the growth of the lf wave height, induced partly by the self‐self interaction of fg, and partly by the nonlinear coupling between the primary frequencies and fg.
An HF and lower VHF spectrum assessment system exploiting instantaneously wideband capture
Authors: Barnes Rod I. , Singh Malkiat , Earl Fred 
Published: August 2017

AbstractWe report on a spectral environment evaluation and recording (SEER) system, for instantaneously wideband spectral capture and characterization in the HF and lower VHF band, utilizing a direct digital receiver coupled to a data recorder. The system is designed to contend with a wide variety of electromagnetic environments and to provide accurately calibrated spectral characterization and display from very short (ms) to synoptic scales. The system incorporates a novel RF front end involving automated gain and equalization filter selection which provides an analogue frequency‐dependent gain characteristic that mitigates the high dynamic range found across the HF and lower VHF spectrum. The system accurately calibrates its own internal noise and automatically subtracts this from low variance, external spectral estimates, further extending the dynamic range over which robust characterization is possible. Laboratory and field experiments demonstrate that the implementation of these concepts has been effective. Sensitivity to varying antenna load impedance of the internal noise reduction process has been examined. Examples of software algorithms to provide extraction and visualization of spectral behavior over narrowband, wideband, short, and synoptic scales are provided. Application in HF noise spectral density monitoring, spectral signal strength assessment, and electromagnetic interference detection is possible with examples provided. The instantaneously full bandwidth collection provides some innovative applications, and this is demonstrated by the collection of discrete lightning emissions, which form fast ionograms called “flashagrams” in power‐delay‐frequency plots.
Aspects of the Energetics of Metal β‐Diketonates and their Derivatives
Authors: Zeiger Diana N. , Liebman Joel F. , Ponikvar‐Svet Maja 
Published: August 2017

AbstractIn this chapter, we will discuss diverse aspects of the energetics of metal β‐diketonates and their derivatives. By “energetics” we mean thermochemical and related studies, and so we include enthalpies of reaction and of formation as well as equilibrium measurements and stability constants. We will also discuss the gain or loss of an electron, and therefore consider ionization potentials, electron affinities, and electrochemical potentials. By metal β‐diketonates and derivatives we mean, most generally, species with a substructure of the type [M(dik)n], where dik (β‐diketonato) is an organic monovalent anion of structure (RC(X)C(R1)C(O)R2)−and M is an arbitrary metal. For completeness and additional insights, in this chapter we will also consider M to be virtually all elements (nonmetal, metalloid, or metal), and eventually we will include hydrogen.
Particle Targeting in Complex Biological Media
Authors: Dai Qiong , Bertleff‐Zieschang Nadja , Braunger Julia A. , Björnmalm Mattias , Cortez‐Jugo Christina , Caruso Frank 
Published: August 2017

AbstractOver the past few decades, nanoengineered particles have gained increasing interest for applications in the biomedical realm, including diagnosis, imaging, and therapy. When functionalized with targeting ligands, these particles have the potential to interact with specific cells and tissues, and accumulate at desired target sites, reducing side effects and improve overall efficacy in applications such as vaccination and drug delivery. However, when targeted particles enter a complex biological environment, the adsorption of biomolecules and the formation of a surface coating (e.g., a protein corona) changes the properties of the carriers and can render their behavior unpredictable. For this reason, it is of importance to consider the potential challenges imposed by the biological environment at the early stages of particle design. This review describes parameters that affect the targeting ability of particulate drug carriers, with an emphasis on the effect of the protein corona. We highlight strategies for exploiting the protein corona to improve the targeting ability of particles. Finally, we provide suggestions for complementing current in vitro assays used for the evaluation of targeting and carrier efficacy with new and emerging techniques (e.g., 3D models and flow‐based technologies) to advance fundamental understanding in bio‐nano science and to accelerate the development of targeted particles for biomedical applications.
A Cooperative Ternary Catalysis System for Asymmetric Lactonizations of α‐Ketoesters
Authors: Murauski Kathleen J. R. , Walden Daniel M. , Cheong Paul Ha‐Yeon , Scheidt Karl A. 
Published: August 2017

AbstractA general and enantioselective N‐heterocyclic carbene (NHC)‐catalyzed lactonization of simple enals and α‐ketoesters has been discovered using a new ternary cooperative catalytic system. The highly selective annulation was achieved by using a combination of a chiral NHC, a hydrogen‐bond donor, and a metal salt, facilitating self‐assembly of the reactive partners. A proposed model for this new mode of NHC chiral relay catalysis is supported by experimental and computational mechanistic studies.magnified image
Palladium‐Catalyzed Carbon–Fluorine and Carbon–Hydrogen Bond Alumination of Fluoroarenes and Heteroarenes
Authors: Chen Wenyi , Hooper Thomas N. , Ng Jamues , White Andrew J. P. , Crimmin Mark R. 
Published: August 2017

AbstractThrough serendipitous discovery, a palladium bis(phosphine) complex was identified as a catalyst for the selective transformation of sp2C−F and sp2C−H bonds of fluoroarenes and heteroarenes to sp2C−Al bonds (19 examples, 1 mol % Pd loading). The carbon–fluorine bond functionalization reaction is highly selective for the formation of organoaluminium products in preference to hydrodefluorination products (selectivity=4.4:1 to 27:1). Evidence is presented for a tandem catalytic process in which hydrodefluorination is followed by sp2C−H alumination.
Fe‐Doped Ni3C Nanodots in N‐Doped Carbon Nanosheets for Efficient Hydrogen‐Evolution and Oxygen‐Evolution Electrocatalysis
Authors: Fan Haosen , Yu Hong , Zhang Yufei , Zheng Yun , Luo Yubo , Dai Zhengfei , Li Bing , Zong Yun , Yan Qingyu 
Published: August 2017

AbstractUniform Ni3C nanodots dispersed in ultrathin N‐doped carbon nanosheets were successfully prepared by carburization of the two dimensional (2D) nickel cyanide coordination polymer precursors. The Ni3C based nanosheets have lateral length of about 200 nm and thickness of 10 nm. When doped with Fe, the Ni3C based nanosheets exhibited outstanding electrocatalytic properties for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For example, 2 at % Fe (atomic percent) doped Ni3C nanosheets depict a low overpotential (292 mV) and a small Tafel slope (41.3 mV dec−1) for HER in KOH solution. An outstanding OER catalytic property is also achieved with a low overpotential of 275 mV and a small Tafel slope of 62 mV dec−1 in KOH solution. Such nanodot‐incorporated 2D hybrid structures can serve as an efficient bifunctional electrocatalyst for overall water splitting.
Real‐Time Intracellular Measurements of ROS and RNS in Living Cells with Single Core–Shell Nanowire Electrodes
Authors: Zhang Xin‐Wei , Qiu Quan‐Fa , Jiang Hong , Zhang Fu‐Li , Liu Yan‐Lin , Amatore Christian , Huang Wei‐Hua 
Published: August 2017

AbstractNanoelectrodes allow precise and quantitative measurements of important biological processes at the single living‐cell level in real time. Cylindrical nanowire electrodes (NWEs) required for intracellular measurements create a great challenge for achieving excellent electrochemical and mechanical performances. Herein, we present a facile and robust solution to this problem based on a unique SiC‐core–shell design to produce cylindrical NWEs with superior mechanical toughness provided by the SiC nano‐core and an excellent electrochemical performance provided by the ultrathin carbon shell that can be used as such or platinized. The use of such NWEs for biological applications is illustrated by the first quantitative measurements of ROS/RNS in individual phagolysosomes of living macrophages. As the shell material can be varied to meet any specific detection purpose, this work opens up new opportunities to monitor quantitatively biological functions occurring inside cells and their organelles.
Discovery of Key Physicochemical, Structural, and Spatial Properties of RNA‐Targeted Bioactive Ligands
Authors: Morgan Brittany S. , Forte Jordan E. , Culver Rebecca N. , Zhang Yuqi , Hargrove Amanda E. 
Published: August 2017

AbstractWhile a myriad non‐coding RNAs are known to be essential in cellular processes and misregulated in diseases, the development of RNA‐targeted small molecule probes has met with limited success. To elucidate the guiding principles for selective small molecule/RNA recognition, we analyzed cheminformatic and shape‐based descriptors for 104 RNA‐targeted ligands with demonstrated biological activity (RNA‐targeted BIoactive ligaNd Database, R‐BIND). We then compared R‐BIND to both FDA‐approved small molecule drugs and RNA ligands without reported bioactivity. Several striking trends emerged for bioactive RNA ligands, including: 1) Compliance to medicinal chemistry rules, 2) distinctive structural features, and 3) enrichment in rod‐like shapes over others. This work provides unique insights that directly facilitate the selection and synthesis of RNA‐targeted libraries with the goal of efficiently identifying selective small molecule ligands for therapeutically relevant RNAs.
Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal‐Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
Authors: Zhang Jing , Li Yang , Xu Ruoyu , Chen Yiyun 
Published: August 2017

AbstractThe alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex‐enabled alkoxyl radical generation under metal‐free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N‐alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)‐C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst‐free approach with linear primary, secondary, and tertiary alkoxyl radicals.
Quasi‐Dual‐Packed‐Kerneled Au49(2,4‐DMBT)27 Nanoclusters and the Influence of Kernel Packing on the Electrochemical Gap
Authors: Liao Lingwen , Zhuang Shengli , Wang Pu , Xu Yanan , Yan Nan , Dong Hongwei , Wang Chengming , Zhao Yan , Xia Nan , Li Jin , Deng Haiteng , Pei Yong , Tian Shi‐Kai , Wu Zhikun 
Published: August 2017

AbstractAlthough face‐centered cubic (fcc), body‐centered cubic (bcc), hexagonal close‐packed (hcp), and other structured gold nanoclusters have been reported, it was unclear whether gold nanoclusters with mix‐packed (fcc and non‐fcc) kernels exist, and the correlation between kernel packing and the properties of gold nanoclusters is unknown. A Au49(2,4‐DMBT)27 nanocluster with a shell electron count of 22 has now been been synthesized and structurally resolved by single‐crystal X‐ray crystallography, which revealed that Au49(2,4‐DMBT)27 contains a unique Au34 kernel consisting of one quasi‐fcc‐structured Au21 and one non‐fcc‐structured Au13 unit (where 2,4‐DMBTH=2,4‐dimethylbenzenethiol). Further experiments revealed that the kernel packing greatly influences the electrochemical gap (EG) and the fcc structure has a larger EG than the investigated non‐fcc structure.
Utilization of industrial waste as a novel adsorbent: Mono/competitive adsorption of chromium(VI) and nickel(II) using diatomite waste modified by EDTA
Authors: Sha Haitao , Wu Yunhai , Fan Yiang 
Published: August 2017

The adsorption of Cr(VI) and Ni(II) using ethylenediaminetetraacetic acid‐modified diatomite waste (EDTA‐DW) as an adsorbent in single and binary systems was investigated. The EDTA‐DW was characterized using various analytical techniques, including Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller measurements, X‐ray diffraction, scanning electron microscopy and energy‐dispersive spectrometry. The adsorption experiment was conducted by varying pH, adsorbent dosage, initial concentration and temperature. In the single system, the sorption data for Cr(VI) fitted the Langmuir isotherm, but the Ni(II) adsorption data fitted well the Freundlich isotherm. The maximum sorption capacity of Cr(VI) and Ni(II) was 2.9 mg g−1 at pH = 3 and 3.64 mg g−1 at pH = 8, respectively. The kinetic data for both Cr(VI) and Ni(II) followed well the pseudo‐second‐order kinetic model in single and binary systems. Meanwhile, the extended Langmuir and extended Freundlich multicomponent isotherm models were found to fit the competitive adsorption data for Cr(VI) and Ni(II). In addition, in the binary system, the existence of Ni(II) hindered the adsorption of Cr(VI), but the presence of Cr(VI) enhanced the removal of Ni(II). This study provides some realistic and valid data about the usage of modified diatomite waste for the removal of metal ions.
Facile synthesis of PtSnZn nanosheet thin film at oil–water interface by use of organometallic complexes: An efficient catalyst for methanol oxidation and p‐nitrophenol reduction reactions
Authors: Sarmoor Sajad Saberi , Hoseini S. Jafar , Hashemi Fath Roghayeh , Roushani Mahmoud , Bahrami Mehrangiz 
Published: August 2017

PtSnZn nanosheet thin film with stable and high activity towards methanol electro‐oxidation was synthesized via a simple reduction of organometallic precursors including [PtCl2(cod)] (cod = cis,cis‐1,5‐cyclooctadiene) and [Sn(CH3)4] complexes, in the presence of [Zn(acac)2] (acac = acetylacetonate) complex at toluene–water interface. Catalytic activities of PtSnZn nanosheets were investigated in the p‐nitrophenol (p‐Nip) reduction and methanol oxidation reactions. The obtained results demonstrate that PtSnZn nanosheets exhibit a good electrocatalytic performance for methanol oxidation reaction, the catalytic activity of the PtSnZn nanosheets being at least 3.5 times higher than that of Pt nanoparticle thin film. Also, the apparent rate constant obtained for p‐Nip reduction with the PtSnZn nanosheets is at least 2.3 times higher than that for Pt nanoparticle thin film due to the appropriate interaction between platinum, tin and zinc metals and geometric properties of PtSnZn nanosheet thin film. Nanosheets are highly favourable for superior catalytic performances due to their geometric properties. A facile and efficient route was used to synthesize trimetallic alloy thin film at oil–water interface.
Synthesis, characterization and photocatalytic application of TiO2/magnetic graphene for efficient photodegradation of crystal violet
Authors: Piranshahi Zahra Aalimohammadi , Behbahani Mohammad , Zeraatpisheh Fatemeh 
Published: August 2017

A magnetized nano‐photocatalyst based on TiO2/magnetic graphene was developed for efficient photodegradation of crystal violet (CV). Scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy and elemental mapping were used to characterize the prepared magnetic nano‐photocatalyst. The photocatalytic activity of the synthesized magnetic nano‐photocatalyst was evaluated using the decomposition of CV as a model organic pollutant under UV light irradiation. The obtained results showed that TiO2/magnetic graphene exhibited much higher photocatalytic performance than bare TiO2. Incorporation of graphene enhanced the activity of the prepared magnetic nano‐photocatalyst. TiO2/magnetic graphene can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, magnetized nano‐photocatalyst dosage, UV light irradiation time, H2O2 amount and initial concentration of dye on the photodegradation efficiency were evaluated and optimized. Efficient photodegradation (>98%) of the selected dye under optimized conditions using the synthesized nano‐photocatalyst under UV light irradiation was achieved in 25 min. The prepared magnetic nano‐photocatalyst can be used in a wide pH range (4–10) for degradation of CV. The effects of scavengers, namely methanol (OH• scavenger), p‐benzoquinone (O2•− scavenger) and disodium ethylenediaminetetraacetate (hole scavenger), on CV photodegradation were investigated.
A nondisruptive reliability approach to assess the health of microseismic sensing networks
Authors: Neira D. , Soto G. , Fontbona J. , Prado J. , Gaete S. 
Published: August 2017

Microseismic sensing networks are important tools for the assessment and control of geomechanical hazards in underground mining operations. In such a setting, the maintenance of a healthy network, that is, one that accurately registers all microseisms above some minimum energy level with acceptable levels of noise, is crucially relevant.In this paper, we develop a nondisruptive method to monitor the health of such a network, by associating with each sensor a set of performance indexes, inspired from reliability engineering, which are estimated from the set of registered signals. Our method addresses 2 relevant features of each of the sensors' behavior, namely, what type of noise is or might be affecting the registering process, and how effective at registering microseisms the sensor is.The method is evaluated through a case study with microseismic data registered at the Chilean underground mine El Teniente. This study illustrates our method's capability to discriminate and rank sensors with satisfactory, poor, or defective sensing performances, as well as to characterize their failure profile or type, an information that can be used to plan or optimize the network maintenance procedures.
REFUND: Untersuchung von Bestandsgründungen für eine Entscheidung zur Wiedernutzung
Authors: Niederleithinger Ernst , Katzenbach Rolf , Klingmüller Oswald , Hillmann Stephan , Willmes Michael 
Published: August 2017

AbstractVor einer geplanten Weiter‐ oder Wiedernutzung von Bestandsgründungen stellt sich die Frage nach deren Lage, Geometrie und Zustand im Untergrund. Hierfür gibt es verschiedene Prüfverfahren. Die Abläufe bei Planung und Prüfung sind jedoch bisher nicht standardisiert und die Möglichkeiten bzw. Grenzen der Prüfverfahren den Planern wenig bekannt. Im Forschungsprojekt REFUND (2014–2016) wurden unter Berücksichtigung der aktuellen Normen und des Stands der Technik Ablaufdiagramme für die Planung der Wiedernutzung sowie die Untersuchung des Bestands entwickelt. Dies geschah getrennt für Einzel‐ und Streifenfundamente, Platten und Pfähle. An zwei Praxisbeispielen wurden die Abläufe getestet und optimiert. Die Ergebnisse wurden in einem Handbuch zusammengefasst. Es soll Planer und andere Verantwortliche bei der wirtschaftlich und technisch optimierten Durchführung von Wiedernutzungsprojekten unterstützen.
Erfahrungen mit wasserabführenden Schalungsbahnen an der zweiten Schleuse Trier
Authors: Müller Hilmar , Mertes Raymund , Kanther Christian 
Published: August 2017

AbstractBeim Bau der zweiten Schleuse Trier wurden die Kammerwandoberflächen in Teilbereichen mit konventioneller, saugender Schalhaut, in anderen Bereichen unter Verwendung einer wasserabführenden Schalungsbahn hergestellt. Die Bauausführung mit der wasserabführenden Schalungsbahn wies gegenüber der saugenden Schalung deutliche Vorteile auf. Die Eigenschaften der Betonrandzone, wie Festigkeit und Dichtigkeit, konnten deutlich verbessert werden. Mit den verbesserten Oberflächeneigenschaften werden eine höhere Dauerhaftigkeit sowie Erleichterungen bei der Unterhaltung erwartet.Die Ausführung mit der zusätzlich aufzubringenden Schalungsbahn bedeutete einen zusätzlichen Aufwand, der aber durch kürzere Nachbehandlungszeiten und deutlich geringere Nacharbeiten weitgehend wieder kompensiert wurde.
Das Archaellum
Authors: Hoffmann Lena , Albers Sonja‐Verena 
Published: August 2017

ZusammenfassungArchaeen bilden eine der drei Domänen des Lebens. Obwohl sie auf den ersten Blick Bakterien sehr ähneln, sind sie in manchen Prozessen wie Transkription und Translation den Eukaryoten viel ähnlicher. Alle drei Domänen des Lebens haben völlig verschiedene Formen der Bewegung entwickelt. Während Bakterien zum Schwimmen das Flagellum benutzen, schwimmen Eukaryoten mittels Cilien, die aus Mikrotubuli aufgebaut sind. Die Archaeen dahingegen haben das Archaellum entwickelt. Diese Struktur ist evolutionär mit Typ IV‐Pili verwandt, da es ähnlich assembliert wird. Im Gegensatz zu diesen kann das Archaellum rotieren, um die Zellen fortzubewegen. In diesem Artikel geben wir einen kurzen Einblick in die Entdeckung der Archaeen sowie aktuelle spannende Entwicklungen und beschreiben, was wir über das Archaellum als faszinierendes Motilitätsorganell wissen.
Naturapotheke Mistel
Authors: Pfüller Uwe , Stürken Christine 
Published: August 2017

ZusammenfassungDie Mistel, ein auf Bäumen wachsender, immergrüner Halbschmarotzer, beeindruckt mit ihrer einzigartigen Erscheinung, ihrer weltweiten Verbreitung und der Vielfalt ihrer Inhalts‐ und Wirkstoffe. Erst in der Neuzeit fand die Mistel mit ihren Wirkstoffen den Weg in die unkonventionelle und schließlich in die molekulare Medizin. Das Wirkstoffspektrum wird anhand der umfassend erforschten Europäischen Mistel (Viscum album) dargestellt.
Seeigel und ihre Beutegreifer im Mittelmeer
Authors: Sievers Diedrich 
Published: August 2017

ZusammenfassungSeeigel sind eine beliebte Beute und trotz unterschiedlicher Schutzanpassungen gelingt es Räubern, diese Verteidigung zu überwinden. Im Mittelmeer machen vor allem wirbellose Tiere, etwa Helmschnecken, Krebse und Seesterne, aber auch verschiedene Fische Jagd auf Seeigel. Helmschnecken verkleben die Stacheln und Pedicellarien mit Schleim und bohren das Kalkskelett der Seeigel mit Hilfe von Schwefelsäure an. Große Krebse, etwa Langusten und Seespinnen, brechen den Panzer der Seeigel mit ihren Laufbeinen oder Scheren auf. Seesterne nehmen kleine Seeigel entweder direkt mit dem Magen auf oder stülpen ihren Magen nach außen, um Seeigel zu verdauen. Fische, vor allem Meerbrassen, beißen zuerst die schützenden Stacheln ab und brechen den Panzer des Seeigels mit ihrem spezialisierten Gebiss auf. Zum Teil bleiben dabei Spuren auf den Skeletten der erbeuteten Seeigel zurück, etwa Bohrlöcher, Kratzspuren, Zahnabdrücke und Bruchmuster, die es ermöglichen, das Geschehen zu rekonstruieren.