bluuebunny/crossref_metadata_2025_split huggingface dataset:
Von den Entwurfsgrundsätzen für Tiefgaragen‐Bodenplatten zur dauerhaften Ausführung
Authors: Dauberschmidt Christoph , Vestner Stephan 
Published: August 2015

AbstractBei der Planung von Tiefgaragen‐Bodenplatten muss infolge der starken Chlorideinwirkung ein besonderes Augenmerk auf die Dauerhaftigkeit der Konstruktion gelegt werden. Dabei ist auf eine ausreichend hohe Betondeckung mit einem möglichst chloriddichten Beton zu achten, bzw. ein Oberflächenschutzsystem ist aufzubringen. Weiterhin sind Maßnahmen zu ergreifen, dass in Risse keine Chloride eindringen. Diese Prinzipien sind in den vorhandenen Regelwerken vorgegeben. Im Entwurf des neuen DBV‐Merkblattes werden darüber hinausgehend Entwurfsgrundsätze vorgegeben, aus denen sich dann Ausführungsvarianten ableiten lassen. Für die Umsetzung der Entwurfsgrundsätze bei der Ausführung von Tiefgaragen‐Bodenplatten werden drei Beispiele aufgezeigt.From the design principles for RC‐ground slabs in underground car parks to the durable executionPlanning of underground floor slabs, special attention must be paid on the durability of the construction as a result of the severe chloride exposure. This durability has to be ensured by a thick concrete cover with a chloride dense concrete or by the application of a surface protection system. Further measures have to be taken to prevent chlorides to penetrate into cracks. These measures are specified within the existing rules and regulations. In the design of new DBV Guide to Good Practise, Design Principles are provided, from which construction alternatives can be derived. For the implementation of the Design Principles at the construction of underground floor slabs three examples are given.
Einsatz von Ultraschallecho zur Spanngliedortung bei der Verstärkung von Brückenbauwerken
Authors: Schulze Sebastian 
Published: August 2015

AbstractBei der nachträglichen Verstärkung vorgespannter Brücken mit externen Spanngliedern ist die schadensfreie Montage der Umlenk‐ und Verankerungsstellen eine besondere Herausforderung. In Abhängigkeit vom Ausnutzungsgrad der Konstruktion ist unter Umständen selbst die Durchtrennung von schlaffer Bewehrung zu vermeiden; in jedem Fall aber dürfen interne Spannglieder nicht beschädigt werden. Die sichere Feststellung der Lage letzterer kann beispielweise bei der Durchbohrung breiter Plattenbalken für die Quervorspannung lasteinleitender Ankerblöcke problematisch werden. Eine zuverlässige zerstörungsfreie Lageortung interner Spannglieder – z. B. mit Radar – ist nicht immer möglich, besonders, wenn diese sehr tief liegen oder durch engmaschige schlaffe Bewehrung verdeckt sind. In diesen Fällen werden üblicherweise Erkundungsbohrungen oder ähnlich fragwürdige Methoden angewendet, um Bewehrungstreffer zu vermeiden.Der vorliegende Beitrag beschreibt eine Lösungsvariante für derartige Fälle, die auf dem Einsatz des zerstörungsfreien Ultraschallecho‐Verfahrens beruht. An der 2014 als erste in der Stadt Hamburg per externer Vorspannung verstärkten Brücke der A7 über die B73 in HH‐Harburg wurden umfangreichen Spanngliedortungen durchgeführt, welche insbesondere im Bereich der Endverankerung über den aktuellen Stand der Technik weit hinausgehen und das Potenzial dieser Methode in der zerstörungsfreien Untersuchung von Bauwerken belegen.Application of the ultrasound echo method for tendon duct detection for the strengthening of bridges – External pre‐stressing of a motorway bridge in HamburgFor strengthening pre‐stressed bridges with external tendons, damage‐free mounting of cradles and end anchorages is one of the major challenges during the reconstruction. Depending on the construction's utilization rate, even conventional reinforcement may not be allowed to be cut, not to mention internal tendons. Localisation of the latter may pose a particular problem, especially when it comes to detecting tendons in greater depths or behind strong reinforcement. A common example is the need to drill through T‐beams for transversal pre‐stressing of external anchorage blocks for load application. Common NDT methods like ground penetrating radar (GPR) might not be able to detect all ducts in every case. Hence, exploratory drilling or other questionable methods had to be used to minimize the chance of hitting and harming the reinforcement.This article describes a possible solution based on the application of nondestructive ultrasound echo methods. Comprehensive tendon duct detections were carried out at a pre‐stressed motorway bridge, which was the first bridge in Hamburg, which was ever strengthened with external tendons. This example exceeds the present state‐of‐the‐art in applied NDT significantly. The results show the potential of the method for further use.
Validation of analytical procedures using HPLC‐ELSD to determine six sesquiterpene lactones in Eremanthus species
Authors: Sousa João Paulo B. , Nogueira Elídia F. , Ferreira Leandro S. , Lopes Norberto P. , Lopes João Luis C. 
Published: August 2015

AbstractEremanthus species display sesquiterpene lactones with therapeutic potential. We are proposing the development of a new analytical method that has been completely validated to qualify Eremanthus species and its main lactones in raw material using HPLC‐ELSD. For the sample preparation, 10.0 mg of powdered Eremanthus leaves was extracted with a 5 mL MeOH/H2O (9:1 v/v) solution containing scopoletin at 140 µg/mL as the internal standard. For the separation of eight compounds, six of which were lactones, one internal (IS) and one secondary standard were performed utilizing monolithic columns with a nonlinear gradient. The selectivity, stability, precision and matrix effects parameters showed values of RSD of <10%. The six lactones and scopoletin (IS) were recovered with a proportion between 74 and 90% with accuracy represented by error at −25.41%. The linear dynamic range was obtained between 10.0 and 310.0 µg/mL for all compounds with r2 > 0.9987. The limits of detection and quantitation ranged from 2.00 to 6.79 µg/mL and from 6.00 to 20.40 µg/mL, respectively. Assessing the robustness study, this method can be used in inter‐laboratory studies. Using the HPLC‐ELSD method, six sesquiterpene lactones including 4β,5‐dihydro‐2′,3′‐dihydroxy‐15‐deoxy‐goyazensolide, goyazensolide, 4β,5‐dihydro‐2′,3′‐epoxy‐15‐deoxy‐goyazensolide, centratherin, 4β,5‐dihydro‐15‐deoxy‐goyazensolide and lychnofolide, were detected and quantified from distinct Eremanthus species, which were collected in different regions. Copyright © 2015 John Wiley & Sons, Ltd.
President's page
Authors: Hirsh Sandy 
Published: August 2015

EDITOR'S SUMMARYASIS&T continues to set new directions with a modernized and reorganized website, option for members to join unlimited number of special interest groups without additional fees and updated online bookstore to come. The Association's self‐evaluation also continues in efforts to position itself for enhanced and extended success, for members and within the information community. The Strategic Planning Task Force has completed data collection through focus groups and surveys with a diverse group of members and nonmembers from three continents and is analyzing the membership database. The group's goal is to address members' changing needs, assess the benefits of membership, better balance the needs of academics and practitioners, promote internal communications and improve awareness of the Association. A draft of priorities and plans will be complete by the 2015 Annual Meeting. Thanks are extended to all who have participated in the process and provided thoughts and suggestions.
Practical Modeling: Making the Invisible Visible
Authors: Elmendorf Joe , Hinton Andrew , Hoff Kaarin 
Published: August 2015

EDITOR'S SUMMARYA fundamental part of information architecture is translating rough ideas through language to a set of organized relationships, understandable to all stakeholders. Modeling information helps visualize the problem to be addressed en route to finding a solution. The process may be complex, iterative and time consuming but necessary to transition from a vague idea to a final implementation. Modeling takes place throughout a project to facilitate analysis of the problem being addressed. It helps clarify relationships and ideas without moving too quickly to specifics, like bubble diagrams of spatial relationships that evolve in phases into detailed architectural drawings. Modeling captures assumptions, even if unstated and invisible, and it can take multiple forms as it progresses to support clear navigation, logical filters and effective discovery.
A Viable Hydrogen Storage and Release System Based on Cesium Formate and Bicarbonate Salts: Mechanistic Insights into the Hydrogen Release Step
Authors: Sordakis Katerina , Dalebrook Andrew F. , Laurenczy Gábor 
Published: August 2015

AbstractThe front cover artwork for Issue 15/2015 is provided by the GCEE—Group of Catalysis for Energy and Environment, LCOM, EPFL, Switzerland. The image shows a safe and effective method for storing hydrogen in cesium formate (CsOOCH) solutions. The opposite reaction takes place upon hydrogenation of cesium bicarbonate (CsHCO3), requiring no change of solvent, catalyst, or pH. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201500359.
Continuous Fuel Cell Catalyst Preparation in a Directly Electrically Heated Tubular Reactor
Authors: Grimm Heiner , Kunz Ulrich 
Published: August 2015

AbstractA continuous process to produce carbon‐supported platinum catalysts by polyol reduction was examined. The reactant dispersion was rapidly heated up to reaction temperature while flowing through a directly electrically heated tube followed by a downstream isothermic tubular reactor. Appropriate inner diameters corresponding to the desired short heating‐up times were calculated. A certain lower limit for the inner diameter is caused by temporary pluggings of particle agglomerates circumventing steady‐state operation. Tube diameters were evaluated with respect to heating‐up times and plugging. It was proved that with a tubular reactor a continuous preparation of carbon nanotube‐supported platinum catalysts with a low particle size and evenly distributed particles is possible.
Palladium Theory of Aqueous‐Phase Heck Alkynylations for Intensification of Discovery and Manufacture
Authors: Sabio Jasmine C. , Domier Ria C. , Moore Jane N. , Shaughnessy Kevin H. , Hartman Ryan L. 
Published: August 2015

AbstractThe influence of water on the catalysis of biphasic Heck alkynylation, a family of palladium‐catalyzed carbon‐carbon bond formations, was investigated. Kinetic theory derived from Hatta moduli and pseudo‐stationary‐state approximations discovered that water, in coordination, reductive elimination, and product dissociation reaction steps of the deprotonation catalytic cycle, increases Gibbs energy barriers compared to values previously estimated by density functional theory calculations of purely organic syntheses involving an aryl iodide. On the contrary, water reduces the energy barrier of reductive elimination in the carbopalladation catalytic cycle. Quantum tunneling in proton transfer mechanism might account for the change. The discoveries permitted E‐factor predictions that could someday help reduce chemical wastes generated during materials, natural products, and pharmaceutical manufactures. Theoretical groundwork is laid that enables data‐driven research in the academic laboratory and data‐driven development by the process chemist.
A Short Multistep Flow Synthesis of a Potential Spirocyclic Fragrance Component
Authors: Baxendale Ian R. 
Published: August 2015

AbstractThe search for novel chemical architectures displaying improved biological properties is a never‐ending synthetic challenge. In this context many new test structures are often conceived by selecting and replicating specific design elements from naturally occurring molecules and displaying them in an alternative format by way of a new chemical assembly. Constructing these newly designed compounds can be a timely and expensive process especially when a large quantity of the target material is required for physiochemical and property testing. To permit easier scale‐up and safer working practice, many chemical researchers are employing flow chemistry approaches to aid in their synthesis challenges. The preparation of a key spirocyclic lactone using flow‐based reaction processing techniques is reported.
Nitrogen‐Doped Carbon with Non‐Precious Metals as Efficient Catalyst for Oxygen Reduction and Na2CO3 Electrolysis
Authors: Huang Mengjie , Tang Yang , Gong Yi , Chen Yongmei , Sun Yanzhi , Yang Xiaojin , Wan Pingyu 
Published: August 2015

AbstractDeveloping oxygen reduction reaction (ORR) catalysts with high activity and low cost is a challenge in the field of electrochemical energy conversion. Here, an efficient catalyst of N‐doped carbon with non‐precious metals (Mn, Fe, Co, and Ni) designated as MFCN/NC has been prepared by using a simple pyrolysis method. Pyridinic nitrogen, graphitic carbon, MnO, and Fe–Co–Ni nanoparticles, which are efficient for catalyzing the ORR individually or synergistically, are successfully introduced into the composite catalyst. The optimized MFCN/NC catalyst exhibits four‐electron reduction of O2 with a more positive ORR onset potential (54 mV) and a more positive half‐wave potential (46 mV) than commercial Pt/C. Moreover, MFCN/NC shows remarkable electrocatalytic activity and long‐term stability in Na2CO3 electrolysis. The cell voltages at 10 and 100 mA cm−2 are only 0.86 and 1.45 V, respectively, suggesting an energy‐saving electrolysis of Na2CO3 to regenerate NaHCO3 and NaOH.
Influence of Electronic Effects on the Reactivity of Triazolylidene‐Boryl Radicals: Consequences for the use of N‐Heterocyclic Carbene Boranes in Organic and Polymer Synthesis
Authors: Telitel Sofia , Vallet Anne‐Laure , Flanigan Darrin M. , Graff Bernadette , Morlet‐Savary Fabrice , Rovis Tomislav , Lalevée Jacques , Lacôte Emmanuel 
Published: August 2015

AbstractA small library of triazolylidene‐boranes that differ only in the nature of the aryl group on the external nitrogen atom was prepared. Their reactivity as hydrogen‐atom donors, as well as that of the corresponding N‐heterocyclic carbene (NHC)‐boryl radicals toward methyl acrylate and oxygen, was investigated by laser flash photolysis, molecular orbital calculations, and ESR spin‐trapping experiments, and benchmarked relative to the already known dimethyltriazolylidene‐borane. The new NHC‐boranes were also used as co‐initiators for the Type I photopolymerization of acrylates. This allowed a structure–reactivity relationship with regard to the substitution pattern of the NHC to be established and the role of electronic effects in the reactivity of NHC‐boryl radicals to be probed. Although their rate of addition to methyl acrylate depends on their electronegativity, the radicals are all nucleophilic and good initiators for photopolymerization reactions.
Concentration Threshold and Amplification Exhibited by a Helicene Oligomer during Helix‐Dimer Formation: A Proposal on How a Cell Senses Concentration Changes of a Chemical
Authors: Kushida Yo , Shigeno Masanori , Yamaguchi Masahiko 
Published: August 2015

AbstractSulfonamidohelicene tetramer (M)‐1 exhibits a concentration threshold and amplification phenomena in solution during helix‐dimer formation from a random‐coil. The (M)‐tetramer is a random‐coil below a threshold concentration, and the concentration of the helix‐dimer is irreversibly amplified once the threshold concentration is exceeded. For example, a 15 % increase in (M)‐tetramer total concentration from 0.6 to 0.7 mM induces an 8‐fold increase in the concentration of the helix‐dimer, being 8:0.15=53‐fold amplification, under temperature oscillation conditions between 47 and 49 °C. Experiments without oscillation also exhibit concentration amplification. The threshold and amplification phenomenon involves concentration hysteresis, being away from equilibrium, and self‐catalysis. On the basis of this study, a proposal on how a biological cell senses concentration changes of a chemical substance is provided.
Liquid Chromatography Enantioseparations of Halogenated Compounds on Polysaccharide‐Based Chiral Stationary Phases: Role of Halogen Substituents in Molecular Recognition
Authors: Peluso Paola , Mamane Victor , Cossu Sergio 
Published: August 2015

AbstractHalogenated chiral molecules have become important in several fields of science, industry, and society as drugs, natural compounds, agrochemicals, environmental pollutants, synthetic products, and chiral supports. Meanwhile, the perception of the halogen moiety in organic compounds and its role in recognition processes changed. Indeed, the recognition of the halogen bond as an intermolecular interaction occurring when the halogen acts as a Lewis acid had a strong impact, particularly in crystal engineering and medicinal chemistry. Due to this renewed interest in the potentialities of chiral organohalogens, here we focus on selected recent applications dealing with enantioseparations of halogenated compounds on polysaccharide‐based chiral stationary phases (CSPs), widely used in liquid chromatography (LC). In particular, recently the first case of halogen bonding‐driven high‐performance LC (HPLC) enantioseparation was reported on a cellulose‐based CSP. Along with enantioseparations performed under conventional HPLC, representative applications using supercritical fluid chromatography (SFC) are reported.Chirality 27:667–684, 2015. © 2015 Wiley Periodicals, Inc.
Entwicklung und Anpassung einer Free‐Flow‐Elektrophorese zur selektiven quantitativen Trennung von Metallionen
Authors: Kotzur Maximilian , König Lea , Egner Siegfried 
Published: August 2015

AbstractEffiziente Technologien im Metallrecycling werden immer bedeutsamer. Hierbei zeigt sich der Metallionentrennschritt als essentiell für den Aufbereitungsprozesses, da Metalle meist in komplexen Gemischen vorliegen. Eine Alternative zu etablierten Trennmethoden stellt die Free‐Flow‐Elektrophorese dar, deren Trennwirkung auf unterschiedlichem Wanderungsverhalten geladener Teilchen im elektrischen Feld beruht. Hierbei wurden sehr gute Trennergebnisse erzielt, die durch den Einsatz von Komplexbildnern auf eine Reinheit von bis zu 100 % gesteigert wurden. Untersucht wurden Gemische aus Fe, Cu, Dy und Yb.
Improved handover authentication and key pre‐distribution for wireless mesh networks
Authors: Yang Xu , Huang Xinyi , Han Jinguang , Su Chunhua 
Published: August 2015

SummaryTicket‐based authentication is a critical technology to secure wireless mesh networks (WMN), which enable efficient communication among laptops, cell phones and other wireless devices. In this paper, we provide a new design of handoff authentication for WMN to reduce the delay caused by handoff. Our major improvement is on the key pre‐distribution for handoff authentication. We apply the attribute‐based encryption to encrypt key pre‐distribution messages for neighbor mesh routers. As a result, key pre‐distribution has constant computation and communication costs, which are independent of the number of neighbor mesh routers. Another advantage of our design is that it can perform immediate handoff authentication once the login authentication is complete, even before key pre‐distribution messages reach the foreign mesh router. The security of our handoff authenticator protocol is also improved by employing home mesh router's digital signature in the handoff ticket and key pre‐distribution messages. Our scheme can efficiently thwart forgery attacks. The proposed scheme provides an efficient and secure solution that meets the requirements of WMN in the era of Big Data. Copyright © 2015 John Wiley & Sons, Ltd.
Entropy‐based denial‐of‐service attack detection in cloud data center
Authors: Cao Jiuxin , Yu Bin , Dong Fang , Zhu Xiangying , Xu Shuai 
Published: August 2015

SummaryCloud data centers today usually lack network resource isolation. Meanwhile, it is easy to deploy and terminate large number of malicious virtual machines in a few seconds, while the administrator is probably difficult to identify these malicious virtual machines immediately. These features open doors for attackers to launch denial‐of‐service (DoS) attacks that target at degrading the quality of cloud service. This paper studies an attack scenario that malicious tenants use cloud resources to launch DoS attack targeting at data center subnets. Unlike traditional data flow‐based detections, which heavily depend on the pattern of data flows, we propose an approach that takes advantage of virtual machine status including CPU usage and network usage to identify the attack. We notice that malicious virtual machines exhibit similar status patterns when attack is launched. Based on this observation, information entropy is applied in monitoring the status of virtual machines to identify the attack behaviors. We conduct our experiments in the campus‐wide data center, and the results show our detection system can promptly and accurately response to DoS attacks. Copyright © 2015 John Wiley & Sons, Ltd.
Spectroscopic Observation of the Hydroxy Position in Butanol Hydrates and Its Effect on Hydrate Stability
Authors: Youn Yeobum , Cha Minjun , Lee Huen 
Published: August 2015

AbstractIn this study, we investigate the crystal structures and phase equilibria of butanols+CH4+H2O systems to reveal the hydroxy group positioning and its effects on hydrate stability. Four clathrate hydrates formed by structural butanol isomers are identified with powder X‐ray diffraction (PXRD). In addition, Raman spectroscopy is used to analyze the guest distributions and inclusion behaviors of large alcohol molecules in these hydrate systems. The existence of a free OH indicates that guest molecules can be captured in the large cages of structure II hydrates without any hydrogen‐bonding interactions between the hydroxy group of the guests and the water‐host framework. However, Raman spectra of the binary (1‐butanol+CH4) hydrate do not show the free OH signal, indicating that there could be possible hydrogen‐bonding interactions between the guests and hosts. We also measure the four‐phase equilibrium conditions of the butanols+CH4+H2O systems.
Direct Production of 5‐Hydroxymethylfurfural via Catalytic Conversion of Simple and Complex Sugars over Phosphated TiO2
Authors: Atanda Luqman , Shrotri Abhijit , Mukundan Swathi , Ma Qing , Konarova Muxina , Beltramini Jorge 
Published: August 2015

AbstractA water–THF biphasic system containing N‐methyl‐2‐pyrrolidone (NMP) was found to enable the efficient synthesis of 5‐hydroxymethylfurfural (HMF) from a variety of sugars (simple to complex) using phosphated TiO2 as a catalyst. Fructose and glucose were selectively converted to HMF resulting in 98 % and 90 % yield, respectively, at 175 °C. Cellobiose and sucrose also gave rise to high HMF yields of 94 % and 98 %, respectively, at 180 °C. Other sugar variants such as starch (potato and rice) and cellulose were also investigated. The yields of HMF from starch (80–85 %) were high, whereas cellulose resulted in a modest yield of 33 %. Direct transformation of cellulose to HMF in significant yield (86 %) was assisted by mechanocatalytic depolymerization—ball milling of acid‐impregnated cellulose. This effectively reduced cellulose crystallinity and particle size, forming soluble cello‐oligomers; this is responsible for the enhanced substrate–catalytic sites contact and subsequent rate of HMF formation. During catalyst recyclability, P–TiO2 was observed to be reusable for four cycles without any loss in activity. We also investigated the conversion of the cello‐oligomers to HMF in a continuous flow reactor. Good HMF yield (53 %) was achieved using a water–methyl isobutyl ketone+NMP biphasic system.