bluuebunny/crossref_metadata_2025 huggingface dataset:
Building International Research Partnerships in the North Atlantic–Arctic Region
Authors: Benway Heather M. , Hofmann Eileen , St. John Michael
Published: September 2014

The North Atlantic–Arctic region, which is critical to the health and socioeconomic well being of North America and Europe, is susceptible to climate‐driven changes in circulation, biogeochemistry, and marine ecosystems. The need for strong investment in the study of biogeochemical and ecosystem processes and interactions with physical processes over a range of time and space scales in this region was clearly stated in the 2013 Galway Declaration, an intergovernmental statement on Atlantic Ocean cooperation (http://europa.eu/rapid/press‐release_IP‐13‐459_en.htm). Subsequently, a workshop was held to bring together researchers from the United States, Canada, and Europe with expertise across multiple disciplines to discuss an international research initiative focused on key features, processes, and ecosystem services (e.g., Atlantic Meridional Overturning Circulation, spring bloom dynamics, fisheries, etc.) and associated sensitivities to climate changes.
Morgan Receives 2013 Paul G. Silver Award for Outstanding Scientific Service: Citation
Authors: Wang Kelin
Published: September 2014

Julia Morgan received her Ph.D. in 1993 from the Cornell University. She joined the Department of Earth Sciences at Rice University in 1999 and has been a full professor since 2009. Julia is well known for a rare combination of skills in field geology and quantitative modeling. Her broad scientific background and leadership quality make her an exemplary leader for a major scientific program as multidisciplinary as Geodynamic Processes at Rifting and Subducting Margins (GeoPRISMS) (http://www.geoprisms.org).
Thompson Receives 2013 Ocean Sciences Early Career Award: Response
Authors: Thompson Andrew
Published: September 2014

I would like to thank my nominator, Jess Adkins, as well as my supporters for their contributions to my nomination and the AGU Ocean Sciences section for its selection. It is an honor to join the past recipients of this award.
A new earthquake model may explain discrepancies in San Andreas fault slip
Authors: Schultz Colin
Published: September 2014

Investigating the earthquake hazards of the San Andreas fault system requires an accurate understanding of accumulating stresses and the history of past earthquakes. Faults tend to go through an “earthquake cycle”—locking and accumulating stress, rupturing in an earthquake, and locking again in a well‐accepted process known as “elastic rebound.” One of the key factors in preparing for California's next “big one” is estimating the fault slip rate, the speed at which one side of the San Andreas fault is moving past the other.
Ionospheric response to sudden stratospheric warming events at low and high solar activity
Authors: Fang Tzu‐Wei , Fuller‐Rowell Tim , Wang Houjun , Akmaev Rashid , Wu Fei
Published: September 2014

The sensitivity of the ionospheric response to a sudden stratospheric warming (SSW) event has been examined under conditions of low and high solar activity through simulations using the whole atmosphere model (WAM) and the global ionosphere plasmasphere model (GIP). During non‐SSW conditions, simulated daytime mean vertical drifts at the magnetic equator show similar solar activity dependence as an empirical model. Model results of ionospheric total electron content (TEC) and equatorial vertical drift for the January 2009 major SSW, which occurred at very low solar activity conditions, show reasonable agreement with observations. The simulations demonstrate that the E region dynamo is capable of creating the semidiurnal variation of vertical drift. WAM and GIP were also run at high solar activity conditions, using the same lower atmosphere conditions as present in the January 2009 SSW event. The simulations indicate that the amplitude and phase of migrating tides in the dynamo region during the event have similar magnitudes for both solar flux conditions. However, comparing the ionospheric responses to a major SSW under low and high solar activity periods, it was found that the changes in the ionospheric vertical drifts and relative changes in TEC decreased with increasing solar activity. The simulations indicate that the F region dynamo becomes more important throughout the daytime and contributes to the upward drift in the afternoon during the event when the solar activity is higher. Our test simulations also confirm that the increase of the ionospheric conductivity associated with increasing solar activity is responsible for the decrease of vertical drift changes during an SSW. In particular, first, the increase in F region conductivity allows the closure of E region currents through the F region, reducing the polarization electric field before noon. Second, the F region dynamo contributes an upward drift postnoon, maintaining upward drifts till after sunset. The direct changes of the thermospheric wind at higher solar activity due to increased dissipation of the tides from the lower atmosphere are relatively minor and do not contribute greatly to the changes of ionospheric responses in the low‐latitude region.
Nanostructured Pseudocapacitors Based on Atomic Layer Deposition of V2O5onto Conductive Nanocrystal‐based Mesoporous ITO Scaffolds
Authors: Rauda Iris E. , Augustyn Veronica , Saldarriaga‐Lopez Laura C. , Chen Xinyi , Schelhas Laura T. , Rubloff Gary W. , Dunn Bruce , Tolbert Sarah H.
Published: September 2014

Solution processing of colloidal nanocrystals into porous architectures using block co‐polymer templating offers a simple yet robust route to construct materials with open porosity and high surface area. These features, when realized in materials that show efficient redox activity and good conductivity, should be ideal for electrochemical energy storage because they allow for efficient electrolyte diffusion and ample surface and near‐surface redox reactions. Here, a route to synthesize nanoporous pseudocapacitors is presented using preformed ITO nanocrystals to make a conductive scaffold, coated with a conformal layer of vanadia deposited using atomic layer deposition (ALD). Two vanadia thicknesses are deposited, 2 and 7 nm, to examine the kinetics of Li+diffusion into vanadia in a system where all other chemical and structural parameters are fixed. Porosity measurements show that the internal surface area of 2 nm vanadia samples is fully accessible; whereas for the 7 nm vanadia, there is some pore blockage that limits electrolyte diffusion. Despite this fact, composites with both thick and thin vanadia layers show high levels of pseudocapacitance, indicating fast diffusion of Li+through even the 7 nm thick vanadia. This work thus sets a minimum accessible length‐scale of 7 nm for intercalation pseudocapacitance in orthorhombic V2O5.
Lubricant‐Infused Nanoparticulate Coatings Assembled by Layer‐by‐Layer Deposition
Authors: Sunny Steffi , Vogel Nicolas , Howell Caitlin , Vu Thy L. , Aizenberg Joanna
Published: September 2014

Omniphobic coatings are designed to repel a wide range of liquids without leaving stains on the surface. A practical coating should exhibit stable repellency, show no interference with color or transparency of the underlying substrate and, ideally, be deposited in a simple process on arbitrarily shaped surfaces. We use layer‐by‐layer (LbL) deposition of negatively charged silica nanoparticles and positively charged polyelectrolytes to create nanoscale surface structures that are further surface‐functionalized with fluorinated silanes and infiltrated with fluorinated oil, forming a smooth, highly repellent coating on surfaces of different materials and shapes. We show that four or more LbL cycles introduce sufficient surface roughness to effectively immobilize the lubricant into the nanoporous coating and provide a stable liquid interface that repels water, low‐surface‐tension liquids and complex fluids. The absence of hierarchical structures and the small size of the silica nanoparticles enables complete transparency of the coating, with light transmittance exceeding that of normal glass. The coating is mechanically robust, maintains its repellency after exposure to continuous flow for several days and prevents adsorption of streptavidin as a model protein. The LbL process is conceptually simple, of low cost, environmentally benign, scalable, automatable and therefore may present an efficient synthetic route to non‐fouling materials.
Competitive Absorption and Inefficient Exciton Harvesting: Lessons Learned from Bulk Heterojunction Organic Photovoltaics Utilizing the Polymer Acceptor P(NDI2OD‐T2)
Authors: Li Zhi , Lin Jason D. A. , Phan Hung , Sharenko Alexander , Proctor Christopher M. , Zalar Peter , Chen Zhihua , Facchetti Antonio , Nguyen Thuc‐Quyen
Published: September 2014

Organic solar cells utilizing the small molecule donor 7,7′‐(4,4‐bis(2‐ethylhexyl)‐4H‐silolo[3,2‐b:4,5‐b′]dithiophene‐2,6‐diyl)bis(6‐fluoro‐4‐(5′‐hexyl‐[2,2′‐bithiophen]‐5‐yl)benzo[c][1,2,5] thiadiazole) (p‐DTS(FBTTh2)2and the polymer acceptor poly{[N,N′‐bis(2‐octyldodecyl)‐1,4,5,8‐naphthalenedicarboximide‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)}(P(NDI2OD‐T2)) are investigated and a power conversion efficiency of 2.1% is achieved. By systematic study of bulk heterojunction (BHJ) organic photovoltaic (OPV) quantum efficiency, film morphology, charge transport and extraction and exciton diffusion, the loss processes in this blend is revealed compared to the blend of [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) and the same donor. An exciton diffussion study using Förster resonant energy transfer (FRET) shows the upper limit of the P(NDI2OD‐T2) exciton diffusion length to be only 1.1 nm. The extremely low exciton diffusion length of P(NDI2OD‐T2), in combination with the overlap in donor and acceptor absorption, is then found to significantly limit device performance. These results suggest that BHJ OPV devices utilizing P(NDI2OD‐T2) as an acceptor material will likely be limited by its low exciton diffusion length compared to devices utilizing functionalized fullerene acceptors, especially when P(NDI2OD‐T2) significantly competes with the donor molecule for photon absorption.
A Top Coat with Solvent Annealing Enables Perpendicular Orientation of Sub‐10 nm Microdomains in Si‐Containing Block Copolymer Thin Films
Authors: Kim Eunjin , Kim Wonjung , Lee Kwang Hee , Ross Caroline A. , Son Jeong Gon
Published: September 2014

Achieving sub‐10 nm high‐aspect‐ratio patterns from diblock copolymer self‐assembly requires both a high interaction parameter (χ, which is determined by the incompatibility between the two blocks) and a perpendicular orientation of microdomains. However, these two conditions are extremely difficult to achieve simultaneously because the blocks in a high‐χ copolymer typically have very different surface energies, favoring in‐plane microdomain orientations. A fully perpendicular orientation of a high‐χ block copolymer, poly(styrene‐block‐dimethylsiloxane) (PS‐b‐PDMS) is realized here using partially hydrolyzed polyvinyl alcohol (PVA) top coats with a solvent annealing process, despite the large surface energy differences between PS and PDMS. The PVA top coat on the block copolymer films under a solvent vapor atmosphere significantly reduces the interfacial energy difference between two blocks at the top surface and provides sufficient solvent concentration gradient in the through‐thickness direction and appropriate solvent evaporation rates within the film to promote a perpendicular microdomain orientation. The effects of interfacial energy differences and the swellability of PVA top coats controlled by the degree of hydrolysis on the orientation of micro­domains are examined. The thickness of the BCP film and top coats also affects the orientation of the BCP film.
Multimodal Magneto‐Plasmonic Nanoclusters for Biomedical Applications
Authors: Wu Chun‐Hsien , Cook Jason , Emelianov Stanislav , Sokolov Konstantin
Published: September 2014

Multimodal nanostructures can help solve many problems in the biomedical field including sensitive molecular imaging, highly specific therapy, and early cancer detection. However, the synthesis of densely packed, multicomponent nanostructures with multimodal functionality represents a significant challenge. Here, a new type of hybrid magneto‐plasmonic nanoparticles is developed using an oil‐in‐water microemulsion method. The nanostructures are synthetized by self‐assembly of primary 6 nm iron oxide core‐gold shell particles resulting into densely packed spherical nanoclusters. The dense packing of primary particles does not change their superparamagnetic behavior; however, the close proximity of the constituent particles in the nanocluster leads to strong near‐infrared (NIR) plasmon resonances. The synthesis is optimized to eliminate nanocluster cytotoxicity. Immunotargeted nanoclusters are also developed using directional conjugation chemistry through the Fc antibody moiety, leaving the Fab antigen recognizing region available for targeting. Cancer cells labeled with immunotargeted nanoclusters produce a strong photoacoustic signal in the NIR that is optimum for tissue imaging. Furthermore, the labeled cells can be efficiently captured using an external magnetic field. The biocompatible magneto‐plasmonic nanoparticles can make a significant impact in development of point‐of‐care assays for detection of circulating tumor cells, as well as in cell therapy with magnetic cell guidance and imaging monitoring.
Hierarchical Ordering of Quantum Dots and Liquid with Tunable Super‐Periodicity into High Aspect Ratio Moiré Superlattice Structure
Authors: Cho Soo‐Yeon , Jeon Hwan‐Jin , Kim Jong‐Seon , Ok Jong Min , Jung Hee‐Tae
Published: September 2014

In this work, a new approach for construction of high aspect ratio complex moiré superlattice structure with versatile super‐periodicity is developed using the moiré fringe and secondary sputtering lithography. Wide assortments of high aspect ratio complex superstructures having different features on a 10 nm scaled wall are easily fabricated from simple starting components. More important is the finding of a new microscale phenomenon, consisting in trapping fluids in the centres of the moiré hexagonal fringes, as the consequence of the modulation of local hydrophilicty of the pattern. Using this phenomenon, target materials can be selectively and hierarchically confined within the moiré superlattice. Hierarchical nanoparticles (QDs) ordering with tunable super‐periodicity into selective area of moiré superlattice are successfully demonstrated by just solution‐casting of toluene based QD solution on patterned surfaces. This observation is expected to elucidate the key morphological factors that govern the physics of liquid behavior on a complex patterned substrate. Accordingly, in the near future, this facile approach for complex superlattice structure could be used as optical substrate for imaging applications and open interesting perspectives in the assembly processes and the handling of the nano‐microsized particles.
Cactus Stem Inspired Cone‐Arrayed Surfaces for Efficient Fog Collection
Authors: Ju Jie , Yao Xi , Yang Shuai , Wang Lin , Sun Ruize , He Yaxu , Jiang Lei
Published: September 2014

With the increasing world population and the rapid development of the global industry, clean water is becoming scarcer and scarcer. Means of translating latent water in fog to dominant available water, i.e., fog collection, therefore becomes highly desirable. Previously, it was demonstrated that the cactus O. Microdasys has an integrated fog collection system arising from the evenly distributed clusters of spines and trichomes on the cactus stem. Here, it is reported that the intersite of the clusters on the cactus stem is densely covered with cones, which are also capable of collecting water from fog efficiently. Inspired by these cones, using a simple method combining mechanical perforating and template replica technology, polydimethylsiloxane (PDMS) cone arrays are fabricated with different arrangements and the one in hexagonal arrangement proves to be more efficient due to the more turbulent flow filed around the staggered cones and the rapid directional movement of water drops along each cone. This investigation opens up new avenue to collect water efficiently and may also provide clues to research about dust filtering and smog removal, which is attracting increasing attention worldwide.
A Compressible Scaffold for Minimally Invasive Delivery of Large Intact Neuronal Networks
Authors: Béduer Amélie , Braschler Thomas , Peric Oliver , Fantner Georg E. , Mosser Sébastien , Fraering Patrick C. , Benchérif Sidi , Mooney David J. , Renaud Philippe
Published: September 2014

Millimeter to centimeter‐sized injectable neural scaffolds based on macroporous cryogels are presented. The polymer‐scaffolds are made from alginate and carboxymethyl‐cellulose by a novel simple one‐pot cryosynthesis. They allow surgical sterility by means of autoclaving, and present native laminin as an attachment motive for neural adhesion and neurite development. They are designed to protect an extended, living neuronal network during compression to a small fraction of the original volume in order to enable minimally invasive delivery. The scaffolds behave as a mechanical meta‐material: they are soft at the macroscopic scale, enabling injection through narrow‐bore tubing and potentially good cellular scaffold integration in soft target tissues such as the brain. At the same time, the scaffold material has a high local Young modulus, allowing protection of the neuronal network during injection. Based on macroscopic and nanomechanical characterization, the generic geometrical and mechanical design rules are presented, enabling macroporous cellular scaffold injectability.
Synthesis, Physical Properties, and Photocurrent Behavior of Strongly Emissive Boron‐Chelate Heterochrysene Derivatives
Authors: Zhang Hailei , Hong Xiaozhong , Ba Xinwu , Yu Bei , Wen Xin , Wang Sujuan , Wang Xuefei , Liu Lei , Xiao Jinchong
Published: September 2014

A BPh2‐chelated heterochrysene derivative has been synthesized and characterized. Single crystal analysis of its analogous BF2 complex shows that all carbon and nitrogen atoms are almost in a plane, while the boron atoms twist out of this plane with a torsion angle of 28.796° measured between plane OBN and plane C1–C4–C4′. The BPh2 and BF2 compounds emit strong yellow and green light in methylene chloride with high fluorescence quantum yields, respectively. Thermogravimetric analysis results indicate that the thermal stability of both compounds is high. In addition, a photoswitching device was fabricated based on a thin film of the BF2 complex spin‐coated onto single‐walled carbon nanotubes, which produces a steady and reproducible photocurrent response.
Palladium‐Catalyzed Desulfinative Iodination of Sodium Sulfinates and Sulfonyl Hydrazides
Authors: Liu Saiwen , Chen Jinjin , Zhang Ran , Zhao Feng , Deng Guo‐Jun
Published: September 2014

The palladium‐catalyzed desulfinative iodination of sodium sulfinates and sulfonyl hydrazides with KI or I2 is described. The reaction proceeds smoothly under mild conditions using O2 or air as an environmentally benign oxidant.
Three‐Residue Turn in β‐Peptides Nucleated by a 12/10 Helix
Authors: Sharma Gangavaram V. M. , Yadav Thota Anupama , Marumudi Kanakaraju , Thodupunuri Prashanth , Reddy Pothula Purushotham , Kunwar Ajit C.
Published: September 2014

A new three‐residue turn in β peptides nucleated by a 12/10‐mixed helix is presented. In this design, β peptides were derived from the 1:1 alternation of C‐linked carbo‐β‐amino acid ester [BocNH‐(R)‐β‐Caa(r)‐OMe] (Boc=tert‐butyloxycarbonyl), which consisted of a D‐ribo furanoside side chain, and β‐hGly residues. The hexapeptide with (R)‐β‐Caa(r) at the N terminus showed the ‘turn’ stabilized by a 14‐membered NH(4)⋅⋅⋅CO(6) hydrogen bond at the C terminus nucleated by a robust 12/10‐mixed helix, thus providing a ‘helix‐turn’ (HT) motif. The turn and the helix were additionally stabilized by intraresidue electrostatic interaction between the furan oxygen in the carbohydrate side chain and NH in the backbone. However, the hexapeptide with a β‐hGly residue at the N terminus demonstrated the presence of a 10/12 helix through its entire length, which again showed the intraresidue interaction between NH and furan oxygen. The intraresidue NH⋅⋅⋅OMe electrostatic interactions observed in the monomer, however, were absent in the peptides.
Unstrained CarbonCarbon Bond Cleavage
Authors: Liu Hui , Feng Minghao , Jiang Xuefeng
Published: September 2014

This Focus Review presents recent developments in the cleavage of CC bonds in organic molecules. Significant progress in CC activation, including the development of a variety of new synthetic strategies, has contributed to the development of this field over the past few decades. Transition‐metal‐mediated CC bond cleavage has been shown to be a quite efficient process and several elegant metal‐free methods have also recently been developed. Strained rings have been widely used in CC cleavage transformations; however, unstrained CC activation has increasingly caught the attention of organic researchers, which inspired us to clarify the developments in this field.
Nichtlinearep‐y‐Beziehung von Stahlbetonpfählen und stahlfaserverstärkten Stahlbetonpfählen in mitteldichtem Sand
Authors: Akdag Cihan Taylan , Özden Gürkan , Stopper Juliane
Published: September 2014

Das Primärziel der vorliegenden Studie besteht darin, den Einfluss des nichtlinearen Materialverhaltens von Gründungspfählen auf die Pfahl‐Boden‐Interaktion zu untersuchen. Dies ist ein Aspekt, der bisher nicht eingehend für Stahlbetonpfähle (RC) erforscht worden ist. Aus diesem Grund wurde ein umfassendes Versuchsprogramm mit RC‐ und stahlfaserverstärkten RC‐Modellpfählen geplant und durchgeführt. Basierend auf Vorkenntnissen zu stahlfaserverstärkten biegebewehrten Modellpfählen (WS‐SFRC) wurde der Stahlfasergehalt auf 1 % festgelegt. Vor den Versuchen zur Pfahl‐Boden‐Interaktion wurden Biegeversuche durchgeführt, um die Moment‐Krümmungs‐Beziehung (M‐Φ) der Modellpfähle zu erhalten. Die Wirkung der Pfahlbiegesteifigkeit (EI) auf diep‐y‐Kurven wurde in der Analyse sorgfältig geprüft. Der Einfluss der Belastungsgeschwindigkeit sowie der Axiallast auf die Pfahl‐Boden‐Interaktion wurde ausgewertet. Es wurde erkannt, dass die Axiallast die Pfahl‐Boden‐Reaktion des RC‐Pfahles signifikant erhöht. Die Belastungsgeschwindigkeit beeinflusst diep‐y‐Kurve des RC‐Pfahles erheblich, während sie geringere Auswirkungen auf diep‐y‐Kurve des stahlfaserverstärkten RC‐Pfahles hat. Eine neue Methodik zur Verbesserung des etablierten Verfahrens zurp‐y‐Kurvenermittlung wird präsentiert, welche die Parameter für die Pfahlflexibilität in diep‐y‐Kurvenermittlung integriert.

Nonlinearp‐yrelationships of reinforced concrete and steel fiber added reinforced concrete piles in medium dense sand

The primary goal of this study is to investigate the influence of nonlinear pile material behavior on soil‐pile interaction (SPI), an aspect of SPI which was not studied extensively for reinforced concrete (RC) piles. For this purpose a model pile test program was implemented, which involved testing of RC piles and RC with steel fiber piles. The steel fiber ratio by volume was decided as 1 % based on previous experience. Prior the model pile tests, bending tests were made on flexural elements to obtain the moment‐curvature relationship of piles. Therefore, the influence of pile bending stiffness was taken into consideration in thep‐ycurve analyses. The effects of loading rate and axial load on soil‐pile interaction were evaluated. It is concluded that axial load significantly increases the soil‐pile stiffness of the RC pile. Rate of loading considerably alters thep‐ycurve of RC pile whereas it slightly influences thep‐ycurve of RC with steel fiber pile. A new methodology to improve currently acceptedp‐ycurve establishment procedures is suggested by incorporating pile flexibility parameters into the formulation.
Einsatz und Anwendungsgrenzen von Schneckenbohrpfählen (Auger‐cast‐in‐place Piles – ACIP‐Piles)
Authors: Schäfer René , Belmann Thomas
Published: September 2014

Für die Gründung einer Düngemittelanlage in Port Neal/Iowa wurden durch den Bauherrn Schneckenbohrpfähle (sog. ACIP‐Piles) als Gründungsentwurf vorgegeben. Angesichts der bis in große Tiefen unterhalb des Grundwassers anstehenden, sehr enggestuften, feinkörnigen Sande wurde die Ausführung im Hinblick auf DIN EN 1536 als kritisch eingestuft. Im Rahmen von umfangreichen Pfahlprobebelastungen konnte jedoch zunächst gezeigt werden, dass bei ausreichender Qualitätssicherung Schneckenbohrpfähle auch bei ungünstigen Baugrundverhältnissen ordnungsgemäß hergestellt und gute Tragfähigkeiten erzielt werden können. Im Rahmen der Ausführung der Bauwerkspfähle sind jedoch erhebliche Schäden aufgetreten, da die Bohrschnecke auf einer Tonschicht höherer Konsistenz aufsaß und Boden in nennenswertem Umfang gefördert wurde. Zurückzuführen sind die Schäden neben den ungünstigen geologischen Randbedingungen auf einen Wechsel des ausführenden Spezialtiefbauunternehmens, welches die nach DIN EN 1536 geforderte örtliche Erfahrung nicht über Probepfähle nachgewiesen hat. Zudem wurden im vorliegenden Fall die Schäden durch die eingesetzte Maschinentechnik des Drehbohrgeräts begünstigt, welche sich in den USA von der in Europa verwendeten Technik unterscheidet.

Application and limitation of auger‐cast‐in‐place (ACIP‐) Piles – Experiences of an industrial project in Iowa/USA

For an industrial complex in Port Neal/Iowa, auger‐cast‐in‐place piles (ACIP‐Piles) haven been chosen for the foundation structure. With reference to the purely graded sand deposits, which have been encountered to greater depth in conjunction with a high ground water level, the installation of such piles has to be critically expected with reference to DIN EN 1536. However, the installation technique as well as acceptable pile capacities could be verified in the course of extensive pile testing. Nevertheless, considerable damages occured during the installation of the working piles. The damages can partly be attributed to an interlayered very stiff to hard cohesive soil layer at a depth of app. 20 m, which couldn't be smoothly drilled and which led to a soil extraction in the vicinity of the pile shaft. Moreover, a new drilling company was commissioned for the installation of the working piles, whose specific experience with the chosen pile type was not directly verified before. Finally, the damages were benefit by the chosen drilling technique.
Nachträgliche Sicherung alter Bergbauschächte
Authors: Stock Lars‐Michael , Spang Christian
Published: September 2014

Mit dem Ende des Steinkohlenbergbaus hat sich der Fokus auf die zugehörigen Ewigkeitslasten und die erforderliche Nachsorge verstärkt. Neben Fragestellungen wie der Nachnutzung der bergbaulich geprägten Flächen oder den Folgen des Grubenwasseranstiegs ist der Zustand vieler alter Bergbauschächte zu klären. Im Zweifelsfall ist zu überprüfen, ob der Zustand eines Schachtes dem Stand der Technik entspricht oder eine nachträgliche Sicherung erfolgen muss. Dabei ist eine Sicherung in der Qualität und Dauerhaftigkeit, wie sie bei der Verwahrung jüngerer Tiefbauschächte nach dem Stand der Technik ausgeführt wird, nachträglich nur schwer zu erreichen. Die begrenzte technische Lebensdauer der nachträglichen Sicherung in Verbindung mit der Ewigkeitslast der Bergbauschächte stellt ein Problem dar, das besonders betrachtet werden muss. Vom Arbeitskreis 4.6 “Altbergbau” der DGGT wurden Empfehlungen zur Sicherung und Verwahrung des Altbergbaus erarbeitet. Für NRW wurde von der Bezirksregierung Arnsberg der Leitfaden für das Verwahren von Tagesschächten herausgegeben. Nach Auffassung der Autoren ist darauf aufbauend eine konkrete und umfassende Richtlinie für die Sicherung alter Bergbauschächte erforderlich, die den Bergwerksgesellschaften, Ingenieurbüros, Behörden und ausführenden Firmen als Richtschnur dient. Mit dem vorliegenden Beitrag liefern die Autoren eine Diskussionsgrundlage für die Erstellung dieser Richtlinie.

Subsequent backup of old mining shafts – concrete guidelines for the planning and execution required

With the end of the coal industry, the focus has intensified on the associated eternity burden and the required follow‐up. In addition to issues such as the use of former mining‐dominated areas or the consequences of the mine water rise in the condition of many old mining shafts should be clarified. If in doubt, check whether the state of the prior art shaft corresponds or must be a subsequent backup. This is an assurance in quality and durability, as performed in the custody of younger civil engineering shafts according to the state of the art, subsequently difficult to achieve. The limited technical lifetime of the subsequent assurance in connection with eternity burden of mining shafts is a problem that needs to be particularly considered. The working circle 4.6 “abandoned mines” of the DGGT recommendations were developed for securing and safekeeping of the old mining. For NRW the “guide to the keep of days manholes” was issued by the district government of Arnsberg. According to the authors concrete and comprehensive guideline for hedging old mining shafts is required on this basis that serves the mining companies, engineering firms, government agencies and contractors as a guide. With this paper the authors provide a basis for discussion in the preparation of this Directive.
Komplexe Bauvorhaben heute – eine rein ingenieurtechnische oder auch gesellschaftspolitische Aufgabe?
Authors: Richter Thomas , Kirsch Fabian
Published: September 2014

Die Motivation zu diesem Essay entspringt der praktischen Erfahrung der Autoren, die bei ihrer Arbeit in einem auf anspruchsvolle geotechnische Projekte spezialisierten Ingenieurbüro immer wieder aufs Neue feststellen, dass bei vielen heute beplanten und leider viel zu oft auf die lange Bank geschobenen Bauvorhaben die überkommenen Strategien nicht ausreichen, um den technischen, ökonomischen und kommunikativen Anforderungen in Verbindung mit dem berechtigten Beteiligungsinteresse der Öffentlichkeit zu genügen. Bei diesen Vorhaben handelt es sich nicht selten um Strukturen, bei denen eine innige Zusammenarbeit der einzelnen Spezialdisziplinen des Bauingenieurwesens erforderlich ist und deren Verzahnung so eng zu sein hat, dass die Aufgabe nur in einem umfassenden Iterationsprozess unter Inkaufnahme aller dabei auftretender und mit entsprechendem Aufwand verbundener Reibungen gelöst werden kann.
What makes a successful undergraduate? The relationship between student characteristics, degree subject and academic success at university
Authors: Smith Emma , White Patrick
Published: September 2014

This paper contributes to the empirical evidence on participation and attainment in higher education by reviewing the patterns of entry and success of undergraduate students. It examines the characteristics of entrants to different subjects and considers the role that subject studied plays in determining the likelihood of graduating with a ‘good’ degree. The data used were drawn from the administrative records of over 38,000 UK‐domiciled undergraduate students from one ‘elite’ British university. Despite considerable between‐subject variation in degree outcomes, multivariate analysis of the relationship between students’ social and academic characteristics and achievement at university revealed that once social background and prior attainment had been controlled for, the subject students studied added little explanatory power to models predicting final degree classifications. Differences in degree outcome were most strongly related to attainment on entry to higher education, sex and ethnicity. In contrast with attainment during the earlier phases of education, the relationship with occupational class was relatively weak. Disparities between the proportion of higher level classifications awarded in different subjects can be largely explained by the background characteristics of the students who choose (and are accepted) to study on these degrees. This finding has particular implications for policies aimed at increasing both the number and quality of Science, Technology, Engineering and Mathematics (STEM) graduates in what is often argued to be a ‘shortage’ or ‘priority’ area.
Entwicklung schlaufenartiger Stahlseilverankerungen in Stahlbetondecken
Authors: Borkowski Gregor , Thoma Karel , Lehmann Rudolf , Müller Franz
Published: September 2014

Zum Befestigen von Fahrstuhlkomponenten im Bauzustand sowie zur Last‐ und Personensicherung beim Einbau dieser Komponenten sind innerhalb von Fahrstuhlschächten Anschlagspunkte in Betondecken für Sicherungsseile notwendig. Diese Anschlagspunkte werden mit einbetonierten Seilschlaufen aus Edelstahl realisiert. Im folgenden Beitrag wird die Entwicklung dieser Lastschlaufen vorgestellt. Entsprechend den Vorgaben der ETAG001 [1] werden Versuche durchgeführt und daraus ein Bemessungskonzept für die Lastschlaufen hergeleitet. Darauf aufbauend konnte eine bauaufsichtliche Zulassung für die Lastschlaufen beim DIBt erlangt werden.

Development of novel steel cable loop anchors for reinforced concrete slabs – Experimental investigations, design concept

During the construction of lift shafts, it is necessary to provide anchor points on the concrete slabs. The anchor points are used to attach safety cables, which serve to secure loads such as elevator components and ensure the safety of construction workers. Generally, stainless steel cable loop anchors are used for these anchor points. The development of a novel type of steel cable loop anchor is presented in this article. Experimental investigations according to the requirements of ETAG001 [1] were carried out. In this paper, a design concept is derived from the experimental findings. Based on the presented results, the DIBt granted a national technical approval for the steel cable loop anchors.
Three‐dimensional models of cancer for pharmacology and cancer cell biology: Capturing tumor complexity in vitro/ex vivo
Authors: Hickman John A. , Graeser Ralph , de Hoogt Ronald , Vidic Suzana , Brito Catarina , Gutekunst Matthias , van der Kuip Heiko , IMI PREDECT consortium
Published: September 2014

Cancers are complex and heterogeneous pathological “organs” in a dynamic interplay with their host. Models of human cancer in vitro, used in cancer biology and drug discovery, are generally highly reductionist. These cancer models do not incorporate complexity or heterogeneity. This raises the question as to whether the cancer models' biochemical circuitry (not their genome) represents, with sufficient fidelity, a tumor in situ. Around 95% of new anticancer drugs eventually fail in clinical trial, despite robust indications of activity in existing in vitro pre‐clinical models. Innovative models are required that better capture tumor biology. An important feature of all tissues, and tumors, is that cells grow in three dimensions. Advances in generating and characterizing simple and complex (with added stromal components) three‐dimensional in vitro models (3D models) are reviewed in this article. The application of stirred bioreactors to permit both scale‐up/scale‐down of these cancer models and, importantly, methods to permit controlled changes in environment (pH, nutrients, and oxygen) are also described. The challenges of generating thin tumor slices, their utility, and potential advantages and disadvantages are discussed. These in vitro/ex vivo models represent a distinct move to capture the realities of tumor biology in situ, but significant characterization work still remains to be done in order to show that their biochemical circuitry accurately reflects that of a tumor.
Titania Nanoparticles Stabilized HPA in SBA‐15 for the Intermolecular Hydroamination of Activated Olefins
Authors: Sawant‐Dhuri Dhanashri , Balasubramanian Veerappan V. , Ariga Katsuhiko , Park Dae‐Hwan , Choy Jin‐Ho , Cha Wang Soo , Al‐deyab Salem S. , Halligudi Shivappa B. , Vinu Ajayan
Published: September 2014

A liquid phase hydroamination (HA) of α,β‐ethylenic compounds with amines was investigated with TiO2 nanoparticles stabilized 12‐tungstophosphoric acid (TPA) in SBA‐15. The catalysts were prepared by wet impregnation of TPA/TiO2 nanoparticles into the SBA‐15 and calcined at different temperatures. The characterization results reveal that the textural properties and the acidity of the prepared catalysts can be finely controlled with the simple adjustment of the calcination temperature and the structure of the support, decorated with the TiO2 and TPA nanoparticles, was intact even after the modification. The prepared catalysts were investigated for HA of ethyl acrylate with different aromatic and aliphatic amines over a wide range of reaction conditions to optimize the yield and the selectivity of product. It was found that this process is 100 % atom efficient and the catalytic performance depended significantly on the loading of TPA over the catalyst and the calcination temperature. Under optimized reaction conditions, the best catalyst, 15 wt %TPA/22.4 wt %TiO2/SBA‐15 calcined at 1123 K, offered the highest conversion of p‐ethylaniline (70 %) with 100 % chemo‐selectivity to the anti‐Markovnikov product, i.e., the mono‐addition product. The reaction was heterogeneously catalyzed and no contribution from leached TPA into the reaction was observed.
Prediction of Phase Split in Horizontal T‐Junctions: Revisited
Authors: Chakrabarti Dhurjati P.
Published: September 2014

The prediction of liquid–liquid two‐phase flow at a horizontal dividing T‐junction is re‐investigated, focusing on a stratified orientation of the liquids. Kerosene (as oil) and water as the test fluids of previous studies are used to predict the distribution of oil and water in a 0.025‐m diameter pipe and tee. In addition to the previously studied models, attempts are made to predict the split for liquid–liquid systems by the already known energy minimization. The earlier model, formulated from geometrical considerations and force balance resulting from centripetal as well as inertial forces, is refurbished by the addition of energy minimization for the calculation of phase depth.
Automatic Low‐Cost Method to Determine the Solubility of Liquid‐Liquid Mixtures by Continuous‐Flow Cloud Point Titration
Authors: Williamson Andrew P. , Kiefer Johannes
Published: September 2014

A low‐cost, accurate, and fast technique to determine the solubility of liquid‐liquid mixtures by continuous cloud point titration is demonstrated. A light‐emitting diode (LED) is employed to illuminate the mixing liquids during the continuous‐flow titration process, and the transmitted light as well as Mie scattering from droplets is monitored using a simple webcam image sensor. The time‐resolved evolution of the signal allows the determination of the solubility. In order to prove the concept and to evaluate its accuracy and reproducibility, experimental results from the binary systems butan‐1‐ol/water and pentan‐1‐ol/water are presented and compared with literature data. The entire setup can be realized with a low investment and delivers results virtually identical to those in literature with established techniques. The approach is suitable for academic and industrial, but due to its simplicity also for educational purposes.
Design and Simulation of a Green Chromate Compound Production Process
Authors: Song Jing , Qu Jing‐Kui , Liu Jing‐Cong , Ma Fei , Qi Tao
Published: September 2014

A green process for the production of chromate compounds from chromite ore was simulated using process simulation software. Firstly, the phase equilibria of the KOH‐K2CrO4‐H2O system were investigated to determine the feasible operating conditions for the separation of K2CrO4 from the KOH alkaline solution. The green process model of chromate production was developed and three cases with different concentrations of alkali solution were simulated based on several assumptions. The mass and energy balances in the three cases were simulated, showing that the energy consumption of the evaporation unit is the largest in the whole process. The simulation results provide important information for the implementation of this green chromate production process.
Three‐Dimensional Tin Nanoparticles Embedded in Carbon Nanotubes on Carbon Cloth as a Flexible Anode for Lithium‐Ion Batteries
Authors: Ren Weina , Kong Dezhi , Cheng Chuanwei
Published: September 2014

With the development of flexible electronic devices, the research on flexible storage devices has received considerable attention. In this paper, we designed novel tin nanoparticles encapsulated in carbon nanotubes (TNEC) arrays on carbon cloth prepared by a facile carbon reduction route as a flexible anode for lithium‐ion batteries. The TNEC electrode shows a high areal capacity (2.15 mAh cm−2) when the current density is 0.1 mA cm−2, Meanwhile, a good cycling performance (84 % of initial capacity) is achieved after 80 charge–discharge cycles, which could be attributed to the high theoretical capacity of metal tin and the tin encapsulated in carbon nanotubes structure that improves the electrical conductivity and structure stability.
CHR‐Insertion (RH, CH3) into Cyclohexyl‐Substituted Silsesquioxanes: Reactivity and Decomposition Studies
Authors: Ward Antony J. , Lesic Rebecca A. , Fisher Keith , Proschogo Nicholas , Fábos Viktória , Masters Anthony F. , Maschmeyer Thomas
Published: September 2014

Amorphous silica plays an important role in heterogeneous catalysis as a support and is frequently presumed to be “inert”. The structure of the supported catalyst is key to understanding the stability and reactivity of catalytic systems. To provide vital insights into the surface reactivity of silica, Polyhedral oligomeric silsesquioxanes (POSSs) can act as realistic homogeneous molecular models for silica surfaces. Here, we report novel reactivities associated with the silica surface, derived from our insights obtained by means of such model systems with potentially significant implications in catalysis when employing silica‐supported catalysts. In this work, the gas‐phase reactivities of two cyclohexyl‐substituted POSSs, namely the completely condensed triganol prism [Si6cy6O9] (a6b0), and the incompletely‐condensed partial cube [Si7cy7O9(OH)3] (a7b3), with cy=c‐C6H11, were studied by using atmospheric pressure chemical ionisation (APCI) and collision‐induced decomposition (CID) spectroscopies. Silsesquioxane a6b0, containing three‐membered rings, was found to be much more reactive, undergoing novel CH2‐insertion on reaction with gas phase molecules—a reaction not observed for a7b3, containing only four‐membered rings. Both silsesquioxanes displayed the ability to trap ammonia formed in situ within the mass spectrometer from N2 in the instrument. This work also demonstrates the applicability of APCI and the role of CID in elucidating reactive POSS structures, highlighting novel gas‐phase reactivities of POSS.
Artificial Neural Networks for Guest Chirality Classification through Supramolecular Interactions
Authors: Granda Jarosław M. , Jurczak Janusz
Published: September 2014

A novel strategy for classification of guest chirality based on the combination of artificial neural networks and anion‐receptor chemistry is reported. The receptor reported herein forms supramolecular complexes with a variety of biologically important carboxylates, in which the chemical shift changes during addition of anions result in complex guest‐stereochemistry‐dependent patterns as followed by 1H NMR spectroscopy. The neural network had learnt these patterns from a training set of 12 anions, and successfully identified the “unknown” chirality of 14 guests present in the test set. Additionally, principal component analysis could discriminate most of the guests studied (26) and allowed for identification of the receptor protons, which are responsible for information transfer of guest chirality.
Out‐of‐core macromolecular simulations on multithreaded architectures
Authors: Aliaga José I. , Badía José M. , Castillo Maribel , Davidović Davor , Mayo Rafael , Quintana‐Ortí Enrique S.
Published: September 2014

We address the solution of large‐scale eigenvalue problems that appear in the motion simulation of complex macromolecules on multithreaded platforms, consisting of multicore processors and possibly a graphics processor (graphics processing unit). In particular, we compare specialized implementations of several high‐performance eigensolvers that, by relying on disk storage and out‐of‐core techniques, can in principle tackle the large memory requirements of these biological problems, which in general do not fit into the main memory of current desktop machines. All these out‐of‐core eigensolvers, except for one, are composed of compute‐bound (i.e., arithmetically intensive) operations, which we accelerate by exploiting the performance of current multicore processors and, in some cases, by additionally off‐loading certain parts of the computation to a graphics processing unit accelerator. One of the eigensolvers is a memory‐bound algorithm, which strongly constrains its performance when the data is on disk. However, this method exhibits a much lower arithmetic cost compared with its compute‐bound alternatives for this particular application. Experimental results on a desktop platform, representative of current server technology, illustrate the potential of these methods to address the simulation of biological activity. Copyright © 2014 John Wiley & Sons, Ltd.
Energetics of Spinels in the FeTiO System at the Nanoscale
Authors: Lilova Kristina I. , Pearce Carolyn I. , Rosso Kevin M. , Navrotsky Alexandra
Published: September 2014

The energetics of nanosized Fe/Ti spinel oxides was studied using high‐temperature oxide melt solution calorimetry. The mixing properties of the solid solution in the system were obtained, and through comparison to macroscopic materials the effect of particle size on the thermodynamics was assessed. The surface energies of the nanosized materials are similar within the errors regardless of the composition, and are consistent with those determined for other spinels. The enthalpies of oxidation to hematite plus rutile of the iron titanium spinels follow a linear trend with the Fe2+ content, which allows them to be calculated for any composition or particle size. The heat of formation of the macroscopic and nanosized titanomagnetites was fit as a polynomial function and the numerical coefficients are presented. The enthalpies of mixing in the titanomagnetite and titanomaghemite solid solutions are similar at the macroscopic and nanoscale.