bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical solutions for stream‐aquifer flow exchange under varying head asymmetry and river penetration: Comparison to numerical solutions and use in regional groundwater models
Authors: Miracapillo Cinzia , Morel‐Seytoux Hubert J.
Published: August 2014

An analytical approach is presented to characterize the local flow exchange conductance and boundary condition between a stream and a hydraulically connected aquifer. Due to the curvilinear nature of the flow pattern in the vicinity of the stream, with numerical procedures, very fine grids would have to be used in order to secure accurate results. This is a waste of numerical efforts when the solution can be obtained analytically. Here, we show that the local analytical procedure for the determination of the stream‐aquifer flow exchange (SAFE) coefficient can be integrated within a regional numerical groundwater model through an original boundary condition. This is a very practical result. With this new approach, it is quite simple to calculate accurately the discharges on the two sides of the river when the heads are different. This is an important capability for example when wells are present near a river. The results show also that the extent of penetration of the stream is a factor in the estimation of the discharges. At the very least, the results can be used to choose a grid size that will yield correct estimates within an a priori selected acceptable level of accuracy.
Water‐saving impacts of Smart Meter technology: An empirical 5 year, whole‐of‐community study in Sydney, Australia
Authors: Davies Kirsten , Doolan Corinna , van den Honert Robin , Shi Rose
Published: August 2014

In 2009–2010 Sydney Water, the primary water utility in Sydney, conducted a comprehensive Smart Metering trial in residential homes in the suburb of Westleigh, in Sydney's north. The trial involved 1923 participants residing in 630 households. A whole‐of‐community method of engagement was applied to capture the views of residents from 12 to 70+ years of age. The trial examined the effects of the technology on the water consumption of an intervention group compared with that of a matched control group. After removing properties that had been sold since the beginning of the trial, properties in the study group were matched with a control group property on the basis of the household size, property size and the presence (or otherwise) of a swimming pool. The effects of the technology on consumption were measured and analyzed for the period July 2009 to June 2010, coupled with qualitative information that was collected throughout the duration of the study. A key finding was that households with the in‐home display (IHD) installed, reduced their consumption by an average of over 6.8% over the study period when compared to the control group. Since completion of the study the community has not had any further interventions. The trial created an opportunity to examine the longer‐term effects of the technology (June 2008 to September 2013). Consumption data collected over the 3 year posttrial period revealed that the participant group consumed 6.4% per month less water when compared to the pretrial period, whilst the matched control group consumed 1.3% per month more water when compared to the pretrial period. The reduced consumption of the participant group was maintained over time, demonstrating the long‐term value of this technology.
Ultra‐Thin Self‐Assembled Protein‐Polymer Membranes: A New Pore Forming Strategy
Authors: van Rijn Patrick , Tutus Murat , Kathrein Christine , Mougin Nathalie C. , Park Hyunji , Hein Christopher , Schürings Marco P. , Böker Alexander
Published: September 2014

Self‐assembled membranes offer a promising alternative for conventional membrane fabrication, especially in the field of ultrafiltration. Here, a new pore‐making strategy is introduced involving stimuli responsive protein‐polymer conjugates self‐assembled across a large surface area using drying‐mediated interfacial self‐assembly. The membrane is flexible and assembled on porous supports. The protein used is the cage protein ferritin and resides within the polymer matrix. Upon denaturation of ferritin, a pore is formed which intrinsically is determined by the size of the protein and how it resides in the matrix. Due to the self‐assembly at interfaces, the membrane constitutes of only one layer resulting in a membrane thickness of 7 nm on average in the dry state. The membrane is stable up to at least 50 mbar transmembrane pressure, operating at a flux of about 21 000–25 000 L m−2 h−1 bar−1 and displayed a preferred size selectivity of particles below 20 nm. This approach diversifies membrane technology generating a platform for “smart” self‐assembled membranes.
Directed Self‐Assembly as a Route to Ferromagnetic and Superparamagnetic Nanoparticle Arrays
Authors: Schelhas Laura T. , Farrell Richard A. , Halim Udayabagya , Tolbert Sarah H.
Published: September 2014

Block co‐polymer patterns are attractive candidates for nanoparticle assemblies. Directed self‐assembly of block co‐polymers in particular allows for long range ordering of the patterns, making them interesting scaffolds for the organization of magnetic particles. Here, a method to tune the channel width of polymer‐derived trenches via atomic layer deposition (ALD) of alumina is reported. The alumnia coating provides a much more thermally robust pattern that is stable up to 250 °C. Using these patterns, magnetic coupling in both ferromagnetic and superparamagnetic nanocrystal chains is achieved.
Orbitally shaken bioreactors—viscosity effects on flow characteristics
Authors: Ducci Andrea , Weheliye Weheliye Hashi
Published: September 2014

Phase‐resolved particle image velocimetry measurements were carried out to assess the flow dynamics occurring in orbitally shaken bioreactors of cylindrical geometry when working fluids of increasing viscosity are considered. Study of the phase‐resolved flow characteristics allowed to built a Re‐Fr map, where four quadrants associated to different flow regimes are identified: in‐phase toroidal vortex (low Fr and high Re), out‐of‐phase precessional vortex (high Fr and high Re), in‐phase single vortex (low Fr and low Re), out‐of‐phase counter‐rotating toroidal vortex (high Fr and low Re). Turbulence levels are found to be significant only in the top right quadrant (high Fr and low Re) and scaling of the turbulent kinetic energy obtained with fluid of varying viscosity is obtained using the ratio of the operating Froude number to the critical Froude number associated to the mean flow transition,
. Estimates of the mean flow strain deformation as well as of the flow dissipative scale are provided, while a comparison is made between the flow circulation times obtained for different regimes. © 2014 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 60: 3951–3968, 2014
Functional Anatomy of the Syrinx of the Chukar Partridge (Galliformes: Alectoris chukar) as a Model for Phonation Research
Authors: Erdoğan Serkan , Sağsöz Hakan , Paulsen Friedrich
Published: September 2014

The phonation process of vertebrates is influenced by the material characteristics of the participating structures, ranging from molecular to macroscopic dimensions. Good animal models for phonation research are still lacking. Due to easy availability and relatively simple structure, the syrinx of birds might serve as a good animal model for this purpose. Our aim was therefore to determine structural features of the syrinx and obtain insights into its mucus layer characteristics. Epithelium and glands were analyzed using histological, histochemical, and immunohistochemical methods and conclusions were drawn on the use of the syrinx as a model for phonation research by comparing the epithelium and its mucus characteristics to human laryngeal secretions. Ten adult partridges were analyzed. The tympanum of the syrinx developed from the last two tracheal cartilages, whereas the caudal part of the syrinx was formed from eight pieces of bronchial cartilages. The tracheal and bronchial epithelia and the pessulus of the syrinx were lined by pseudo‐stratified columnar epithelium in which goblet cells and intraepithelial glands were localized. Collagen fibers were distributed in the lamina propria of all parts of the syringeal mucosa. Elastic fibers in the membranes of the syrinx showed evident distribution. All glandular epithelial cells and goblet cells were positive for neutral, acidic and carboxylated mucins were dominant in particular. Epithelium and glands revealed positive reactivity with antibodies to the mucins MUC1, MUC2, and MUC5AC. Of these, MUC2 and MUC5AC were dominant. The syrinx of partridge can serve as a good ex vivo model for phonation research. Anat Rec, 298:602–617, 2015. © 2014 Wiley Periodicals, Inc.
2‐(Pro‐1‐ynyl)‐5‐(5,6‐dihydroxypenta‐1,3‐diynyl) Thiophene Induces Apoptosis Through Reactive Oxygen Species‐Mediated JNK Activation in Human Colon Cancer SW620 Cells
Authors: Xu Dao Gun , Lv Wang , Dai Chun Yan , Zhu Fan Fan , Xu Gua Hua , Ma Zhong Jun , Chen Zhe
Published: September 2014

2‐(Pro‐1‐ynyl)−5‐(5,6‐dihydroxypenta‐1,3‐diynyl) thiophene (PYDDT) is a naturally occurring thiophene isolated from the roots of Echinops grijsii, a Chinese herbal medicine used to treat colon cancer, breast cancer, and lung cancer. There are many reports on the clinical use of Echinops grijsii alone or in combination with other herbs to treat malignant tumors. We previously reported that the expression and activity of phase II enzymes including GSTs and NQO1 could be induced through the activation of Keap1‐Nrf2 pathway by the treatment of PYDDT. In this study, we reported the anticancer effect and mechanism of PYDDT against human colon cancer SW620 cells. Our results demonstrate that treatment of SW620 cells with PYDDT leads to induction of mitochondrial‐mediated apoptosis, which is characterized by the cleavage of PARP, activation of caspase 9 and caspase 3, release of cytochrome c from mitochondria, loss of mitochondrial membrane potential, down‐regulation of Bcl‐2, and mitochondrial translocation of Bax. The PYDDT treatment caused the production of reactive oxygen species (ROS), and the activation of JNK but not p38 mitogen‐activated protein kinases and ERK1/2. Specific JNK inhibitor SP600125 prevented the PYDDT‐induced down‐regulation of Bcl‐2, mitochondrial translocation of Bax, activation of caspase 3, and apoptosis of SW620 cells. Moreover, PYDDT‐induced apoptosis as well as activation of JNK was abrogated by the pretreatment with antioxidant N‐acetylcysteine. Taken together, these findings suggest that PYDDT induces apoptosis in SW620 cells through a ROS/JNK‐mediated mitochondrial pathway. Anat Rec, 298:376–385, 2015. © 2014 Wiley Periodicals, Inc.
Output Feedback Adaptive Neural Control Without Seeking SPR Condition
Authors: Pan Yongping , Er Meng Joo , Chen Rongjun , Yu Haoyong
Published: September 2014

For output‐feedback adaptive control of affine nonlinear systems based on feedback linearization and function approximation, the observation error dynamics usually should be augmented by a low‐pass filter to satisfy a strictly positive real (SPR) condition so that output feedback can be realized. Yet, this manipulation results in filtering basis functions of approximators, which makes the order of the controller dynamics very large. This paper presents a novel output‐feedback adaptive neural control (ANC) scheme to avoid seeking the SPR condition. A saturated output‐feedback control law is introduced based on a state‐feedback indirect ANC structure. An adaptive neural network (NN) observer is applied to estimate immeasurable system state variables. The output estimation error rather than the basis functions is filtered and the filter output is employed to update NNs. Under given initial conditions and sufficient control parameter constraints, it is proved that the closed‐loop system is uniformly ultimately bounded stable in the sense that both the state estimation errors and the tracking errors converge to small neighborhoods of zero. An illustrative example is provided to demonstrate the effectiveness of this approach.
Installation und Tragverhalten von Bucketgründungen für Offshorebauwerke
Authors: Achmus Martin , Schröder Christian
Published: September 2014

Eine Bucketgründung besteht aus einem oder bei aufgelösten Gründungsstrukturen aus mehreren oben geschlossenen Stahlzylindern, welche offshore mittels Abpumpen von Wasser und damit durch Realisierung eines Unterdrucks in den Baugrund bzw. Seeboden eingebracht werden. Diese Installationsmethode, derentwegen auch die Bezeichnung Suction Bucket für dieses Gründungselement verwendet wird, benötigt relativ wenig Aufwand und vermeidet Rammschallemissionen, weshalb die Bucketgründung eine interessante Alternative zu herkömmlichen Offshoregründungen mit Rammpfählen darstellt. Allerdings muss der Installationsvorgang genau berechnet und kontrolliert werden, um einen hydraulischen Grundbruch, Schalenbeulen oder unzulässige Schiefstellung zu vermeiden. Überdies bestehen hinsichtlich des Tragverhaltens von Bucketgründungen insbesondere unter transienten oder zyklischen Belastungen noch offene Fragen. In dem Aufsatz werden Methoden zur Prognose der Eindringwiderstände bei der Installation vorgestellt und beispielhaft für typische Baugrundverhältnisse in der deutschen Nordsee angewandt. Außerdem werden die spezifischen Anforderungen an das Tragverhalten von Bucketgründungen für Offshore‐Windenergieanlagen beschrieben und die diesbezüglichen Kenntnisse, aber auch die noch vorhandenen Kenntnislücken dargestellt. Abschließend werden die Grundzüge eines Dimensionierungskonzepts für Bucketgründungen von Offshore‐Windenergieanlagen vorgestellt und die diesbezüglich noch offenen Fragen diskutiert.

Installation and bearing behaviour of bucket foundations for offshore structures

A bucket foundation consists of one or, in case of a jacket or tripod structure, of three or four steel cylinders with a steel lid on top, which is installed offshore by pumping water and thus inducing underpressure below the lid. This installation method, which is the reason for the often used term 'suction bucket', is rather simple and avoids driving noise emissions. This makes it an interesting alternative to usual offshore foundations with driven piles instead of buckets. However, the installation process must be accurately calculated and controlled to avoid hydraulic failure, buckling and inadmissible rotations. Moreover, open questions regarding the bearing behavior of bucket foundations particularly under transient or cyclic loads exist. The paper firstly presents methods for the prediction of penetration resistances during installation and applies them exemplarily for typical soil conditions of the German North Sea. Secondly, the specific requirements on the behavior of buckets for offshore wind energy converter foundations are described and the respective state of knowledge is outlined. Finally, the basics of a general design concept for buckets as foundation elements of offshore wind energy converters are presented and open questions are discussed.
Rückverankerte Betonsohlen – Nachweise in den Grenzzuständen UPL, GEO‐2 und STR
Authors: Kinzler Steffen , Morgen Karl
Published: September 2014

Rückverankerte Betonsohlen dienen der Sohlabdichtung gegen drückendes Grundwasser z. B. bei Trogbaugruben. Durch rückverankerte Betonsohlen wird eine grundwasserschonende Bauweise ermöglicht, da auf Grundwasserhaltungsmaßnahmen verzichtet werden kann.

Rückverankerte Betonsohlen sind anspruchsvolle Ingenieurbauwerke. Die Nachweise im Grenzzustand des Versagens durch Verlust der Lagesicherheit infolge Aufschwimmen sowie im Grenzzustand des Versagens der Verankerung erfolgen auf Grundlage der DIN EN 1997‐1. Der Nachweis im Grenzzustand des inneren Bauteilversagens für die Betonsohle erfolgt gemäß DIN EN 1992‐1‐1.

Im vorliegenden Beitrag werden die normativen Grundlagen zusammengestellt und ihre Anwendung an einem Beispiel veranschaulicht. Neben der Nachweisführung auf Grundlage der aktuell gültigen Regelwerke wird ein Bemessungsmodell für den Lastabtrag im Sohlbeton vorgestellt. Dem Tragverhalten der in der Regel unbewehrten Sohlen wird dabei im Hinblick auf den Ansatz stabilisierender Einwirkungen entlang der Sohlränder, die Unterscheidung zwischen Rand‐ und Mittelbereich sowie die aus der Schlankheit der Sohle resultierenden Anforderungen besondere Aufmerksamkeit gewidmet.

Der vorliegende Beitrag greift einen Beitrag aus dem Jahr 2008 in dieser Zeitschrift auf [3]. Behandelt werden die Änderungen durch die Einführung der Eurocodes sowie die Nachweise der inneren Tragfähigkeit der Betonsohle.

Anchored concrete base slabs – Structural analysis in limit states UPL, GEO‐2 and STR

Anchored concrete base slabs are used as base sealing against pressurized groundwater e. g. at watertight excavations. Anchored concrete base slabs allow a minimum effect on groundwater.

Anchored concrete base slabs are sophisticated engineering structures. The ultimate limit states by loss of static equilibrium due to uplift as well as anchorage failure are based on DIN EN 1997‐1. The ultimate limit state of structural failure considering the concrete base slab is based on DIN EN 1992‐1‐1.

In this paper the normative basics are compiled and their application is illustrated with an example. Besides the analysis based on the currently valid regulations a mechanical model for the load transfer in the concrete base is shown. The structural behavior of the generally non‐reinforced base slabs is shown taking stabilizing effects along the edges as well as the distinction between peripheral and central region and the results from the slenderness ratio of the base slab into consideration.

This paper refers to a paper from 2008 in this journal [3]. It features the changes through the introduction of the Eurocodes and the ultimate limit state of the concrete base.
Entnahmebauwerk Kohlekraftwerk Wilhelmshaven
Authors: Brand Thomas , Bauer Matthias , Hamm Friderike , Merkel Holger
Published: September 2014

In Wilhelmshaven wird derzeit in unmittelbarer Nähe zur Jade ein Kohlekraftwerk gebaut. Das Kühlwasser für die gesamte Anlage wird durch zwei Entnahmetürme aus der Jade entnommen. Für die Herstellung dieser Entnahmetürme kam als Sondervorschlag ein Einschwimm‐ und Absenkverfahren zur Ausführung. Hierbei wurden beide Entnahmetürme mit einem Schwimmkörper zusammengefasst. Der erste Teilabschnitt wurde in einem Schwimmdock gefertigt und anschließend über die offene See bis in den Hafen von Wilhelmshaven verschleppt. Im Hafen von Wilhelmshaven wurde das Bauwerk in mehreren Phasen – teilweise schwimmend, teilweise auf einer temporären Pfahlgründung abgesetzt – vervollständigt. Da der fertige Rohbau zwar schwimmfähig, jedoch nicht schwimmstabil war, wurde für das Verschwimmen zum Endstandort eine zusätzliche temporäre Schwimmeinheit aus gekoppelten Flexifloat‐Elementen sowie für das Anheben und Absenken Litzenheber, installiert. Nach dem Absenken des Entnahmebauwerks wurde der Spalt zwischen Bodenplatte und Gründungssohle mittels Dämmer verpresst. Abschließend erfolgten der Anschluss der Kühlwasserleitungen, die Befüllung der Ballastkammern mit Sand und der Einbau des Kolkschutzes.

Intake riser for a coal‐fired power station in Wilhelmshaven – Design and construction using an extraordinary floating‐in and submerging method

At present, a coal‐fired power station is being built adjacent to the River Jade in Wilhelmshaven. The cooling water for the whole plant will be taken from the Jade by means of two intake structures. In order to construct the intake structures, it was decided to use an alternative proposal involving floating‐in and submerging of the structure. For this, both the intakes and buoyancy tanks were incorporated in one structure . The first section of the intake structure was constructed in a dry dock, and subsequently towed on the open sea to the port of Wilhelmshafen. The structure was then completed in several phases in the port of Wilhelmshaven, in some phases floating, and in others supported on a temporary pile foundation. In the completed condition the structure was buoyant, but however unstable. Therefore coupled Flexifloat‐units were used for additional buoyancy during the tow to the final location, with strand jacks installed for raising and lowering the structure. After submersion of the intake structure, the joint between the base slab and formation level was sealed using grout. The cooling water pipelines were then connected, the ballast compartments were filled with sand, and scour protection was installed.
Ausführungsplanung für die Baugrube des Trogbauwerkes 2852‐08 im Zuge der B 96n auf Rügen
Authors: Herbort Johannes , Helfers Björn
Published: September 2014

Nach der Fertigstellung der 2. Strelasundquerung, einschließlich der Anbindung an die BAB1, BAB11 und BAB20 ist die Insel Rügen schnell und komfortabel zu erreichen. Zur Abwicklung der an‐ und abfahrenden Verkehre ist der Neubau der B 96n auf Rügen erforderlich.

Mit einem ca. 485 m langen Trogbauwerk (BW 2852‐08) kreuzt die neue Trasse der B 96n die Bahnstrecke 6321 niveaufrei. Das Bauwerk wurde 2014 fertiggestellt.

Gegenstand des Berichtes sind die bauablauf‐ und geotechnisch begründeten Planungsherausforderungen zur Umsetzung und wirtschaftlichen Optimierung der Baugrube sowohl in der Angebots‐ als auch in der Ausführungsplanung.

Detailed design for the excavation pit of the trough construction 2852‐08 in the course of B 96n on Rügen

After completion of the 2nd Strelasundquerung, including the transport connection to the motorways A1, A11 and A20, the isle of Rügen will be quickly and comfortable accessible. The construction of the B 96n on Rügen is required in order to handle the in‐ and outbound traffic.

Due to the new construction of the 485 meter trough construction 2852‐08, the B 96n crosses the railway line 6321 without changing height above terrain level. The construction has been completed in 2014.

The report is based on the building process and the geotechnical planning challenge concerning the implementation and the economical optimization of the excavation pit. Both refer to the tender planning as well as to the detailed engineering.
Bemessungsrelevante Einwirkungskombinationen im Hochbau
Authors: Kohoutek Jaroslav , Tran Ngoc Linh , Graubner Carl‐Alexander
Published: September 2014

Für die Bemessung von Stahlbetonbauteilen im Grenzzustand der Tragfähigkeit nach DIN EN 1992‐1‐1 ist die Kenntnis der maßgebenden Einwirkungskombination eine Grundvoraussetzung, um eine hinreichende Tragwerkszuverlässigkeit nachweisen zu können. Hinsichtlich der Wirkungen aus Eigenwicht ist zu überprüfen, ob der minimale oder der maximale Bemessungswert der Eigenlast zu ungünstigeren Ergebnissen führt. Gleichzeitig sind Nutzlasten in ungünstiger Laststellung anzuordnen. Bei mehreren voneinander unabhängigen veränderlichen Einwirkungen ist nach DIN EN 1990 zwischen der Leiteinwirkung Qk,1 sowie den parallel wirkenden Begleiteinwirkungen Qk,i zu differenzieren. Dies führt bei der Berechnung der Schnittgrößen von Stahlbetonbauteilen des üblichen Hochbaus zu zahlreichen Kombinationsmöglichkeiten der verschiedenen Einwirkungen, welche in diesem Beitrag analysiert werden, um daraus die für die Bemessung relevanten Einwirkungskombinationen zu identifizieren.

Relevant combinations of actions in conventional buildings

For the design of reinforced concrete members in ultimate limit state according to DIN EN 1992‐1‐1 the knowledge of the most unfavorable combination of different actions is important to meet the necessary structural reliability. Concerning dead loads it has to be proved, whether the maximal or the minimal design value results in more unfavorable actions. Imposed loads have to be positioned in unfavorable load arrangements and different variable actions must be separated into leading actions Qk,1 and accompanying actions Qk,i according to DIN EN 1990. Calculating concrete members this results in numerous possible combinations of actions, which are analyzed in order to identify the relevant combinations for the design.
Innovativer Betonbau: Sicht‐Stein‐Betonbauweise
Authors: Voit Klaus , Arnold Roland , Bergmeister Konrad
Published: September 2014

Betonflächen in Sichtbeton‐Optik erfreuen sich immer größerer Beliebtheit. Während bei klassischem Sichtbeton die Gesteinskörnung selbst von außen nicht erkennbar ist, wurde nun eine Herstellungsmethode entwickelt, bei welcher die Gesteinskomponenten sichtbar im Betonverbund in Erscheinung treten. Diese sogenannte Sicht‐Stein‐Betonbauweise bietet durch ihre hohe Flexibilität bezüglich Bauausführung und verwendeter Komponenten eine Vielzahl neuer gestalterischer Möglichkeiten. Durch die Variabilität der verwendeten Gesteinskörnung stellt die Sicht‐Stein‐Betonbauweise auch eine Möglichkeit zur Wiederverwertung von Tunnelausbruchmaterial dar und trägt damit zur Ressourcenschonung und Erhöhung der Nachhaltigkeit bei. Die Sicht‐Stein‐Betonbauweise wurde beim Bau der Kapelle Padastertal in der Gemeinde Steinach am Brenner, welche im Rahmen des Brenner Basistunnels als Ersatzbaumaßnahme errichtet wurde, erstmals erfolgreich angewendet. Als Gesteinskörnung diente hierbei ein Kalkschiefer der Bündnerschieferserie aus dem Vortrieb des Brenner Basistunnels.

Innovative concrete engineering: Rock‐exposing concrete construction

Exposed concrete surfaces have become increasingly popular. Whereas in classic exposed concrete the aggregate is not visible, a new manufacturing process, the so called rock‐exposing‐concrete construction method, was developed, which ensures the visibility of the rock components in the concrete bond. Due to the high degree of variability because of its variable construction work and applied components, this construction method offers a wide range of design possibilities. By using recycled rock material as aggregate for concrete, limited natural resources like gravel or sand are saved and sustainability is improved. The rock‐exposing‐concrete construction method has already been applied by building the Padastertal chapel in Steinach am Brenner. A calc‐schist from the Bündner schist formation from the tunnel driving of the Brenner Base Tunnel was used as aggregate for concrete.
Auswirkung von Lageabweichungen bei der Verwendung der freien Spanngliedlage – Ansatz der Vorspannkräfte im GZT
Authors: Laugesen Arne , Schmidt‐Thrö Gerald , Fischer Oliver , Busler Hubert
Published: September 2014

Der vorliegende Beitrag gibt einen Überblick zu derzeitigen Regelungen zur freien Spanngliedlage in Deutschland und beschreibt eine Möglichkeit, wie Lageabweichungen während dem Betonieren erfasst und im Grenzzustand der Tragfähigkeit berücksichtigt werden können. Darüber hinaus wird anhand eines Beispiels der ansetzbare Spannungszuwachs der verbundlosen Vorspannung bei punktgestützten Flachdecken kritisch diskutiert.

Effect of displacements of monostrands in free tendon layout – Consideration of monostrand forces in the ultimate limit state (ULS)

The present article gives an overview on the current regulations for the free tendon layout in Germany and introduces a method to systematically take into account possible displacements of monostrands being generated during concreting. Consequently, the effect of those displacements on the ultimate limit state design is discussed. Furthermore, the article generally deals with the maximum tendon stress increase to be considered in floor slab systems utilizing post‐tensioning without bond.
Fachwerkmodellbildung mit topologischen Optimierungsverfahren
Authors: Putke Thomas , Mark Peter
Published: September 2014

Diskontinuitätsbereiche in Stahlbetonkonstruktionen werden in der Regel auf der Grundlage von Fachwerkmodellen bemessen und konstruktiv durchgebildet. Zu den typischen Anwendungsfällen gehören Konsolen, Rahmenecken, Aussparungen oder volumenartige Betonkörper. Dabei erweisen sich solche Fachwerkmodelle als günstig, die am Kraftfluss orientiert sind und nur geringe Umlagerungen oder Rissbildungen hervorrufen. Meist werden Trajektorienbilder linear‐elastischer Berechnungen zur Ableitung verwendet. Als Alternative bieten sich topologische Optimierungsergebnisse für die Modellfindung an. Dabei bilden sich Streben und Knoten als Materialdichten direkt heraus und sind auch bei komplexen Geometrien leicht in Fachwerke zu überführen.

Der Beitrag zeigt die grundsätzliche Methodik der topologischen Optimierung, günstige Steuerungsparameter zur Ableitung von Fachwerkmodellen, die Vereinfachung zum Strebensystem und die abschließende Umsetzung zur Bewehrungskonstruktion. Beispiele sind Sprengwerke, Konsolen und Querkraftkopplungen an Tübbings mit verschiedenen Bewehrungskonzepten klassischer Stabbewehrung, Stahlfaserverstärkung oder netzartiger Mikrobewehrung.

Strut‐and‐tie modelling with topological optimisation

Design and detailing of discontinuous or shear critical regions in reinforced concrete structures are usually based on strut‐and‐tie modelling. Typical examples of such structures are corbels, frame corners, block‐outs or spatial concrete structures. Strut‐and‐tie models that are developed from the inner distribution of forces, and therefore evoke only minor redistributions or crack formations, have proven especially suitable for such design purposes. In general, the stress trajectories used to develop such models are derived from linear‐elastic calculations. Alternatively, similar models can be derived from topological optimisation results. The strut and node locations are indicated directly by calculated material densities. These results can then be easily transferred into strut‐and‐tie models and generated for arbitrary complex structures.

This contribution shows the basic principles of topology optimisation, favourable parameter adjustments to derive appropriate models, simplifications for strut‐and‐tie models and finally its implementation in reinforcement design. Truss frames, corbels and shear‐coupling mechanisms w.r.t concrete lining segments with various reinforcement concepts, e.g. conventional rebars, steel fibres or mesh‐like micro reinforcement, are presented as examples.
Technologies and strategies to characterize and quantitate metabolites in drug discovery and development
Authors: Ravindran Selvan , Jadhav Amol , Surve Prashant , Lonsane Ganesh , Honrao Pradnya , Nanda Bidyut
Published: September 2014

Pharmacokinetics and toxicokinetics studies rely on the quantitation of drugs and its metabolites. Drug metabolism studies are based on the characterization of the structure of drugs and their metabolites. Liquid chromatography coupled with mass spectrometry is an undisputed technology for the routine analysis of drugs and metabolites in the drug discovery set‐up. Advancements in liquid chromatography and mass spectrometry have accelerated and improved drug discovery and development. Identification and quantitation of drugs and metabolites have gained importance because of their relevance to clinical research. In the present review, we present a bird's eye view of qualitative and quantitative analysis of drugs and their metabolites. Various technologies available to characterize and quantitate metabolites are analyzed. Characterization of metabolites of the sulfonyl urea drug glyburide and the kinetics of glyburide metabolism are discussed in detail. Copyright © 2014 John Wiley & Sons, Ltd.
Polymerase Synthesis of DNAs Bearing Vinyl Groups in the Major Groove and their Cleavage by Restriction Endonucleases
Authors: Mačková Michaela , Pohl Radek , Hocek Michal
Published: September 2014

DNA molecules containing 5‐vinyluracil, 5‐vinylcytosine, or 7‐deaza‐7‐vinyladenine were prepared by polymerase incorporation of the corresponding vinyl‐modified 2′‐deoxyribonucleoside triphosphates, and the influence of the vinyl group in the major groove of DNA on the cleavage by diverse type II restriction endonucleases (REs) was studied. The presence of 5‐vinyluracil was tolerated by most of the REs, whereas only some REs were able to cleave sequences containing 7‐deaza‐7‐vinyladenine. The enzyme ScaI was found to cleave DNA containing 5‐vinylcytosine efficiently but not DNA containing the related 5‐ethynylcytosine. All other REs failed to cleave sequences containing any cytosine modifications.
Differences determined by optical coherence tomography volumetric analysis in non‐culprit lesion morphology and inflammation in ST‐segment elevation myocardial infarction and stable angina pectoris patients
Authors: Galon Micheli Zanotti , Wang Zhao , Bezerra Hiram G. , Lemos Pedro Alves , Schnell Audrey , Wilson David L. , Rollins Andrew M. , Costa Marco A. , Attizzani Guilherme F.
Published: September 2014

Background

While the current methodology for determining fibrous cap (FC) thickness of lipid plaques is based on manual measurements of arbitrary points, which could lead to high variability and decreased accuracy, it ignores the three‐dimensional (3‐D) morphology of coronary artery disease.

Objective

To compare, utilizing optical coherence tomography (OCT) assessments, volumetric quantification of FC, and macrophage detection using both visual assessment and automated image processing algorithms in non‐culprit lesions of STEMI and stable angina pectoris (SAP) patients.

Methods

Lipid plaques were selected from 67 consecutive patients (1 artery/patient). FC was manually delineated by a computer‐aided method and automatically classified into three thickness categories: FC < 65 μm (i.e., thin‐cap fibroatheroma [TCFA]), 65–150 μm, and >150 μm. Minimum thickness, absolute categorical surface area, and fractional luminal area of FC were analyzed. Automated detection and quantification of macrophage was performed within the segmented FC.

Results

A total of 5,503 cross‐sections were analyzed. STEMI patients when compared with SAP patients had more absolute categorical surface area for TCFA (0.43 ± 0.45 mm2 vs. 0.15 ± 0.25 mm2; P = 0.011), thinner minimum FC thickness (31.63 ± 17.09 µm vs. 47.27 ± 26.56 µm, P = 0.012), greater fractional luminal area for TCFA (1.65 ± 1.56% vs. 0.74 ± 1.2%, P = 0.046), and greater macrophage index (0.0217 ± 0.0081% vs. 0.0153 ± 0.0045%, respectively, P < 0.01).

Conclusion

The novel OCT‐based 3‐D quantification of the FC and macrophage demonstrated thinner FC thickness and larger areas of TCFA coupled with more inflammation in non‐culprit sites of STEMI compared with SAP. © 2014 Wiley Periodicals, Inc.
Catalytic Performance of Brønsted and Lewis Acid Sites in Phenylglyoxal Conversion on Flame‐Derived Silica–Zirconia
Authors: Wang Zichun , Jiang Yijiao , Hunger Michael , Baiker Alfons , Huang Jun
Published: September 2014

Flame‐derived silica–zirconia has been used for the promising one‐step catalytic conversion of phenylglyoxal (PG) to mandelates, important intermediates in pharmacy and fine chemistry. In the literature it was proposed that Lewis acid sites (LAS) on solid acids promote mandelate production, whereas Brønsted acid sites (BAS) only generate acetal byproducts during PG conversion. Herein it is shown that ZrO2, which contains only LAS and no BAS, exhibits a very low activity for PG conversion to afford a yield of mandelate of only 8 % after 6 h. The activity of this ZrO2 catalyst was confirmed by the condensation of acetone, in which its LAS could activate the carbonyl groups immediately for the fast condensation of all acetone molecules. The introduction of BAS by the admixing of silica precursor to the feed in the flame‐spray pyrolysis enhanced the yield of mandelate up to 52–67 %. This indicates that BAS are mainly responsible for the PG conversion to mandelate on silica–zirconia catalysts and that their LAS are nearly inactive for this reaction.
Catalytic Hydrogen Evolution by Tungsten Disulfide at Liquid–Liquid Interfaces
Authors: Aslan Emre , Hatay Patir Imren , Ersoz Mustafa
Published: September 2014

WS2, which is composed of cheap and earth‐abundant elements, catalyzes the hydrogen‐evolution reaction efficiently using the organic electron‐donor decamethylferrocene. This catalytic activity has been investigated at liquid–liquid interfaces (water–1,2‐dichloroethane) by voltammetry and biphasic reactions observed by UV/Vis spectroscopy and GC.
Fundamental Properties of Phenylboronic‐Acid‐Coated Gate Field‐Effect Transistor for Saccharide Sensing
Authors: Kajisa Taira , Sakata Toshiya
Published: September 2014

We report the surface and electrical characteristics of a phenylboronic acid (PBA)‐coated gate field effect transistor (FET) biosensor for a highly sensitive detection of various saccharides. 4‐mercaptophenylboronic acid (MPBA) was self‐assembled on a Au extended‐gate electrode, which was used as a saccharide recognition substrate of the PBA–FET. The binding affinity of PBA with various monosaccharides and disaccharides were evaluated by the amount of voltage changes on the Au gate surface in response to sugar concentrations using the PBA–FET. The specific diol‐binding of PBA with saccharides induces molecular charges onto PBA, resulting in the detection of charges at a lower concentration of 50 μM. In particular, the binding affinities of PBA with the saccharides contributes to the different electrical signals. The platform based on the PBA–FET is useful for a convenient and highly sensitive detection of various saccharides in the fields of food engineering and medicine.
The Multicomponent Hantzsch Reaction: Comprehensive Mass Spectrometry Monitoring Using Charge‐Tagged Reagents
Authors: Santos Vanessa G. , Godoi Marla N. , Regiani Thaís , Gama Fernando H. S. , Coelho Mirela B. , de Souza Rodrigo O. M. A. , Eberlin Marcos N. , Garden Simon J.
Published: September 2014

A novel strategy for the ESI‐MS monitoring of reaction solutions involving the alternate use of permanently charge‐tagged reagents has been used for comprehensive mass spectrometry monitoring of the multicomponent Hantzsch 1,4‐dihydropyridine reaction. By placing a charge tag on either, or both, of the two key reactants, ion suppression effects for ESI were eliminated or minimized, and comprehensive detection of charge‐tagged intermediates was achieved. The strategy allowed the trapping and characterization of the important intermediates in the mechanism for 1,4‐dihydropyridine formation.
Biofunctionalization of Multiwalled Carbon Nanotubes by Electropolymerized Poly(pyrrole‐concanavalin A) Films
Authors: Papper Vladislav , Elouarzaki Kamal , Gorgy Karine , Sukharaharja Ayrine , Cosnier Serge , Marks Robert S.
Published: September 2014

The synthesis and electropolymerization of a pyrrolic concanavalin A derivative (pyrrole‐Con A) onto a multiwalled carbon nanotube (MWCNT) deposit is reported. Glucose oxidase was then immobilized onto the MWCNT‐poly(pyrrole‐Con A) coating by affinity carbohydrate interactions with the polymerized Con A protein. The resulting enzyme electrode was applied to the amperometric detection of glucose exhibiting a high sensitivity of 36 mA cm−2 mol−1 L and a maximum current density of 350 μA cm−2.
On the Reaction Mechanism of the Complete Intermolecular O2 Transfer between Mononuclear Nickel and Manganese Complexes with Macrocyclic Ligands
Authors: Zapata‐Rivera Jhon , Caballol Rosa , Calzado Carmen J. , Liakos Dimitrios G. , Neese Frank
Published: September 2014

The recently described intermolecular O2 transfer between the side‐on Ni‐O2 complex [(12‐TMC)Ni‐O2]+ and the manganese complex [(14‐TMC)Mn]2+, where 12‐TMC and 14‐TMC are 12‐ and 14‐membered macrocyclic ligands, 12‐TMC=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane and 14‐TMC=1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane, is studied by means of DFT methods. B3LYP calculations including long‐range corrections and solvent effects are performed to elucidate the mechanism. The potential energy surfaces (PESs) compatible with different electronic states of the reactants have been analyzed. The calculations confirm a two‐step reaction, with a first rate‐determining bimolecular step and predict the exothermic character of the global process. The relative stability of the products and the reverse barrier are in line with the fact that no reverse reaction is experimentally observed. An intermediate with a μ‐η1:η1‐O2 coordination and two transition states are identified on the triplet PES, slightly below the corresponding stationary points of the quintet PES, suggesting an intersystem crossing before the first transition state. The calculated activation parameters and the relative energies of the two transition sates and the products are in very good agreement with the experimental data. The calculations suggest that a superoxide anion is transferred during the reaction.
Domino‐Hydroformylation/Aldol Condensation Catalysis: Highly Selective Synthesis of α,β‐Unsaturated Aldehydes from Olefins
Authors: Fang Xianjie , Jackstell Ralf , Franke Robert , Beller Matthias
Published: September 2014

A general and highly chemo‐, regio‐, and stereoselective synthesis of α,β‐unsaturated aldehydes by a domino hydroformylation/aldol condensation reaction has been developed. A variety of olefins and aromatic aldehydes were efficiently converted into various substituted α,β‐unsaturated aldehydes in good to excellent yields in the presence of a rhodium phosphine/acid–base catalyst system. In view of the easy availability of the substrates, the high atom‐efficiency, the excellent selectivity, and the mild conditions, this method is expected to complement current methodologies for the preparation of α,β‐unsaturated aldehydes.
New Insight into the Hydrocarbon‐Pool Chemistry of the Methanol‐to‐Olefins Conversion over Zeolite H‐ZSM‐5 from GC‐MS, Solid‐State NMR Spectroscopy, and DFT Calculations
Authors: Wang Chao , Chu Yueying , Zheng Anmin , Xu Jun , Wang Qiang , Gao Pan , Qi Guodong , Gong Yanjun , Deng Feng
Published: September 2014

Over zeolite H‐ZSM‐5, the aromatics‐based hydrocarbon‐pool mechanism of methanol‐to‐olefins (MTO) reaction was studied by GC‐MS, solid‐state NMR spectroscopy, and theoretical calculations. Isotopic‐labeling experimental results demonstrated that polymethylbenzenes (MBs) are intimately correlated with the formation of olefin products in the initial stage. More importantly, three types of cyclopentenyl cations (1,3‐dimethylcyclopentenyl, 1,2,3‐trimethylcyclopentenyl, and 1,3,4‐trimethylcyclopentenyl cations) and a pentamethylbenzenium ion were for the first time identified by solid‐state NMR spectroscopy and DFT calculations under both co‐feeding ([13C6]benzene and methanol) conditions and typical MTO working (feeding [13C]methanol alone) conditions. The comparable reactivity of the MBs (from xylene to tetramethylbenzene) and the carbocations (trimethylcyclopentenyl and pentamethylbenzium ions) in the MTO reaction was revealed by 13C‐labeling experiments, evidencing that they work together through a paring mechanism to produce propene. The paring route in a full aromatics‐based catalytic cycle was also supported by theoretical DFT calculations.
Droplet Separation from the Gas Phase in Small‐Scale Ring Chamber Centrifuges
Authors: Piesche Manfred , Junker Malte , Grabe Cornelia
Published: September 2014

Hier werden laminare Strömungsvorgänge in kleinskaligen Ringkammerzentrifugen untersucht, um das Abscheideverhalten von Ölaerosolen mithilfe von Modellregeln und Ähnlichkeitsgesetzen zu beschreiben. Dabei sind die Ermittlung des Trenngrades in Abhängigkeit der Zentrifugengeometrie, die Stoffeigenschaften der kontinuierlichen und dispersen Phasen sowie Betriebsparameter wie Winkelgeschwindigkeit und Volumenstrom von Interesse. Zudem wurden experimentelle Untersuchungen durchgeführt, um den Gültigkeitsbereich, die Brauchbarkeit und die Genauigkeit der Rechenmodelle zu bewerten.
Preparation of Coals for Negativ‐Ion Laser Desorption/Ionization Mass Spectrometry
Authors: Kroll Marius Matthias , Otto Matthias
Published: September 2014

Für die Negativ‐Ionen‐Laserdesorptions‐Ionisations‐Massenspektrometrie von Kohlen existiert nur eine geringe Anzahl an Präparationsmethoden, die jedoch eine geringe Probenkapazität aufweisen. In dieser Arbeit wird daher eine neue Probenpräparationsmethode für Kohlen vorgestellt. Dabei wird die Probe als Dispersion mit Glycerin oder Polyethylenglycol 400 und Wasser auf einen Probeträger aufgebracht. Die Messungen dieser Präparate zeigen eine hohe Probenkapazität, sind stabil und liefern gut reproduzierbare Ergebnisse.
Color scheme adjustment by fuzzy constraint satisfaction for color vision deficiencies
Authors: Yanagida Takuto , Okajima Katsunori , Mimura Hidenori
Published: September 2014

Color schemes or color combinations are widely used in printed materials and their digital versions, including web pages. These schemes convey information and create aesthetic appeal. Consequently, graphic designers have to strike a balance between accessibility and aesthetics with the color schemes they select. However, certain color schemes make the represented information confusing when viewers have color vision deficiencies (CVDs), which may lead to decrease in discriminability between used colors. What we will call the color‐scheme‐recoloring problem is the difficulty of optimizing a color scheme so as to preserve its original design and yet be simultaneously discriminable for all viewers, with or without CVDs. To address the problem, we formulated it within a framework of a fuzzy constraint satisfaction problem, a technique of artificial intelligence, and developed a tool for graphic designers. By utilizing the practical color co‐ordinate system (PCCS), we introduce concepts used in the field of graphic design. This work combines pre‐publication recoloring techniques for CVD viewers with elements of artificial intelligence, psychophysics, and psychology. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 446–464, 2015
De Novo Design of an Endohedral Heteronuclear Dimetallofullerene (UGd)@C60 with Exceptional Structural and Electronic Properties
Authors: Dai Xing , Han Jie , Gao Yang , Wang Zhigang
Published: September 2014

Ever since the first synthesis of La@C82 and U@C28, there has been a growing interest in the study of endohedral metallofullerenes (EMFs) because of their great potential in various applications. Here we design a novel heteronuclear EMF (U‐Gd)@C60, by using density functional theory (DFT), which shows an encapsulation energy of about −5.53 eV, comparable to that of U2@C60, La2@C80, and Lu2@C76. (U‐Gd)@C60 is found to have a surprising twofold, single‐electron UGd bond that results from the strong nanoconfinement of the fullerene, dominated by uranium′s 5f and 6d and gadolinium′s 5d atomic orbitals. The ground state shows an 11‐et high spin state, and the net spins distributed on the U‐pole carbons are relatively scattered, while they are highly concentrated on the Gd‐pole carbons. The exceptional electronic characteristics of this novel EMF, containing both uranium and gadolinium atoms encapsulated, might prove useful for future applications in nuclear energy and biomedicine.