bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of RF pulse sequence on temperature elevation for a given time‐average SAR
Authors: Wang Zhangwei , Collins Christopher M.
Published: October 2010

In calculations of temperature increase during MRI, it is typically assumed adequate to consider the specific energy absorption rate (SAR) levels averaged over an entire repetition time (TR) rather than explicitly consider the heating (as it occurs in reality) during the RF pulses only. Here, we investigate this assumption with numerical calculations of SAR and temperature increase for a human head in a volume coil at 64 and 300 MHz during three very different pulse sequences, each having a TR of 200 ms and a time‐average whole‐head SAR of 3.0 W/kg, as well as with semianalytical calculations considering a gradient‐echo sequence in a segment of tissue with SAR of 10 W/kg delivered in a 1‐ms pulse with TR of up to 5,000 ms. Although it is possible to calculate a temporal effect of specific pulse sequence on temperature, the difference between pulse sequences is so small and so transient that it should typically be adequate to consider only the time‐average SAR in each TR. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 215–219, 2010.
Finite‐length shim coil design using a fourier series minimum inductance and minimum power algorithm
Authors: Hudson Parisa , Hudson Stephen D. , Handler William B. , Chronik Blaine A.
Published: October 2010

High field magnetic resonance (MR) imaging and spectroscopy are sensitive to magnetic field inhomogeneities caused by susceptibility differences between tissues, bone, and air. These inhomogeneities cause MR image artifacts and line broadening in MR spectra. To correct for these inhomogeneities, specialized shim coils are used in combination with the usual gradient systems. To produce realistic coils for use in human or small‐animal studies, direct control over the length of the coils is necessary. In this article, a simple method for the design of shim coils of arbitrary order and with predetermined length is presented. The method is based on a simple Fourier series expansion of the current density and either power or inductance can be minimized subject to a series of field constraints. The method is mathematically simple, easy to implement and computationally fast. A quantitative comparison of figures of merit for inductance and resistance was made as a function of shim coil length. Coils of 40 cm diameter were designed with lengths of 50, 60, 80, and 100 cm. Comparison of results obtained using the two design methods across all shim axes and coil lengths indicate very little performance difference between the two methods. The decreased complexity of the minimum power designs appears to outweigh any small benefits obtainable using the minimum inductance algorithm for the range of coils investigated. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 245–253, 2010.
Three‐channel receive‐only RF coil for vertical‐field MR‐guided focused ultrasound surgery
Authors: Xuegang Xin , Yanqiu Feng , Jijun Han , Wufan Chen
Published: October 2010

Focused ultrasound plays an important role in local hyperthermia treatment. Magnetic resonance imaging (MRI) can be used for monitoring temperature during a thermal ablation of tumor tissues. The combination of these two technologies offers great advantages for oncology treatment. Currently, only horizontal‐field MR‐guided focused ultrasound systems are available clinically, but the circular magnetic field restricts the operational space during surgery. Vertical‐field open MR could provide wider access to patients during the ultrasound surgery and thus increase the potential clinical applications. A key component to facilitate such a system is the radio frequency (RF) coils. Common RF coils of vertical‐field MR are not adaptive to a combined system because there is no unhindered path for ultrasound beams to pass. A special three‐channel receive‐only RF coil with a 27 cm aperture to pass ultrasound beams was designed and reported first time. Phantom scan, body imaging, and temperature measurements were all taken with the specially designed prototype coil. The results show that the designed coil was functionally adaptive to the vertical‐field MR‐guided focused ultrasound system. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 237–244, 2010.
Language in Humans and Animals: Contribution of Brain Stimulation and Recording
Authors: Ojemann George A. , Creutzfeldt Otto D.
Published: October 2010

The sections in this article are:

Human Language Localization Based on Intraoperative Investigations with Electrical Stimulation Mapping

Electrical Stimulation as a Technique for Functional Localization

Intrahemispheric Cortical Language Localization as Derived from Electrical Stimulation Mapping

Nondominant Hemisphere: Language Localization as Derived from Electrical Stimulation Mapping

Role of Subcortical Structures in Language as Derived from Electrical Stimulation Mapping

Electrophysiological Correlates of Human Language Recorded Directly from the Brain

Electrocorticographic Correlates of Language

Single‐Neuron Activity During Language

Parallel Investigations in Animals: Localization and Physiological Correlates of Brain Mechanisms Related to Vocalization

Electrical Stimulation

Physiological Correlates in Single‐Neuron Studies
Regulation of Airway Secretions, Ion Transport, and Water Movement
Authors: Nadel Jay A. , Widdicombe Jonathan H. , Peatfield Anthony C.
Published: October 2010

The sections in this article are:

Airway Secretions

Surface Mucus

Submucosal Glands

Effects of Drugs and Mediators

Hypertrophy of Mucus‐Secreting Cells

Ion Transport and Water Movement

Introduction

Mechanisms of Ion Transport

Regulation of Ion Transport

Relationship Between Ion Transport and Water Movement
Function‐Structure Correlations in Cilia from Mammalian Respiratory Tract
Authors: Satir Peter , Dirksen Ellen Roter
Published: October 2010

The sections in this article are:

Distribution and General Organization of Cilia

Ciliogenesis

Axoneme

Ciliary Membrane

Ciliary Crown

Freeze‐Fracture Studies and Membrane Organization

Ciliary Necklace

Sliding‐Microtubule Mechanism

Geometry of Sliding

Direct Examination of Sliding

Structure and Function of the Dynein Arm

Human Dynein

Control of Sliding

Mutant Studies

Sliding and Switching Mechanisms

Calcium Ions and Ciliary Arrest

Membrane Control of Calcium Ion Concentration

Calmodulin

Ciliary Beat

Mucociliary Transport

Periciliary Fluid

Mucous Layer

Function of Metachronism

Factors Influencing Mucociliary Clearance

Effects of Sympathomimetic and Parasympathomimetic Drugs

Effect of Local Anesthetics

Relationship of Drug Effects to Axonemal Controls

Ciliary Dysfunction in Humans

Genetic and Structural Implications
Does corporate social responsibility influence profit margins? a case study of executive perceptions
Authors: Blomgren Atle
Published: October 2010

The literature on the business case for Corporate Social Responsibility (CSR) has identified possible mechanisms for CSR to increase profits. Other parts of the CSR literature argue that any strategy yielding above‐average profits will be imitated by competitors and profits driven down to industry average; consequently, CSR may only be a strategy for achieving average profits. The empirical research on the relationship between CSR and profits, consisting mostly of quantitative studies, has thus far proved inconclusive and many studies are challenged on methodological grounds. This paper presents the results of interviews with senior executives of 15 of the largest textile companies on the Norwegian market. The aim of the paper is to investigate the relationship between CSR and profits while avoiding the most important methodological pitfalls of the quantitative research and acknowledging the distinction between CSR as a strategy for achieving average profits and as a strategy for achieving above‐average profits. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Preliminary results from an analog implementation of first‐order TDCNN dynamics
Authors: Ip Henry M. D. , Drakakis Emmanuel Mic. , Bharath Anil A.
Published: October 2010

This work falls into the category of linear cellular neural network (CNN) implementations. We detail the first investigative attempt on the CMOS analog VLSI implementation of a recently proposed network formalism, which introduces time‐derivative ‘diffusion’ between CNN cells for nonseparable spatiotemporal filtering applications—the temporal‐derivative CNNs (TDCNNs). The reported circuit consists of an array of Gm‐C filters arranged in a regular pattern across space. We show that the state–space coupling between the Gm‐C‐based array elements realizes stable and linear first‐order (temporal) TDCNN dynamics. The implementation is based on linearized operational transconductance amplifiers and Class‐AB current mirrors. Measured results from the investigative prototype chip that confirms the stability and linearity of the realized TDCNN are provided. The prototype chip has been built in the AMS 0.35 µm CMOS technology and occupies a total area of 12.6 mm sq, while consuming 1.2 µW per processing cell. Copyright © 2010 John Wiley & Sons, Ltd.
Active‐terminated transmitter and receiver circuits for high‐speed low‐swing duobinary signaling
Authors: Rao P. Vijaya Sankara , Mandal Pradip
Published: October 2010

In this work, we propose transmitter and receiver circuits for high‐speed, low‐swing duobinary signaling over active‐terminated chip‐to‐chip interconnect. In active‐termination scheme port impedance of transmitter and receiver is matched with characteristic impedance of the interconnect. Elimination of the passive terminators helps in reducing the transmitted signal level without degrading the 0signal detectability of the receiver. High‐speed current‐mode receiver and transmitter circuits are designed, so that the input port impedance of the receiver and the output port impedance of the transmitter are matched with characteristic impedance of the link. These Tx–Rx pair is used to validate the proposed active‐termination scheme. We also propose a duobinary precoder architecture suitable for high‐speed operation and a low‐power broadband equalizer topology for compensating the lossy long interconnect. The duobinary transmitter and receiver circuits are implemented in 1.8 V, 0.18 µm Digital CMOS technology. The designed high‐speed duobinary Tx/Rx circuits work up to 8 Gb/s speed while transmitting the data over 29.5 in. FR4 PCB trace for a targeted bit error rate (BER) of 10−15. The power consumed in the transmitter and receiver circuits is 42.9 mW at 8 Gb/s. Copyright © 2010 John Wiley & Sons, Ltd.
FDCCII‐based electronically tunable voltage‐mode biquad filter
Authors: Kaçar Fırat , Yeşil Abdullah
Published: October 2010

In this work, a voltage‐mode biquad filter realizing low‐pass, band‐pass and high‐pass characteristics is presented. The proposed filter, which employs two FDCCIIs, two grounded capacitors and two NMOS transistors, provides electronic tunability with the control voltage applied to the gate. NMOS transistors act as linear resistor. Furthermore, the proposed circuit still enjoys realization using a low number of active and passive components, no requirement with the component choice conditions to realize specific filtering functions, high input impedance, and low active and passive sensitivities performance. Simulation results using SPICE program are given to show the performance of the filter and verify the theory. Copyright © 2010 John Wiley & Sons, Ltd.
Anti‐inflammatory and antiproliferative activities of crude extract and its fractions of the defensive secretion from the Mediterranean sponge, Spongia officinalis
Authors: Dellai Afef , Laroche‐Clary Audrey , Mhadhebi Lamia , Robert Jacque , Bouraoui Abderrahman
Published: October 2010

The fact that conventional and newly emerging treatment procedures like chemotherapy, catalytic therapy, photodynamic therapy, and radiotherapy have not succeeded in reversing the outcome of many cancers alternative treatment options has been explored. This study documents the identification of component(s) from the Mediterranean sponge, Spongia officinalis that have anti‐inflammatory and antiproliferative activities. In the present study we investigated the efficacy of a crude extract and its semi‐purified fractions (F1–F3) of the defensive secretion from Spongia officinalis for in vivo anti‐inflammatory activity using the carrageenan‐induced paw edema assay in rats and their in vitro antiproliferative effects against three human cancer cell lines (A549, lung cell carcinoma; HCT15, colon cell carcinoma; and MCF7, breast adenocarcinoma). Among the series, the crude extract exhibited interesting anti‐inflammatory activity associated with significant growth and concentration‐related colony inhibitory effects against the three cell lines. The fractions F2 and F3 showed, respectively, interesting anti‐inflammatory and antiproliferative activities in a dose‐dependent manner. The purification and the determination of chemical structures of compounds of these active fractions are under investigation. Drug Dev Res 71: 412–418, 2010. © 2010 Wiley‐Liss, Inc.
Sulbutiamine in sports
Authors: Sobolevsky Tim , Rodchenkov Grigory
Published: October 2010

Sulbutiamine (isobutyryl thiamine disulfide) is a lipophilic derivative of thiamine used for the treatment of asthenia and other related pathological conditions. It is available over‐the‐counter in several countries either as a component of nutritional supplements or as a pharmaceutical preparation. The presence of sulbutiamine in urinary doping control samples was monitored to evaluate the relevance of its use in sports. As one of the sulbutiamine metabolites has very close retention time and the same characteristic ion (m/z 194) as the main boldenone metabolite, the raw data files generated from the screening for anabolic steroids were automatically reprocessed to identify the samples containing sulbutiamine. It was found that of ca. 16 000 samples analyzed in the Russian laboratory during 2009, about 100 samples contained sulbutiamine. It is important to note that most of these samples were collected in‐competition, and sulbutiamine concentration was estimated to be greater than 500 ng/ml. This may indicate that sulbutiamine was intentionally administered for its ergogenic and mild stimulating properties. Copyright © 2010 John Wiley & Sons, Ltd.
Role of fibroblast growth factor signaling during proepicardium formation in the chick embryo
Authors: Torlopp Angela , Schlueter Jan , Brand Thomas
Published: October 2010

COVER PHOTOGRAPH: 3‐D reconstruction of the Tbx18 expression domain demarcating the proepicardium of a HH stage 16 embryo. The proepicardium is viewed from the ventral side and is characterized by extensive outgrowth of mesothelial cells forming the typical villous structure of the proepicardium in the chick. On the left side a small Tbx18 stained proepicardium, which lacks the villous outgrowth is seen. From Torlopp et al., Developmental Dynamics 239:2393–2403, 2010.
Comparison of protein precipitation methods for various rat brain structures prior to proteomic analysis
Authors: Fic Ewelina , Kedracka‐Krok Sylwia , Jankowska Urszula , Pirog Artur , Dziedzicka‐Wasylewska Marta
Published: October 2010

Sample preparation is a fundamental step in proteomic methodologies. The quality of the results from a proteomic experiment is dependent on the nature of the sample and the properties of the proteins. In this study, various pre‐treatment methods were compared by proteomic analysis; we analysed various rat brain structures after chloroform/methanol, acetone, TCA/acetone and TCA protein precipitation procedures. The protein content of the supernatant was also examined by 2‐DE. We found that for four of the rat brain structures, precipitation with chloroform/methanol and acetone delivered the highest protein recovery for top‐down proteomic analysis; however, TCA precipitation resulted in good protein separation and the highest number of protein spots in 2‐DE. Moreover, TCA precipitation also gave high efficiency of protein recovery if prior sonication procedure was performed.
Study on the influence of cross‐sectional area and zeta potential on separation for hybrid‐chip‐based capillary electrophoresis using 3‐D simulations
Authors: Wu Zeng‐Qiang , Cao Xiao‐Dan , Chen Lu , Zhang Jian‐Rong , Xia Xing‐Hua , Fang Qun , Chen Hong‐Yuan
Published: October 2010

Hybrid chips combing microchips with capillaries have displayed particular advantages in achieving UV‐vis and mass spectroscopic detection. In this work, systematic 3‐D numerical simulations have been carried out to explore the influence of junction interface cross‐sectional area and ζ‐potential distribution on sample band broadening in hybrid‐chip electrophoresis separation. In this case, the ratio of cross‐sectional area of chip to capillary channel (Sratio) is used as the parameter of the variation in junction interface cross‐sectional area. Theoretical simulations demonstrated that the decrease of the Sratio would increase the separation efficiency in the hybrid‐chip‐based CE with uniform ζ‐potential distribution. ζ‐potential distribution along the axial direction of the channel also affects mass transport in hybrid‐chip‐based CE. Therefore, the effect of ζ‐potential distribution has been considered in the 3‐D simulation. Theoretical simulation results reveal that ζ‐potential distribution rather than the interface cross‐sectional area variation (Sratio) controls the sample band broadening and manipulates sample separation efficiency in the hybrid‐chip‐based CE with non‐uniform ζ‐potential distribution. Both the theoretical simulations and experimental results show that optimal hybrid‐chip CE separation efficiency can be achieved at Sratio=1.
Novel and highly sensitive mixed‐polymeric electrokinetic chromatography system for determination of contaminants and impurities of heparin samples
Authors: Tripodi Valeria , Flor Sabrina , Dobrecky Cecilia , Contin Mario , Lucangioli Silvia
Published: October 2010

A mixed‐polymeric electrokinetic chromatography system has been developed for the simultaneous determination of a contaminant like oversulfated condroitin sulfate (OSCS) and impurities expressed as dermatan (Der) in heparin (Hep) samples. The EKC system consisted of 0.5% w/v polymeric β‐CD, 0.4% w/v tetronic® 1107 and 400 mM tris‐phosphate buffer at pH 3.5. The optimized electrophoretic conditions included the use of an uncoated‐silica capillary of 50 cm of total length and 75 μm id, an applied voltage of −7 kV, a temperature of 30°C and 200 nm UV‐detection. The highly sensitive method developed showed low values of LOD, 0.07% w/w (0.07 μg/mL) (OSCS) and 0.1% w/w (0.1 μg/mL) (Der), and values of LOQ 0.2% w/w (0.2 μg/mL) (OSCS) and 0.3% w/w (0.3 μg/mL) (Der) with a concentration level of Hep sample as low as 0.1 mg/mL. Additional parameters of validation such as specificity, linearity, accuracy, and robustness were evaluated according to international guidelines. Owing to its simplicity, high sensitivity, and reliability, the proposed method can be an advantageous alternative to the traditional methodologies for the analysis of Hep in raw material and specially in finished products because of the low amounts of Hep sample required.
Multifunctional protein processing chip with integrated digestion, solid‐phase extraction, separation and electrospray
Authors: Wang Can , Jemere Abebaw B. , Harrison D. Jed
Published: October 2010

We describe a microfluidic device in which integrated tryptic digestion, SPE, CE separation and electrospray ionization for MS are performed. The chip comprised of 10×30 μm channels for CE, and two serially connected 150 μm deep, 800 μm wide channels packed with 40 to 60 μm diameter beads, loaded with either immobilized trypsin, reversed‐phase packing or both. On‐chip digestion of cytochrome c using the trypsin bed showed complete consumption of the protein in 3 min, in contrast to the 2 h required for conventional solution phase tryptic digestion. SPE of 0.25 μg/mL solutions of the peptides leu‐enkephalin, angiotensin II and LHRH gave concentration enhancements in the range of 4.4–12, for a ten times nominal volume ratio. A 100 nM cytochrome c sample concentrated 13.3 times on‐chip gave a sequence coverage of 85.6%, with recovery values ranging from 41.2 to 106%. The same sample run without SPE showed only five fragment peaks and a sequence coverage of 41.3%. When both on‐chip digestion and SPE (13.3 volume ratio concentration enhancement) were performed on 200 nM cytochrome c samples, a sequence coverage of 76.0% and recovery values of 21–105% were observed. Performing on‐chip digestion alone on the same sample gave only one significant fragment peak. The above digestion/peptide concentration step was compared to on‐chip protein concentration by SPE followed by on‐chip digestion with solution phase trypsin. Both procedures gave similar recovery results; however, much larger trypsin autodigestion interference in the latter approach was apparent.
Miniature flowing atmospheric‐pressure afterglow ion source for facile interfacing of CE with MS
Authors: Jecklin Matthias C. , Schmid Stefan , Urban Pawel L. , Amantonico Andrea , Zenobi Renato
Published: October 2010

Here, we present a miniaturized version of the flowing atmospheric‐pressure afterglow (miniFAPA) ion source and use it for sheathless coupling of CE with MS. The simple design of the CE‐miniFAPA‐MS interface makes it easy to separate the electric potentials used for CE and for ionization. A pneumatically assisted nebulization of the CE effluent transfers the analytes from the liquid phase into the gas phase before they are ionized by interacting with reactive species produced by the FAPA. An important advantage of this interface is its high stability during operation: optimization of five different parameters indicated that the interface is not sensitive to minor deviations from the optimum values. Other advantages include ease of construction and maintenance, as well as relatively low cost. Samples with complex matrices, such as yeast extract, soil extract and urine, spiked with the test compounds, were successfully analyzed using the CE‐miniFAPA‐MS setup.
Hydrolytic bacteria in mesophilic and thermophilic degradation of plant biomass
Authors: Zverlov Vladimir V. , Hiegl Wolfgang , Köck Daniela E. , Kellermann Josef , Köllmeier Tanja , Schwarz Wolfgang H.
Published: October 2010

Adding plant biomass to a biogas reactor, hydrolysis is the first reaction step in the chain of biological events towards methane production. Maize silage was used to enrich efficient hydrolytic bacterial consortia from natural environments under conditions imitating those in a biogas plant. At 55–60°C a more efficient hydrolyzing culture could be isolated than at 37°C. The composition of the optimal thermophilic bacterial consortium was revealed by sequencing clones from a 16S rRNA gene library. A modified PCR‐RFLP pre‐screening method was used to group the clones. Pure anaerobic cultures were isolated. 70% of the isolates were related to Clostridium thermocellum. A new culture‐independent method for identification of cellulolytic enzymes was developed using the isolation of cellulose‐binding proteins. MALDI‐TOF/TOF analysis and end‐sequencing of peptides from prominent protein bands revealed cellulases from the cellulosome of C. thermocellum and from a major cellulase of Clostridium stercorarium. A combined culture of C. thermocellum and C. stercorarium was shown to excellently degrade maize silage. A spore preparation method suitable for inoculation of maize silage and optimal hydrolysis was developed for the thermophilic bacterial consortium. This method allows for concentration and long‐term storage of the mixed culture for instance for inoculation of biogas fermenters.
Use of the Cone Calorimeter and ConeTools software for development of innovative intumescing graphite systems
Authors: van Hees Patrick , Andersson Petra , Hjohlman Maria , Wenne Nils , Hassan Mohamed Aly
Published: October 2010

The Cone Calorimeter test method has been one of the most used small‐scale fire test method for years now and is at present widely spread over the world. In contrast to many other fire test methods, the Cone Calorimeter provides a range of data with sound scientific basis, which allows a wide range of applications. It can be used for modelling and also for enhanced product development. This paper describes the use of the Cone Calorimeter for the development of new innovative materials in combination with a mathematical model. As example, the cost effective development of an innovative intumescing graphite system for protecting particle board is explained. The performance goal of the project is to obtain the threshold values for a B class in the Single Burning Item (SBI) test method used for the newly developed Euroclass system. The focus of this paper is on the development tools and not on the chemical development of the protective system. During the research it was necessary to develop a new sample holder for the Cone Calorimeter. The results from the project show that the industry can save development time and resources by using the Cone Calorimeter in combination with a simple mathematical model. Copyright © 2010 John Wiley & Sons, Ltd.
Current awareness in flavour and fragrance
Authors:   John Wiley & Sons, Ltd.
Published: October 2010

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of flavour and fragrance. Each bibliography is divided into 7 sections: 1 Flavour of food; 2 Fragrances; 3 Essential oils; 4 Food constituents; 5 Taints & off‐flavours; 6 Sensory evaluation & psychophysics; 7 Apparatus & methodology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted (13 weeks journals. Search ended 6th. Oct. 2010)
Interaction of EC7 with EC2 in tunnelling
Authors: Hofmann Robert , Suda Jürgen , Poisel Rainer
Published: October 2010

Eurocode 7 (EN 1997‐1 (November 2004) + AC (February 2009)) does not specifically mention tunnelling in the scope of application. In the literature, tunnelling is linked with the retaining structures of Eurocode 7. Tunnelling is not covered by Eurocode 2 (Austrian standards ÖNORM EN 1992‐1‐1 and ÖNORM B 1992‐1‐1: 2007 02 01) either. This article discusses the possible interactions of these two Eurocodes and also takes into consideration the Austrian guideline RVS 9.32 (Mai 2004). This guideline has already introduced the partial safety factor concept for reinforced concrete construction and geotechnical engineering.

Im Eurocode 7 (EN 1997‐1 (November 2004) + NAD (Februar 2009)) ist der Tunnelbau im Anwendungsbereich nicht explizit erwähnt. In der Literatur wird der Tunnelbau mit den Stützbauwerken des Eurocodes 7 in Verbindung gebracht. Im Eurocode 2 (ÖNORM EN 1992‐1‐1 und ÖNORM B 1992‐1‐1: 2007 02 01) wird ebenfalls nicht auf den Tunnelbau eingegangen. In diesem Beitrag wird auf mögliche Verbindungsmöglichkeiten dieser beiden Eurocodes hingewiesen. Dies erfolgt unter Berücksichtigung der RVS 9.32 (Mai 2004). In dieser Richtlinie wurde bereits auf das Teilsicherheitskonzept für den Stahlbetonbau und die Geotechnik eingegangen.
Do Eurocodes make a difference?
Authors: Cheung Karen , West Kim , Yeow Hoe , Simpson Brian
Published: October 2010

By 2010, Eurocodes will replace the current British Standards as the primary basis for civil engineering design in the UK. With the introduction of Eurocode 7 Geotechnical design, a very substantial gap in the coverage of the Eurocodes in underground structures including tunnels has now been closed. This paper describes the design of soft ground tunnels using the Eurocodes, reviews some key aspects of these codes in tunnel design and highlight the discussion with examples of recent design cases.

Im Jahre 2010 werden die Eurocodes in Großbritannien die aktuellen Britischen Normen als Grundlage für die Bemessung im Bauingenieurwesen ersetzen. Mit der Einführung des Eurocodes 7 “Entwurf, Berechnung und Bemessung in der Geotechnik” wird nun eine wesentliche Lücke im Geltungsbereich der Eurocodes für unterirdische Bauwerke einschließlich Tunnel geschlossen. Der Beitrag erläutert die Bemessung eines Tunnels im Lockergestein bei Anwendung der Eurocodes, behandelt einige Schwerpunkte dieser Normen hinsichtlich Tunnelbemessung und beleuchtet die Diskussion mit Beispielen aus neueren Entwurfsaufgaben.
Application of the partial safety factor concept for the structural design of tunnels in Germany
Authors: Städing Axel , Krocker Tina
Published: October 2010

The calculation and design of engineering structures in Germany has changed from a global safety factor concept to a partial safety factor concept introducing a number of partial safety factors. The report presents the current rules for transport tunnels and explains the new method of structural design and serviceability by means of a practical example.

Die statische Berechnung und Bemessung von Ingenieurbauwerken in Deutschland ist in den letzten Jahren von einem Globalsicherheitskonzept mit einem einzigen Sicherheitsbeiwert auf ein Teilsicherheitskonzept mit zahlreichen Teilsicherheitsbeiwerten umgestellt worden. Der Bericht stellt die maßgebenden Regelwerke für Verkehrstunnel vor und erläutert die neuen Tragfähigkeits‐ und Gebrauchstauglichkeitsnachweise an einem praxisnahen Beispiel.
Nonlinear FE‐analysis of tunnel excavation – comparison of EC7 design approaches
Authors: Schweiger Helmut F. , Marcher Thomas , Nasekhian Ali
Published: October 2010

Although Eurocode 7 does not mention tunnelling explicitly it is under discussion amongst practitioners to what extent the principles of EC7 can be applied to the design of tunnels. In EC7 three different design approaches, which differ in the application of partial factors on actions, soil strength and resistance, have been established. A characteristic feature of tunnelling is that the surrounding soil or rock represents loading and support for tunnel, similar to deep excavation problems. In addition, the highly nonlinear behaviour of shotcrete linings needs special attention and therefore care must be taken when choosing partial factors of safety. In this contribution the applicability of the different design approaches for tunnelling employing numerical methods are investigated and the differences obtained are discussed. Two examples are presented, namely a station tunnel in soil and a tunnel in rock, both constructed based on NATM principles.

Obwohl Tunnelbau im Eurocode 7 nicht explizit erwähnt wird, steht zur Diskussion, ob der EC7 prinzipiell auch für die Bemessung im Tunnelbau anwendbar ist. Im EC7 sind drei Nachweisverfahren definiert, die sich in der Anwendung der Teilsicherheitsfaktoren auf Einwirkungen, Widerstände und Bodenkennwerte unterscheiden. Ein wesentlicher Aspekt im Tunnelbau ist, dass der Baugrund sowohl Einwirkung als auch Widerstand sein kann, und somit sind Parallelen zur Bemessung von Baugruben gegeben. Zusätzlich kommt hinzu, dass das mechanische Verhalten von Spritzbeton hochgradig nichtlinear ist, was bei der Wahl der Teilsicherheitsbeiwerte beachtet werden muss. In diesem Beitrag wird die Anwendbarkeit der unterschiedlichen Nachweisverfahren des EC7 für den Tunnelbau bei Anwendung numerischer Methoden untersucht und die Unterschiede in den Ergebnissen aufgezeigt. Zwei Beispiele wurden gewählt, ein Stationstunnel im Lockergestein und ein Tunnel im Fels, beide nach der Neuen Österreichischen Tunnelbauweise aufgefahren.
Is the OeGG guideline for geotechnical design compatible with the EC7?
Authors: Schubert Wulf
Published: October 2010

The Austrian Society for Geomechanics has published a guideline for the geotechnical design for underground structures with conventional excavation in 2001, which was revised in 2008. The guideline clearly focuses on the observational approach due to the uncertainties in the ground model and ground parameters in the design stage. In this paper the requirements stipulated in the Eurocode regarding the observational method are compared to the respective formulations in the guideline.

Die Österreichische Gesellschaft für Geomechanik hat 2001 erstmals eine Richtlinie für die geotechnische Planung von Untertagebauten mit konventionellem Vortrieb herausgegeben, die 2008 nach Überarbeitung neu aufgelegt wurde. Die Richtlinie konzentriert sich wegen der vielen Unsicherheiten im Baugrundmodell und den Baugrundeigenschaften klar auf die Beobachtungsmethode. Die Anforderungen im Eurocode 7 bezüglich der Beobachtungsmethode werden in diesem Beitrag den Ausführungen in der ÖGG‐Richtlinie gegenübergestellt.
Requirements for the observational approach in deep tunnelling
Authors: Schubert Peter
Published: October 2010

The author shortly reviews the requirements of the Eurocode 7 regarding the Observational Method for use during tunnel construction. The particularities and problems of applying the Observational Method at deep tunnels are listed. A recommendation is given to improve the situation and to bring the approaches used in normal ground engineering problems and deep tunnels closer together.

Zunächst werden die Anforderungen des Eurocodes 7 hinsichtlich der Anwendung der Beobachtungsmethode im Tunnelbau kurzbetrachtet. Anschließend werden die Besonderheiten und Probleme bei deren Anwendung bei tiefliegenden Tunneln analysiert. Dabei zeigen sich wesentliche Unterschiede zu anderen bodenmechanischen Anwendungen. Schließlich werden Empfehlungen gegeben, wie die Anwendung der Beobachtungsmethode verbessert und die Vorgangsweisen vereinheitlicht werden können.
New Semmering Base Tunnel – the investigation programme 2008/2009 and the knowledge gained in the areas of geology, hydrogeology and geotechnical engineering /
Authors: Fasching Alfred , Vanek Robert , Stadlmann Thomas , Reichl Peter , Domberger Gunnar , Forstinger Gerhard , Wagner Oliver K.
Published: October 2010

After the completion of the route selection process for the ÖBB New Semmering Base Tunnel rail project, a geological, hydrogeological and geotechnical investigation programme was developed for the chosen “Pfaffensattel” route and implemented in 2008/2009. The programme included drilling cores with an extensive programme of geophysical, geotechnical and hydraulic borehole investigations, geophysical measurements on the surface and laboratory testing to determine geological, hydrogeological and geotechnical parameters. The results of this investigation programme and the knowledge gained form the basis for the specialist contributions for the production of the environmental impact assessment and also the documents required for the application under the Railway Law.

Im Anschluss an das Trassenauswahlverfahren für das ÖBB Bahnprojekt Semmering‐Basistunnel neu wurde für die gewählte Trasse “Pfaffensattel” ein geologisches, hydrogeologisches und geotechnisches Erkundungsprogramm entwickelt und im Zeitraum 2008/2009 umgesetzt. Dieses Erkundungsprogramm setzte sich aus Kernbohrungen mit einem umfangreichen geophysikalischen, geotechnischen und hydraulischen Bohrlochversuchsprogramm, geophysikalischen Oberflächenmessungen sowie einem Laborprogramm zur Ermittlung geologischer, hydrogeologischer und geotechnischer Parameter zusammen. Die Ergebnisse und die daraus resultierenden Erkenntnisse dieses Untersuchungsprogramms bilden die Grundlage für die fachspezifischen Beiträge zur Erstellung der Umweltverträglichkeitserklärung sowie der Einreichunterlagen nach Eisenbahngesetz.
New Semmering Base Tunnel – the current state of tunnel design taking the newest investigation results into account /
Authors: Daller Josef , Vigl Alois , Wagner Oliver K.
Published: October 2010

As result of the two‐year route selection process, the southernmost variant Pfaffensattel was chosen in April 2008 as the best variant for the New Semmering Base Tunnel, which run from Gloggnitz to the Mürzzuschlag‐Langenwang area, and the route has since been optimised for design through a detailed programme of investigations. As a result of this, the final route of the tunnel was fixed in autumn 2009. All design work for the partially concentrated approvals process are now based on this route.

This article is concerned with the essential technical tunnel construction aspects of the design to be handed in for approval, above all the construction concept and the procedure for geotechnical design to be used as a basis. At the time of writing this article, the final evaluation of the geomechanical and hydrogeological investigations and the geotechnical design are still underway.

Als Ergebnis eines rund zweijährigen Trassenauswahlverfahrens wurde im April 2008 die südlichste Variante Pfaffensattel als die beste Variante für den Semmering‐Basistunnel neu, der zukünftig Gloggnitz mit dem Raum Mürzzuschlag‐Langenwang verbinden soll, ausgewählt und seither im Rahmen der Maßnahmenplanung mit einem detaillierten Erkundungsprogramm optimiert. Als Ergebnis konnte die endgültige Lage des Tunnels im Herbst 2009 fixiert werden. Auf dieser Trasse bauen nun sämtliche Planungen für das teilkonzentrierte Genehmigungsverfahren auf.

Der gegenständliche Beitrag befasst sich mit den wesentlichen tunnelbautechnischen Aspekten für die Einreichplanungen, allen voran das zugrunde liegende Baukonzept sowie dem prinzipiellen Vorgehen in der geotechnischen Planung. Zum Zeitpunkt der Erstellung dieses Beitrags lag das geologische Baugrundmodell weitgehend vor, die endgültige Auswertung der geomechanischen und hydrogeologischen Untersuchungen sowie die geotechnische Planung waren jedoch noch im Gang.
The ventilation and tunnel safety concept for the New Semmering Base Tunnel /
Authors: Bopp Rudolf , Neumann Christof , Langner Verena , Wagner Oliver K.
Published: October 2010

For the conception of the emergency ventilation and the design of the ventilation system for the New Semmering Base Tunnel, particular demands apply, which are based on specific protection objectives and defined in the Tunnel Safety Concept. The main objective is to keep the safe areas (the refuge room at the emergency station, opposite tube, portals) free of smoke. This paper deals with the Safety Concept and the tunnel ventilation. A methodical approach was applied to prevent single critical scenarios being weighted too heavily in the design of the ventilation equipment. This achieved an optimisation of the entire system instead of designing the ventilation system for isolated extreme scenarios.

Für die Konzeption der Ereignisfalllüftung und für die Bemessung der Lüftungsanlagen für den Semmering‐Basistunnel neu gelten besondere Anforderungen, die auf spezifischen Schutzzielen basieren, die im Tunnelsicherheitskonzept definiert sind. Im Vordergrund steht dabei das Ziel, die sicheren Bereiche (Warteraum der Nothaltestelle, Gegenröhre, Portale) rauchfrei zu halten. Der Beitrag behandelt das Sicherheitskonzept und die Tunnellüftung. Durch einen methodischen Ansatz wird verhindert, dass bei der Bemessung der Lüftungsanlagen einzelne kritische Szenarien zu stark gewichtet werden. Anstatt das Lüftungssystem auf einzelne Extremszenarien zu bemessen wird so eine Optimierung des Gesamtsystems erreicht.
Solution methods for the design and construction of contract KAT3 of the Koralm Tunnel /
Authors: Handke Dieter , Nolden Mario , Mussger Klaus , Steidl Arnold
Published: October 2010

The very variable geological conditions require two completely independent machine concepts for contract KAT3 of the Koralm Tunnel, which have been taken into account with the planned use of a shield machine capable of being rebuilt. This article discusses the essential constructional requirements for machinery and construction methods based on the current state of design and knowledge.

Die stark variierenden geologischen Verhältnisse erfordern für das Baulos KAT3 des Koralmtunnels zwei komplett eigenständige Maschinenkonzepte, die planerisch durch das Lösungskonzept einer umbaubaren Schildmaschine berücksichtigt werden. In dem Beitrag werden auf Basis des derzeitigen Planungs‐ und Kenntnisstands die wesentlichen konstruktiven Anforderungen an die Maschinen‐ und Verfahrenstechnik dargelegt.
New development of a crack‐limited invert slab /
Authors: Vill Markus , Schweighofer Anton , Pichler Walter , Wagner Hanns , Huber Helmut , Kollegger Johann
Published: October 2010

In the course of the design work of an Austrian railway tunnel, an extensive efficiency raising campaign was carried out by ÖBBInfrastruktur AG, the construction arm of Austrian Railways, which resulted in innovations to the conventional system of constructing the invert slab of waterproof concrete to seal against service water. According to the requirements for rail tunnels, a waterproof invert slab has to be constructed to prevent water from getting into the drainage pipe and thus prevent contact with formation water. In the conventional construction, this necessitates an umbrella waterproofing in the vault and a reinforced invert slab according to the ÖVBB guidelines.

The slab is subject to constraints arising from the discharge of the heat of hydration, from temperature differences and from shrinkage processes. Therefore, a high ratio of reinforcement is normally required. This led to the consideration whether for economic reasons and under the special conditions of this project it would be possible to reduce or even leave out the high percentage of reinforcement steel completely. For this reason, a comprehensive testing program with laboratory tests, a full‐scale test as well as analytical and numerical investigations carried out to verify the practical applicability of this innovative system.

Im Rahmen eines umfassenden Effizienzsteigerungsprogrammes seitens der ÖBB‐Infratruktur AG wurde die Untersuchung eines neuartigen Sohlplattensystems für Eisenbahntunnel initiiert. Bei dem Sohlplattensystem handelt es sich um eine dichte Betonplatte, die ein Eindringen von Betriebswässern in die Drainageleitung des Tunnels verhindern soll. Im Regelfall erfordert dies eine Regenschirmabdichtung im Gewölbebereich und eine bewehrte Sohlplatte gemäß Richtlinie Innenschalenbeton der ÖVBB.

In dem Zusammenhang ist eine rissbreitenbeschränkende Bewehrung notwendig, die ein Auftreten von wasserführenden Rissen verhindert und einen hohen Bewehrungsgrad ergibt, da die Platte unter Zwangsspannungen aus unterschiedlichen Einflüssen steht. Aufbauend darauf wurde bei den speziellen Randbedingungen dieses Projektes überlegt, den hohen Anteil an Bewehrungsstahl zu reduzieren oder gänzlich wegzulassen. Durch die betontechnologisch günstigen Eigenschaften der Gesteinskörnungen, die bei dem Projekt zur Verwendung kommen, ergeben sich Vorteile, die eine neuartige Ausbildung der Sohlplatte ermöglichen. Aus diesem Grund wurden umfangreiche Untersuchungen mit Labortests, einem maßstäblichen Großversuch sowie analytischen und numerischen Berechnungen durchgeführt um die praktische Einsetzbarkeit der Innovation zu verifizieren.
Improvement of the safety and profitability of tunnel drives through the use of automated measurement and alarm systems – examples in practice /
Authors: Chmelina Klaus , Rabensteiner Klaus
Published: October 2010

The article describes current examples of the application of automatic surveying and alarm systems, with a closer description of the systems installed in the Mitterpichling West investigation tunnel for the Koralm Tunnel, the Tyne Tunnel project and in the metro projects in Budapest, Athens und Thessaloniki. The contribution such systems could make to improve the safety and costeffectiveness of tunnel drives is looked into in general. Finally, two visionary research projects are presented.

Im Beitrag werden aktuelle Ausführungsbeispiele automatisierter Mess‐ und Alarmsysteme erläutert, wobei auf die installierten Systeme im Erkundungstunnel Mitterpichling West des Koralmtunnels, im Projekt Tyne Tunnel und in den U‐Bahnprojekten in Budapest, Athen und Thessaloniki näher eingegangen wird. Der Beitrag, den derartige Systeme zur Verbesserung der Sicherheit und Wirtschaftlichkeit von Vortrieben leisten können, wird allgemein erörtert. Abschließend wird über zwei visionäre Forschungstrends zu diesem Thema informiert.
Innovative solutions for driving cross passages in bored tunnels with segmental lining /
Authors: Mayer Peter‐Michael , Frodl Stephan , Friedemann Wolf , Jouaux Rainer
Published: October 2010

Construction time and project risks in mechanized tunnelling are determined to a great extent by the number and difficulty of the cross passages and emergency exits. This article presents innovative solutions that lead to more flexibility in ground freezing measures, enable a high‐quality watertight connection between the cross passage and the running tunnels and permit the simple coupling of segments under high overburden pressures. Either experience from completed projects or results of tests on construction elements is available for the proposed solutions.

Bauzeit und Projektrisiken bei maschinellen Tunnelvortrieben werden maßgeblich von der Anzahl und dem Schwierigkeitsgrad der herzustellenden Querschläge und Notausstiege bestimmt. Im vorliegenden Beitrag werden innovative Lösungen vorgestellt, die zu höherer Flexibilität bei Vereisungsmaßnahmen führen, einen hochwertigen Dichtungsanschluss zwischen Querschlag und Haupttunnel erlauben und eine einfache Tübbingkopplung bei hohen Gebirgslasten gestatten. Für die vorgeschlagenen Lösungen liegen entweder bereits Erfahrungswerte aus Ausführungsprojekten oder Ergebnisse von Bauteilversuchen vor.
Requirements for ground investigations in shield tunnelling /
Authors: Placzek Dietmar
Published: October 2010

The success of a tunnel project depends on successfully overcoming the ground conditions and the geological risks. Despite this basic fact, the production of technical regulations and guidelines, the further development of machine technology and improving methods of surveying and control, mishaps still often occur during tunnel drives, affecting either the tunnel itself or the surroundings, e.g. existing infrastructure or buildings. The causes are often multifaceted but can almost always be attributed to the existing ground conditions, which had not been appropriately determined, described, or considered in the design, or taken into account during construction. The following explanations describe the risks inherent in ground conditions and show how these risks can be countered by appropriate ground investigations for tunnelling.

Der Erfolg eines Tunnelvortriebs hängt von der sicheren Beherrschung des Baugrunds und der hierin liegenden Risiken ab. Trotz dieser grundlegenden Erkenntnis, der Erarbeitung von technischen Vorschriften und Richtlinien, der Weiterentwicklung der Maschinentechnik sowie einer verfeinerten Mess‐ und Steuerungstechnik kommt es immer Tunnelvortrieb wieder beim zu Schäden, die entweder unmittelbar den Vortrieb selbst oder das Umfeld, z. B. bestehende Infrastruktur oder Bauwerke, betreffen. Die Ursachen sind häufig vielfältiger Natur, lassen sich aber überwiegend auf die vorherrschenden Baugrundverhältnisse zurückführen, die entweder nicht zutreffend ermittelt, beschrieben, planerisch umgesetzt oder ausführungstechnisch berücksichtigt wurden. Die nachfolgenden Ausführungen beschreiben die im Baugrund vorhandenen Risiken und zeigen auf, wie diesen Risiken durch gezielte Baugrunduntersuchungen für den Tunnelbau begegnet werden kann.