bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interaction of ground, TBM and segment lining with closed shield machines /
Authors: Göbl Arthur 
Published: October 2010

AbstractThe article explains the interaction of the overall system of ground, TBM and segment lining based on recent experience of projects using TBMs with active face support in Austria and abroad. The alternating dependencies and their consequences for tunnel construction are discussed in more detail. Of particular interest is the influence of the support medium and how it functions at the face and the tunnel side walls. The interaction of support pressure, thrust force and the centre of gravity of the TBM and its effect on steering behaviour are also considered. The effects of the compression of the segment tube by the TBM (prestress) are considered in relation to the improvement of the bedding and the problem of floating.Der Beitrag beleuchtet die Interaktion des Gesamtsystems “Untergrund – Tunnelvortriebsmaschine – Tübbingausbau” basierend auf aktuellen Erfahrungen zuletzt realisierter Projekte im In‐ und Ausland bei TVM‐Einsätzen mit aktiver Ortsbruststützung. Dabei wird insbesondere auf die wechselweisen Abhängigkeiten und deren Auswirkungen auf die Tunnelherstellung eingegangen. Ein Schwerpunkt liegt beim Einfluss des Stützmediums und der zugehörigen Wirkungsweise an der Ortsbrust und der Tunnellaibung. Berücksichtigung findet die Wechselwirkung von Stützdruck, Vortriebskraft und der Schwerpunktlage der TVM auf deren Steuerverhalten. Die Auswirkung des Zusammendrückens der Tübbingröhre durch die TVM (Vorspannung) wird in Bezug auf die Bettungsverbesserung und die Problematik des Aufschwimmens betrachtet.
Tunnelling in swelling rock – a solved problem? /
Authors: Zettler Alfred , Poisel Rainer , Preh Alexander , Konietzky Heinz 
Published: October 2010

AbstractIn some sedimentary rocks, the admission of water results in an expansion of volume, which results from the chemical conversion of anhydrite into gypsum (anhydrite swelling) or the physical adsorption of water in certain clay minerals (clay swelling). This expansion leads to heavy loading of the tunnel lining and has already caused significant damage to some structures. In addition, sulphate attack on the lining concrete can lead to softening due to the formation of ettringite. Damage can be in the form of shear failure, spalling or bending tension cracks. The location and nature of the damage, which depends on the location of the ground containing clay or anhydrite and susceptible to swelling, is illustrated with some examples. Numerical modelling is applied to demonstrate the load transfers, which lead to these phenomena. Recent attempts to counter the problem have been based on the strengthening of the lining (resistance principle) or by installing compressible zones between rock mass and lining (yielding principle). The design rules for each principle are explained.Bei einigen Sedimentgesteinen ereignet sich bei Wasserzutritt eine Volumenzunahme, die eine Folge der chemischen Umwandlung von Anhydrit in Gips (Schwellen) oder der physikalischen Anlagerung von Wasser an bestimmte Tonminerale (Quellen) ist. Diese Volumenzunahme führt zu starken Beanspruchungen der Tunnelauskleidung und hatte bei einigen Bauwerken bedeutende Schäden zur Folge. Darüber hinaus führt ein möglicher Sulfatangriff auf den Auskleidungsbeton zur Entfestigung durch Ettringitbildung. Diese Schäden können Scherbrüche, Abplatzungen und Biegezugrisse sein. Ort und Art der Schäden in Abhängigkeit vom Ort der quellenden bzw. schwellenden Gebirgsbereiche werden anhand einiger Beispiele aufgezeigt. Mittels numerischer Untersuchungen wird ein Einblick in die Lastumlagerungen gegeben, die zu den genannten Phänomenen führen. In neuerer Zeit wurde versucht, den Schäden einerseits durch eine Verstärkung der Auskleidung (Widerstandsprinzip) und andererseits durch nachgiebige Zonen zwischen Gebirge und Ausbau (Nachgiebigkeitsprinzip) zu begegnen. Die Entwurfsgrundsätze für diese Prinzipien werden dargelegt.
Chienberg Tunnel: Rehabilitation using yielding elements of the section in Keuper sediments affected by heave /
Authors: Chiaverio Flavio , Thut Arno 
Published: October 2010

AbstractRocks containing clay and anhydrite exhibit the property of increasing their volume by absorbing water. The paper first discusses the mechanisms causing swelling and outlines their effects on tunnels. Next the hazard scenario of heaving of the tunnel tube as a whole, the structural consequences of this and the concept of the Modular Yielding System for tunnelling in stretches where heave is unavoidable are discussed. Taking the case of the Chienberg road tunnel in Switzerland, the paper also reports on experience during construction and field measurements after putting the repaired sections into operation. Special attention is given to the technical aspects of yielding supports with cement as a basic constituent for loads up to 10 MN and a yielding capacity of up to 50 %.Ton‐ und anhydritführende Gesteine haben die Eigenschaft, ihr Volumen durch Aufnahme von Wasser zu vermehren. Der Beitrag behandelt einleitend die Mechanismen, die den Quellvorgang auslösen und die Auswirkungen des Quellvorgangs auf Tunnel. Anschließend wird das Gefährdungsbild der Hebungen der Tunnelröhre als Ganzes, deren Folgen auf die Tragkonstruktion und das Konzept des modularen Knautschsystems] für den Tunnelbau in unvermeidbaren Hebungsstrecken erörtert. Am Beispiel des Chienbergtunnels in der Schweiz wird auch über Bauerfahrung und Feldmessungen nach der Inbetriebnahme der sanierten Strecken berichtet. Besondere Aufmerksamkeit wird den technischen Merkmalen von Knautschkörpern auf Zementbasis für Belastungen von bis zu 10 MN und einem Stauchvermögen von bis zu 50 % gewidmet.
A9 Bosruck Tunnel – design approaches for swelling rock /
Authors: Lenz Franz , Marcher Thomas , Neumayr Thomas 
Published: October 2010

AbstractConstruction works were started for the 2nd tube of the Bosruck road tunnel on the A9 Pyhrn motorway in December 2009, as part of the ongoing upgrade to full motorway standard by ASFINAG. In the course of the more than 100‐year history of tunnelling under the Grosse Bosruck, this tunnel is the fourth tunnel to be built in this part of the central mountain range of the Eastern Alps. The 4,766 m long single‐track railway tunnel was constructed between 1901 and 1906, the ventilation and drainage tunnel for the road tunnel between 1978 and 1980, and the approximately 5,500 m long road tunnel for two‐way traffic was constructed between 1980 and 1983.Soon after being opened for traffic, substantial damage became apparent in the road tunnel. It was only possible to maintain operation by means of continuous and costly rehabilitation measures. In 2005, the extent of damage finally led to the decision to add a second tube to the road tunnel and to carry out a general rehabilitation of the existing tube of the road tunnel. The main conclusions regarding the swelling and squeezing behaviour drawn from the damage that had occurred in the first tube of the road tunnel were exploited for the design and construction of the second tube and are the subject of this paper.Im Dezember 2009 wurde im Rahmen des laufenden Vollausbauprogramms der ASFINAG mit den Bauarbeiten für die zweite Röhre des Bosruck Straßentunnels der A9 Pyhrn Autobahn begonnen. Dabei handelt es sich in der über hundertjährigen Geschichte des Tunnelbaues am großen Bosruck um den vierten Tunnel, der in diesem Abschnitt des Ostalpenhauptkamms errichtet wird. Der eingleisige 4.766 m lange Eisenbahntunnel wurde 1901 bis 1906, der Lüftungs‐ und Entwässerungsstollen für den Straßentunnel 1978 bis 1980 und die 5.500 m lange Oströhre des Straßentunnels 1980 bis 1983 errichtet. Bald nach der Inbetriebnahme kam es im Straßentunnel zu massiven Schäden. Der Betrieb konnte nur durch aufwändige laufende Sanierungsmaßnahmen aufrecht erhalten werden. Der Schadensverlauf führte letztendlich im Jahr 2005 zur Entscheidung des vorzeitigen Vollausbaus und der anschließenden Generalsanierung der bestehenden Röhre des Straßentunnels. Die wesentlichen geomechanischen Schlüsse hinsichtlich des quellenden und druckhaften Gebirgsverhaltens, die aus den Schadensbildern der ersten Röhre des Straßentunnels für die Errichtung der zweiten Röhre gezogen werden können, sind Gegenstand dieses Beitrags.
Postoperative myocardial injury after major head and neck cancer surgery
Authors: Nagele Peter , Rao Lesley K. , Penta Mrudula , Kallogjeri Dorina , Spitznagel Edward L. , Cavallone Laura F. , Nussenbaum Brian , Piccirillo Jay F. 
Published: October 2010

AbstractBackground.Patients with head and neck cancer often have multiple risk factors for coronary artery disease. Yet, little is known about the incidence of postoperative myocardial injury after major head and neck cancer surgery and its clinical relevance. The aim of this study was to determine the risk of postoperative myocardial injury in patients undergoing major head and neck cancer surgery.Methods.This was a retrospective cohort study of all patients who underwent major head and neck cancer surgery (n = 378) at a single major academic center from April 2003 to July 2008. Peak postoperative troponin I (TnI) concentration was the primary outcome.Results.Of 378 patients who underwent major head and neck cancer surgery, 57 patients (15%) had development of an elevated TnI; 90% of these occurred within the first 24 hours after surgery. Preexisting renal insufficiency (unadjusted OR [OR]: 4.60; 95% CI 1.53–13.82), coronary artery disease (OR: 2.33; 95% CI 1.21–4.50), peripheral vascular disease (OR: 2.83; 95% CI 1.31–6.14), hypertension (OR: 2.22; 95% CI 1.20–4.12), and previous combined chemotherapy and radiation (OR: 2.68; 95% CI 1.04–6.91) were associated with elevated postoperative TnI levels. Patients with elevated TnI levels had a significantly longer length of stay in the hospital (8.5 vs 10.1 days; p = .014) and ICU (3 vs 4.5 days; p = .001) and an 8‐fold increased risk of death at 60 days after surgery (adjusted OR: 8.01, 95% CI 2.03–31.56). At 1 year, patients with an abnormal postoperative TnI level were twice as likely to die (OR 1.93; 95% CI 1.02–3.63).Conclusions.Patients who undergo major head and neck cancer surgery are at significant risk for postoperative myocardial injury, which is a strong predictor of 60‐day mortality after surgery. Monitoring of myocardial injury during the first postoperative days, as well as optimizing preventive cardiac care, may be helpful to reduce postoperative mortality rates. Head Neck, 2011
Warnings in manufacturing: Improving hazard‐mitigation messaging through audience analysis
Authors: Goldsworthy Richard C. , Mayhorn Christopher B. , Meade Adam W. 
Published: October 2010

AbstractHazard mitigation, including warning development, validation, and dissemination, is an important aspect of product safety and workplace and consumer protection. Understanding our audiences—workers and consumers—is an especially important, often overlooked, aspect of risk and harm reduction efforts. In this article, particular attention is paid to audience analysis in hazard communication and warning messaging, with a focus on the potential role of latent class analysis (LCA). We provide an example of using LCA to analyze a hazardous behavior: prescription medicine sharing and borrowing. Four distinct groups of people—ranging from abstainers to at‐risk sharers—are identified and discussed. Building better warnings and risk communication techniques is essential to promoting occupational and consumer safety. Audience analysis is a vital component of these efforts. LCA appears to be a worthwhile addition to our analytical toolbox by allowing risk reduction and hazard‐mitigation efforts to tailor interventions to a diverse target audience. © 2010 Wiley Periodicals, Inc.
A new semiempirical kinetic method for the determination of ion exchange constants for counterions of cationic micelles: Study of the rate of pH‐independent hydrolysis of phthalimide as the kinetic probe
Authors: Khan M. Niyaz , Sinasamy Sharmilah 
Published: October 2010

AbstractPseudo‐first‐order rate constants (kobs) for pH‐independent hydrolysis of phthalimide (1), obtained at a constant total concentration of cetyltrimethylammonium bromide and hydroxide ([CTABr]T), 2.0 × 10−4 M 1, 0.02 M MOH (M+ = Li+, Na+ and K+) and various concentrations of inert salt MX (= LiCl, LiBr, NaCl, NaBr, KCl and KBr), follow a relationship derived from the pseudophase micellar (PM) model coupled with an empirical equation. This relationship gives empirical constants, FX/S and KX /S, with S representing anionic 1. The magnitude of FX/S is the measure of the fraction of micellized anionic 1 (S−M) transferred to the aqueous phase by the limiting concentration of X−. The value of KX/S is the measure of the ability of the counterions (X−) to expel the reactive counterions (S−) from the cationic micellar surface to the aqueous phase. The values of FX/ S are ∼ 1 for MBr (M+ = Li+, Na+ and K+) and in the range ⩽ 0.7 to ⩾ 0.5 for MCl (M+ = Na+ and K+) at 0.006, 0.010 and 0.016 M CTABr. For LiCl, the values of FX/S become ∼1 at 0.006 and 0.010 M CTABr and 0.8 at 0.016 M CTABr. The values of the empirical constants, FX/S and KX/S, have been used to determine the usual ion exchange constant (KClBr). The mean values of KClBr are 3.9 ± 0.5, 2.7 ± 0.1, and 2.6 ± 0.3 for LiX, NaX, and KX, respectively. These values of KClBr are comparable with those obtained directly by other physicochemical techniques. Thus, this new method for the determination of ion exchange constants for various counterions of cationic micelles may be considered as a reliable one. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 9–20, 2011
Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI
Authors: Sakellariou Dimitris , Hugon Cédric , Guiga Angelo , Aubert Guy , Cazaux Sandrine , Hardy Philippe 
Published: October 2010

AbstractWe introduce a cylindrical permanent magnet design that generates a homogeneous and strong magnetic field having an arbitrary inclination with respect to the axis of the cylinder. The analytical theory of 3 D magnetostatics has been applied to this problem, and a hybrid magnet structure has been designed. This structure contains two magnets producing a longitudinal and transverse component for the magnetic field, whose amplitudes and homogeneities can be fully controlled by design. A simple prototype has been constructed using inexpensive small cube magnets, and its magnetic field has been mapped using Hall and NMR probe sensors. This magnet can, in principle, be used for magic angle field spinning NMR and MRI experiments allowing for metabolic chemical shift profiling in small living animals. Copyright © 2010 John Wiley & Sons, Ltd.
Magnetization transfer ratio mapping of intervertebral disc degeneration
Authors: Wang Chenyang , Witschey Walter , Goldberg Ari , Elliott Mark , Borthakur Arijitt , Reddy Ravinder 
Published: October 2010

AbstractThe magnetization transfer ratio of the lumbar discs was spatially quantified from age‐matched subjects and the nucleus pulposus magnetization transfer ratio was correlated with T2‐weighted Pfirrmann grades. A moderate and significant linear correlation between magnetization transfer ratio and Pfirrmann grades was observed, suggesting that nucleus pulposus collagen relative density increases with degeneration. High‐resolution axial magnetization transfer ratio maps revealed elevated magnetization transfer ratio in the nucleus pulposa of injured and heavily degenerated discs. In the injured disc, significant elevation in nucleus pulposa magnetization transfer ratio was not accompanied by significant decrease in disc height. This observation may suggest a possible increase in absolute collagen content, in addition to increased collagen relative density. In summary, magnetization transfer MRI of the disc may serve as a noninvasive diagnostic tool for disc degeneration, in addition to other MRI techniques specific to proteoglycan content. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Low‐power adiabatic sequences for in vivo localized two‐dimensional chemical shift correlated MR spectroscopy
Authors: Andronesi Ovidiu C. , Ramadan Saadallah , Mountford Carolyn E. , Sorensen A.Gregory 
Published: October 2010

AbstractNovel low‐power adiabatic sequences are demonstrated for in vivo localized two‐dimensional correlated MR spectroscopy, such as correlated spectroscopy and total correlated spectroscopy. The design is based on three new elements for in vivo two‐dimensional MRS: the use of gradient modulated constant adiabaticity GOIA‐W(16,4) pulses for (i) localization (correlated spectroscopy and total correlated spectroscopy) and (ii) mixing (total correlated spectroscopy), and (iii) the use of longitudinal mixing (z‐filter) for magnetization transfer during total correlated spectroscopy. GOIA‐W(16,4) provides accurate signal localization, and more importantly, lowers the SAR for both total correlated spectroscopy mixing and localization. Longitudinal mixing improves considerably (fivefolds) the efficiency of total correlated spectroscopy transfer. These are markedly different from previous 1D editing total correlated spectroscopy sequences using spatially nonselective pulses and transverse mixing. Fully adiabatic (adiabatic mixing with adiabatic localization) and semiadiabatic (adiabatic mixing with nonadiabatic localization) methods for two‐dimensional total correlated spectroscopy are compared. Results are presented for simulations, phantoms, and in vivo two‐dimensional spectra from healthy volunteers and patients with brain tumors obtained on 3T clinical platforms equipped with standard hardware. To the best of our knowledge, this is the first demonstration of in vivo adiabatic two‐dimensional total correlated spectroscopy and fully adiabatic two‐dimensional correlated spectroscopy. It is expected that these methodological developments will advance the in vivo applicability of multi(spectrally)dimensional MRS to reliably identify metabolic biomarkers. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Computational fluid dynamics applied to the aerodynamic design of a land‐based supersonic vehicle
Authors: Evans B.J. , Hassan O. , Jones J.W. , Morgan K. , Remaki L. 
Published: October 2010

AbstractThe BLOODHOUND SSC project was publicly announced in October 2008, with a primary engineering objective of designing, constructing and running a vehicle capable of achieving a speed of 1000 mph on land. The aerodynamic design of this vehicle is to be accomplished using computational simulation only and this paper describes the development and application of the approach adopted. The computational model employs a cell vertex finite volume algorithm for the solution of compressible viscous flow problems on unstructured hybrid meshes. A one equation turbulence model is adopted and the solution of the steady flow equations is obtained by explicit relaxation. For the combination of high Mach number, complex geometry and complex boundary conditions, involving rotating surfaces and a rolling ground, a consistent HLLC numerical flux function is adopted to ensure a stable procedure. To illustrate the impact of the approach upon the final configuration, a number of simulations undertaken to aid the aerodynamic design are described. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010
Do quality perceptions of health and social services vary for different ethnic groups? An empirical investigation
Authors: Bandyopadhyay Subir K. , Pardasani Manoj 
Published: October 2010

AbstractThe United States is now more ethnically diverse than any other time in its history. In 2000, minority ethnic groups comprised 26% of the US population; by 2010, they comprise 35%, and in 2080 they will form the majority of American citizens. And among these ethnic groups, African Americans (12.4%), Hispanics (15.4%) and Asians (4.4%) were the most predominant in 2000.The growth of this segment of the population is not only in terms of numbers but also in terms of economic development. Minority groups are showing marked improvement in income and education levels leading to greater purchasing power. As a result, for‐profit companies are increasingly targeting minority populations with products and promotions specifically designed for specific minority groups. Even non profit organizations such as educational programs, social service and healthcare agencies are striving to design specific services and culturally competent outreach models in order to serve this increasingly diverse marketplace. But despite the strides made by non profit agencies, several studies note the tremendous disparities between the ethnic and racial groups in the seeking and the receipt of health‐care and social services. Additionally, there is limited empirical information about the perceptions of minority consumers. In order to effectively serve minority groups, it is essential to understand their experiences with the non profit service industry and to assess their ongoing concerns.In this study, we focus on two critical components of the non profit world – healthcare and social services. We conducted a survey to compare and contrast the social service and health‐care quality perceptions of three ethnic groups: Caucasians, African‐Americans and Hispanics. Our study, undertaken in collaboration with community health centers, reveals distinct differences in perceptions between the three ethnic groups. Based on our findings, we outline a set of implementable strategies for social service and community health organizations. Copyright © 2010 John Wiley & Sons, Ltd.
“Music to our ears”: understanding why Canadians donate to arts and cultural organizations
Authors: Barnes Martha L. 
Published: October 2010

AbstractThe contribution of donations and volunteer time to North American arts and cultural organizations is impressive. Growing economic uncertainty coupled with the increasingly competitive nature of philanthropic work and fluctuating volunteerism rates describe some of the challenges facing nonprofit managers in the arts and cultural field today. The intent of this study was to explain charitable giving to an arts and cultural organization in a Canadian context using variables supported in the literature related to philanthropic behavior. The variables included the norm of social responsibility, donor benefits, philanthropic behavior, and household income. Data (233 questionnaires) were collected at a renowned community symphony with revenue from various sources including over $1 million annually in private support. Multiple regression analysis determined two of the four hypotheses were supported and two were partially confirmed. While the norm of social responsibility and household income did confirm existing literature, philanthropic behavior seemed only defined by length of time as donor rather than by volunteering for arts and cultural organizations and donor benefits included tax incentives but not receiving a “gift” in exchange for a support. Research such as this, which contributes to our understanding of arts and cultural donors and the benefits they seek, continues to be important with the potential to inform nonprofit managers. Copyright © 2010 John Wiley & Sons, Ltd.
Prioritized constraint handling NMPC using Volterra series models
Authors: Aliyev T. L. , Gatzke E. P. 
Published: October 2010

AbstractThis paper presents a nonsquare Nonlinear Model Predictive Control (NMPC) formulation that uses prioritized soft output constraints and hard input constraints. The proposed method uses empirical Volterra series models to represent the plant dynamics and is a closed loop tested on multivariable refinery facility simulation. The process exhibits significant open‐loop nonlinearity such as input steady‐state multiplicity and nonlinear dynamics near the nominal operating point. The results show improvement when compared with traditional linear control methods. Copyright © 2010 John Wiley & Sons, Ltd.