bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pseudo‐static analysis of tunnel face stability using the generalized Hoek–Brown strength criterion
Authors: Saada Z. , Maghous S. , Garnier D. 
Published: April 2013

SUMMARYThe stability of a tunnel face driven by a pressurized shield is investigated in the light of a limit analysis kinematic approach formulated in the context of the modified Hoek–Brown strength criterion. The analysis focuses on evaluating the destabilizing effects induced by seismic loading. The pseudo‐static approach is adopted to account for the effects of inertial forces developed in the rock mass by the passage of seismic waves. Taking advantage of the ability to compute analytically, the expressions of the support functions for the modified Hoek–Brown strength criterion, rigorous limit analysis solutions can be derived semi‐analytically for the tunnel face stability. Particular emphasis is given to the description of the Horn failure mechanism and associated lower bound estimates of the limit face supporting pressure. The approach is then applied to investigate the influence of some relevant strength and loading parameters in the tunnel face stability.Copyright © 2013 John Wiley & Sons, Ltd.
A posteriori analysis and adaptive error control for operator decomposition solution of coupled semilinear elliptic systems
Authors: Carey V. , Estep D. , Tavener S. 
Published: April 2013

SUMMARYIn this paper, we develop an a posteriori error analysis for operator decomposition iteration methods applied to systems of coupled semilinear elliptic problems. The goal is to compute accurate error estimates that account for the combined effects arising from numerical approximation (discretization) and operator decomposition iteration. In an earlier paper, we considered ‘triangular’ systems that can be solved without iteration. In contrast, operator decomposition iterative methods for fully coupled systems involve an iterative solution technique. We construct an error estimate for the numerical approximation error that specifically addresses the propagation of error between iterates and provide a computable estimate for the iteration error arising because of the decomposition of the operator. Finally, we develop an adaptive discretization strategy to systematically reduce the discretization error.Copyright © 2013 John Wiley & Sons, Ltd.
The fiber‐free approach in the evaluation of the tangent stiffness matrix for elastoplastic uniaxial constitutive laws
Authors: Marmo Francesco , Rosati Luciano 
Published: April 2013

SUMMARYIt has been shown in a previous paper that the normal stress resultants for an arbitrary polygonal section endowed with a uniaxial elastoplastic law can be computed exactly by means of a general approach; it has been denominated fiber free as no fiber discretization of the section is required. The aim of this paper was to extend the fiber‐free approach to the evaluation of the tangent stiffness matrix to allow for the analytical integration of all the basic quantities required by the section state determination occurring in nonlinear frame analysis. The numerical examples showed that the general properties of the fiber‐free approach, already discussed with reference to the stress resultants, carry over to the tangent stiffness matrix as well. Namely, independent from the complexity of the constitutive law, the accuracy in the evaluation of the tangent stiffness matrix allowed by the number of fibers adopted in commercial software for nonlinear frame analysis is even worse than that associated with the computation of the stress resultants. Copyright © 2013 John Wiley & Sons, Ltd.
Discordant noninvasive prenatal testing results in a patient subsequently diagnosed with metastatic disease
Authors: Osborne C. Michael , Hardisty Emily , Devers Patricia , Kaiser‐Rogers Kathleen , Hayden Melissa A. , Goodnight William , Vora Neeta L. 
Published: April 2013

What's already known about this topic?

Noninvasive prenatal testing for detection of trisomies 21, 18, and 13 is clinically available and is reported to have a false positive rate of 1% or less
This technology utilizes massively parallel shotgun sequencing of cell‐free DNA, of maternal and placental origin, present in maternal plasmaWhat does this study add?

Unexplained abnormal noninvasive prenatal testing results should prompt consideration of a maternal source of the abnormal cell‐free DNA, such as malignancy
Differences in utilisation of gastroprotective drugs between 2001 and 2005 in Australia and Nova Scotia, Canada
Authors: Tett Susan E. , Sketris Ingrid , Cooke Charmaine , van Zanten Sander Veldhuyzen , Barozzi Nadia 
Published: April 2013

ABSTRACTPurposeThis study aimed to compare use of histamine H2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs), 2001–2005, in the elderly and social security beneficiaries in Australia (AUS) and Nova Scotia, Canada (NS).MethodsPrescription dispensing data were collected for all subsidised H2RAs and PPIs. In AUS, dispensing data for concession beneficiaries were obtained from the Pharmaceutical Benefits Scheme database. In NS, data were sourced from the Pharmacare database. Relevant population data were used to convert to World Health Organisation Anatomic Therapeutic Chemical defined daily doses (2005) per 1000 beneficiaries per day (DDD/1000/day).ResultsOverall use of gastroprotective agents was similar and rising in NS and AUS (100–160 DDD/1000/day) over this 5‐year time window. However, the proportion of this use accounted for by PPIs was far higher in AUS (over 85% by 2005) than in NS (23% rising to 35% over the 5 years). In AUS, PPI use rose from 50 to about 140 DDD/1000/day over the 5 years, whereas PPI use in NS rose slowly to less than 60 DDD/1000/day by 2005. H2RA use in NS was always high (over 100 DDD/1000/day), whereas in AUS, H2RA use fell from 54 to around 24 DDD/1000/day over this period.ConclusionsAUS had much higher use of PPIs than NS over 2001–2005. The proportion of PPIs in all gastroprotective agents rose in AUS to be nearly 90%. The differences in utilisation during this time window could lead to differences in health outcomes from either lower gastro‐intestinal bleeding risk or higher long‐term adverse effects of PPIs. Copyright © 2013 John Wiley & Sons, Ltd.
High use of health services in patients with suboptimal asthma drug regimens: a population‐based assessment in British Columbia, Canada
Authors: Zhang Tingting , Smith M. Anne , Camp Pat G. , Carleton Bruce C. 
Published: April 2013

ABSTRACTBackgroundDespite numerous clinical guidelines on asthma management, patients often receive suboptimal drug therapy. This study identified patients who received suboptimal regimens according to the National Heart, Lung and Blood Institute (NHLBI) Guidelines for the Diagnosis and Management of Asthma in a complete population (residents of British Columbia, Canada) and determined the association between patients' regimens and utilization of healthcare services.MethodsA total of 65 345 asthma patients were identified using provincial health service utilization data (including all respiratory‐related prescription medication dispensings, physician and hospital visits) for the 2009 fiscal year. Patient‐specific regimens of inhaled short‐acting bronchodilators (SABA) with or without inhaled corticosteroids (ICS) were categorized as optimal or suboptimal. Logistic regression models were used to determine the association between regimen optimality and health service utilization, adjusted for socioeconomic status, prior year hospital and emergency department (ED) visits for asthma.ResultsPatients with suboptimal regimens had significantly greater risk of using health services than patients with optimal regimens of SABA and/or ICS. In particular, adolescents with suboptimal regimens were the most likely to have hospital admissions (odds ratio (OR) 3.8; 95% confidence interval (CI) 1.8–7.8), visit the ED (OR 2.2; 95% CI 1.6–3.1) and be high users of family physician services (OR 5.7; 95% CI 4.0–8.1) compared with patients in other age groups.ConclusionsSuboptimal regimens are associated with significantly high usage of health services. Identifying patients with suboptimal regimens and improving their medication management in accordance with asthma clinical guidelines are likely to result in lower health service utilization. Copyright © 2013 John Wiley & Sons, Ltd.
Dynamic mechanical behavior and nanostructure morphology of hyperbranched‐modified polypropylene blends
Authors: Ganjaee Sari Morteza , Stribeck Norbert , Moradian Siamak , Zeinolebadi Ahmad , Bastani Saeed , Botta Stephan , Bakhshandeh Ehsan 
Published: April 2013

AbstractPolypropylene (PP) was modified utilizing two types of polyesteramide‐based hyperbranched polymers (amphiphilic PS and hydrophilic PH). A maleicanhydride‐modified PP (PM) was used as a reactive dispersing agent to enhance the modification by grafting the hyperbranched polymers onto the PP chains. Pure PP, two different non‐reactively modified samples, i.e. excluding PM, and two different reactively modified samples, i.e. including PM, were studied. Investigating the morphology of the samples was performed by scanning electron microscopy. To follow the effect of the modification on the dynamic mechanical properties, dynamic mechanical analysis experiments both in the melt (rheometric mechanical spectrometry) and in solid state (dynamic mechanical thermal analysis) were carried out. In the next step, the nanocrystalline structure of the samples was studied by small angle X‐ray scattering (SAXS) in two different modes, i.e. static and recrystallization. Hundreds of SAXS patterns were analyzed automatically using procedures written in PV‐WAVE image‐processing software. The chord distribution function (CDF) was calculated and the long period (lp) of the crystal lamellae was extracted from the CDFs. The rheometric mechanical spectrometry results show that both hyperbranched polymers decrease complex viscosity η* and enhance liquid‐like behavior. This happens more significantly when PM is included. The dynamic mechanical thermal analysis results reveal that Tg decreases when PS and PH are added. In the reactively modified samples this reduction is compensated most probably because of the crosslinked structure formed through the grafting reaction between the hyperbranched polymers and PM. Such structure is confirmed by SAXS data and calculated CDFs in the recrystallization mode. Static SAXS data also show enhancement in the crosshatched morphology of the crystalline lamellae of PP for reactively modified samples compared with non‐reactively modified samples. © 2013 Society of Chemical Industry
Nitrile sulphides. Part 8. Polymer‐bound nitrile sulphides; generation from polymeric 1,3,4‐oxathiazol‐2‐ones, and 1,3‐dipolar cycloaddition reactions
Authors: Mortier Roy M. , Paton R. Michael , Scott Gillian , Stobie Ian 
Published: April 2013

AbstractCopolymers of 5‐isopropenyl‐ and 5‐vinyl‐1,3,4‐oxathiazol‐2‐ones with styrene and methyl methacrylate have been prepared and characterised by elemental analysis, g.p.c., i.r. and 13C n.m.r. spectroscopy. On heating at 135–140°C the copolymers undergo thermal decarboxylation affording polymer‐bound nitrile sulphides, which may be trapped as their 1,3‐dipolar cycloadducts with dimethyl acetylenedicarboxylate, ethyl propiolate, ethyl cyanoformate, diethyl fumarate and chloral. The products are identified as terpolymers comprising units of styrene or methyl methacrylate, methacrylonitrile or acrylonitrile, and the respective heterocyclic cycloadducts [isothiazoles(3) and (7), l,2,4‐thiadiazole(8), isothiazoline(10), and 1,3,4‐oxathiazole(12)]. In the absence of a dipolarophile the oxathiazolone units are converted to nitriles. Treatment of polymeric ethyl thiadiazolecarboxylate(8c) with 1‐aminobutane yields amide(14c). On heating copolymer(12c) at 165°C in the presence of ethyl cyanoformate, thiadiazole(8c) is formed, presumably via cycloreversion to polymeric nitrile sulphide followed by cycloaddition to the nitrile. An alternative approach to copolymers incorporating isothiazoles and 1,2,4‐thiadiazoles is provided by copolymerisation of their 3‐isopropenyl derivatives, (16) and (17).
Glass transitions and relaxations in comb‐branch poly(di‐p‐alkoxyphenyl itaconate)s
Authors: Cowie John M. G. , Ho Chu Yat 
Published: April 2013

AbstractA series of poly(diphenyl itaconate)s, in which the phenyl ring has been substituted in the para position by alkoxy units containing up to seven carbon atoms, has been synthesised and characterised. Glass transition temperatures were observed to decrease as the number of atoms in the p‐substituent rose to six, but increased when the chain became longer. Heat capacity changes, ΔCP, at Tg were measured and the value of the Wunderlich parameter ΔCp/bead was found to lie between 7 0 and 10 3 JK−1mol−1 depending on the size of the alkoxy unit. Dynamic mechanical analysis revealed up to three sub‐glass‐transition damping peaks centred on 290 K, 200 K and 110 K. These have been assigned respectively to (a) oxycarbonyl group rotation, (b) motion involving the pendant phenyl rings and (c) limited bond reorientation in the p‐alkoxy groups when these contain four or more atoms.
Acoustoelectric devices incorporating Langmuir—Blodgett films
Authors: Roberts G. G. , Holcroft B. , Ross J. , Barraud A. , Richard J. 
Published: April 2013

AbstractThis paper presents data for LB films coated on to acoustoelectric devices. Both bulk single crystals and surface acoustic wave oscillators have been used. Results have been obtained using a range of different materials including ω‐tricosenoic acid and substituted phthalocyanine and tetracyanoquinodimethane. Using piezoelectric quartz crystal resonators we have demonstrated the reproducibility of the LB film coating procedure and their potential use as sensors. With a specially designed s.a.w. device, we have been able to differentiate between mass loading and electric field effects due to an LB film overlay. This has enabled us to calculate the resistivity of substituted TCNQ films.
Poiy(hexamethyienebigyanidiniym chloride) as a reagent for the determination of water‐soluble naturai carboxylate and sulphate polymers
Authors: Kennedy John F. , Bradshaw Ian J. 
Published: April 2013

AbstractThe poly(hexamethylenebiguanidinium chloride) [PHMBH + Cl−] assay method developed originally for sodium alginate determination in solution (0 01‐0 5 %) has been applied to a wide range of other acidic polysaccharides. The simple procedure consists of the addition of a known excess of PHMBH + Cl− to precipitate the sample quantitatively and thereafter measuring the u.v. absorption of residual PHMBH + Cl− in the supernatant. Response to the method is dependent upon the acidic group‐monosaccharide molar ratio and can be conveniently altered for polysaccharides with different anionic charge densities by simple adjustment of assay conditions. For acidic polysaccharides with very low charge densities, such as propylene glycol alginates with a high degree of esterification, the response to the assay can be increased by addition of borate ions which complex with the polymer molecules to increase the negative charge. The electrostatic nature of the response also allows the assay method to be used for the determination of extent of esterification in propylene glycol alginates with up to ∼70% derivatisation. The method has been shown to be suitable for low molecular weight samples. Therefore, it is more reliable than other assay methods for acidic polysaccharides which involve a precipitation step with doubtful quantitative recovery for low molecular weight material. The simplicity, rapidity and reliability of the method makes it a suitable procedure for both carboxylated and sulphated polysaccharides in a range of applications.
Sepiolite‐supported urease
Authors: García‐Segura Juan M. , Cid Concepción , de Llano Javier Martín , Gavilanes José G. 
Published: April 2013

AbstractThe properties of the fibrous clay sepiolite as a support for enzyme immobilization have been studied using urease. Simple adsorption does not result in enzyme inactivation and appears to be a valuable method of immobilizing the enzyme at high ionic strength. This behaviour has been related to the existence of protein‐clay hydrophobic interactions. The sepiolite‐supported urease has been characterized in terms of pH and ionic strength dependencies, thermal and storage stability, reusability, and kinetic parameters. These studies indicate that sepiolite is a valuable support for simple adsorption of enzymes.
Photoreflectance and photocurrent measurements using pressure tuned laser diodes
Authors: Bercha Artem , Piechal Bernard , Dybala Filip , Klimczak Mariusz , Ivonyak Yurii , Trzeciakowski Witold A. 
Published: April 2013

AbstractPhotoreflectance (PR) and photocurrent (PC) measurements have been demonstrated in the 1250–1600 nm spectral range using an external‐cavity pressure‐tuned laser diode as the source of monochromatic light. Compared to conventional PR and PC methods using monochromated light from the lamp, it allows to achieve a smaller spot so that micro‐PR and micro‐PC are possible either directly or with fiber coupled beam. In case of PR, it also allows to eliminate spurious photoluminescence signal.
Leakage current in 808 nm laser diodes analyzed using high hydrostatic pressure and temperature
Authors: Bercha Artem , Ivonyak Yurii , Klimczak Mariusz , Dybala Filip , Piechal Bernard , Trzeciakowski Witold A. , Dabrowska Elzbieta , Teodorczyk Marian , Malag Andrzej 
Published: April 2013

AbstractThreshold current in 808 nm GaAsP/AlGaAs laser diode has been measured as a function of pressure (up to 1.8 GPa) and temperature (from 80 to 300 K). The results have been analyzed in order to separate leakage current from radiative current and to determine the effective barrier for leakage and its pressure dependence. Our data indicates that both X and L minima in the barriers and in the claddings contribute to leakage.
ASSESSING THE CUMULATIVE IMPACTS OF HYDROPOWER REGULATION ON THE FLOW CHARACTERISTICS OF A LARGE ATLANTIC SALMON RIVER SYSTEM
Authors: Birkel C. , Soulsby C. , Ali G. , Tetzlaff D. 
Published: April 2013

ABSTRACTWe assessed the influence of hydropower on the flow characteristics of the river Tay, one of the UK's most heavily regulated catchments and important Atlantic salmon fisheries. Hydropower developments in the mid‐20th century preceded flow data collection, resulting in knowledge gaps over how far regulated flows deviate from natural and how ecosystem functioning might have been impacted. We used 29 unregulated catchments in and around the Tay to assess the relationships between hydroclimatic conditions, landscape structure and the overall flow regime, as well as the annual, monthly and daily flow metrics. This allowed the identification of flow characteristics by using an integrated suite of regression approaches (nonlinear, MLR and random forests) to assess likely impacts at 11 regulated sites. The results showed that the impacts of regulation are highly variable in both space and time. Headwater sub‐catchments are most heavily affected, and water imports or exports as part of hydropower schemes can increase or decrease annual runoff by up to 50%, respectively. On a monthly basis, regulation primarily increased summer low flows; winter high flows increased in catchments affected by water imports and reduced where there was a net water export. At larger catchment scales, impacts were relatively small, as unregulated tributaries re‐naturalize the flows and the effects of intra‐basin transfers balance. Non‐stationarity in climate and water use in the catchment dictates that adaptive management of flows may be necessary to protect ecosystems services. Copyright © 2013 John Wiley & Sons, Ltd.
Transparente Klebstoffe für Glas‐Metall‐Verbindungen
Authors: Weller Bernhard , Wünsch Jan 
Published: April 2013

AbstractDer Einsatz von lastabtragenden Klebverbindungen zählt zu den Fügetechniken des Konstruktiven Glasbaus. Dabei sind transparente und hochfeste Klebstoffe als Alternativen zu den derzeit verwendeten Silikon‐Klebstoffen von besonderem Interesse. Der vorliegende Beitrag enthält eine Ergebnisauswahl verschiedener Untersuchungen an Klebeverbindungen mit transparenten Acrylaten, Epoxidharzen und Polyurethanen. Die experimentelle Studie umfasst Analysen zu den thermomechanischen Eigenschaften der Klebstoffe sowie zu den Zugfestigkeiten und den lichttechnischen Eigenschaften der geklebten Verbindungen.Transparent Adhesives for Glass‐and‐Metal Joints. The use of load‐bearing joints is one of the relevant joining techniques in glass construction. Here, transparent and high‐strength adhesives are alternatives to the currently used silicone adhesives. Therefore, they are of particular interest. This article contains a selection of various results from studies of adhesive joints using transparent acrylics, epoxy resins and polyurethanes. The experimental study includes analyses of the thermo mechanical behavior of the adhesives as well as investigations of the tensile strength and the optical properties of bonded joints.
DIN 18008 Teile 1‐5: Neuerungen gegenüber eingeführten Regelungen
Authors: Siebert Geralt 
Published: April 2013

AbstractNach Veröffentlichung der Endfassung für DIN 18008 Teil 1 und 2 im Dezember 2010 wurde mit Datum Oktober 2011 die Entwurfsfassung für Teile 3, 4 und 5 veröffentlicht. Damit sind für die Mehrzahl der Anwendungen nunmehr Regelungen nach dem Konzept der Teilsicherheitsbeiwerte vorhanden. Diese gehen sowohl hinsichtlich Regelungsumfang wie ‐tiefe über die aktuell eingeführten TRXV hinaus. Nach der Einspruchssitzung im ersten Halbjahr 2012 gilt es, die Veröffentlichung der Endfassungen abzuwarten. Parallel wird an der Entwurfsfassung für Teil 6 weitergearbeitet. Bei diesem Beitrag handelt es sich um eine aktualisierte Fassung des entsprechenden Beitrags aus dem Vorjahr. Die Ergebnisse der Einspruchssitzung sind berücksichtigt.DIN 18008 parts 1‐5: New regulations compared to previous standards. After publication of DIN 18008 Part 1 and 2 in a final version in December 2010 a draft for parts 3, 4 and 5 was published in October 2011. So for most applications of architectural glass design regulations according to the modern principle of partial safety factor do exist. Compared to the existing regulations not only a wider field of application is covered but they also have a more detailed view. After objection meeting in first half of 2012 the final version of part 3, 4 and 5 will be published soon, work is continued on draft version of part 6. Meanwhile an English version of part 1 and 2 does exist.
Combating “I Hate This Stupid Book!”: Black Males and Critical Literacy
Authors: Wood Summer , Jocius Robin 
Published: April 2013

AbstractToo often, instruction designed to improve literacy achievement for black male readers and writers focuses on skill‐based learning, ignoring cultural, social, and personal development. This article calls for the use of critical literacy strategies with African American male students, which can raise expectations for academic achievement by challenging traditional notions of literacy instruction, encouraging cooperative learning, and allowing students to develop a sense of social justice. Three dimensions (the 3 Cs) of critical literacy for young black males are explored: culturally relevant texts, collaboration, and critical conversations. In addition, suggestions and examples are offered to help teachers create critical literacy experiences in which black male elementary students can have the opportunity to become socially conscious text users who see themselves and their cultural histories reflected in texts.