bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling the effects of surface finish on fatigue limit in austenitic stainless steels
Authors: KURODA M. , MARROW T. J. 
Published: October 2008

ABSTRACTExisting short fatigue crack models have been reviewed to determine the most suitable fatigue model to analyse the effect of the surface finish on the fatigue limit of Type 304 austenitic stainless steels. A mechanistic model firstly proposed by Navarro and Rios (N‐R model) was selected as the most suitable generic model, because the model can include the effects of surface finishing parameters such as surface roughness and residual stress depth profile on the fatigue limit. The N‐R model has been implemented for fatigue specimens with various surface finishing conditions, and the effect of the surface finish on the fatigue limit was simulated. The material/surface properties required for the implementation were fully characterized by experiments. The applicability of the model to this study was also discussed. It is concluded that a development of the model would be required for proper prediction of the surface effects on fatigue in austenitic stainless steels.
Life assessment of multiaxially cyclic loaded turbine components
Authors: RAUCH M. , ROOS E. 
Published: October 2008

ABSTRACTRotors of turbines are exposed to high thermo‐mechanical loads, especially during start‐up and shut‐down procedures. Especially in the notched region of the blade‐connection to the rotor a complex multiaxial elastic‐plastic stress state is present. The reason is the multi‐surface contact in combination with fatigue and creep‐fatigue load. Within the scope of this work the blade‐disc‐connection of a gas turbine made of the nickel‐based alloys IN792 (blades) and IN718 (disc) was investigated at typical local service temperature of 550 °C. The aim was the investigation of mutual influence of adjoining blades as well as the effect on cycles to failure by variation of friction behaviour due to different coatings on the surface of the blade root. An already existing life assessment method based on a local strain approach could be confirmed for this more complex loading situation.In contrast to this, a blade‐shaft‐connection of a steam turbine made of X12CrMoWVNbN10‐1‐1 was investigated at its typical service temperature of 600 °C. During cyclic loading, the martensitic 10Cr steel reacts with ongoing cyclic softening. The fundamental result of the work discussed here is the development of a new life assessment method based on a damage parameter, which is a function of accumulated plastic strain. This damage parameter is included in a complex material model considering static, cyclic and viscoplastic materials behaviour. Thus, the life assessment method could be verified with inelastic finite element calculations of the model specimens, which were especially designed for the low‐cycle fatigue tests of blade‐shaft‐connection presented in this paper.
Determination of the bilinear stress‐crack opening curve for normal‐ and high‐strength concrete
Authors: FATHY A. M. , SANZ B. , SANCHO J. M. , PLANAS J. 
Published: October 2008

ABSTRACTAn improved version of the method proposed to ACI committee 446 and to RILEM TC 187‐SOC to determine the fracture parameters of concrete is applied in this study to several mixtures of normal and high‐strength concretes. The results are processed with a C++ program developed by the authors to automatise the mathematical operations required to obtain the bilinear softening curve of concrete from the experimental results. Numerical simulations of the tests are also carried out using finite elements with an embedded cohesive crack. The comparison between numerical and experimental results confirms that the experimental and numerical procedures are appropiate for normal‐strength concretes and high‐strength concretes.
Progressive damage analyses of angle‐ply laminates exhibiting free edge effects using continuum damage mechanics with layer‐wise finite element method
Authors: MOHAMMADI B. , HOSSEINI‐TOUDESHKY H. , SADR‐LAHIDJANI M. H. 
Published: October 2008

ABSTRACTCapability of continuum damage mechanics (CDM) to predict the damage mechanism evolution of composite laminates has rarely been carried out, and most of the previous CDM works mainly focused on the overall response of the laminates. In this paper, progressive damage and overall response of the composite laminates under quasi‐static, monotonic increasing loading are investigated using three‐dimensional (3D) CDM implementation in a finite element method that is based on the layer‐wise laminate plate theory. In the damage formulation, each composite ply is treated as a homogeneous orthotropic material exhibiting orthotropic damage in the form of distributed microscopic cracks that are normal to the three principal material directions. The progressive damage of different angle‐ply composite laminates under quasi‐static loading that exhibit free edge effects is investigated. It is shown that using CDM global behaviour and various damage mechanisms affected by the complex nature of free edges can be qualitatively well predicted.
Evaluation of the T‐stress and stress intensity factor for a cracked plate in general case using eigenfunction expansion variational method
Authors: CHEN Y. Z. , LIN X. Y. , WANG Z. X. 
Published: October 2008

ABSTRACTThis paper investigates the T‐stress and stress intensity factor for a cracked plate in general case. In the general case, the shape of boundary and the applied loading are arbitrary. The eigenfunction expansion variational method (EEVM) is developed to evaluate the T‐stress and stress intensity factor. For the traction boundary value problem, the EEVM is equivalent to the theorem of least potential energy in elasticity. Therefore, the EEVM possesses a clear physical meaning and it does not depend on any boundary collocation scheme. Several numerical examples are presented, which include: (1) a line crack in circular plate and (2) a line crack in rectangular plate. Numerical examination for convergence in an example is carried out.
Residual stress effects on fatigue crack growth in a Ti‐6Al‐4V friction stir weld
Authors: PASTA S. , REYNOLDS A. P. 
Published: October 2008

ABSTRACTRecent studies have illustrated a predominant role of the residual stress on the fatigue crack growth in friction stir welded joints. In this study, the role of the residual stress on the propagation of fatigue cracks orthogonal to the weld direction in a friction stir welded Ti‐6Al‐4V joint was investigated. A numerical prediction of the fatigue crack growth rate in the presence of the residual stresses was carried out using AFGROW software; reasonable correspondence between the predictions and the experimental results were observed when the effects of residual stress were included in the simulation.
Comparative analysis of three thermal fatigue experiments
Authors: ANCELET O. , CHAPULIOT S. , HENAFF G. 
Published: October 2008

ABSTRACTThis paper presents an analysis of the ability of different criteria to predict fatigue crack initiation under thermal loading. More precisely the predictions of the number of cycles to crack initiation are compared with experimental results obtained using five different fatigue criteria in three types of thermal fatigue tests (namely the FAT3D, JRC and SPLASH test campaigns).This analysis has revealed that:

The conventional criteria based on equivalent strain variation substantially overestimate the lifespan of a structure subjected to thermal loading.
A criterion making account for loading multiaxiality is required to estimate thermal fatigue life.

Three of the criteria studied give satisfactory results: the Zamrik criterion, the Park and Nelson criterion and a criterion taking hydrostatic pressure into consideration proposed by Amiable et al. The latter should be preferred for the accuracy of its results and the Zamrik criterion for its simplicity.
Biomedicine, holism and general medical practice: responses to the 2004 General Practitioner contract
Authors: Checkland Kath , Harrison Stephen , McDonald Ruth , Grant Suzanne , Campbell Stephen , Guthrie Bruce 
Published: October 2008

AbstractIn 2004 a new contract was introduced for General Practitioners in the UK, which introduced a significant element of ‘pay‐for‐performance’, including both clinical and organisational targets. The introduction of this contract has caused interest across the world, particularly amongst those responsible for commissioning primary care services. It can be argued that the clinical targets in the contract (known as the Quality and Outcomes Framework, QOF) represent a move towards a more biomedical model of health and illness, which is contrary to the ideal of providing holistic (or biopsychosocial) care that has been traditionally espoused by GPs. This paper reports results from two linked studies (in England and Scotland) investigating the early stages of the new contract. We describe the way in which four practices with different organisational approaches and espoused identities have all changed their practice structures, consultations and clinical care in response to QOF in ways which will result in patients receiving a more biomedical type of care. In spite of these observed changes, respondents continued to maintain discursive claims to holism. We discuss how this disconnection between rhetoric and reality can be maintained, and consider its implications for the future development of GPs’ claims to a professional identity.
Waking up to sleepiness: Modafinil, the media and the pharmaceuticalisation of everyday/night life
Authors: Williams Simon J. , Seale Clive , Boden Sharon , Lowe Pam , Steinberg Deborah Lynn 
Published: October 2008

AbstractThis paper examines the social construction of the new wakefulness‐promoting drug Modafinil (brand name Provigil) in the British press. Key themes in this newspaper coverage include the potential ‘uses’ and ‘abuses’ of this drug in relation to: (i) medical conditions; (ii) lifestyle choices; (iii) military operations; and (iv) sporting competition. The British press, we show, play a dual role in reporting on these trends and developments: on the one hand constructing this as something of a ‘wonder drug’ in relation to the treatment of a number of medical complaints or conditions, on the other hand articulating and amplifying a range of cultural concerns and anxieties about the non‐medical ‘uses’ and ‘abuses’ of this drug, both now and in the future. These issues, it is argued, are best interpreted in terms of media concerns over the pharmaceuticalisation rather than the medicalisation of everyday/night life. The paper concludes with some further thoughts and reflections on these issues, including the potential reworking of notions of ‘pharmaceutical Calvinism’ and the ‘elective affinity’ between this ‘smart’ new drug and the spirit of (bio)capitalism.
Becoming a ‘real’ smoker: cultural capital in young women's accounts of smoking and other substance use
Authors: Haines Rebecca J. , Poland Blake D. , Johnson Joy L. 
Published: October 2008

AbstractThis paper draws from a qualitative study of tobacco use by young women in Toronto, Canada. Narrative interviews were used to understand the multiple roles and functions of smoking within the everyday lives of female adolescents. Guided by a Bourdieusian theoretical framework this study employed the core construct of cultural capital in order to position tobacco and other substance use as field‐specific capital that young women accumulate while navigating the social worlds of adolescence. Departing from the psychosocial or peer‐influence models that inform the majority of tobacco research with young people, this analysis provides a nuanced understanding of how smoking, drinking, using drugs are much more than simple forms of teenage experimentation or rebellion, but can also serve as key resources for defining the self, acquiring status and making social distinctions within adolescent social worlds. In this context it is also argued that initiation into substance use practices is a way that young women demonstrate and develop social and cultural competencies.
Regional Trade Agreements versus Global Trade Liberalisation: Implications for a Small Island Developing State
Authors: Asafu‐Adjaye John , Mahadevan Renuka 
Published: October 2008

AbstractThis study undertakes an empirical investigation of the macroeconomic and sectoral impacts of two forms of regional trade agreements vis‐à‐vis global trade liberalisation on a small island country, using Fiji as a case study. In order to capture the feedback effects of such a complex set of policies, we employ a dynamic computable general equilibrium model of the Fijian economy to investigate (i) the impact of the Pacific Island Countries Trade Agreement (PICTA), (ii) the impact of PICTA, the Pacific Agreement for Closer Economic Relations (PACER), and the Economic Partnership Agreements (EPAs), (iii) the impact of full tariff liberalisation (i.e. tariff removal only), and (iv) the impact of full trade liberalisation, with removal of both tariff and non‐tariff barriers. While PICTA consistently provides the least benefits across a range of macroeconomic indicators including real output, welfare, trade volumes and employment, full trade liberalisation involving the removal of tariff and non‐tariff barriers provides the greatest benefits compared to the other scenarios in terms of real output. However, the latter scenario is outperformed by PICTA, PACER, the EPAs and full tariff liberalisation in terms of welfare effects, trade volumes and employment. The policy implications hold important lessons for developing countries considering trade liberalisation.
Prospective cohort study investigating the reliability of the AmnioSense™ method for detection of spontaneous rupture of membranes
Authors: Mulhair L , Carter J , Poston L , Seed P , Briley A 
Published: October 2008

Objective  This study investigated the reliability, sensitivity and specificity of a commercially available absorbent pad, AmnioSense™, compared with speculum examination for detection of spontaneous ruptured membranes (SRM).Design  Prospective cohort study.Setting  Antenatal Day Unit (ADU) of a UK inner‐city teaching hospital.Population  Women attending the ADU with a history of suspected ruptured membranes between 18 and 42 weeks of gestation.Methods  Eligible women were asked to use the absorbent pad in accordance with the manufacturer’s instructions. A midwife recorded the result. A second midwife performed a speculum examination according to unit protocol. Results were entered onto a password‐protected study‐specific database. Both midwives were blind to the other test result.Main outcome measures  Comparability between the index test (AmnioSense™) and reference standard (speculum).Results  A total of 157 women were recruited and results were analysed in 139 cases. Median gestational age at recruitment was 37+2 weeks. The prevalence of SRM was 42% (59/139) with AmnioSense™ giving a sensitivity of 98% (58/59) and specificity of 65% (52/80).Conclusions  Thirty‐eight percent (53/139 women) with SRM would have been correctly identified as having intact membranes without the need for a speculum examination. Twenty‐five percent of AmnioSense™ false‐positive results were associated with positive high vaginal swab results (7/28). These data suggest that a negative AmnioSense™ result can provide reassurance of intact membranes. Use of the AmnioSense™ test before considering speculum examination could reduce the number of speculum examinations undertaken, with benefit to women and concomitant health resource savings.
Climate anomalies provide opportunities for large‐scale mapping of non‐native plant abundance in desert grasslands
Authors: Huang Cho‐ying , Geiger Erika L. 
Published: October 2008

ABSTRACTAim  Native plant communities are susceptible to climate anomalies, which would favour the invasion of non‐native species. However, climate anomalies may also provide opportunities for detecting non‐native plants at a regional scale using remote sensing. Based on this mechanism, we propose a direct and effective remote sensing approach to map the abundance of South African Eragrostis lehmanniana Nees (Lehmann lovegrass), a highly invasive, non‐native plant in the desert grasslands of southwestern North America.Location  The desert grassland of Fort Huachuca Military Reservation (31°34′N, 110°26′W) in southern Arizona, USA.Methods  Simple linear regression models were used to examine the relationships between additional (comparing to the normal level) remotely sensed greenness (delta Enhanced Vegetation Index (ΔEVI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS)), and field actual (g m−2) and percentage (%) biomass of E. lehmanniana in an abnormal wet, cool period in October 2000.Results  There was a strong and positive agreement (P < 0.005) between ΔEVI and field observations (R2 = 0.72 and 0.64 for actual and percentage biomass of E. lehmanniana, respectively). These relationships allowed us to estimate the abundance of E. lehmanniana in the desert grassland.Main conclusions  Phenology of native grass communities is quite similar to systems dominated by E. lehmanniana but responses differ when there are substantial amounts of precipitation in cool seasons. Eragrostis lehmanniana can produce significant amount of new tissues and seeds with sufficient cool season moisture, while native grasses are still in senescence or dormancy. Therefore, amplitude of ΔEVI during wet, cool seasons would indicate the abundance of E. lehmanniana. Long‐term climate records denote an amplification of cool season precipitation in the southwestern USA. This regional climatic trend should allow us to monitor E. lehmanniana and possibly other non‐native species frequently in this vast arid region.
Widespread resistance of Mediterranean island ecosystems to the establishment of three alien species
Authors: Vilà Montserrat , Siamantziouras Akis‐Stavros D. , Brundu Giuseppe , Camarda Ignazio , Lambdon Philip , Médail Frédéric , Moragues Eva , Suehs Carey M. , Traveset Anna , Troumbis Andreas Y. , Hulme Philip E. 
Published: October 2008

ABSTRACTAlthough some invasive plants are cosmopolitan, not all ecosystems are invaded to the same degree. Yet there is little experimental work on how ecosystem resistance to invasion at the establishment phase differs among ecosystems. We conducted two field sowing experiments in two consecutive years to examine establishment of the deciduous tree Ailanthus altissima, the succulent subshrub Carpobrotus spp. and the annual geophyte Oxalis pes‐caprae in coastal dunes, shrublands and oldfields in more than 200 sites across six Mediterranean Basin islands differing in climatic conditions and local species richness.Establishment success (i.e. percentage of plots with at least one seedling) and rates (i.e. seedling to sown seed ratio) were low, especially for Ailanthus even when accounting for differences in seed viability. Oxalis was capable of producing a new cohort of seedlings the year following planting. By contrast, all Ailanthus seedlings and half the Carpobrotus seedlings died following the first summer. Differences in establishment success and rates among ecosystems were species‐, island‐ and year‐dependent.Differences in precipitation and mean temperature were associated with differences in establishment rates across sites. Establishment rates tended to be positively correlated with cumulative precipitation and negatively with mean Ta. Unexpectedly, native species richness was not a good predictor of seedling establishment, except for higher Oxalis establishment success in species rich habitats.By conducting field sowing tests at multiple sites across a region we found that except for Oxalis, Mediterranean island ecosystems are quite resistant to invader establishment. These results suggest that differences in the degree of invasion between ecosystems and islands might be more dependent upon the influence of invasion event factors (e.g. propagule pressure) or factors acting at a later life‐history stages rather than differences in the resistance imposed by ecosystems to invader recruitment. Moreover, our results support the notion that in Mediterranean ecosystems invasions are highly idiosyncratic events and strongly dependent on water availability conditions.
Additive partitioning of butterfly diversity in a fragmented landscape: importance of scale and implications for conservation
Authors: Ribeiro Danilo Bandini , Prado Paulo I. , Brown Jr Keith S. , Freitas André V. L. 
Published: October 2008

ABSTRACTAim  Most of the Atlantic Forest in Brazil occurs in fragments of various sizes. Previous studies indicate that forest fragmentation affects fruit‐feeding butterflies. Conservation strategies that seek to preserve organisms that are distributed in high‐fragmented biomes need to understand the spatial distribution of these organisms across the landscape. In view of the importance of understanding the fauna of these forest remnants, the objective of the present work is to investigate the extent to which the diversity of this group varies across spatial scales ranging from within‐forest patches to between landscapes.Location  South America, south‐eastern Brazil, São Paulo State.Methods  We used bait traps to sample fruit feeding butterflies at 50 points in 10 fragments in two different landscapes during a period of 12 months. Total species richness and Shannon index were partitioned additively in diversity at trap level, and beta diversity was calculated among traps, among forest patches, and between landscapes. We used permutation tests to compare these values to the expected ones under the null hypothesis that beta diversity is only a random sampling effect.Results  There was significant beta diversity at the smallest scale examined; however, the significance at higher scales depends on the diversity measurement used. Beta diversity with Shannon index was smaller than expected by chance among fragments, whereas species richness was not. Among landscapes, only beta diversity in richness was higher than expected by chance.Main conclusions  The results observed occur because there is great variability in species composition among forest patches in the same landscape, changing this diversity even though the communities are formed from the same pool of species. At the largest scale evaluated (between landscapes), these pattern changes and differences in beta diversity in richness were detectable. This difference is probably caused by the presence of rare species. Thus, a conservation strategy that seeks to preserve as many species as possible per unit of area in high‐fragmented biomes should give priority to protecting fragments in different landscapes, rather than more fragments in the same landscape.