bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic deformation behaviour and lifetime calculation of Al‐3Mg‐Mn
Authors: Rojek N. , Smaga M. , Walther F. , Eifler D. 
Published: April 2007

AbstractPlastic strain amplitude, temperature and electrical resistance measurements were performed on the aluminium‐magnesium alloy Al‐3Mg‐Mn (AA5454) in recrystallised condition to describe and evaluate the cyclic deformation behaviour in detail. The endurance limit was estimated in load increase tests (LIT). In stress‐controlled single step tests at ambient temperature the cyclic deformation behaviour is characterised by pronounced cyclic hardening, which leads to a saturation state with a plastic strain amplitude of nearly zero. Due to far‐reaching cross effects of the applied measuring techniques, the plastic strain amplitude, the change of the specimen temperature due to cyclic plastic loading and the change of the electrical resistance show a strong interrelation with the underlying fatigue processes. A new lifetime calculation method “PHYBAL” on the basis of the plastic strain amplitude, the change of the temperature and the change of the electrical resistance yields an excellent accordance with experimentally determined lifetimes. Microstructural details were investigated by light and scanning electron microscopy.
Eigenspannungen als Messgröße zur Qualitätssicherung
Authors: Betzold J. , Pucelik J. , Eisenberg S. 
Published: April 2007

AbstractDie röntgenografische Methode wird im Konzern der Volkswagen AG an diversen weltweiten Standorten als Standardverfahren zur Ermittlung von Eigenspannungen eingesetzt. Als wichtige Messgröße zur Qualitätssicherung sind die Eigenspannungen bei verschiedenen Bauteilen als Sollvorgaben in den Zeichnungen festgeschrieben (z. B. Getriebeteile, Federn). Die Messungen erfolgen im Bereich der Qualitätssicherung, in der Fertigung, der Schadensanalyse, der technischen Entwicklung und der Bemusterung der Bauteile von Lieferanten. Ein optimaler Nutzeffekt wird erzielt, wenn die Eigenspannungswerte eine eindeutige Korrelation mit der Bauteilbelastbarkeit ausweisen und wenn die Arbeitsprozesse zur Einbringung von Eigenspannungen mittels Eigenspannungsmessungen schon im Produktionsbereich optimiert werden können.
The effect of grain orientation on the tensile‐compressive asymmetry of polycrystalline NiTi shape memory alloy
Authors: Wang Y. F. , Yue Z. F. , Wang J. 
Published: April 2007

AbstractThe purpose of the present study is to thoroughly understand the influence of crystallographic texture on the stress‐strain asymmetric behavior of polycrystalline NiTi shape memory alloy under tension and compression. To do this, a 3D thermo‐mechanical model has been implemented in a finite element program and textured and untextured polycrystalline NiTi have been considered. In our polycrystalline finite element model, each element represents one grain and a set of crystal orientations which approximate the initial crystallographic texture of the NiTi are assigned to the elements. From the calculated results, it is found that the crystallographic texture is the important reason for the tension‐compression asymmetry. For the textured polycrystal, the tension‐compression asymmetry can be observed clearly, but for the polycrystal containing randomly oriented grains, the stress‐strain curves show low levers of asymmetry between tensile and compressive loading, and the evolutions of martensite volume fractions are similar under two stress states.
Continuous dependence on the geometry and on the initial time for a class of parabolic problems II
Authors: Philippin G. A. , Proytcheva V. 
Published: April 2007

AbstractExtending the investigations initiated in an earlier paper, the authors deal in this paper with the solutions of another class of initial‐boundary value problems for which continuous dependence inequalities on the geometry and the initial time are established. Copyright © 2007 John Wiley & Sons, Ltd.
A method for removing global effects in small‐animal functional MRI
Authors: Lowe Andrew S. , Barker Gareth J. , Beech John S. , Ireland Matthew D. , Williams Steve C. R. 
Published: April 2007

AbstractGlobal effects in functional MRI are temporal modulations in signal intensity resulting from various scanner and subject phenomena. These effects contribute to the overall variance, reducing the effect size associated with an experimental paradigm. Statistical estimations that include an approximation for concurrent global effects will reduce the residual error within the model and so improve statistical power of the study. Conventionally, estimates of global effects are derived from mean intracerebral signal intensities, but these may be prone to contributions from localised experimentally evoked signal changes. In such cases, inaccurate estimates of global effects may result in erroneous inferences of neural modulations based on statistical artefact. A novel, computationally simple, method of estimating global effects is proposed using muscle tissue acquired within the same acquisition volume. Quantitative improvements in sensitivity are reported for a somatosensory stimulation paradigm using global muscle signal intensities as a covariate of no‐interest. The method is independent of local neurogenic signal changes and, under particular experimental conditions, may be more representative of true global effects. The utility of this strategy to applications in small‐animal functional MRI that evoke systemic physiological changes as a result of the experimental manipulation is critically discussed. Copyright © 2007 John Wiley & Sons, Ltd.
An extended model and a column generation algorithm for the planar multicommodity flow problem
Authors: Alvelos Filipe , de Carvalho J. M. Valério 
Published: April 2007

AbstractWe present a new model and a column generation algorithm for the linear minimum cost multicommodity flow problem. The new model has two differences when compared to the classic formulation based on flows on paths: it has an additional set of variables and an additional set of inequalities. The extra variables are associated with flows on circuits where some arcs are reversed. The extra inequalities assure that an optimal solution to the extended model can be converted to an optimal solution to the path formulation. In order to obtain an optimal solution to the extended model, we use column generation. The extra variables are explicitly considered in the restricted master problem, from the beginning of the column generation process. The subproblem remains a set of shortest path problems. Our present work is related to the use of dual–optimal inequalities in the sense that we extend a model with additional primal variables/dual inequalities. However, our extended model also has additional primal inequalities/dual variables. We present computational results of our method in planar instances and compare them with standard column generation, a bundle method, and a general‐purpose solver. For the tested instances, there is an effective improvement in computational time of the column generation method when the extended model is used. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(1), 3–16 2007
Network design arc set with variable upper bounds
Authors: Atamtürk Alper , Günlük Oktay 
Published: April 2007

AbstractIn this paper we study the network design arc set with variable upper bounds. This set appears as a common substructure of many network design problems and is a relaxation of several fundamental mixed‐integer sets studied earlier independently. In particular, the splittable flow arc set, the unsplittable flow arc set, the single node fixed‐charge flow set, and the binary knapsack set are facial restrictions of the network design arc set with variable upper bounds. Here we describe families of strong valid inequalities that cut off all fractional extreme points of the continuous relaxation of the network design arc set with variable upper bounds. Interestingly, some of these inequalities are also new even for the aforementioned restrictions studied earlier. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(1), 17–28 2007
Joint optimization of pricing and resource allocation in competitive telecommunications networks
Authors: Bouhtou Mustapha , Erbs Guillaume , Minoux Michel 
Published: April 2007

AbstractYield management techniques have been used by companies in various competitive industrial contexts in order to keep a high level of revenue. With the opening of the telecommunications markets, operators are looking for ways of including competition in their decision process. By analyzing the customers' preferences, the market can be segmented into groups of similar preferences, and offers targeted to a particular market segment. In this paper, we study a problem of revenue management for a network operator offering services on end‐to‐end markets, while facing competition. We present a natural formulation for this problem that uses bilinear bilevel programming models, similar to those used in the airline industry [Côté et al., J Revenue Pricing Manage 2 (2003), 23–36]. However, such an approach leads to optimization problems that are very difficult to solve exactly on the large scale instances found in the telecommunications industry. To address difficulties solving large problems, we introduce a new alternative formulation for the problem, give a proof of NP‐hardness, and propose solution methods related to this formulation. The first one is an exact method based on a branch‐and‐bound algorithm; then we propose two approximate methods, one based on Lagrangian relaxation, and one based on a concave approximation of the objective function to be maximized. Comparative results are given. We show that this approach is practically efficient and leads to exact solutions for instances of telecommunications networks of a size larger than previously possible. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(1), 37–49 2007
A non‐linear programming method approach for upper bound limit analysis
Authors: Vicente da Silva M. , Antão A. N. 
Published: April 2007

AbstractThis paper presents a finite element model based on mathematical non‐linear programming in order to determine upper bounds of colapse loads of a mechanical structure.The proposed formulation is derived within a kinematical approach framework, employing two simultaneous and independent field approximations for the velocity and strain rate fields. The augmented Lagrangian is used to establish the compatibility between these two fields. In this model, only continuous velocity fields are used.Uzawa's minimization algorithm is applied to determine the optimal kinematical field that minimizes the difference between external and dissipated work rate. The use of this technique allows to bypass the complexity of the non‐linear aspects of the problem, since non‐linearity is addressed as a set of small local subproblems of optimization for each finite element.The obtained model is quite versatile and suitable for solving a wide range of collapse problems. This paper studies 3D strut‐and‐tie structures, 2D plane strain/stress and 3D solid problems. Copyright © 2007 John Wiley & Sons, Ltd.
Assessment of anthrax vaccination data in the Defense Medical Surveillance System, 1998–2004
Authors: Payne Daniel C. , Rose Charles E. , Aranas Aaron , Zhang Yujia , Tolentino Herman , Weston Emily , McNeil Michael M. , Ruscio Bruce 
Published: April 2007

AbstractPurposeUnderstanding the completeness and accuracy of U.S. military anthrax vaccination data is important to the design and interpretation of studies to assess the safety of anthrax vaccine. We estimated the agreement between electronically recorded anthrax vaccination data in the Defense Medical Surveillance System (DMSS) versus anthrax vaccination data abstracted from hardcopy medical charts in a representative sample of the U.S. military from 1998 to 2004.MethodsMedical chart abstractions were conducted at 28 military treatment facilities for 4201 personnel. Abstracted anthrax vaccination data for 1817 personnel, representing 7400 anthrax vaccine doses, were compared with electronically captured data in the DMSS from 1998 to 2004. Sensitivity, positive predictive value (PPV), specificity and negative predictive value (NPV) were calculated using weighted analyses.ResultsWeighted person‐level analysis revealed DMSS sensitivity = 93.8% (95%CI = 91.1, 95.8), specificity = 87.0% (79.0, 92.3), PPV = 85.6% (77.2, 91.3) and NPV = 94.5% (91.7, 96.4). Report of anthrax vaccination within a ±7 days window in both medical chart and DMSS electronic data had a sensitivity of 88.3% (85.4, 90.7) and a PPV of 86.6% (84.9, 88.2) in the vaccine dose‐level analysis.ConclusionsThese results support that anthrax vaccination data captured by the DMSS are adequate for post‐marketing surveillance investigations in the U.S. military and are of comparable quality to data captured by other vaccine safety databases. Copyright © 2007 John Wiley & Sons, Ltd.
Duration of therapy with metoclopramide: a prescription claims data study
Authors: Kaplan Sigal , Staffa Judy A. , Dal Pan Gerald J. 
Published: April 2007

AbstractPurposeMetoclopramide‐induced tardive dyskinesia is associated with cumulative drug exposure, which can result from prolonged use of the drug. We estimated therapy duration with metoclopramide, and measured the extent of therapy beyond the maximum time period of 12 weeks evaluated in the clinical trials and recommended in the label.MethodsPrescription claims for metoclopramide from 2002 to 2004 were extracted for participants residing throughout the US and contained within the Caremark pharmacy benefit manager (PBM) database. An episode of therapy was defined as one or a series of consecutive claims with no more than a 30‐day lag between the dispensing date of a new claim and the ending date of the preceding claim. Episode duration was calculated by subtracting the start date from the end date for each episode.ResultsDuring the study period, almost 80% of participants (total = 200 907) had only one episode of therapy. The length of the longest episode for most patients (85%) varied from 1 to 90 days, yet 15% of the patients appeared to have received prescriptions for metoclopramide for a period longer than 90 days. Cumulative therapy for longer than 90 days was recorded for almost 20% of the patients.ConclusionsThese results suggest that despite the known risk of tardive dyskinesia and the labeled recommendations on duration of metoclopramide use, many patients appear to use the drug for relatively long time periods beyond the labeled recommendations. Physicians should carefully consider the risk‐benefit profile of the drug and, if possible, avoid increased risk of tardive dyskinesia due to prolonged exposure. Published in 2007 by John Wiley & Sons, Ltd.
Results of forty years Yellow Card reporting for commonly used perioperative analgesic drugs
Authors: Richardson Jennifer , Holdcroft Anita 
Published: April 2007

AbstractBackgroundA variety of analgesics are used perioperatively and associated adverse drug reactions (ADRs) may complicate anaesthesia and recovery.MethodsWe aimed to measure the demographics of reported suspected ADRs to alfentanil, fentanyl, ketorolac, morphine, nalbuphine, papaveretum, pethidine and remifentanil. We report a retrospective analysis of Yellow Card reports of suspected ADRs from 1965–2004 as classified in the Adverse Drug Reaction On‐line Tracking database (ADROIT) of the Medicines and Healthcare products Regulatory Agency (MHRA).ResultsIn total, 1312 reactions were retrieved. A single drug was reported in 908, 39 were fatal and 219 categorised as ‘allergic’. Allergic phenomenon varied from 2/33 (6%) for remifentanil to 11/53 (21%) for alfentanil. ‘Cardiovascular’ reactions were reported frequently with remifentanil (18/33, 55%) and alfentanil (19/53, 36%) and these generated a signal for possible hazards from proportional reporting ratios (PRRs). The opioid fentanyl was associated with similar hazard signals for muscular and psychiatric ADRs.ConclusionsPerioperative vigilance may reduce morbidity and mortality from preventable ADRs to analgesic drugs. Denominator and diagnostic data are essential for prospective studies. Copyright © 2007 John Wiley & Sons, Ltd.
Aggregative structure of the 1‐octadecyl‐3‐methylimidazolium cation in the interlayer of montmorillonite and its effect on polypropylene melt intercalation
Authors: Ding Yunsheng , Xiong Renyan , Wang Sengshan , Zhang Xiaomin 
Published: April 2007

AbstractA series of organomontmorillonites were synthesized from pristine sodium montmorillonite via ion exchange in toluene with 1‐octadecyl‐3‐methylimidazolium chloride, a kind of ionic liquid with high thermal stability, as a modifier. The amount and aggregative state of the 1‐octadecyl‐3‐methylimidazolium cation ([C18mim]+) adsorbed in the interlayer of organomontmorillonite (MMT) were investigated with thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), and differential scanning calorimetry. XRD patterns showed that [C18mim]+ was successfully intercalated into the interlayer of MMT, and the interlayer distances of the clays increased dramatically. On the basis of the TGA results, three types of arrangement models of [C18mim]+ could be seen, and they were related to the loading level of [C18mim]+ in the gallery of MMT. The effects of the aggregative structure of [C18mim]+ in the interlayer of MMT on polypropylene melt intercalation was also examined. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1252–1259, 2007
Integrated control of pests in tropical and subtropical sweet pepper production
Authors: Weintraub Phyllis G 
Published: April 2007

AbstractSweet pepper is now grown, in tropical and subtropical areas, under the integrated pest management (IPM) tactic of ‘physical barrier’, whereas it was once grown primarily in open fields. This management tactic, when properly employed, has the advantage of eliminating many of the larger open‐field pests, and has resulted in greatly increased pepper yields. However, certain other pest populations are exacerbated by this IPM tactic. This paper reviews the primary pests and current control tactics in sweet pepper. Copyright © 2007 Society of Chemical Industry
Effect of pyriproxyfen on developing stages and embryogenesis of California red scale (CRS), Aonidiella aurantii
Authors: Eliahu Miriam , Blumberg Daniel , Horowitz A Rami , Ishaaya Isaac 
Published: April 2007

AbstractDuring the past decade, the insect growth regulator pyriproxyfen has been the most used insecticide for controlling the California red scale (CRS), Aonidiella aurantii (Maskell), an important pest in citrus groves worldwide. The aim of the present research was to develop bioassays for determining the effect of pyriproxyfen on developing stages and embryogenesis of CRS that can serve as baselines for monitoring resistance. Pyriproxyfen was very effective against first‐ and second‐instar nymphs of a susceptible strain of CRS; 0.1 and 0.2 mg AI L−1, resulting in 80 and 100% mortality of first‐instar nymphs, and in 62.5 and 91.7% mortality of second‐instar nymphs respectively. According to probit analysis, the LC50 and LC90 values of pyriproxyfen for first‐instar nymphs were 0.03 and 0.15 mg AI L−1, and for second‐instar nymphs they were 0.05 and 0.25 mg AI L−1 respectively. Pyriproxyfen was quite effective on first‐instar nymphs of a CRS field strain originating from a citrus grove where two successive applications of the compound had been applied. Mortality rates were 86 and 100% at concentrations of 0.2 and 0.4 mg AI L−1 respectively. Pyriproxyfen suppressed embryogenesis when CRS females were treated with pyriproxyfen. Young CRS females treated with 1.0 and 5.0 mg AI L−1 pyriproxyfen produced 6.6 N1/F and 2.4 N1/F as compared with 10.9 N1/F in untreated control. Copyright © 2007 Society of Chemical Industry
Managing arable weeds for biodiversity
Authors: Storkey Jonathan , Westbury Duncan B 
Published: April 2007

AbstractAs a result of the recent intensification of crop production, the abundance and diversity of UK arable weeds adapted to cultivated land have declined, with an associated reduction in farmland birds. A number of questions need to be addressed when considering how these declines can be reversed. Firstly, can the delivery of crop production and biodiversity be reconciled by spatially separating cropping from designated wildlife areas? A number of subsidised environmental schemes in the UK take this approach and are focused on establishing vegetation cover on uncropped land. However, because of the lack of regular disturbance in these habitats, they are dominated by perennials and they therefore have limited potential for promoting the recovery of annual weed populations. A number of farmland bird species also rely on the provision of resources in field centres, and it is therefore likely that the recovery of their populations will rely on weed management options targeted at the cropped areas of the field. This raises two further questions. Firstly, is it possible to identify beneficial weed species that are relatively poor competitors with the crop and also have biodiversity value? Secondly, are the tools available to manage these species at acceptable levels while controlling pernicious weeds? A number of approaches are being employed to answer these questions, including predicting yield loss from weed competition models and exploiting herbicide selectivity. The further development of these tools is crucial if farmer opposition to managing weeds in crops is to be overcome. Copyright © 2007 Society of Chemical Industry