bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technical and industrial approaches for super plastic forming and diffusion bonding (SPF/DB) titanium alloy leading edge manufacturing
Authors: Ortiz A. A. , Gago J. , Sanchez P. , Gil V. , Rubio L. 
Published: September 2014

The A330/340 HTP leading edge has shifted the prior composite into a new metallic design based on a SPF/DB manufacturing process for a two sheet D‐nose. Superplastic forming and diffusion bonding were the technological means to obtain an integrated detailed part.Moreover, this component was part of the set that made introduction and development SPF/DB feasible within EADS CASA at its facilities located in Cadiz. The main driving factor to launch this program was the weight saving intended for the A330/340 horizontal stabilizer.The design concept was based on two raw material sheets (with initial nominal thicknesses of 3 mm and 0.8 mm) forming skins and spars. The skin was shaped into an aerodynamic nose and the flat spar was also stiffened by swages. It was diffusion bonded to the above mentioned skin by means of two flanges. The final shape is denominated by the term D‐nose, due to the resulting geometrical configuration.The initial manufacturing process was based on a two step press forming process, with part integration as the main goal. This process was robust enough to achieve structural parts with industrial tolerance ranges. Since tighter tolerances ranges and higher than expected ramp up arose, creative improvements were set up to meet the program expectations. A single press forming phase was implemented, resulting in a lower press labour time and a higher quality product.Further increased mass production rates challenged the industrial means to reach higher efficiency. A compromise between part integration, costs and industrial means best practices has shown how detail parts assembly constitutes also a cost effective solution under specific industrial conditions.This article describes the advantages and drawbacks of three alternative SPF manufacturing processes to fabricate superplastic titanium alloys leading edges, which have been validated for mass production purposes.
The study of the technology parameters on the superplasticity of the new Al–Zn–Mg–Cu–Ni–Zr base alloy
Authors: Mikhaylovskaya A. V. , Kotov A. D. , Levchenko V. S. , Portnoy V. K. 
Published: September 2014

Al–Zn–Mg–Cu aluminum alloy contain 0.3% Zr and 4% Ni was processed by traditional hot and cold rolling with a total reduction from 0 to 80%. The relationship between superplastic behavior and reduction of cold deformation and casting cooling rate was analyzed. It is shown that the decrease in the reduction of cold rolling do not significantly influence on flow stress and elongation. Decrease in casting cooling rate leads to insignificantly decrease in superplastic indicators. Alloy exhibits advanced superplasticity: the elongation of 400–800% at the strain rates of (5 × 10–3–1 × 10–1) s–1.
Material saving and cost reduction with hot forming of U‐shaped titanium part
Authors: Stutz L. , Beck W. , Arends S. , Horstmann M. , Ventzke Volker , Kashaev N. 
Published: September 2014

Titanium alloy sheets are widely used for highly loaded components in the aerospace industry as well as spacecrafts. The unique combination of high strength, outstanding corrosion resistance and thermal endurance makes titanium alloys the preferred material for applications with severe requirements.Due to the limited formability at room temperature, forming processes have to be conducted in a multitude of steps what is costly and labour intensive. Additionally, typical titanium alloy sheets show a significant anisotropy of mechanical properties and material flow. Undesired earing, wall thickness variation and residual stresses are the result.Complex shaped parts can be produced at elevated temperatures to avoid named drawbacks. The present work introduces a newly developed hot deep drawing process, applied to titanium sheets at FormTech. In comparison with conventional superplastic forming processes via gas pressure, hot deep drawing comes with a significantly reduced process time and hence, increased output over time.Titanium sheets of the work horse alloy Ti–6Al–4V were formed in a single stroke to a U‐shaped component at process temperatures ranging from 750 to 890 °C. Specimens were extracted to validate the neglectable influence of the hot forming process on mechanical properties and fatigue behaviour. In conclusion, hot deep drawing of titanium sheets offers a cost efficient alternative to a gas pressure superplastic forming process, while maintaining its main benefits such as significantly improved formability, low residual stresses and tight tolerances.
Low peak power multiband spokes pulses for B1+ inhomogeneity‐compensated simultaneous multislice excitation in high field MRI
Authors: Sharma Anuj , Bammer Roland , Stenger V. Andrew , Grissom William A 
Published: September 2014

PurposeTo design low peak and integrated power simultaneous multislice excitation radiofrequency pulses with transmit field inhomogeneity compensation in high field MRI.Theory and MethodsThe “interleaved greedy and local optimization” algorithm for small‐tip‐angle spokes pulses is extended to design multiband (MB) spokes pulses that simultaneously excite multiple slices, with independent spokes weight optimization for each slice. The peak power of the pulses is controlled using a slice phase optimization technique. Simulations were performed at 7T to compare the peak power of optimized MB spokes pulses to unoptimized pulses, and to compare the proposed slice‐independent spokes weight optimization to a joint approach. In vivo experiments were performed at 7T to validate the pulse's function and compare them to conventional MB pulses.ResultsSimulations showed that the peak power‐minimized pulses had lower peak power than unregularized and integrated power‐regularized pulses, and that the slice‐independent spokes weight optimization consistently produced lower flip angle inhomogeneity and lower peak and integrated power pulses. In the brain imaging experiments, the MB spokes pulses showed significant improvement in excitation flip angle and subsequently signal homogeneity compared to conventional MB pulses.ConclusionThe proposed MB spokes pulses improve flip angle homogeneity in simultaneous multislice acquisitions at ultrahigh field, with minimal increase in integrated and peak radiofrequency power. Magn Reson Med 74:747–755, 2015. © 2014 Wiley Periodicals, Inc.
Several variants of the Hermitian and skew‐Hermitian splitting method for a class of complex symmetric linear systems
Authors: Wu Shi‐Liang 
Published: September 2014

SummaryThis paper is concerned with several variants of the Hermitian and skew‐Hermitian splitting iteration method to solve a class of complex symmetric linear systems. Theoretical analysis shows that several Hermitian and skew‐Hermitian splitting based iteration methods are unconditionally convergent. Numerical experiments from an n‐degree‐of‐freedom linear system are reported to illustrate the efficiency of the proposed methods. Copyright © 2014 John Wiley & Sons, Ltd.
Women's views and the impact of noninvasive prenatal testing on procedures in a managed care setting
Authors: Tiller George E. , Kershberg Hilary B. , Goff John , Coffeen Christin , Liao Wayne , Sehnert Amy J. 
Published: September 2014

AbstractObjectiveTo prospectively determine the impact of noninvasive prenatal testing (NIPT) on invasive procedure utilization in a managed care setting and to elucidate women's views.MethodsPregnant women at 10–20 weeks' gestation with high‐risk indications for fetal aneuploidy in the Kaiser Permanente Southern California organization were eligible. Enrolled patients received routine prenatal counseling, completed a questionnaire and were offered the option of NIPT by a genetic counselor. Downstream data through 28 weeks' gestation were collected from the electronic medical record (EMR). The EMR was also used to identify a matched historical cohort from 1 year prior to NIPT availability. Rates of invasive prenatal procedures were compared using McNemar's test.ResultsTwo hundred women completed the questionnaire and underwent NIPT. Twenty‐two subjects (11%) in the prospective cohort underwent an invasive prenatal procedure compared with 58 (29%) in the historical cohort (p<0.0001). Safety and accuracy were the most important factors in considering NIPT. At the time of survey, only 12% indicated being very comfortable with the possibility of undergoing amniocentesis.ConclusionThis prospective study demonstrates a 62% reduction in invasive prenatal procedures after NIPT testing and finds safety, accuracy, and personal beliefs key to women's decision‐making. © 2014 John Wiley & Sons, Ltd.
Plasticity for axolotl lens regeneration is associated with age‐related changes in gene expression
Authors: Sousounis Konstantinos , Athippozhy Antony T. , Voss S. Randal , Tsonis Panagiotis A. 
Published: September 2014

AbstractMexican axolotls lose potential for lens regeneration 2 weeks after hatching. We used microarrays to identify differently expressed genes before and after this critical time, using RNA isolated from iris. Over 3700 genes were identified as differentially expressed in response to lentectomy between young (7 days post‐hatching) and old (3 months post‐hatching) axolotl larvae. Strikingly, many of the genes were only expressed in the early or late iris. Genes that were highly expressed in young iris significantly enriched electron transport chain, transcription, metabolism, and cell cycle gene ontologies, all of which are associated with lens regeneration. In contrast, genes associated with cellular differentiation and tissue maturation were uniquely expressed in old iris. Many of these expression differences strongly suggest that young and old iris samples were collected before and after the spleen became developmentally competent to produce and secrete cells with humoral and innate immunity functions. Our study establishes the axolotl as a powerful model to investigate age‐related cellular differentiation and immune system ontogeny within the context of tissue regeneration.
Global Warming Effects on Faecal Coliform Bacterium Watershed Impairments in Portugal
Authors: Fonseca A. , Botelho C. , Boaventura R. A. R. , Vilar V. J. P. 
Published: September 2014

AbstractImpairment of surface water quality by faecal coliform bacteria is an issue of great importance across the globe. A water quality model, Hydrological Simulation Program FORTRAN, was used to predict the impacts of farming and climate change on faecal coliform loads and concentrations in streams of the Lis River watershed, in the Leiria region, Portugal. The calibrated faecal coliform model simulated well the patterns and range of observed faecal coliform concentrations. The accuracy of the model was evaluated by the per cent bias coefficient and the coefficient of determination. The results indicate a general deterioration of the water quality regarding faecal contamination in Lis River. Maximum daily loads were calculated for each of the impaired streams; an average of 77% reduction in the current faecal coliform load from the watershed is necessary to achieve the established water quality goals by the Council Directive 75/440/EEC (). Climate change scenarios (increments on temperature and precipitation) were assumed to predict the behaviour of faecal coliform bacteria in the watershed. The simulated results showed that an increase of 1°C in air daily temperature results in an increase of water temperature of 1.1°C and a 1.5% decrease on faecal coliform bacteria in stream concentration. The combined effect of air temperature (+1°C) and precipitation (+7%) increment leads to an increase of ~2% in bacteria inflow to the basin. Copyright © 2014 John Wiley & Sons, Ltd.
Flooding and Surface Connectivity of Taxodium‐Nyssa Stands in a Southern Floodplain Forest Ecosystem
Authors: Kupfer J. A. , Meitzen K. M. , Gao P. 
Published: September 2014

AbstractAn understanding of the factors controlling the permanent and episodic links between the main stem of a river and the ecosystems of its alluvial floodplain is necessary for evaluating the influence of modern river processes on floodplain ecology and habitat diversity and for the successful implementation of flow regimes that meet human needs for water in a manner that sustains the ecological integrity of affected systems. In this study, we examined relationships between river hydrology and lateral hydrological connectivity, which is crucial to directing fluxes of water, material, and organisms into and across a floodplain. We did so by translating measures of river discharge for the Congaree River into high resolution maps of flood conditions for the floodplain at Congaree National Park using a 2D flood inundation model. Utilizing a graph network approach, we then analyzed the connectivity of a key wetland ecosystem, Taxodium‐Nyssa forested swamps, to the main stem river and to each other under different flows. Our results underscore that floodplain connectivity is initiated at sub‐bankfull discharges and does not depend on levee overtopping, while also clarifying that various sources of connectivity are triggered at different flow levels in specific reaches. Further, our findings demonstrate the sensitive and non‐linear response of floodplain connectivity to river flows and provide useful information to facilitate the management of flood processes in the Congaree River watershed. Copyright © 2014 John Wiley & Sons, Ltd.
Venous anomalies of the fetal heart
Authors: Bloomfield Sue 
Published: September 2014

AbstractVenous anomalies of the fetal heart are rare, difficult to diagnose and often not appreciated on routine antenatal ultrasound. When not identified, these anomalies may have potentially devastating outcomes. With practice, these anomalies can be recognised on standard views of the heart at the morphology scan. The aim of this article is to discuss the anatomy, pathology and sonographic findings of anomalies of the superior vena cava, inferior vena cava and pulmonary veins in the fetus and discuss some of the associated findings and outcomes.
“The Brown Face of Hope”
Authors: Meier Terry 
Published: September 2014

AbstractAfrican American children's literature has a potentially powerful role to play in increasing reading engagement for African American boys. Unfortunately, this body of literature is not always used effectively in schools. Many teachers use African American books as an add‐on to pre‐exisiting curriculum rather than fully exploring the topics, themes, and images that characterize the literature and that speak in powerful ways to issues of relevance in the lives of African American boys. A close examination of nine picture book biographies and one historical fiction account of famous African American men reveals the rich potential of this literature for making a difference in children's lives.
Software for predicting the 3D structure of RNA molecules
Authors: Dufour David , Marti‐Renom Marc A. 
Published: September 2014

AbstractRNA is not regarded anymore as a simple transfer molecule between DNA and proteins. Indeed, over the past decades a plethora of new functional roles have been assigned to RNA molecules. Such functions are carried out either by RNA molecules alone or through interactions with DNA, other RNA molecules, or proteins. In all cases, the structure that the RNA molecule adopts will impact its function, as it happens with proteins. Therefore, to fully characterize the function of an RNA molecule, its structure needs to be either determined by experiments or predicted by computation. Unfortunately, our knowledge of the atomic mechanism by which RNA molecules adopt their biological active structures is still limited. Such hurdle is now being addressed by the development of new computational methods for RNA structure prediction, which complement experimental methods such as X‐ray crystallography, nuclear magnetic resonance, small‐angle X‐ray scattering, and cryo‐electron microscopy. This software focus is not dedicated to a single computational method but aims at outlining the most adopted methods for computational RNA structure prediction. WIREs Comput Mol Sci 2015, 5:56–61. doi: 10.1002/wcms.1198This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics
Software > Simulation Methods
An investigation of in‐field blockage effects in closely spaced lateral wind farm configurations
Authors: McTavish S. , Rodrigue S. , Feszty D. , Nitzsche F. 
Published: September 2014

AbstractA method of increasing the performance of wind farms has been established by limiting the lateral separation between neighbouring wind turbines. The close proximity of the wind turbines creates a beneficial in‐field blockage effect that results in a core of increased speed that is accelerated through the gap between the turbines. A preceding study indicated that the performance of three wind turbines can be increased by over 10% with tip‐to‐tip separation of 0.5 diameters (D) compared with the power output of the respective turbines in isolation. A corresponding flow‐mapping study has been completed in the current work using a single‐normal hot‐wire anemometer to characterize the increased flow speed through a narrow lateral gap, leading to the observation of a region of increased speed that occurs between 0D and 2.5D downstream of the gap between laterally spaced wind turbines. The experimental results were confirmed by conducting a series of computational simulations with the generalized unsteady vortex particle discrete vortex method code. The simulations were conducted with three rotors arranged in five different configurations, and the increase in power generated by the multi‐rotor configurations closely followed the observed experimental trends. The closely spaced lateral wind turbine configurations may have the ability to increase the annual capacity factor of wind farms while reducing wind farm land use requirements. Copyright © 2014 John Wiley & Sons, Ltd.
The large-scale influence of the Great Barrier Reef matrix on wave attenuation
Authors: Gallop Shari L. , Young Ian R. , Ranasinghe Roshanka , Durrant Tom H. , Haigh Ivan D. 
Published: September 2014

Abstract

Offshore reef systems consist of individual reefs, with spaces in between, which together constitute the reef matrix. This is the first comprehensive, large-scale study, of the influence of an offshore reef system on wave climate and wave transmission. The focus was on the Great Barrier Reef (GBR), Australia, utilizing a 16-yr record of wave height from seven satellite altimeters. Within the GBR matrix, the wave climate is not strongly dependent on reef matrix submergence. This suggests that after initial wave breaking at the seaward edge of the reef matrix, wave energy that penetrates the matrix has little depth modulation. There is no clear evidence to suggest that as reef matrix porosity (ratio of spaces between individual reefs to reef area) decreases, wave attenuation increases. This is because individual reefs cast a wave shadow much larger than the reef itself; thus, a matrix of isolated reefs is remarkably effective at attenuating wave energy. This weak dependence of transmitted wave energy on depth of reef submergence, and reef matrix porosity, is also evident in the lee of the GBR matrix. Here, wave conditions appear to be dependent largely on local wind speed, rather than wave conditions either seaward, or within the reef matrix. This is because the GBR matrix is a very effective wave absorber, irrespective of water depth and reef matrix porosity.
Rural Neighborhoods and Child Aggression
Authors: Bowen Natasha K. , Wretman Christopher J. 
Published: September 2014

AbstractStructural equation modeling with latent variables was used to evaluate the direct and mediated effects of a neighborhood risk factor (negative teen behaviors) on the parent‐report aggressive behavior of 213 students in grades 3 through 5 attending a school in a low‐income, rural community. Contagion and social control hypotheses were examined as well as hypotheses about whether the neighborhood served as a microsystem or exosystem for rural pre‐adolescents. Analyses took into account the clustering of students and ordinal nature of the data. Findings suggest that rural neighborhoods may operate as both a microsystem and exosystem for children, with direct contagion effects on their aggressive behaviors as well as indirect social control effects through parenting practices. Direct effects on aggression were also found for parenting practices and child reports of friends’ negative behaviors. Pre‐adolescence may be a transitional stage, when influences of the neighborhood on child behavior begin to compete with influences of caregivers. Findings can inform the timing and targets of violence prevention in rural communities.
The Search-Coil Magnetometer for MMS
Authors: Le Contel O. , Leroy P. , Roux A. , Coillot C. , Alison D. , Bouabdellah A. , Mirioni L. , Meslier L. , Galic A. , Vassal M. C. , Torbert R. B. , Needell J. , Rau D. , Dors I. , Ergun R. E. , Westfall J. , Summers D. , Wallace J. , Magnes W. , Valavanoglou A. , Olsson G. , Chutter M. , Macri J. , Myers S. , Turco S. , Nolin J. , Bodet D. , Rowe K. , Tanguy M. , de la Porte B. 
Published: September 2014

Abstract
The tri-axial search-coil magnetometer (SCM) belongs to the FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission (Torbert et al. in Space Sci. Rev. (2014), this issue). It provides the three magnetic components of the waves from 1 Hz to 6 kHz in particular in the key regions of the Earth’s magnetosphere namely the subsolar region and the magnetotail. Magnetospheric plasmas being collisionless, such a measurement is crucial as the electromagnetic waves are thought to provide a way to ensure the conversion from magnetic to thermal and kinetic energies allowing local or global reconfigurations of the Earth’s magnetic field. The analog waveforms provided by the SCM are digitized and processed inside the digital signal processor (DSP), within the Central Electronics Box (CEB), together with the electric field data provided by the spin-plane double probe (SDP) and the axial double probe (ADP). On-board calibration signal provided by DSP allows the verification of the SCM transfer function once per orbit. Magnetic waveforms and on-board spectra computed by DSP are available at different time resolution depending on the selected mode. The SCM design is described in details as well as the different steps of the ground and in-flight calibrations.