bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal Periconceptional Exposure to Cigarette Smoking and Congenital Limb Deficiencies
Authors: Caspers Kristin M. , Romitti Paul A. , Lin Shao , Olney Richard S. , Holmes Lewis B. , Werler Martha M. ,   National Birth Defects Prevention Study
Published: July 2013

AbstractBackgroundCongenital limb deficiencies (LD)s are characterised by the failure or disruption in formation of limbs or digits. Epidemiological research on maternal exposure to cigarette smoke and LDs is inconclusive.MethodsData from the National Birth Defects Prevention Study were used to examine LDs and maternal exposure to active or passive cigarette smoke. Mothers of LD case (n = 906) and unaffected control (n = 8352) pregnancies from October 1997 through December 2007 reported on exposure type and quantity. Logistic regression was used to estimate adjusted odds ratio (OR) and 95% confidence interval [95% CI]; interactions with folic acid (FA) intake were tested.ResultsFor any LD, ORs were elevated for active (1.24 [95% CI 1.01, 1.53]), passive (home) (1.28 [95% CI 1.03, 1.59]), and ‘active and passive’ (1.34 [95% CI 1.05, 1.70]) exposures. The ORs for longitudinal LDs were elevated for passive (home) (1.62 [95% CI 1.14, 2.31]) and ‘active and passive’ (1.62 [95% CI 1.09, 2.41]) exposures. The OR for pre‐axial LDs were elevated for any (1.39 [95% CI 1.01, 1.90]), active (1.53 [95% CI 1.03, 2.29]), passive (home) (1.82 [95% CI 1.23, 2.69]), and ‘active and passive’ (1.87 [95% CI 1.20, 2.92]) exposures. For lower limbs, ORs were elevated for passive (home) (1.44 [95% CI 1.01, 2.04]) and smoking 15 or more cigarettes/day (2.25 [95% CI 1.27, 3.97]). Interactions showed that ORs for any passive smoke exposure were 0.43 and 0.59 higher in the absence of FA intake for any and terminal transverse LDs.ConclusionsMaternal active smoking and exposure to passive cigarette smoke emerged as a potential teratogen that affects limb and digit formation. FA was not found to mitigate the impact.
The zebrafish (Danio rerio) as a model organism, with emphasis on applications for finfish aquaculture research
Authors: Ribas Laia , Piferrer Francesc 
Published: July 2013

AbstractThe zebrafish (Danio rerio) is a freshwater teleost of the family Cyprinidae that is established as a model organism in many research fields. Here, we define the characteristics that a fish species should have to serve as a model for finfish aquaculture research and argue that the zebrafish fulfils essentially most of them. We first describe several aspects of the biology of the zebrafish including phylogenetic relationships, development and growth and reproduction, both in the wild and under laboratory conditions. Next, we review the work already carried out in zebrafish that is related to different aspects of aquaculture research (reproduction, stress, pathology, toxicology nutrition and growth). We assess critically the areas in which zebrafish still offers further potential as a model organism for aquaculture, which include, but are not limited to, development, immunology, genomics and reproduction. In other areas, however, limitations must be borne in mind and caution must be taken when extrapolating results. This is, for example, the case of some growth studies. Finally, we provide information on resources for research with zebrafish. Current general limitations of work with zebrafish come from the fact that in contrast to other laboratory animal models such as rodents, strict breeding protocols are generally not adopted. Nevertheless, as there is no major obstacle to overcome these limitations and due to its intrinsic advantages, we conclude that the zebrafish is likely to play an increasing role as a model organism in many areas of research for finfish aquaculture.
Emotional Reactivity and Regulation in Head Start Children: Links to Ecologically Valid Behaviors and Internalizing Problems
Authors: Morgan Judith K. , Izard Carroll E. , Hyde Christopher 
Published: July 2013

AbstractChildren's emotional reactivity may interact with their regulatory behaviors to contribute to internalizing problems and social functioning even early in development. Ninety‐one preschool children participated in a longitudinal project examining children's reactivity and regulatory behaviors as predictors of internalizing problems, and positive and negative social behavior in the classroom. Children who paired negative emotion expression with disengagement during a laboratory task showed higher levels of internalizing problems and more negative social behavior in the classroom 6 months later. Positive emotion expression paired with engagement during a laboratory task predicted more positive social behavior in the classroom 6 months later. Physiological reactivity and regulation also predicted children's social behavior in the classroom. Findings suggest that preschool children with maladaptive reactivity and regulatory patterns may be at greater risk for internalizing problems even in early childhood.
Serologic and molecular investigations of DAR1 (weak D Type 4.2), DAR1.2, DAR1.3, DAR2 (DARE), and DARA
Authors: Lejon Crottet Sofia , Haer‐Wigman Lonneke , Gowland Peter , Fontana Stefano , Niederhauser Christoph , Hustinx Hein 
Published: July 2013

BackgroundThe partial D variant DAR1 (weak D Type 4.2) is caused by three single‐point mutations, 602C>G, 667T>G, and 1025T>C. Here we report a molecular study on different D variants belonging to the DAR category (DAR1, DAR1.2, DAR1.3, and DAR2) and their serologic data.Study Design and MethodsA total of 42 samples belonging to the DAR category were screened for the presence of the silent mutations 744C>T and 957G>A. The samples were phenotyped for RhD and RhCE, characterized for RhD epitope expression, and sequenced for RHD exons. Flow cytometry was performed to determine RhD antigen density.ResultsThe silent mutation 744C>T was found in all six samples previously typed as RHD*DAR2 (602C>G, 667T>G, 957G>A, 1025T>C). In addition to the three nucleotide changes originally reported for the RHD*DAR1 allele, the silent mutations 744C>T and 957G>A were found in 14 of 16 samples previously typed as RHD*DAR1. In the remaining two samples one additional silent mutation, 744C>T, was found. Serologically the DAR1.2 and DAR1.3 samples analyzed in this study showed no distinct difference in their anti‐D reaction pattern compared to each other. The anti‐D reaction pattern of DARA/DAR2 showed some distinct differences compared to those of DAR1.2 and DAR1.3.ConclusionRHD*DARA and RHD*DAR2 are the same allele. Furthermore, the alleles RHD*DAR1.2 and RHD*DAR1.3 both exist; however, the silent mutation 957G>A (V319) showed no influence on the RhD phenotype.
Application of Limit Load Analysis to Complex Structures
Authors: Towse Adam , Martin Michael , Hurrell Paul , Philipson Rob , Allen Adrian , Andrews Chris 
Published: July 2013

There is currently little specific guidance on the application of Finite Element Based Limit Load Analysis to determine the primary load capacity of structures in the current ASME BPVC Section III. Consequently, a draft Code Case is currently under development to provide a structured framework within which such assessments may be made.
In this paper, the proposed Code Case methodology has been applied to demonstrate the process by which the primary load capacity of two geometrically complex structures may be calculated. The first structure is a curved pipe elbow into which a nozzle entry is placed, the second structure a large pressure vessel incorporating bolted joints.
The proposed Code Case step-by-step methodology is followed, including investigations into the propensity of the structures to exhibit geometric weakening or strengthening. The initial limit loads are calculated, and by selective application of elastic material, subsequent failure loads are calculated allowing design factors beyond initial failure to be determined.
Additional studies are also presented, investigating the effect of element types and secondary pre-stress effects on the failure modes.
Detailed Fatigue Checks Based on a Local Monitoring Concept
Authors: Rudolph Jürgen , Bergholz Steffen , Hilpert Roland 
Published: July 2013

The Detailed Fatigue Calculation (DFC) of nuclear power plant components is part of the three staged approach to lifetime assessment and lifetime management of the AREVA Fatigue Concept (AFC). It is applied for fatigue relevant components showing high usage factors by application of the Simplified Fatigue Evaluation (SFE) and/or the Fast Fatigue Evaluation (FFE), e.g. the preceding stages of the AFC. The quality of the fatigue lifetime assessment essentially depends on one hand on the fatigue model assumptions and on the other hand on the load data as the basic input. In the case of nuclear power plant components thermal transient loading is most fatigue relevant.
The issue of qualified determination of the real operating loads is crucial and closely connected to the fatigue monitoring strategy to be applied in the plant. As regards fatigue monitoring, two possible basic approaches are practiced: global and local concepts.
The first mentioned relies on signals from the standard plant instrumentation in connection with transfer functions whereas the second one requires additional measurement sections at fatigue relevant locations. As a compensation to the additional instrumentation effort, the application of a local fatigue monitoring strategy paves the way of delivering continuously (at a frequency of 1 Hz) realistic load data. Disposal of these data constitutes the first step within the flowchart of fatigue assessment. The according methods of qualified processing of these data are discussed in detail. The processing of arbitrary operational load sequences and the derivation of representative model transients are essential steps. Appropriate cycle counting approaches and the consideration of Environmentally Assisted Fatigue (EAF) by way of Fen-factors are addressed in this context.
Within the fatigue evaluation model the appropriate consideration of cyclic plasticity effects and the identification of fatigue damaging events are central modules. Plasticity correction is equally proposed in a staged approach by the application of established and more advanced Ke-factors within the simplified elasto-plastic analysis, the application of direct methods (such as the simplified theory of yield zones) and the general elasto-plastic analysis based on appropriate material models.
These three stages are characterized by increasing calculation effort and (usually) decreasing degree of conservatism. Their application is case dependent. Additionally, the general elasto-plastic analysis entails a cycle-by-cycle ratcheting check based on an appropriate material model as part of the detailed fatigue check (not elaborated in detail in this paper).
The application of the integrated AFC approach is explained by way of a representative example.
Environmentally Assisted Fatigue Assessment Considering an Alternative Method to the ASME Code Case N-792
Authors: Courtin Stéphan , Lefrançois André , Le Duff Jean-Alain , Le Pécheur Anne 
Published: July 2013

The conservatism of the austenitic stainless steel fatigue design curve has been severely questioned since the release of the NUREG/CR-6909 document [1] where a new methodology to assess environmentally assisted fatigue (EAF), including also a new in-air fatigue design curve, have been proposed. In the same way, the ASME Code Case N-792 [2] suggests calculating EAF usage factors via the multiplication of the in-air fatigue usage factors by Fen penalty factors, this resulting in a significant increase of these parameters.
In this context, AREVA NP SAS has performed, for several years, its own Pressurized Water Reactor (PWR) Low Cycle Fatigue (LCF) test program to better identify environmental effects in representative industrial conditions [3]. Among others, these experimental works have pointed out the over-conservatism of the NUREG/CR-6909 design approach. From these results, AREVA NP SAS has developed an alternative EAF assessment method which has been approved by the Finnish Nuclear Safety Authority [4]. This paper proposes to give an overview of this approach and to illustrate it on an EAF EPRI sample problem [5].
Development of Stress Intensity Factors for Deep Surface Cracks in Plates and Cylinders
Authors: Li Yinsheng , Itoh Hiroto , Hasegawa Kunio , Osakabe Kazuya , Okada Hiroshi 
Published: July 2013

A number of deep surface cracks have been detected in components of nuclear power plants in recent years. The depths of these cracks are even greater than the half of crack lengths. When a crack is detected during in-service inspections, methods provided in the ASME Boiler and Pressure Vessel Code Section XI or JSME Rules on Fitness-for-Service for Nuclear Power Plants can be used to assess the structural integrity of cracked components. The solution of the stress intensity factor is very important in the assessment of structural integrity. However, in the current codes, the solutions of the stress intensity factor are provided for semi-elliptical surface cracks with a limitation of a/l ≤ 0.5, where a is the crack depth, and l is the crack length.
In this study, in order to assess the structural integrity in a more rational manner, the solutions of the stress intensity factor were calculated using finite element analysis with quadratic hexahedron elements for deep semi-elliptical surface cracks in plates, and for axial and circumferential semi-elliptical surface cracks in cylinders. The crack dimensions were focused on the range of a/l = 0.5 to 4.0. Solutions were provided at both the deepest and the surface points of the cracks. Furthermore, some of solutions were compared with the available existing studies and with solutions obtained using finite element analysis with quadratic tetrahedral elements and the virtual crack closure-integral method. As the conclusion, it is concluded that the solutions proposed in this paper are applicable in engineering applications.
Strain-Based Fatigue Methods Using Modern Finite Element Analysis for the Assessment of Pressure Vessels Equivalent to the ASME III Code
Authors: Rawson Lindsay , Rice David 
Published: July 2013

The use of ASME III Design-By-Analysis assessment methodologies pre-dates the routine use of finite element software which can make the assessment of complex 3D geometries difficult. Recent progress in computing power and software have led to the increased possibility to utilise these developments and undertake ASME III type assessments on 3D components in more efficient and less labour intensive ways. The use of finite element software and post-processing codes is now widespread and full procedures for direct shakedown analysis and whole component fatigue assessment using software applications are becoming more readily available. Utilisation of these procedures can lead to a more robust assessment in a reduced analysis time therefore leading to reduced assessment costs.
This paper focuses on the use of strain-based fatigue post-processing software to predict the fatigue life of a component. Strain-based fatigue life prediction provides a direct assessment of plasticity in the component which will lead to less conservative assessment and a less pessimistic fatigue life. Utilising this software also means a fatigue analysis of the whole model can be undertaken potentially reducing the subjectivity of any results obtained. This paper will discuss how strain-based fatigue methods can be applied to results from finite element models and how they compare to fatigue life calculations using traditional methods. Some of the practical implications of undertaking a fatigue assessment using these methods such as cycle counting for multiple transient histories are also discussed. An example based upon a typical reactor plant pressure vessel geometry using these methods is presented in this paper.
Development of Ultra Large Scale Computation for Transient Welding Deformation and Stress Using Idealized Explicit FEM Accelerated by GPU
Authors: Ikushima Kazuki , Itoh Shinsuke , Shibahara Masakazu 
Published: July 2013

Numerical simulations such as Finite Element Method (FEM) are widely used as tool of structural analyses in both design and production. However, in the application of FEM to welding problems, the simulation scale is usually limited to the welding joint level. Only a few large-scale welding analyses are performed on existing research because welding problems are transient and show strong nonlinearity. In such cases, it is necessary to use static implicit FEM to achieve an accurate analysis, but the larger analysis scale requires larger memory consumption and computing time. Thus, we previously proposed idealized explicit FEM (IEFEM) to achieve shorter computing time and lower memory consumption.
Since IEFEM is based on dynamic explicit FEM, it is not needed to solve the stiffness matrix of the whole system and it is possible to analyze by only performing the calculation for each degree of freedom (DOF) and element. Such characteristic indicates that IEFEM is suitable for parallelization. Then, in this study, we developed parallelized IEFEM using a graphics processing unit (GPU). The usefulness and validity of the developed method are considered by analyzing a 3-dimensional multi-pass moving heat source problem, which is very difficult to analyze with commercial FEM software because of its analytical scale. As a result, it is found that parallelized IEFEM accelerated by a GPU can analyze a large-scale problem having over 1,000,000 DOFs on a single PC.
Shakedown and Ratcheting Assessment of a Tubeplate Using the Linear Matching Method
Authors: Reece-Barkell H. , Stevens M. , Tipping D. J. , Sole J. 
Published: July 2013

Power plant components may be subject to severe ranges of pressure and temperature when in-service. As a result, significant pressure and thermal stresses may occur which are cyclic in nature. For such components it is necessary to demonstrate an acceptable creep and fatigue life. However, before any such assessment can take place it must first be demonstrated that the cyclic loading would not lead to incremental plasticity, also known as ratcheting, and ultimately plastic collapse. If ratcheting does occurs then the calculation of creep and fatigue lives based upon a steady cyclic behaviour is invalid. It is therefore useful for find out how close structures are to ratcheting.
A power plant tubeplate has been analysed using non-linear finite element methods to assess its susceptibility to ratcheting and the potential for plastic collapse to occur. This is referred to as a shakedown assessment. Finite element analysis is a traditional method for assessing shakedown, however this approach is computationally expensive. An alternative method of assessing shakedown, which is significantly more efficient, although not as well validated, is the Linear Matching Method.
In this work, both finite element analysis and the Linear Matching Method have been used on a real world problem. The objective of this work is to assess the advantages and disadvantages of the LMM when compared to traditional non-linear finite element methods.
Ratchet Boundary Evaluation and Comparison With Ratcheting Experiments Involving Strain Hardening Material Models
Authors: Indermohan H. , Reinhardt W. 
Published: July 2013

Pressure components in nuclear power plants are designed to prevent the failure mechanism of incremental deformation or “ratcheting” due to the simultaneous application of mechanical loads such as pressure and cyclic loads. Design criteria using elastic methods that are specified in NB-3200 of ASME Section III Code are derived from a perfectly-plastic material model. The Code allows the use of plastic methods to demonstrate an acceptable response to cyclic loading, but does not provide clear guidance on any specific plasticity model to use.
It has been shown in previous studies that some strain hardening plasticity models are unsuitable for establishing the absence of ratcheting. In this paper, the ratchet boundary obtained from the perfectly plastic and the strain hardening Armstrong-Frederick material models are examined based on the published experimental investigations of the classical Bree problem, pipe bends under in-plane bending and tension-torsion tests. Suitable criteria for evaluating the cyclic analysis response are discussed.
Computations of Stress Intensity Factors for Deep Cracks in Plates by Using the Tetrahedral Finite Element
Authors: Okada Hiroshi , Koya Hirohito , Kawai Hiroshi , Li Yinsheng 
Published: July 2013

In this paper, stress intensity factor solutions for deep half-elliptical cracks that are applicable to the structural integrity evaluations of welded structures are presented. Welded structures generally have some weld residual stresses resulting in stress corrosion crackings (SCCs). This paper describes a simple way to compute the stress intensity factors under the weld-residual stresses and the mode I stress intensity factor solutions for deep half-elliptical cracks. The residual stresses are set to vary proportional to the constant, the linear, the quadratic and the cubic functions of x which is the distance from the plate surface.
Although we use a straightforward finite element method to perform the computations, we can quickly generate the stress intensity factor solutions as we make use of automatic mesh generation program for the tetrahedral finite element. Thus, it is very tractable to generate the finite element models with cracks. Furthermore, present solutions can be compared with those of Li et al. which are also presented in PVP 2012. We conclude that present method is useful for the evaluations of SIFs of cracks under the residual stresses.
Ageing Management of Cast Stainless Steel Components in French PWRs
Authors: Faidy Claude 
Published: July 2013

During the past 20 years many works have been done on Ageing Management Program (AMP) of Safety classed components in EDF.
To-day, EDF is starting the 3rd ten-year shutdown of all these 3-loop plants (34 plants). During the associated Safety Review, a specific task is devoted to ageing effects and management of all the safety concerned components. A large list of components has been reviewed: mechanical, civil engineering, instrumentation and control, cables, non metallic components.
Cast duplex stainless steel components are an example of these reviews. This material is used in many PWR components: elbows, pump casing, valves…A specific Ageing Management Program has been developed in France in the past 20 years in order to consider thermal ageing consequences on different components.
This program considers:
- Degradation mechanism understanding;
- Diagnostic: what are the more sensitive components;
- Monitoring in operation: thermal power;
- In-service inspection: radiography and other laboratory methods;
- Flaw evaluation and material properties;
- Replacement of elbows, alone or associated to steam generator replacement.
The paper will give a short description of each topic. In the moment EDF is planning a large replacement program of CF8M elbows to assure safety margins for 60 years of operation.