bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial and temporal expression patterns of auxin response transcription factors in the syncytium induced by the beet cyst nematode Heterodera schachtii in Arabidopsis
Authors: Hewezi Tarek , Piya Sarbottam , Richard Geoffrey , Rice J. Hollis
Published: January 2014

Plant‐parasitic cyst nematodes induce the formation of a multinucleated feeding site in the infected root, termed the syncytium. Recent studies point to key roles of the phytohormone auxin in the regulation of gene expression and establishment of the syncytium. Nevertheless, information about the spatiotemporal expression patterns of the transcription factors that mediate auxin transcriptional responses during syncytium formation is limited. Here, we provide a gene expression map of 22 auxin response factors (ARFs) during the initiation, formation and maintenance stages of the syncytium induced by the cyst nematode Heterodera schachtii in Arabidopsis. We observed distinct and overlapping expression patterns of ARFs throughout syncytium development phases. We identified a set of ARFs whose expression is predominantly located inside the developing syncytium, whereas others are expressed in the neighbouring cells, presumably to initiate specific transcriptional programmes required for their incorporation within the developing syncytium. Our analyses also point to a role of certain ARFs in determining the maximum size of the syncytium. In addition, several ARFs were found to be highly expressed in fully developed syncytia, suggesting a role in maintaining the functional phenotype of mature syncytia. The dynamic distribution and overlapping expression patterns of various ARFs seem to be essential characteristics of ARF activity during syncytium development.
Excess adiposity and survival in patients with colorectal cancer: a systematic review
Authors: Parkin Edward , O'Reilly Derek A , Sherlock David J , Manoharan Prakash , Renehan Andrew G
Published: January 2014

Excess adiposity is an established risk factor for incident colorectal cancer (CRC) but whether this association extrapolates to poorer survival is unclear. We undertook a systematic review to examine relationships between measures of adiposity and survival in patients with CRC. For distinction, we included pre‐diagnosis exposure and CRC‐related mortality. We performed dose‐response meta‐analyses and assessed study quality using eight domains of bias. Six study categories were identified based on (i) timing of adiposity measurement relative to survival analysis time zero and (ii) clinical setting. Several types of adiposity measurements were reported; body mass index (BMI) was the commonest. For pre‐diagnosis cohorts, baseline BMI negatively impacted on CRC‐related mortality in men only (risk estimate per 5 kg m−2 = 1.19, 95% confidence intervals: 1.14–1.25). The other groups were pre‐diagnosis BMI but diagnosis as time zero; population‐based cohorts; treatment cohorts; observational analyses within adjuvant chemotherapy trials; patients with metastatic CRC – each had several biases (e.g. treatment selection, reverse causality) and sources of confounding (e.g. chemotherapy ‘capping’). Overall, there was insufficient evidence for a strong link between adiposity and survival. These findings demonstrate an important principle: an established link between an exposure (here, adiposity) and increased cancer incidence does not necessarily extrapolate into an inferior post‐treatment outcome.
A systematic review of persuasive marketing techniques to promote food to children on television
Authors: Jenkin G. , Madhvani N. , Signal L. , Bowers S.
Published: January 2014

The ubiquitous marketing of energy‐dense, nutrient‐poor food and beverages is a key modifiable influence on childhood dietary patterns and obesity. Much of the research on television food advertising is focused on identifying and quantifying unhealthy food marketing with comparatively few studies examining persuasive marketing techniques to promote unhealthy food to children. This review identifies the most frequently documented persuasive marketing techniques to promote food to children via television. A systematic search of eight online databases using key search terms identified 267 unique articles. Thirty‐eight articles met the inclusion criteria. A narrative synthesis of the reviewed studies revealed the most commonly reported persuasive techniques used on television to promote food to children. These were the use of premium offers, promotional characters, nutrition and health‐related claims, the theme of taste, and the emotional appeal of fun. Identifying and documenting these commonly reported persuasive marketing techniques to promote food to children on television is critical for the monitoring and evaluation of advertising codes and industry pledges and the development of further regulation in this area. This has a strong potential to curbing the international obesity epidemic besieging children throughout the world.
A review of the nutritional value of legumes and their effects on obesity and its related co‐morbidities
Authors: Rebello C. J. , Greenway F. L. , Finley J. W.
Published: January 2014

Since the 1970s, the proportion of overweight and obese people in the United States has grown at an alarming rate. An awareness of the consequences of obesity on the health and well‐being of individuals is evident in the plethora of strategic plans at the local and national levels, most of which have largely fallen short of their goals. If interventions continue to be unsuccessful, it is estimated that approximately three of four Americans will be overweight or obese by 2020. Prevention of excess weight gain can be accomplished with relatively small changes in lifestyle behaviours to control body weight. Small sustainable changes are perhaps better than efforts to achieve larger changes that cannot be sustained. Legumes can be a valuable food by which the needs of the undernourished or under‐served populations could be met. They can be incorporated into meat products, such as sausages and burgers, to lower the energy density of these foods while providing important nutrients. Replacing energy‐dense foods with legumes has been shown to have beneficial effects on the prevention and management of obesity and related disorders, such as cardiovascular disease, diabetes and the metabolic syndrome. This review explores the nutritional value and obesity‐related health benefits of legume consumption while focusing on pulses.
Depression in informal caregivers of persons with dementia
Authors: D'Aoust Rita F. , Brewster Glenna , Rowe Meredeth A.
Published: January 2014

Background

Worldwide, there are more than 35 million individuals diagnosed with Alzheimer's disease. Many of these individuals are cared for at home by unpaid caregivers who often report high levels of depressive symptoms and depression. The majority of studies conducted to predict which caregivers are at risk for depression have examined non‐modifiable risk factors. Therefore, it is important to discover modifiable factors that may be associated with risk for depression in caregivers.

Objectives

The aims of this research were to identify a set of factors that are modifiable and known to be associated with high levels of depression/depressive symptomology (D/DS) in other populations and to determine whether these factors are predictive of D/DS after controlling for non‐modifiable, demographic, and clinical factors.

Design

Secondary data analysis.

Methods

Fifty‐three participants provided direct care to a person with dementia with night‐time activity. Inclusion criteria included not undergoing treatment for sleep disorders; living with the care recipient; and a Mini‐Mental Status Exam score > 27. Baseline data collected by questionnaires, sleep diary and actigraphy.

Results

In multivariate analyses of the modifiable factors, only high levels of negative affect predicted higher levels of depressive symptomatology. When non‐modifiable factors were included in the model, negative affect and high levels of perceived caregiver burden predicted 52.6% of the variance in depressive symptomology. In secondary analyses, wake after sleep onset misperception was associated with higher depression scores.

Conclusions

While negative affect had a moderate effect on depressive symptoms, modifiable factors often associated with depressive symptoms in other studies were not associated with caregiver depression in this study. Possibly caregivers’ overall poor sleep causes a floor effect and masks a potential relationship.

Implications for practice

Both caregivers’ affect and perceived burden are strongly related to depressive symptoms, so healthcare practitioners need to frequently assess both so as to provide timely interventions.
Family caregivers’ assessments of caring for a relative with dementia: a comparison of urban and rural areas
Authors: Ehrlich Kethy , Boström Anne‐Marie , Mazaheri Monir , Heikkilä Kristiina , Emami Azita
Published: January 2014

Aim

This study aimed to describe and compare urban and rural family caregivers’ reactions to caring for a relative with dementia and to examine the associations between caregiving and socio‐demographic factors.

Background

Most studies on family caregivers’ experiences caring for older people with dementia have been conducted in urban areas, and little is known about the experiences of family caregivers living in rural areas.

Design

A cross‐sectional study design was used.

Methods

A total of 102 caregivers (response rate 85%) from urban (n = 57) and rural (n = 46) areas completed the Caregiver Reaction Assessment (CRA) Scale and demographic information. Data were analysed using descriptive and inferential statistics and linear regression models.

Results

Overall, family caregivers reported high satisfaction even if they also reported high impact on finances and daily living. Rural caregivers experienced a higher negative impact on finances but reported more support from family members than urban caregivers. Age, gender and relationship were significantly associated with four of the five CRA subscales. Educational level and geographical setting were not associated with any of the CRA subscales.

Conclusions

The results of the study raise questions about the financial situation of older female caregivers and on the expectations of built‐in family structures in urban and rural areas. Further studies focusing on the meaning and constitution of a family would help us to understand how these factors influence family caregiving both in rural and urban areas.

Implications for practice

To provide person‐centred care and to avoid stereotyped caregiving, a better picture of traditions in family caregiving can improve a more differentiated and appropriate professional caregiving pliable with the cultural context in which it is carried out.
Awareness of impending death for residents of long‐term care facilities
Authors: Cable‐Williams Beryl , Wilson Donna
Published: January 2014

Aim

To explore awareness of impending death for very old persons in long‐term care facilities.

Background

The trajectories of decline that are associated with chronic progressive diseases in advanced old age have few prognostic markers. Consequently, it is difficult to determine when to start palliative or end‐of‐life care.

Design

Mixed methods.

Methods

Data were collected in three long‐term care facilities in Canada. Statistical data were subjected to basic descriptive analysis. Qualitative data were collected using methods commonly associated with ethnography including interviews, focus groups, observations and artefact review. Constant‐comparative analysis of qualitative data occurred as data were collected.

Results

A 2‐stage layered awareness of impending death was identified: first generalised and then clinical awareness. Generalised awareness was characterised by an understanding of human mortality and an understanding of the person's nearness to the end of an expected lifespan. Care routines and use of resources were not influenced by this early awareness. Clinical awareness of impending death was later acknowledged when health status changes suggested that death was likely within a few hours or days. The care then changed substantially to palliative in nature.

Conclusions

Despite an awareness that death occurs naturally at the end of a long life and/or long illness, a serious decline towards death was not noticed or acknowledged until the last few hours or days of life, thus limiting palliative care to late‐stage pain and symptom management.

Implications for practice

Although this late‐stage awareness of impending death is arguably the first necessary step for a change in nursing homes to a palliative‐oriented approach to care for people who are nearing death in late life, timely acknowledgement of the potential for death is needed to facilitate improvements in care for residents of long‐term facilities.
Pectic arabinan side chains are essential for pollen cell wall integrity during pollen development
Authors: Cankar Katarina , Kortstee Anne , Toonen Marcel A.J. , Wolters‐Arts Mieke , Houbein Rudolf , Mariani Celestina , Ulvskov Peter , Jorgensen Bodil , Schols Henk A. , Visser Richard G.F. , Trindade Luisa M.
Published: January 2014

Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure–function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pectin composition was analysed. The expression of genes encoding enzymes involved in pectin acetylation, degradation of the rhamnogalacturonan backbone and type and length of neutral side chains, arabinan and galactan in particular, has been altered. Upon crossing of different transgenic lines, some transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different developmental stages were microscopically examined to study the phenotype in more detail. Scanning electron microscopy of flowers showed collapsed pollen grains in mature anthers and in earlier stages cytoplasmic protrusions at the site of the of kin pore, eventually leading to bursting of the pollen grain and leaking of the cytoplasm. This phenomenon is only observed after the microspores are released and the tapetum starts to degenerate. Timing of the phenotype indicates a role for pectic arabinan side chains during remodelling of the cell wall when the pollen grain is maturing and dehydrating.
Identification of molecular markers linked to salt‐tolerant genes at germination stage of rice
Authors: Mardani Z. , Rabiei B. , Sabouri H. , Sabouri A.
Published: January 2014

An F2 : 4 population derived from the cross between salt‐tolerant variety ‘Gharib’ (indica) and salt‐sensitive variety Sepidroud (indica) was used to determine the germination traits. The seeds were treated with 80 mm NaCl (salt stress), and 11 traits were determined as indicators for salt‐tolerant including germination rate, germination percentage, radicle length, plumule length, coleoptile length, plumule fresh and dry weight, radicle fresh and dry weight and coleoptile fresh and dry weight. A linkage map of 2475.7 cM with an average interval of 10.48 cM was constructed using 105 amplified fragment length polymorphism (AFLP) markers and 131 SSR markers. As many as that 17 quantitative trait loci (QTLs) were detected related to germination traits under salt stress condition; some of them are being reported for first time. Also, overlapping of QTLs related to salt tolerance was observed in this study. The identification of genomic regions associated with salt‐tolerant and its components under salt stress will be useful for marker‐based approaches to improve salt‐tolerant for farmers in salt‐prone rice environments.
Expression profiles of Pr5CS1 and Pr5CS2 genes and proline accumulation under salinity stress in perennial ryegrass (Lolium perenne L.)
Authors: Li Huiying , Guo Huijuan , Zhang Xunzhong , Fu Jinmin
Published: January 2014

Proline is an important osmoprotectant in plant in response to osmotic stresses. Delta 1‐pyrroline‐5‐carboxylate synthetase (P5CS) is a key enzyme in proline biosynthesis. In this study, two P5CS genes (PrP5CS1 and PrP5CS2) were isolated for the first time from perennial ryegrass. Expression analysis revealed that the transcript of PrP5CS1 in leaves was significantly up‐regulated in two ryegrass cultivars exposed to 255 mm NaCl. The up‐regulated level of PrP5CS1 was higher in salt‐tolerant ‘Overdrive’ than in sensitive ‘Pizzazz’. PrP5CS2 was significantly induced in ‘Overdrive’ but suppressed in ‘Pizzazz’ by NaCl treatment. In stems, however, there was no significant transcript change for both genes under salt treatment. The proline accumulation was significantly induced in both cultivars after salt treatment, and it was higher in ‘Overdrive’ than in ‘Pizzazz’ after 2 days of salt treatment. The results suggested that both genes are salt inducible and may be associated with salt‐stress tolerance in perennial ryegrass.
Development and study of a maize cultivar rich in anthocyanins: coloured polenta, a new functional food
Authors: Lago Chiara , Cassani Elena , Zanzi Cecilia , Landoni Michela , Trovato Riccardo , Pilu Roberto
Published: January 2014

Among the phytonutrients, anthocyanins have been extensively studied because of their antioxidant power, the characteristic supposedly responsible for their capacity for chronic disease prevention. Anthocyanins can also be synthesized in maize even though in Europe the colourless varieties have always been preferred. The aim of this study was to develop and characterize a new polenta variety of maize rich in anthocyanins, bred by a recurrent selection scheme, to increase the antioxidant power of this food. The recurrent selection was based on the anthocyanin content and other specific traits of the kernel. The coloured polenta obtained was analysed by TLC (Thin Layer Chromatography) analysis and DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging ability, before and after cooking. The results obtained showed that even though cooking reduced the anthocyanin content by about 22%, the remaining anthocyanins exhibited twofolds higher antioxidant capacity, expressed as ARP (antiradical power) using acetone/water extraction buffer in DPPH assay, compared to the colourless control. Furthermore, our data showed that the anthocyanin content did not alter the taste of the coloured polenta.
A comprehensive study of thiol reduction gene expression under stress conditions in Arabidopsis thaliana
Authors: BELIN C. , BASHANDY T. , CELA J. , DELORME‐HINOUX V. , RIONDET C. , REICHHELD J. P.
Published: January 2014

Thiol reduction proteins are key regulators of the redox state of the cell, managing development and stress response programs. In plants, thiol reduction proteins, namely thioredoxin (TRX), glutaredoxin (GRX), and their respective reducers glutathione reductase (GR) and thioredoxin reductase (TR), are organized in complex multigene families. In order to decipher the function of the different proteins, it is necessary to have a clear picture of their respective expression profiles. By collecting information from gene expression databases, we have performed a comprehensive in silico study of the expression of all members of different classes of thiol reduction genes (TRX, GRX) in Arabidopsis thaliana. Tissue expression profiles and response to many biotic and abiotic stress conditions have been studied systematically. Altogether, the significance of our data is discussed with respect to published biochemical and genetic studies.
Cadmium induces two waves of reactive oxygen species in Glycine max (L.) roots
Authors: PÉREZ‐CHACA MARÍA VERÓNICA , RODRÍGUEZ‐SERRANO MARÍA , MOLINA ALICIA S. , PEDRANZANI HILDA E. , ZIRULNIK FANNY , SANDALIO LUISA M. , ROMERO‐PUERTAS MARÍA C.
Published: January 2014

Cadmium (Cd) is a non‐essential heavy metal that may be toxic or even lethal to plants as it can be easily taken up by the roots and loaded into the xylem to the leaves. Using soybean roots (Glycine max L.) DM 4800, we have analysed various parameters related to reactive oxygen metabolism and nitric oxide (NO) during a 6 day Cd exposure. A rise in H2O2 and NO, and to a lesser extent O2·− content was observed after 6 h exposure with a concomitant increase in lipid peroxidation and carbonyl group content. Both oxidative markers were significantly reduced after 24 h. A second, higher wave of O2·− production was also observed after 72 h of exposure followed by a reduction until the end of the treatment. NOX and glicolate oxidase activity might be involved in the initial Cd‐induced reactive oxygen species (ROS) production and it appears that other sources may also participate. The analysis of antioxidative enzymes showed an increase in glutathione‐S‐transferase activity and in transcript levels and activity of enzymes involved in the ascorbate‐glutathione cycle and the NADPH‐generating enzymes. These results suggest that soybean is able to respond rapidly to oxidative stress imposed by Cd by improving the availability of NADPH necessary for the ascorbate‐glutathione cycle.
The Boomerang Pattern: Verification and Modification
Authors: Bassano David
Published: January 2014

When Margaret E. Keck and Kathryn Sikkink published Activists Beyond Borders in 1998, they offered the emergent field of human rights history the first clear model of the relatively new phenomenon of international human rights activism. Termed the Boomerang Pattern, the model demonstrates how NGOs of the (predominantly) Third World work with international NGOs to address human rights violations in their own countries. A document from the archival collection of Amnesty International USA, created in the 1980s but only available to the public since 2007, verifies the accuracy of the Boomerang Pattern in describing transnational human rights activism. However, the Boomerang Pattern primarily describes how activism is designed to work, rather than present the complications and difficulties that NGOs encounter in their international campaigns. This article complicates the Boomerang Pattern in order to more accurately describe transnational human rights activism by drawing on examples from the Nicaraguan and Salvadoran human rights movements of the 1980s.
“Lubricating the Machine of Social Change”: The National PTA and Desegregation Debates, 1950–1970
Authors: Heath Sarah E.
Published: January 2014

This article focuses on the intersecting strands of the movement for desegregation in public schools and in the National Parent Teacher Association (PTA), the largest volunteer organization dedicated to youth and education in the twentieth century. The PTA underwent a slow, contentious transition in at least two significant ways. First, while the National PTA office at first supported the rights of state and local chapters to dictate their own affairs, eventually it asserted control on all policy (including desegregation) for its branches. Second, the unification of the PTA's membership did not occur until 1970. While the PTA suffered from internal divisions along racial lines, black women wished to sustain their guidance on school policies and programs for young people in their communities. Eventually, PTA members enacted a policy that guaranteed inclusion and authority for black members. Leaders in the PTA, therefore, guided a significant shift in policy over time away from acceptance of segregation to an overt insistence on inclusion.
Relevance of UV filter/sunscreen product photostability to human safety
Authors: Nash J. Frank , Tanner Paul R.
Published: January 2014

Photostability or photo‐instability of sunscreen products is most often discussed in undesirable terms with respect to human safety. The health risks, specifically associated with sunscreens, photostable or photo‐unstable, include phototoxic/photoirritation or photoallergic responses and, longer‐term, an increased risk of skin cancers or photoageing. The aims of this paper are to define photostability/photo‐instability and objectively assess the acute and chronic toxicological consequences from the human exposure to UV filter/sunscreens and any probable photo‐degradation products. The reported prevalence of photoirritation and photoallergic responses to sunscreens is rare compared with adverse events, for example, skin irritation or sensitization, produced by cosmetics or topically applied drugs and do not directly implicate potential photo‐degradation products of UV filters. Moreover, for at least one photo‐unstable combination, octyl methoxycinnamate and avobenzone, the long‐term benefits to humans, i.e., reduction in skin cancers, seem to outweigh any potential adverse consequences attributed to photo‐degradation. Sunscreen products are formulated to achieve maximum efficacy which, by necessity and design, incorporate measures to support and promote photostability since all organic UV filters have the potential to photo‐degrade. Current performance measures, in vivo SPF and in vitro UVA, conducted under standardized conditions, in part account for photostability. The concerns expressed when considering human exposure to potential photo‐unstable UV filters or sunscreen products may not manifest as health risks under conditions of use. Still, improvement in sunscreen product photostability continues to be a key strategic objective for manufacturers.
Of Physics and Factory Physics
Authors: Spearman Mark L.
Published: January 2014

The “Principle of Least Action" is the foundational principle of fundamental physics. Application of this principle to the supply chain naturally results in an “uncertainty principle” linking variation in production to variation in net‐inventory. The model also provides an easy means of determining the stationary distribution of net‐inventory for a variety of control strategies. The formalism results in a control strategy that outperforms commonly used control methods.
Interpreting Political Apologies: The Neglected Role of Performance
Authors: Cels Sanderijn
Published: January 2014

In recent years, state leaders have increasingly apologized for historical wrongdoing. This article argues that there are scant conceptual tools available in current apology theory to capture the meanings of such political apologies. Salient theories treat apologies predominantly as “speech acts,” and this perspective produces frameworks of analysis that are preoccupied with linguistic features (e.g., the phrasing of the utterance of the apologizer). This article points to the limitations of this approach by arguing that dramaturgical aspects of performance are equally important. Political apologies are frequently offered during public ceremonies. Reactions in their aftermath indicate that the setup of those ceremonies matter to the victims, who, as primary addressees, assign meanings to the act. Current apology theory, however, gives little consideration to this observation. “What is said” matters most; “where and how it is said” is being neglected. The article concludes with a proposal for future research, which includes the reimagining of political apology as “performance” –a concept that gives credence to both formal speech and dramaturgy.
A New Approach to Unidimensional Poverty Analysis: Application to the Tunisian Case
Authors: Zedini Asma , Belhadj Besma
Published: January 2014

Fuzzy conceptualization of privation has been a step closer to more realistic handling of poverty. However, fuzzy approaches to poverty are still grounded on parametric axioms. Moreover, construction of poverty lines within these approaches still relies on ad‐hoc methods. In this paper, we advance instead a fuzzy procedure based on the non‐parametric bootstrap method, allowing us to depict fuzzy unidimensional privation states with boundaries drawn spontaneously from data. Fuzzy non‐parametric measures of privation within each state as well as a collective fuzzy non‐parametric index of poverty are derived, along with their corresponding confidence intervals. The new approach is applied to the analysis of poverty in Tunisia in 2005.
Analysing the Notch Effect Within the Ductile-to-Brittle Transition Zone of S275JR Steel
Authors: Cicero Sergio , García Tiberio , Madrazo Virginia , Cuervo Jorge , Ruiz Estela , Gutiérrez-Solana Federico
Published: January 2014

This paper analyses the notch effect in ferritic-pearlitic steel S275JR in a range of temperatures within the material Ductile-to-Brittle Transition Zone (DBTZ). The notch effect is evaluated in terms of load-bearing capacity, apparent fracture toughness (modeled here using the Theory of Critical Distances) and fracture micromechanisms. The concept of Master Curve in notched conditions is also presented.

To this end, experimental results obtained in S275JR notched specimens are presented, together with Scanning Electron Microscopy (SEM) fractographies. The analysis is performed at −50 °C, −30 °C and −10 °C, the material Transition Temperature (T0) being −26.1 °C, with the notch radii ranging from 0 mm (crack-type defects) up to 2.0 mm.

The results show how the lower the temperature the larger the notch effect, and also that the evolution of both the load bearing capacity and the apparent fracture toughness is directly related to the evolution of fracture micromechanisms. Moreover, the proposed Master Curve in notched conditions has provided good predictions of the experimental results.
Consideration of Design Assessments for Pipeline/Facilities Dynamic Behavior
Authors: Motriuk Roman W.
Published: January 2014

Information of PTQ (pressure, temperature, flow) in hydrocarbon transmission pipelines or facilities is critical because modeling of such systems, or their parts, involves fluid transport-properties that critically influence any fluid-pipe and soil-pipe interactions. These properties across soil varieties are integral to predicting pipeline systems’ behavior.

The mechanical/fluid aspect of analysis is reviewed in this work, with emphasis on steady-state and transient system responses. In general terms, the necessary steps of dynamic analysis used at the design stage of pipelines and facilities are described. Comments on sources of excitation and the response of pipe/pipelines, which take into account transient and steady-state system behavior, as well as the importance of using accurate fluid transport properties are discussed.
Factors That Influence the Sealing Behavior of Spiral Wound Gaskets
Authors: Veiga José C. , da Silva Gustavo Monteiro , Kavanagh Nelson
Published: January 2014

Spiral wound gaskets are used worldwide in piping and equipment flanges and can be manufactured in several combinations of materials, in a wide range of dimensions, winding densities and shapes. This paper shows factors like winding density, surface finish and flatness that have major influence in the sealability which are not specified by the current Spiral Wound ASME B16.20 gasket standard.
Experimental Investigation of Flow-Acoustic Coupling in a Deep Axisymmetric Cavity
Authors: Oshkai Peter , Barannyk Oleksandr
Published: January 2014

In this paper, the phenomenon of self-sustained pressure oscillations due to the flow past a deep, circular, axisymmetric cavity is investigated. In many engineering applications, such as flows through open gate valves, there exists potential for coupling between the vortex shedding from the upstream edge of the cavity and a diametral mode of the acoustic pressure fluctuations. In the present study, the unsteady pressure was measured at several azimuthal locations at the bottom of the cavity walls, and the associated acoustic mode shapes were calculated numerically for the four representative cases of the internal cavity geometry, which involved a reference case with sharp, 90°edges as well as several modifications that involved chamfers of various length of the upstream and the downstream edges of the cavity. In addition, the flow velocity in the vicinity of the cavity opening in selected cases was measured using digital particle image velocimetry (PIV). The optical access to the highly confined internal flow was provided by implementing an endoscope attached to the camera. This global, quantitative imaging approach yielded patterns of velocity, streamlines and out-of-plane vorticity component. Instantaneous and time-averaged flow patterns provided insight into the mechanism of the flow tone generation. Among the considered cavity geometries, the configuration that corresponded to the most efficient noise suppression was identified.
Small Punch Testing of Exposed High-Pressure Steam Pipelines
Authors: Dymáček Petr , Dobeš Ferdinand
Published: January 2014

Non-disruptive material sample scooping is frequently applied to a range of operating components since it is supposed that removal of small amount of material from the surface has no effect on components integrity. As-removed material is then subjected to mechanical testing by small punch test to estimate tensile, creep and fracture properties necessary for assessment of residual life of the component. The question arises whether the assumption that measurements on surface specimens are representative for the characterization of whole component is justified. For the verification of this assumption, four steam pipes after either plant- or simulated-exposure up to 104 000 hours were used. Small punch specimens were prepared from different positions within pipes. The dimensions of specimens enable to estimate mechanical properties for several dozens of specimens along available power-plant pipes’ walls. The paper summarizes the results of small punch tests at both constant deflection rate and constant force and at room and elevated temperature, respectively. In the walls of the investigated pipes, the results obtained on surface specimens do not differ substantially from the results on specimens prepared from central parts.
Evaluation of Mechanical Properties of Primary Circuit Components Using SPT Technique
Authors: Březina Martin , Petzová Jana , Kupča Ľudovít
Published: January 2014

The paper deals with the evaluation of mechanical properties of safety-related components of the primary circuit of nuclear power plants (NPPs). During a long-term operation of NPPs, changes of mechanical properties occur. To ensure the safe operation of NPP it is necessary to monitor and evaluate these changes. One possibility how to solve this problem is a direct sampling and the assessment of the actual mechanical properties using the small punch test (SPT) technique. By the SPT technique it is possible to evaluate the basic tensile properties such as the ultimate tensile strength and the yield stress of the tested materials as well as the transition temperature.

The authors describe model examples of surface sampling using the special Rolls Royce equipment SSam™-2. The SPT specimens were prepared from the removed samples by application of the wire electrical discharge machining and fine grinding. The prepared specimens were tested and the obtained data were evaluated. Original pieces of primary tubes with diameter 500 mm made of stainless steel type 08Ch18N10T (AISI 321) were used for these model examples. Another experimental material used was a block of the reactor pressure vessel wall cut from NPP Greifswald Unit 7 which contains a weld joint. Those experiments were a part of the preparatory activities for the planned sampling and the assessment of the actual mechanical properties of primary components such as the main primary coolant piping, the steam generator shell and the reactor pressure vessel.
Framework for Key Influences on Tensile Strain Capacity of Flawed Girth Welds
Authors: Hertelé Stijn , Denys Rudi , Horn Anthony , Van Minnebruggen Koen , De Waele Wim
Published: January 2014

A key influence factor in the strain-based assessment of pipeline girth weld flaws is weld strength mismatch. Recent research has led to a framework for tensile strain capacity as a function of weld flow stress overmatch. This framework is built around three parameters: the strain capacity of an evenmatching weldment, the sensitivity of strain capacity to weld flow stress overmatch and the strain capacity at gross section collapse. A parametric finite element study of curved wide plate tests has been performed to identify the influence of various characteristics on each of these three parameters. This paper focuses on flaw depth, tearing resistance of the weld, stress-strain behaviour of the base metal, and weld geometry. Influences of these characteristics are mostly found to be limited to one or two of the three framework parameters. A preliminary structure is proposed for equations that further develop the strain capacity framework.
Evaluation of Ductile Tearing of X-80 Pipeline Girth Welds Using SE(T), SE(B) and C(T) Fracture Specimens
Authors: Mathias Leonardo L. S. , Sarzosa Diego F. B. , Ruggieri Claudio
Published: January 2014

Structural integrity assessments of pipe girth welds play a key role in design and safe operation of piping systems, including deep water steel catenary risers. Current methodologies for structural integrity assessments advocate the use of geometry dependent resistance curves so that crack-tip constraint in the test specimen closely matches the crack-tip constraint for the structural component. Testing standards now under development to measure fracture resistance of pipeline steels (J and CTOD) most often employ single edge notched specimens under tension (SENT) to match a postulated defect in the structural component. This paper presents an investigation of the ductile tearing properties for a girth weld of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves (J-R curves). Testing of the girth weld pipeline steels employed clamped SE(T) specimen with center-crack weld and three-point bending SE(B) (or SENB) specimens to determine the J-R curves. Tests involving SE(B) specimens are usually considered conservative, however, the comparison between this two methods may point an accurate alternative for girth weld assessments, since adequate geometry is adopted to describe accurately the structure’s behavior.
Modeling and Simulation of Optimal Blank Design and Hot Pressing Process for Manufacturing Large Francis Turbines Blades From Very Thick Plates
Authors: Feng Zhengkun , Champliaud Henri , Mathieu Louis , Sabourin Michel
Published: January 2014

Hot pressing process is widely used in automotive, shipbuilding, energy production and civil engineering. However, the trial and error technique that is intensive time and energy consuming is still used. Particularly, the design of Francis turbines of hydropower plants is not standard, but variable from site to site due to hydraulic conditions and cost of energy. As a result, the blade hydraulic profile of each Francis turbine is different. The blades, one of the key components of Francis turbine runners, are produced in small batches and the setup of the dedicated punch and die increases significantly the unit production costs. In this paper, the blade unfolding process for optimal blank design will be firstly presented, and then a hot pressing process for very thick plates is proposed. The pressing process of high strength steel at hot temperature is characterized by thermo-mechanical behaviors, three-dimensional unsteady deformation, high nonlinearity, continuous local forming. The analyses of residual stress distribution and applied forces are carried out.
Effect of Thickness Measurement Procedure on Stress Analysis of Pipes With Local Metal Loss
Authors: Yoshida Nobuyuki , Yamaguchi Atsushi
Published: January 2014

Fitness-For-Service (FFS) assessment using Finite Element Analysis (FEA) has been a problem in deciding yes-no which vary from evaluator to evaluator. The difference in decision making is caused by the degree of freedom in modeling a FEA model. In this study, burst pressures of pipes with local metal loss were calculated by using FEA in order to investigate the influence of thickness measurement intervals on FFS assessment. The analyzed pressures by FEA were verified by burst tests. A pipe specimen, which was thinned by corrosion under insulation in the actual plant, was used for the burst tests. Shape of the pipe specimen was measured by laser displacement meter and extracted at several types of interval. It is concluded that the analyzed pressures in various measurement intervals showed almost no difference, but were higher than the actual burst pressure of the specimen.
Passive Control of Liquid Sloshing in Floating Roof Tank With Multi Dynamic Absorber
Authors: Kobayashi Nobuyuki , Sato Tomohiro , Torisaka Ayako
Published: January 2014

A multi dynamic absorber for suppressing liquid sloshing in a floating roof tank is presented. As well known, many seismic damages on floating roof tanks by the sloshing of their contained liquid due to long periodic components of earthquake motion were reported. Since the natural period of sloshing varies according to the height of liquid surface, robustness for parameters such as natural period is required for the sloshing suppression device to obtain a good suppression performance. From this point of view, we developed a multi dynamic absorber instead of the single dynamic absorber which is sensitive to the parameter variance. A multi degree of freedom mechanical model for sloshing of the contained liquid and the presented multi dynamic absorber which sets up on the floating roof of the tank is derived to design the optimal tuning for parameters of the multi dynamic absorber and to evaluate the sloshing suppression performance. Numerical simulations for an actual size floating roof tank were conducted to examine the performance of the present device. As the result the effect of the presented multi dynamic absorber was effective to suppress the sloshing response of the floating roof and to be robust for the natural period variance.
Hydrogen Dragging by Moving Dislocation and Enhanced Lattice Defect Formation in 316L and 304 Stainless Steels
Authors: Takai Kenichi , Kitamura Megumi
Published: January 2014

Little is known about an enhanced lattice defect formation due to an interaction between hydrogen and dislocation in face-centered cubic (fcc) metals such as stainless steels. In the present study, hydrogen spectra evolved from Type 316L and 304 stainless steels during elastic and plastic deformation were detected using a quadrupole mass spectrometer. The amount of lattice defect enhanced by hydrogen and strain was measured using thermal desorption analysis. For 316L stainless steel, hydrogen desorption increased rapidly when plastic deformation began, since the dislocation dragged hydrogen to the surface of the specimen. In contrast, hydrogen desorption increased with applying strain for 304 stainless steel, because of phase transformation from austenite into martensite with larger hydrogen diffusivity. And the amount of desorbed hydrogen increased with decreasing strain rate. These results indicate that dislocation can drag and transport large amounts of hydrogen when the dislocation velocity approaches the hydrogen diffusion rate. The amount of lattice defects in stainless steels was enhanced by hydrogen and applied strain. The most probable reason for the increase in the amount of lattice defects can be ascribed to the increase in the amount of vacancy clusters. These findings lead to the conclusion that the interaction between dislocation and hydrogen enhances the formation of vacancy clusters, as a result, causes hydrogen embrittlement.
An Enhanced Methodology for Estimating the Natural Frequency of Valves Using Raleigh’s Energy Principle
Authors: Ezekoye L. Ike , Farrell Ronald S. , Vock Preston A. , Gradle Richard J.
Published: January 2014

This paper presents a model for calculating the minimum natural frequency of valve assemblies using the Raleigh’s energy principle. Raleigh’s principle states that the point where the kinetic energy of a multi-mass system and its potential energy are equal defines the minimum natural frequency of the system. This principle was used by Ezekoye to calculate the natural frequency of valve superstructures [1]. The early Ezekoye paper provided the fundamental tools for estimating the natural frequency of valves. However, over the years, with increasing valve testing to support Generation 3 nuclear power plants requirements, where natural frequency testing is required to complement analytical predictions, it has been noted that the Ezekoye simplified model adequately addressed valves with symmetric actuators and valves with minimal center of gravity (CG) offsets but over predicts the natural frequencies of valves with large CG offset actuators. Testing experience shows that a valve’s extended structure has two fundamental natural frequencies whose values are dictated primarily by the structural flexibility in bending and torsion. This paper extends the Ezekoye model by incorporating mass inertia of the structures with the more traditional methods that are based on a lumped mass model to determine displacements. In the process, the flexibility of the extended structure (otherwise referred to as the superstructure) and the valve body itself are considered. The approach covered in this paper combines classical statics, dynamics, and strength of materials techniques to model the natural frequency of a valve assembly. The resultant natural frequencies from the enhanced model are expected to provide better predictions of the minimum natural frequencies of valve assemblies.
Advanced Pipeline Vibroacoustic Monitoring
Authors: Bernasconi Giancarlo , Del Giudice Silvio , Giunta Giuseppe , Dionigi Francesco
Published: January 2014

Remote real-time monitoring of pipelines reliability is becoming a key factor for the environmental sustainability of oil&gas industry. Multipoint Acoustic Sensing (MAS) technology makes use of multi sensors placed at discrete distances to detect Third Party Interference (TPI) and fluid leaks along the pipeline. In fact, any interaction with the pipe generates pressure waves that are guided within the fluid (gas or oil) for long distances, carrying information on the source event. Pressure propagation is mainly governed by the absorption coefficient and the sound speed. These parameters are in turn complicated functions of the frequency, the geometrical and elastic parameters of the pipe shell, the elastic parameters of the surrounding medium, and the acoustic and thermodynamic properties of the transported fluid. We have analyzed these aspects while processing acoustic data collected on crude oil and gas transportation pipelines, in different operational and flow conditions. This study describes the acquisition campaigns and the data analysis steps used for the experimental derivation of fluid properties and pipe anomalies. The results are also used for the validation of mathematical models of pressure waves propagation in fluid filled pipes.
Fitness-for-Service of Steam-Methane Reformer Hot Outlet Manifolds
Authors: Jaske Carl E. , Finneran Shane
Published: January 2014

A majority of steam-methane reformers (SMRs) have hot outlet manifold systems that operate at temperatures in the range of 750 to 900 °C (1382 to 1652 °F) and internal pressures in the range of 2000 to 3500 kPag (290 to 510 psig). Under these operating conditions, the materials used in the manifold systems, including weld joints, are subject to degradation from high-temperature creep. Thus, fitness-for-service (FFS) assessment of the manifold systems requires evaluation of material degradation as a result of creep damage (voids, micro-fissures and cracks) and creep deformation (strain). This paper reviews a general approach to FFS assessment of SMR hot outlet manifold systems. Using data on operating temperature, pressure, and time in service stresses and strains in the manifold sections are calculated by the finite-element method. The calculated stress-strain data are then used to compute creep damage accumulation as a function of time in service for both base metal and weld joints using available creep-rupture data for the materials. These results are then used to predict remaining creep life and establish recommended inspection protocols.