bluuebunny/crossref_metadata_2025 huggingface dataset:
The meaning of person‐centred care in the perioperative nursing context from the patient's perspective – an integrative review
Authors: Arakelian Erebouni , Swenne Christine Leo , Lindberg Susan , Rudolfsson Gudrun , von Vogelsang Ann‐Christin
Published: November 2016

Aims and objectives

To determine the meaning of person‐centred care from the patient's perspective and in the context of perioperative nursing.

Background

Person‐centred care is used, but not defined in the perioperative context. The concept indicates an interest in the patient's own experience of health, illness, needs and preferences. As with many terms that are frequently used, there is a tendency for person‐centred care to mean different things to different people in different contexts.

Design

Integrative Review.

Methods

A two‐part search strategy was employed: first, a computerised database search of PubMed and CINAHL, using Medical Subject Headings and free terms to search articles dating from 2004–2014, was performed, and second, a hand‐search of those articles’ reference lists was performed. Twenty‐three articles were selected, and an integrative review was conducted.

Results

Four themes were discovered: ‘being recognised as a unique entity and being allowed to be the person you are’, ‘being considered important by having one's personal wishes taken into account’, ‘the presence of a perioperative nurse is calming, prevents feelings of loneliness and promotes well‐being, which may speed up recovery’ and ‘being close to and being touched by the perioperative nurse during surgery’.

Conclusions

Person‐centred care means respecting the patient as a unique individual, considering the patient's particularities and wishes and involving the patient in their own care. Person‐centred care also implies having access to one's own nurse who is present both physically and emotionally through the entire perioperative process and who guides the patient and follows up postoperatively, guaranteeing that the patient is not alone.

Relevance to clinical practice

By having a common understanding of the concept of person‐centred care, the nurse anaesthetists’ and theatre nurses’ caring actions or concerns will be directed towards the patient, resulting in personalisation of care rather than simply defining the concept.
Patient participation in postoperative pain assessment after spine surgery in a recovery unit
Authors: Kaptain Kirsten , Bregnballe Vibeke , Dreyer Pia
Published: November 2016

Aims and objectives

To explore how patients undergoing spine surgery participated in postoperative pain assessment in a recovery unit.

Background

Despite advances in medicine, pharmaceutical and technical knowledge, patients report considerable postoperative pain after spine surgery. Research shows that patients require efficient individual pain treatment and that their participation has a positive effect on pain treatment.

Design

This study was based on a phenomenological hermeneutic design.

Methods

Fifteen qualitative interviews were conducted in 2014. Meaning condensation was used to analyse data.

Results

Three themes emerged: (1) communication and knowledge; anaesthesia, analgesics and severe pain affected patients’ ability to assess and communicate their pain. (2) Pain assessment using a numerical rating scale; this theme was characterised by individual differences in rating perception. Also, new postoperative pain sensations were described as different kinds of pain and variation in the pain intensity during activity. (3) Patient–nurse relationship; this theme was characterised by reports of frequent and direct contact on the part of the nurses about pain assessment. Patients’ lack of knowledge about pain treatment resulted in inactivity and uncertainty of when to ask for analgesics.

Conclusion

This study indicates that nurses and patients would benefit from building a mutual understanding of pain perceptions and numerical rating scale as this would pave the way for a more accurate pain assessment. Patients’ ability to participate in pain assessment was affected by anaesthesia, analgesics and severe pain. Patients needed knowledge about complications and needed to understand when they should ask for analgesics.

Relevance to clinical practice

Results indicate that patient perceptions of numerical rating scale and variation in patients’ ability to communicate in the initial postoperative period should be given more attention to underpin patients’ pain assessment. This may be a key factor in ensuring patient participation in pain assessment and thereby improving postoperative pain management.
Evaluation of a Novel Computer Color Matching System Based on the Improved Back‐Propagation Neural Network Model
Authors: Wei Jiaqiang , Peng Mengdong , Li Qing , Wang Yining
Published: November 2016

Purpose

To explore the feasibility of a novel computer color‐matching (CCM) system based on the improved back‐propagation neural network (BPNN) model by comparing it with the traditional visual method.

Material and Methods

Forty‐three metal‐ceramic specimens were fabricated by proportionally mixing porcelain powders. Thirty‐nine specimens were randomly selected to train the BPNN model, while the remaining four specimens were used to test and calibrate the model. A CCM system based on the improved BPNN model was constructed using MATLAB software. A comparison of the novel CCM system and the traditional visual method was conducted by evaluating the color reproduction results of 10 maxillary central incisors. Metal‐ceramic specimens were fabricated using two color reproduction approaches. Color distributions (L*, a*, and b*) of the target teeth and of the corresponding metal‐ceramic specimens were measured using a spectroradiometer. Color differences (ΔE) and color distributions (ΔL*, Δa*, and Δb*) between the teeth and their corresponding specimens were calculated.

Results

The average ΔE value of the CCM system was 1.89 ± 0.75, which was lower than that of the visual approach (3.54 ± 1.11, p < 0.01). With respect to color distributions, substantial differences were found between the two color‐matching systems, except for ΔL* (p > 0.05).

Conclusion

The novel CCM system produced greater accuracy in color reproduction within the given color space than the traditional visual approach.
Design of an intraocular pressure curve protocol for use in dogs
Authors: Sanchez R. F. , Vieira da Silva M. J. , Dawson C.
Published: November 2016

Objectives

To establish an intraocular pressure curve protocol that is safe for corneal health and detects harmful elevations of intraocular pressure outside normal clinic hours. To determine inter‐user variability and if repeated measurements affect intraocular pressures.

Materials and Methods

Intraocular pressures were measured in dogs with glaucoma using three protocols: Protocol 1 used applanation tonometry every 2 hours over a 24‐hour period; Protocols 2 and 3 used applanation or rebound tonometry, respectively, and measured intraocular pressures every 3 hours over a 30‐hour period. A total of 60 additional intraocular pressure curves from dogs with glaucoma and 20 from healthy dogs were then analysed for inter‐user variability.

Results

A total of 128 intraocular pressure curves were determined in 30 dogs. Protocol 1 resulted in one ulcer in five pressure curves, Protocol 2 in one ulcer in 62 pressure curves and Protocol 3 in no ulcers in 61 pressure curves. Elevated intraocular pressures were detected on 61 occasions, of which 26 developed outside normal clinic hours. A total of 61 additional intraocular pressure curves revealed that repeated measurements had no effect on intraocular pressure.

Clinical Significance

Protocol 3, using rebound tonometry every 3 hours for 30 hours is safe corneal health and identified elevated intraocular pressures outside normal clinic hours in 12 of 30 (40%) patients that single intraocular pressure measurement during consultation hours would not have identified. Intraocular pressure curves may be recommended for clinical practice and glaucoma studies.
A Parallel Branch and Bound Algorithm for the Resource Leveling Problem with Minimal Lags
Authors: Ponz‐Tienda J. L. , Salcedo‐Bernal A. , Pellicer Eugenio
Published: November 2016

The efficient use of resources is a key factor to minimize the cost while meeting time deadlines and quality requirements; this is especially important in construction projects where field operations make fluctuations of resources unproductive and costly. Resource Leveling Problems (RLP) aim to sequence the construction activities that maximize the resource consumption efficiency over time, minimizing the variability. Exact algorithms for the RLP have been proposed throughout the years to offer optimal solutions; however, these problems require a vast computational capability (“combinatorial explosion”) that makes them unpractical. Therefore, alternative heuristic and metaheuristic algorithms have been suggested in the literature to find local optimal solutions, using different libraries to benchmark optimal values; for example, the Project Scheduling Problem LIBrary for minimal lags is still open to be solved to optimality for RLP. To partially fill this gap, the authors propose a Parallel Branch and Bound algorithm for the RLP with minimal lags to solve the RLP with an acceptable computational effort. This way, this research contributes to the body of knowledge of construction project scheduling providing the optimums of 50 problems for the RLP with minimal lags for the first time, allowing future contributors to benchmark their heuristics methods against exact results by obtaining the distance of their solution to the optimal values. Furthermore, for practitioners, the time required to solve this kind of problem is reasonable and practical, considering that unbalanced resources can risk the goals of the construction project.
Cases of advanced visual field loss at referral to glaucoma clinics – more men than women?
Authors: Crabb David P. , Saunders Luke J. , Edwards Laura A.
Published: November 2016

Purpose

In many medical conditions ‘late presentation’ of disease is more of a problem for men than women. Risk of sight loss from glaucoma is certainly greater in those detected with advanced disease. We performed a retrospective study to test the hypothesis that men are more likely than women to have advanced visual field loss at referral to glaucoma clinics.

Methods

We used 152 918 Humphrey visual fields from 32 147 patients from three regionally different hospitals in England; no other clinical data were made available apart from patient's age, sex and examination dates. The study population was defined as patients with measureable visual field loss in at least one eye at referral to glaucoma clinics. Cases of advanced visual field loss as defined by the Enhanced Glaucoma Severity Staging method at the first visit to secondary care were used as a proxy measure for late presentation of glaucoma. Age‐adjusted relative risk (RR) was calculated as the ratio of the proportion of men to women with this proxy measure.

Results

Median (interquartile range) age and MD (worse eye) for 3733 men and 4264 women was 72 (63, 79) and 74 (64, 81) years and −6.4 (−11.7, −3.8) and −6.3 (−11.0, −3.8) dB respectively. Overall proportion of patients with advanced visual field loss at referral to glaucoma clinics was slightly higher in men (25.0%) than in women (22.3%); this difference was statistically significant (p < 0.01). Overall age‐standardised RR was statistically significant (1.16; p < 0.001); a person with late presentation of glaucoma is 16% (95% confidence interval: 7–25%) more likely to be a man than a woman.

Conclusions

A large number of patients with glaucomatous visual field defects are estimated to have advanced loss in at least one eye on referral to secondary care in England; risk for men more likely presenting with late disease is slightly greater than for women.
Leaf hydraulic conductance and mesophyll conductance are not closely related within a single species
Authors: Loucos Karen E. , Simonin Kevin A. , Barbour Margaret M.
Published: November 2016

Stomata represent one resistor in a series of resistances for carbon and water exchange between the leaf and the atmosphere; the remaining resistors occurring within the leaf, commonly represented as mesophyll conductance to CO2, gm, and leaf hydraulic conductance, kLeaf. Recent studies have proposed that gm and kLeaf may be coordinated across species because of shared pathways. We assessed the correlation between gm and kLeaf within cotton, under growth CO2 partial pressure and irradiance treatments and also with short‐term variation in irradiance and humidity. gm was estimated using two isotopic techniques that allowed partitioning of total gm (Δ13C‐gm) into cell wall plus plasma membrane conductance (Δ18O‐gm) and chloroplast membrane conductance (gcm). A weak correlation was found between Δ13C‐gm and kLeaf only when measured under growth conditions. However, Δ18O‐gm was related to kLeaf under both short‐term environmental variation and growth conditions. Partitioning gm showed that gcm was not affected by short‐term changes in irradiance or correlated with kLeaf, but was strongly reduced at high growth CO2 partial pressure. Thus, simultaneous measurements of gm, kLeaf and gcm suggest independent regulation of carbon and water transport across the chloroplast membrane with limited coordinated regulation across the cell wall and plasma membrane.
Feminist Metaphysics and Philosophical Methodology
Authors: Mikkola Mari
Published: November 2016

Over the past few decades, feminist philosophy has become recognised as a philosophical sub‐discipline in its own right. Among the ‘core’ areas of philosophy, metaphysics has nonetheless until relatively recently remained largely dismissive of it. Metaphysics typically investigates the basic structure of reality and its nature. It examines reality's putative building blocks and inherent structure supposedly ‘out there’ with the view to uncovering and elucidating that structure. For this task, feminist insights appear simply irrelevant. Moreover, the value‐neutrality of metaphysics seemsprima facieincompatible with feminism's explicitly normative stance in that feminist philosophy involves advocacy: speaking on behalf of some group on political grounds. The prospects of feminist metaphysics thus look grim.

Nonetheless, feminist philosophers have in recent years increasingly taken up explicitly metaphysical investigations. The basic ideas behind such investigations can be summed up as follows: feminist metaphysics is about negotiating the natural and going beyond the fundamental. In so doing, feminist investigations have expanded thescopeof metaphysics. Further, feminist philosophers typically bring newmethodologicalinsights to bear on traditional ways of doing philosophy. With this in mind, the article considers the following questions: when thinking about philosophical methodology, how does feminist metaphysics fare relative to ‘mainstream’ metaphysics? More specifically, is feminism's political advocacy inconsistent with apparent objectivity that some prominent contemporary versions of metaphysics are committed to?
Materialism and the Activity of Matter in Seventeenth‐Century European Philosophy
Authors: Duncan Stewart
Published: November 2016

Early modern debates about the nature of matter interacted with debates about whether matter could think. In particular, some philosophers (e.g. Cudworth and Leibniz) objected to materialism about the human mind on the grounds that matter is passive, thinking things are active, and one cannot make an active thing out of passive material. This paper begins by looking at two 17‐century materialist views (Hobbes's, and one suggested but not endorsed by Locke) before considering that objection (which I call here the Activity Argument). In discussion, I note that several philosophers of the time believed that matter was active. That view opens up a possible response to the Activity Argument. The paper concludes by looking at the views of two materialists of the time who also believed that matter was active, Toland and Cavendish.
Optimization and Degradation Mechanism of Photocatalytic Removal of Bisphenol A Using Zn0.9Fe0.1S Synthesized by Microwave‐assisted Method
Authors: Su Rongjun , Xue Yanei , Zhang Guangshan , Wang Qiao , Hu Limin , Wang Peng
Published: November 2016

The sulfide photocatalyst of Zn0.9Fe0.1S was successfully synthesized by a facile microwave‐assisted method, and Zn0.9Fe0.1S photocatalysts were characterized using SEM, EDX, XRD and BET. The specific surface area of synthesized Zn0.9Fe0.1S is 78.1 m2 g−1, and total pore volume is 0.4 cm3 g−1. With bisphenol A (BPA) as a target pollutant, photocatalytic system of UV + Zn0.9Fe0.1S + H2O2 was set up. Some influencing parameters, including H2O2 dosage, initial pH value, initial concentration of BPA and Zn0.9Fe0.1S dosage, were investigated, and the stability of the Zn0.9Fe0.1S was also studied during the photocatalysis. The optimum values of operating parameters were found at an initial pH value of 5.0, a H2O2 dosage of 0.15 mmol L−1 and a Zn0.9Fe0.1S dosage of 0.08 g when the initial concentration of BPA was 10 mg L−1. Under the optimal conditions, the highest removal rate of BPA achieved 95%. After seven consecutive reaction cycles, the degradation efficiency of BPA could still reach 85% and there was only a little dissolution of Zn2+ and Fe2+. Compared with the traditional photo‐Fenton system, the UV + Zn0.9Fe0.1S + H2O2 system can not only improve the degradation efficiency of BPA, but also reduce the dosage of H2O2 and thus reduce the processing cost.
The National Flood Insurance Program: A Case Study in Policy Failure, Reform, and Retrenchment
Authors: Strother Logan
Published: November 2016

In this paper, I present an intensive case study of the development of the National Flood Insurance Program to advance two key arguments. First, the conventional model of adoption of general interest reform neglects an important aspect of political context: whether the relevant policy domain is one with or without “publics.” I argue that in domains without publics the politics of reform will differ substantially from the accepted model. Second, I argue that the type of learning necessary to address a given policy failure matters in reform politics. Instrumental learning is necessary but may not be sufficient for successful general interest reforms. When the social construction of a policy failure is such that many people misconceive of the fundamental purpose of a policy, social learning must take place before instrumental learning can be effective.
Policy and Management: Considering Public Management and Its Relationship to Policy Studies
Authors: Sowa Jessica E. , Lu Jiahuan
Published: November 2016

As part of this special issue, this article explores the relationship of public management research to the study of public policy and the policy process. Beginning with a review of the study of public management, this article then examines some current big questions in public management, with a focus on where these questions intersect with policy studies. This article concludes with several recommendations for fostering cross‐field research.
On the Estimation of the Density of a Directional Data Stream
Authors: Amiri Aboubacar , Thiam Baba , Verdebout Thomas
Published: November 2016

Many directional data such as wind directions can be collected extremely easily so that experiments typically yield a huge number of data points that are sequentially collected. To deal with such big data, the traditional nonparametric techniques rapidly require a lot of time to be computed and therefore become useless in practice if real time or online forecasts are expected. In this paper, we propose a recursive kernel density estimator for directional data which (i) can be updated extremely easily when a new set of observations is available and (ii) keeps asymptotically the nice features of the traditional kernel density estimator. Our methodology is based on Robbins–Monro stochastic approximations ideas. We show that our estimator outperforms the traditional techniques in terms of computational time while being extremely competitive in terms of efficiency with respect to its competitors in the sequential context considered here. We obtain expressions for its asymptotic bias and variance together with an almost sure convergence rate and an asymptotic normality result. Our technique is illustrated on a wind dataset collected in Spain. A Monte‐Carlo study confirms the nice properties of our recursive estimator with respect to its non‐recursive counterpart.
Changing the Direction of Suicide Prevention in the United States
Authors: Reidenberg Dan , Berman Alan L.
Published: November 2016

It is axiomatic that the goal of suicide prevention is the prevention of suicide. Yet in spite of significant efforts to this end since the middle of the last century, and most notably in the last decade, the rate of suicide in the U.S. has not declined; rather, it has increased. To address this issue, Suicide Awareness Voices of Education (SAVE) brought together leading prevention specialists from other public health problems where successes have been achieved, representatives from countries where suicide rates have declined, and U.S. based suicide prevention researchers and program directors, to “think outside the box” and propose innovative, scalable approaches that might better drive success in achieving desired results from U.S. suicide prevention efforts. The recommendations should challenge our preconceptions and force us outside our own mental constraints to broaden our perspectives and suggest catalysts for real change in suicide prevention.
The Framing of Sustainability in Sustainability Assessment Frameworks for Agriculture
Authors: Slätmo Elin , Fischer Klara , Röös Elin
Published: November 2016

Various frameworks for assessing sustainability in agriculture have emerged in recent years. We analysed how sustainability is framed as a governing concept for agriculture within three such frameworks. The results suggest that in all three frameworks sustainability is perceived as a fixed, definable end goal, rather than a process, and its assumed that if all stake holders understand each other and are informed about the negative impacts of agriculture, sustainability will be achieved. The characteristics of the assessment frameworks, which are primarily developed by and based on expert knowledge, provide limited possibilities for farmers to influence how sustainable agriculture is framed and acted upon, limiting the utility of the frameworks. A number of challenges that need to be solved for successful implementation were uncovered, including how assessment frameworks should be used in practice and identification of conflicts between different goals in relation to assessment results.
Investigation of oxidative stress parameters in different lifespan erythrocyte fractions in young untrained men after acute exercise
Authors: Gwozdzinski Krzysztof , Pieniazek Anna , Tabaczar Sabina , Jegier Anna , Brzeszczynska Joanna
Published: November 2016

New Findings

What is the central question of this study?

What is the influence of a single bout of exercise on the properties of erythrocyte fractions at different ages?

What is the main finding and its importance?

A single bout of exercise in untrained men induced oxidative stress in erythrocytes and had an influence on antioxidant defense in these cells. Old erythrocytes were more sensitive to oxidative damage than young and middle‐aged cells. Higher levels of glutathione in old erythrocyte fractions did not protect them against oxidative stress. It seems that exercise may promote the removal of old erythrocytes from the circulation.

The objective of this study was to establish the role of exercise‐induced oxidative stress in the erythrocyte fractions [young (YF), middle‐aged (MAF) and old (OF)] of young untrained men after acute exercise. Blood samples were collected before exercise, immediately after and 1 h after exercise. The maximal power generated was 292 ± 27 W, and exercise duration was 8.73 ± 0.9 min. Different optical properties and oxidative stress parameters were found in each erythrocyte fraction. Total thiols in YF and MAF after exercise and after 1 h rest were similar to values before exercise; however, in OF {32.7 ± 9.8 nmol [mg haemoglobin (Hb)]−1} the concentration was lower in comparison to YF [55.5 ± 3.2 nmol (mg Hb)−1] and MAF [56.8 ± 7.7 nmol (mg Hb)−1] and increased 1 h later (P < 0.0002). The glutathione concentration was higher in OF [8.4 ± 0.4 nmol (mg Hb)−1] than in YF [4.5 ± 0.6 nmol (mg Hb)−1] and MAF [4.8 ± 0.5 nmol (mg Hb)−1; P < 0.0002] and did not change after exercise or 1 h later. In OF, the peroxide level was higher after exercise [1.2 ± 0.2 nmol (mg Hb)−1] and 1 h later [1.1 ± 0.2 nmol (mg Hb)−1], when compared with samples before exercise [0.9 ± 0.1 nmol (mg Hb)−1; P < 0.05]. Similar results were observed in YF and MAF. The level of thiobarbituric acid reactive substances (TBARS) was ∼2.5‐fold higher in OF [0.19 ± 0.04 nmol (mg Hb)−1] when compared with YF [0.07 ± 0.01 nmol (mg Hb)−1] and MAF [0.08 ± 0.02 nmol (mg Hb)−1; P < 0.0002] and was increased after exercise, remaining unchanged 1 h later. In YF and MAF, no difference in the level of TBARS was detected after exercise or 1 h later. No difference in membrane fluidity was observed in all fractions. The erythrocyte OF appeared to be more sensitive to cellular oxidative damage.
Single Edge Notched Tension (SENT) Testing at Low Temperatures
Authors: Moore Philippa L. , Crintea Andreea M.
Published: November 2016

Much of the established data from SENT tests has been generated on ductile materials in the form of tearing resistance curves (R-curves) in terms of J. The testing of SENT specimens is now standardised in BS 8571 [1] and there is potential to use SENTs for high and low temperature tests, but there is little recently published data showing SENT behaviour at low temperature. This paper presents a comparison of fracture toughness data for equivalent SENT and SENB specimens in three different steels as ductile-to-brittle transition curves over a range of temperatures. SENT specimens in comparison to SENBs show higher fracture toughness on the upper shelf, lower transition temperature, but also a much steeper transition from ductile to brittle behaviour. It is therefore important to characterise SENT behaviour at the lowest anticipated service temperatures to ensure that this sudden change in fracture behaviour will be avoided in service.

This paper also describes methods for carrying out SENT tests at very low temperatures, including the use of threaded ends to allow testing inside a temperature controlled test chamber, while preventing the specimen from yielding at locations away from the intended notch tip.
Measuring Critical Strains in Dent Defect of Oil and Gas Pipes
Authors: Oshana-Jajo Jandark , Zohrehheydariha Jamshid , Ghaednia Hossein , Das Sreekanta
Published: November 2016

Steel pipelines are exposed to harsh environmental, geotechnical and other conditions and hence, they can be damaged. The damage can threaten the structural integrity of the pipeline and can cause economic loss and environmental damage if a failure occurs. A common way for pipelines to be damaged is through physical contact, creating a structural imperfection, dent, wrinkle, crack, and/or other damages or defects. A dent disrupts the pipeline’s circularity causing increased strains in concentrated areas. A research program was established and carried out to study the strain concentration of dented pipes. The study was completed using full-scale laboratory testing and numerical analysis at the Centre for Engineering Research in Pipelines (CERP). This study included four lab tests on two different pipe materials (X70 and X56) and finite element analysis (FEA) based parametric study.
An Experimental Study to Evaluate the Performance of Competing Filler Materials Used With Type B and Stand-Off Steel Sleeves
Authors: Alexander Chris , Beckett Alan
Published: November 2016

An experimental study was conducted to evaluate the performance of various filler materials used in Type B tight-fit and stand-off steel sleeve designs. Full-scale testing was performed to examine the performance of three filler materials and two sleeve types reinforcing four separate dents subjected to cyclic internal pressure. All filler materials were installed with the test pipe at 55°F and allowed to cure for 7 days. The metric for comparing filler material performance was stress concentration factors (SCFs) measured in the dents in the unrepaired and repaired configurations. The filler materials included a two-component epoxy, an epoxy-based grout, and a cement-based grout. The average SCF for the unreinforced dents was 5.64, while after reinforcement the average SCF was 1.2 (an average reduction of 79%).

The results of this study generated two important findings. First, the stand-off sleeve design was able to provide reinforcement similar to what was measured for the tight-fit sleeve. Second, the study determined that the cement-based grout actually slightly outperformed the epoxy-based grout, the latter being the filler material of choice prior to this study. This paper provides readers with practical information and data on the performance of competing filler material types, while also presenting a systematic method for evaluating different methods of reinforcement.
Assessment of In-Line Inspection Performance and Interpretation of Field Measurements for Characterization of Complex Dents
Authors: Torres Luis A. , Fowler Matthew J. , Stenerson Jordan G.
Published: November 2016

Integrity management of dents on pipelines is currently performed through the interpretation of In-Line Inspection (ILI) data; this includes Caliper, Magnetic Flux Leakage (MFL), and Ultrasonic Testing (UT) tools. Based on the available ILI data, dent features that are recognized as threats from a mechanical damage perspective are excavated and remediated. Federal codes and regulations provide rules and allow inference on what types of dent features may be a result of mechanical damage; nonetheless, there are challenges associated with identifying dents resulting from mechanical damage. One of the difficulties when managing the mechanical damage threat is the lack of information on how MFL and UT ILI tool performance is affected by dented areas in the pipe. ILI vendors do not offer any technical specifications for characterizing and sizing metal loss features in dents. It is generally expected that metal loss tool performance will be affected in dented areas of the pipe, but it is not known to what degree. It is likely that degradation will vary based on feature shape, sensor design, and sensor placement. Because metal loss tool performance is unknown within the limits of the dented pipe, other methods for recognizing mechanical damage have been incorporated into the management strategies of mechanical damage. Some of these methods include strain based assessments and characterization of shape complexity. In order to build a more effective integrity management program for mechanical damage, it is of critical importance to understand how tool technology performance is affected by dented areas in the pipe and what steps can be taken to use ILI information more effectively. In this paper, the effectiveness of MFL and UT wall measurement tools in characterizing and sizing metal loss features within dents is studied by evaluating against field results from non-destructive examinations of mechanical damage indications. In addition, the effectiveness of using shape complexity indicators to identify mechanical damage is evaluated, introducing concepts such as dents in close proximity and multi-apex dents. Finally, the effectiveness of ILI tools in predicting dent association with girth welds is also explored by comparing ILI and field results.
Review of Phase II for the Comprehensive Study to Understand Longitudinal ERW Seam Failures
Authors: Young Bruce A. , O’Brian Jennifer M. , Nanney Steve
Published: November 2016

In response to the National Transportation Safety Board (NTSB) Recommendation P-09-1, the Department of Transportation (DOT) Pipeline and Hazardous Material Safety Administration (PHMSA) initiated a comprehensive study to identify actions that could be implemented by pipeline operators to significantly reduce longitudinal seam failures in electric resistance weld (ERW) pipe. The purpose of this paper is to provide a review of Phase II of the project with focus on the study objectives and results.

Phase II of the project consisted of five tasks with the following objectives relevant to the ERW and flash weld (FW) process: 1) develop and optimize viable hydrotest protocols for ERW/FW seam defects 2) improve the sensors, interpretive algorithms, and tool platforms in regard to In-Line-Inspection (ILI) and In-the-Ditch-Methods (ITDM) to better ensure structural integrity by developing and optimizing concepts to address problems in detecting and sizing, 3) bridge gaps in defect characterization in regard to types, sizes, geometries, and idealizations, to increase pipeline safety through improvements needed to implement both ILI and hydrotesting, 4) validate existing failure prediction models and, where gaps preclude validation, refine or develop these models needed to assess and quantify defect severity for cold welds, hook cracks, and selective seam weld corrosion (SSWC) (the primary ERW/FW seam threats) for failure subject to loadings that develop both during hydrotests and in service, and 5) develop software to support integrity management of seam welds with enough flexibility to benefit from the experience gained during this project.

The reports generated during the course of the project are publically available and are located on following PHMSA website:

http://primis.phmsa.dot.gov/matrix/PrjHome.rdm?prj=390.
Anisotropic Material Characterization and its Effect on Structural Integrity
Authors: Hilgert Oliver , Kalwa Christoph
Published: November 2016

In recent years anisotropic pipe material properties have gained more interest due to offshore; strain based design and fracture arrest topics.

The effect of anisotropic UOE pipe material characteristic is analyzed in this contribution. Both, anisotropic strain dependent values (Lankford) and anisotropic strength dependent factors (Hill) are compared, and their impact on load bearing and plastic strain capacity is investigated.

Several common load cases as internal and external pressure as well as bending are investigated. An analysis of the structural behavior concerning burst pressure and transverse strain capacity, collapse pressure, maximum bending moment and critical buckling strain is performed depending on yield strength variation. Therefore the above load and strain capacities are investigated based on present material anisotropy as well as numerical parametric studies.

For the internal pressure as dominating load case, it was found that a higher yield strength in the longitudinal direction decreases burst pressure and increases transverse strain capacity. An increase of radial yield strength increases burst pressure as well as transverse strain capacity.

For collapse applications, higher radial and transverse yield strength is beneficial as well as a lower longitudinal yield strength.

Increasing longitudinal and radial yield strength leads to beneficial structural responses in terms of bending. Increase of transversal yield strength is thus not recommended as the maximum bending moment is not affected and critical buckling strain is decreased.

Further it becomes clear from the above various parametric studies that the structural behavior is prone to differ for every set of distinct anisotropic parameters and the load cases. On the other hand selection of distinct anisotropic material can promote the desired structural behavior.
FortisBC 36-Inch High Pressure Line Isolation Using Double Block and Bleed Technology
Authors: Bolger Neil , Whiteis Kyle , Marwaha Raghav , Treece Jim
Published: November 2016

This paper discusses the benefit of using single-tap double block and bleed (DBB) technology to isolate large diameter (24-inch and 36-inch) natural gas transmission lines during tie-in of a pig launcher and receiver in Surrey, British Columbia, Canada. The pipeline, which is owned by FortisBC, is the only source of supply for the city of Coquitlam, the Vancouver Island system, and a major power generation facility. As such, shutting down the line was not an option. Instead, the project required a bypass. However, the footprint of the jobsite was too small for a traditional bypass. In addition, the jobsite’s location adjacent to a major highway and a tight timeline meant that first time isolation success was mandatory.
Stress Corrosion Cracking (SCC) Integrity Management Plans for Onshore Liquid and Gas Pipelines: Saudi Aramco Comprehensive Study
Authors: Tehsin Nauman , Al-Otaibi Nader , Al-Usaimi Waleed A. , Polasik Steven J. , Bubenik Thomas A.
Published: November 2016

Stress corrosion cracking (SCC) on buried pipelines results from simultaneous presence of tensile stress, a corrosive environment, and a material that is susceptible to SCC. ASME B31.8S provides a basic framework for determining the SCC susceptible segments of buried pipelines. In-line inspection (ILI) has been effective in the industry for locating and sizing SCC on pipelines. There are some inherent limitations in ILI tools that should be recognized in the development of a comprehensive SCC Integrity Management Plan.

Saudi Aramco operates a combined pipeline network of approximately 22,000 kilometers in length. A significant number of Saudi Aramco pipelines were built prior to 1980 with tape coating, thereby increasing the susceptibility to SCC. ILI results from 26 pipelines showed presence of SCC out of 93 pipelines inspected using electromagnetic acoustic transducer (EMAT) and ultrasonic crack detection (UTCD) technologies. These cracks were later verified through direct examination. Besides the basic framework provided in ASME B31.8S, there were no existing criteria to prioritize the susceptible pipeline segments for the SCC threat.

Therefore, Saudi Aramco conducted a comprehensive three-phase study to establish a robust integrity management plan for pipelines with SCC. This paper covers details of the third phase of the study, which is about SCC integrity management planning. Companion papers address Phases 1 and 2.

The third phase of the study developed SCC integrity management plans (SCC IMPs) for pipelines with SCC based on the work completed on the first and second phases. The SCC IMPs covered SCC susceptibility profiling along pipeline segments, engineering assessment of SCC features, growth analysis, and a process to respond to the SCC threat. The SCC response strategy included further ILI plans, excavations plans, hydrotest benefit assessments and other mitigation measures, such as pipeline partial replacement and recoating. The approach of the SCC IMP will be deployed on all Saudi Aramco pipelines in the future, to prioritize SCC susceptible segments and their mitigation plans.
Under Pressure Welding on CO2 Pipelines: The Effect of Thermal Decay on Mechanical Properties
Authors: Slater Simon , Barnett Julian , Boothby Peter , Andrews Robert
Published: November 2016

Whilst there is extensive industry experience of under pressure welding onto operational natural gas and liquid pipelines, there is limited experience for Carbon Dioxide (CO2) pipelines, either in the gaseous or dense phase. National Grid has performed a detailed research program to investigate if existing natural gas industry under pressure welding procedures are applicable to CO2 pipelines, or if new specific guidance is required.

At IPC 2014 a paper was presented (IPC2014-33223) that dealt with the results from one part of a comprehensive trial program, which defined the cooling time from 250 °C to 150 °C (T250-150) in CO2 pipelines and compared them to the typical decay times for natural gas pipelines. The results from this part of the work identified that maintaining the pre-heat using the established guidance in T/SP/P/9 during under pressure welding on dense phase CO2 pipelines would be very difficult, leading to potential operational issues.

The previous paper gave a brief summary of the effect that cooling time had on the mechanical properties. The aim of this paper is to present the findings of the T800-500 weld decay trials in more detail including the full testing programme, detailing the affect that variables such as CO2 phase, CO2 flow velocity and the welding parameters had on the weld and heat affected zone (HAZ) hardness.

The main finding is that although there is an indication that a higher cooling rate measured in the weld pool (characterized by the cooling time from 800 °C to 500 °C) leads to increased hardness in the HAZ region, there are no clear correlations. No hardness values were recorded that were considered unacceptable, even for the dense phase CO2 case which delivered the fastest cooling time. A significant finding was the requirement for controlling the buttering run procedure. A discussion of the critical aspects, including the link between weld cooling time and hardness, is presented with guidance on how this essential variables need to be controlled.

The paper is aimed at technical, safety and operational staff with CO2 pipeline operators. Read in conjunction, this paper and the previous IPC paper form a comprehensive review of this critical work that is contributing to the development of dense phase CO2 transportation pipelines and will facilitate the implementation of Carbon Capture and Storage (CCS)1 projects which is a critical part of the transition to a low carbon economy.
Continuous Depth Sizing of ILI Ultrasonic Crack Detection
Authors: Atto Abdullahi , Grigat Marius , Voss Jens
Published: November 2016

Since the market launch of Ultrasonic crack detection tools, the conventional crack depth sizing is based on four depth classes or buckets. A more differentiated, continuous depth sizing is becoming increasingly relevant for the pipeline operators and especially for pipelines with large populations of planar anomalies (SCC colonies, lack-of-fusion in ERW seam-welds, etc.). The ILI industry is introducing a continuous crack depth sizing. Next to the better differentiation and the linearity of the depth reporting, the main advantage of the continuous depth sizing is the direct comparability to the results of the field verifications. The continuous depth sizing improves the ability to assess the performance validation of the depth sizing and thus, contributes to a general improvement of the crack depth sizing. This paper describes the development and implementation of a continuous crack depth sizing approach and shows its advantages in comparison to the conventional depth classes. A sizing model is introduced, making use of an empirically derived function, that relates the amplitude measurement to the defect depth. The continuous depth sizing applies to crack-like defects with depths ranging from 1mm to 4mm. The parameters of the model are derived from performance tests based on artificial flaws. In addition, the model is validated by means of field verification results. The depth sizing accuracy and confidence levels are obtained from the performance test data in accordance to API 1163 [1] and POF 2009 [2].

In addition, the paper discusses the extraction of the crack depth profiles from inspection data, making use of the newly developed continuous depth sizing model. In comparison to standard reporting of maximum depth and length, crack depth profiles deliver more accurate and more valuable input to the integrity assessment for pipeline operators. Examples of a direct comparison of these crack depth profiles to field verification data are included.
Shear-Wave Ultrasonic Crack Inspection Tool Performance for Cracks Associated With Metal Loss
Authors: Scholte Mendoza Paola , Bott Steven , Hubert Yvan
Published: November 2016

Shear-wave ultrasonic in-line tools are used for crack management in liquids pipelines. An ultrasonic pulse is generated, travels in the pipe wall and reflects on axially oriented artifacts that could be geometric or crack-like in nature. If several geometrical artifacts are present, detection and sizing efficiency of these ultrasonic inspection tools could be reduced. Cracking located within corrosion is one possible interacting set of geometrical artifacts that could affect in-line inspection (ILI) performance.

As part of continuous improvement, a comprehensive review of two thousand three hundred and thirty eight in-the-ditch measurements of cracking in corrosion were compared to crack ILI reported features in order to determine the tool performance in cases where cracks were associated with metal loss. Relationships of depth and predicted burst pressures were reviewed and compared to cracks not associated with metal loss. Additionally, field NDE results that had incomplete information in the ILI-NDE correlation files with indications of being potential defects were reviewed to examine the possibility of undocumented coincident cracking in metal loss that could represent an integrity threat. This paper summarizes the results and potential implications for management of cracking in corrosion using shear-wave ultrasonic crack ILI.
Restored Crossings: When and Where to Apply Stream Restoration Techniques to Protect Exposed Pipelines
Authors: Salas Dan , Steber Aaron
Published: November 2016

Maintenance of existing rights-of-way often involve dealing with exposed pipelines near stream crossings. Streams often shift over time. This adjustment can lead to erosion of the streambed and streambanks, exposing pipelines or other infrastructure to threats such as hydraulic pressure, buoyancy, debris collisions, or pipe vibration and fatigue. Under these conditions, managers can be faced with relocating the pipe, performing localized streambank stabilization, or employing stream restoration techniques to provide long-term protection.

When localized stabilization is the preferred approach, selection of techniques is often determined by what will protect the pipeline without consideration of the stream context surrounding it. However, due to site conditions, manager preferences, and regulatory considerations, techniques from the disciplines of stream restoration and habitat enhancement can provide cost-effective alternatives to traditional hard-armoring by concrete or stone depending on the site context. Using past experience and a series of decision analysis tools, it was determined that geomorphic context should be factored as a foremost consideration when evaluating the most stable and cost effective approach to correcting exposed pipelines. One of the most critical factors in assessing the feasibility of stabilization options is the height and orientation of exposed pipes relative to the stream’s bankfull elevation.
The Effects of Pressure Fluctuations on Hydrogen Embrittlement in Pipeline Steels
Authors: Xing Xiao , Yu Mengshan , Tehinse Olayinka , Chen Weixing , Zhang Hao
Published: November 2016

Hydrogen embrittlement is one of the most severe steel degradation mechanisms. Using hydrogen enhanced decohesion (HEDE) and hydrogen enhanced local plasticity (HELP), we can predict if more hydrogen atoms will accumulate into the plastic zone, enhancing the hydrogen embrittlement and the crack growth rate. In the current study, a relationship has been proposed between operations of pipeline steels and hydrogen accumulation to quantify the effects of hydrogen embrittlement. The study find that hydrogen accumulation rate is proportional to stress intensity and inversely proportional to temperature; hence, higher stress intensity and lower temperature will enhance hydrogen accumulation and crack propagation. Hydrogen potential, diffusivity, hydrostatic stress near the crack tip, and the critical loading frequency have been considered in the new model to predict crack propagation rates in pipeline steels. The predicted values are compared with experimental results of X-65 steel in two near-neutral pH solutions to verify the model. This hydrogen diffusion model helps show former neglected hazard operations such as minor cycles, and offers an easier way to optimize operations that will prolong the life of pipeline steels.