bluuebunny/crossref_metadata_2025 huggingface dataset:
A Discussion of the Using of Pressure Relief Devices for On-Board High-Pressure Hydrogen Storage Tanks
Authors: Ou Kesheng , Zheng Jiong , Luo Weijian , Li Xufeng , Yang Jingbiao , Wang Lei
Published: December 2016

To prevent the on-board storage tank from burst at vehicle fire scenario, pressure relief device (PRD) is required to be installed to the tank and timely activated to release internal high-pressure hydrogen. Actually, there are two types of PRDs (i.e. thermally-activated and pressure-activated PRDs), and four types of tanks such as all-metal, hoop/fully-wrapped with metal liner and fully-wrapped with plastic liner. Great importance should be attached to the using of PRDs for all types of tanks in consideration of the risk of tank burst caused by fire. However, there are great differences in the requirements for the using of PRDs in hydrogen storage tank standards such as GTR-HFCV, ISO/TS 15869, JARI S 001 and TSG R006. Compared with compressed natural gas tank standards, PRD requirements in hydrogen storage tank standards are discussed in this paper. Moreover, key influencing factors on the activation of thermally-activated and pressure-activated PRDs are analyzed in detail based on fire test data. Finally, some advices for the using of PRDs of hydrogen storage tanks are proposed.
Fracture Toughness Characterization of Vessel Forging With Hydrogen Flaked Specimens
Authors: Chaouadi Rachid , Gérard Robert , van Walle Eric
Published: December 2016

The 2012 in-service vessel inspections performed at Doel-III and Tihange-II Nuclear Power Plant revealed a large number of ultrasonic indications in the forged core shells suggesting nearly-laminar defects attributed to hydrogen flakes induced during the component manufacturing process. These observations have initiated a very large experimental test program not only for reliably and accurately characterizing the ultrasonic indications but also to characterize the mechanical properties in presence of hydrogen flakes. A key point of the Safety Case was the justification of the material properties to be used in the structural integrity analysis, in particular the local fracture toughness of the material ahead of hydrogen flakes. An innovative methodology was used to manufacture fracture toughness specimens, including both compact tension and Charpy size specimens, with a hydrogen flake substituting the standard fatigue pre-crack. As a result, it is possible to measure the fracture toughness directly at the tip of real hydrogen flakes. This paper describes the procedure and the results that were obtained in comparison to standard fatigue precracked specimens.
Revisiting the Bree Diagram
Authors: Spring Daniel W. , Panzarella Charles , Osage David A.
Published: December 2016

As early as the 1950’s, practitioners observed progressive distortion in thin-walled pressure vessels subjected to a constant axial stress and a cyclic thermal stress. In the late 1960’s, Bree [1] developed a theory and corresponding diagram plotting the primary membrane stress versus the cyclic thermal stress which delineates the various zones of plastic behavior. The zones include elastic cycling, plastic cycling, elastic cycling after initial plasticity, and ratcheting leading to incremental growth. This paper revisits the original Bree problem and investigates many of the recent advancements made to alleviate several of the simplifying assumptions Bree made in developing the diagram, to bring it in line with more modern operating conditions. In particular, a novel modification to the Bree diagram to account for the ratio of the yield stress at the operating extremums is proposed. This paper also reviews some advancements made to incorporate creep into the problem and discusses the operating conditions wherein creep effects may be significant. The outcomes of this paper will help expand the applicability of the Bree diagram, broadening its scope to encompass operating conditions more representative of modern applications.
Probabilistic Financial Analysis of Coke Drum Life Cycle Management
Authors: Panzarella Charles H. , Gassama Edrissa , Spring Daniel
Published: December 2016

The cycle time, and, in particular, the duration of the quenching phase, is known to play an important role in the rate of damage accumulation in a coke drum. A shorter cycle is desirable because it allows for increased production but this comes at the cost of more frequent repairs and a shorter overall life. Therefore, a trade-off decision needs to be made in order to balance these two effects and maximize profitability.

This paper provides guidance for making these sorts of decisions by looking at several different coke drum operating strategies from the perspective of a high level financial analysis, taking into account many cost/benefit factors in order to determine the optimal strategy that maximizes profitability with various levels of confidence. It is shown that the most critical factor is predicting the rate of repairs as the drum ages. This depends on many factors and can only be determined probabilistically due to the many uncertainties involved. One of the most important factors driving the repair rate is the frequency at which fatigue cracks initiate and grow. A probabilistic fatigue model is used to describe this, taking into account the large surface area of the coke drum, which provides more potential nucleation sites for fatigue crack initiation.

It is shown that there is, indeed, an optimal, intermediate cycle time for certain conditions. For other situations running with the shortest possible cycle time is shown to be the best choice.
Development of Acceptance Criteria for Soil-Structure Interaction Solutions Using Linear SSI Techniques
Authors: Costantino Michael C. , Houston Thomas W. , Maham Andrew S.
Published: December 2016

Seismic analysis and design of high-hazard nuclear facilities requires evaluation of soil-structure interaction (SSI) effects on structure and soil response due to earthquake ground motions. The industry-wide methodology of computing SSI response of buildings is through linear SSI techniques using the computer code SASSI.

Technical issues were identified by users and regulators (Ref. 1) resulting in the U.S. Department of Energy (DOE) commissioning a large scale, multi-year Validation and Verification (V&V) Project for SASSI (Ref. 2). The project was a highly peer reviewed process that included an esteemed Participatory Peer Review Team, DOE oversight, as well as regulatory and stakeholder input.

The project goal was to develop benchmark SSI solutions for the range of SSI problems associated with high-hazard facilities within the DOE complex. As per industry software quality control requirements, an acceptance limit for the benchmark solutions must be provided to define the acceptable accuracy of the results produced by SASSI relative to the benchmark. In order to define this limit, variation in the solution of foundation impedance must be related to an expected level of accuracy in structural design quantities of interest (e.g., response spectra, base shear, etc.). Therefore, extensive parametric analyses were performed for coupled soil-structure systems having a broad range of SSI parameters defined by foundation size, soil properties, building stiffness and mass properties, building height, etc.

Based on the results of the parametric analyses, ASCE 4 code guidance, and engineering judgment of CJC&A and the peer review team, an acceptable level of accuracy in computed foundation impedance was determined for SASSI solutions. This supported the successful qualification of SASSI for use in two large-scale DOE projects.
Critical Plane Search Method for Biaxial and Multiaxial Fatigue Analysis
Authors: Karpanan Kumarswamy
Published: December 2016

For complex cyclic loadings, stress- or strain-based critical plane search methods are commonly used for fatigue analysis of the structural components. Complex loadings can result in a non-proportional type loading in which it is difficult or impossible to determine the plane with maximum shear stress/strain amplitude. ASME Sec VIII, Div-3 fatigue analysis for non-welded components is a shear stress based fatigue analysis method and, for non-proportional loading, uses the critical plane search method to calculate the plane with maximum shear stress amplitude.

For a two-dimensional non-proportional stress state, analytical stress transformation equations can be used to calculate the shear stress or strain amplitude on any plane at a point. The shear stress range on each plane is the difference between the maximum and minimum shear stress. For a three-dimensional stress state, shear stress amplitude calculations are much more complicated because the shear stress is a vector and both magnitude and direction change during the loading cycle. In ASME VIII-3, the maximum shear stress range among all planes, along with the normal stress on the plane, is used to calculate the stress amplitude. This paper presents a method to calculate the shear stress/strain amplitude using 3D transformation equations. This method can be used for any stress- or strain-based critical plane search method. This paper also discusses ASME proportional and non-proportional fatigue analysis methods in detail.
Behaviour of Polymers in High Pressure Environments as Applicable to the Hydrogen Infrastructure
Authors: Menon Nalini C. , Kruizenga Alan M. , Alvine Kyle J. , San Marchi Chris , Nissen April , Brooks Kriston
Published: December 2016

Polymeric materials have played a significant role in the adoption of a multi-materials approach towards the development of a safe and cost-effective solution for hydrogen fuel storage in Fuel Cell Vehicles (FCVs). Numerous studies exist with regards to the exposure of polymeric materials to gaseous hydrogen as applicable to the hydrogen infrastructure and related compression, storage, delivery, and dispensing operations of hydrogen at fueling stations. However, the behavior of these soft materials under high pressure hydrogen environments has not been well understood. This study involves exposure of select thermoplastic and elastomeric polymers to high pressure hydrogen (70–100 MPa) under static, isothermal, and isobaric conditions followed by characterization of physical properties and mechanical performance. Special attempt has been made to explain hydrogen effects on polymer properties in terms of polymer structure-property relationships, and also understand the influential role played by additives such as fillers, plasticizers, and processing aids in polymers exposed to hydrogen. Efforts have also been focused on deriving suitable conditions of static testing in high pressure hydrogen environments as a valuable part of developing a suitable test methodology for such systems. Understanding the relationships between polymer composition and microstructure, time of exposure, rate of depressurization, purge and exposure conditions, etc. in this simple study will help better define the test parameters for upcoming high pressure cycling experiments in hydrogen.
Development of High Acceleration Shaking Table System Using Resonance Vibration
Authors: Sakai Michiya , Kanazawa Kenji , Ohtori Yasuki
Published: December 2016

High acceleration shaking table system to be called “Strong Shake Generator” (SSG) using resonance vibration has been developed. New concept of setting the resonance table on outside shaking table is devised. Maximum acceleration of 200 m/s2 with 5 ton specimen weight is achieved. At the trial operation of SSG, the environmental influence exceeding the regulation value of vibration level has been occurred at the site boundary of CRIEPI. In order to suppress vibration of SSG, the semi-active mass damper (SAMD) has been additionally installed on base of shaking table. Vibration of SSG was reduced by counterforce of the SAMD. For the confirmation of the earthquake-proof safety for various nuclear facilities, strong shake generator will be utilized.
Thoughts on Improving Confidence in Probabilistic Fracture Mechanics Analyses
Authors: Rudland D. , Kirk M. , Raynaud P.
Published: December 2016

In the past, the US Nuclear Regulatory Commission (NRC) has typically regulated the use of nuclear structural materials on a deterministic basis. Safety factors, margins, and conservatisms were used to account for model and input uncertainty. However, in the mid-1990s, the NRC issued a policy statement that encouraged the use of Probabilistic Risk Assessments (PRA) to improve safety decision making and improve regulatory efficiency. Since that time, the NRC has made progress in its efforts to implement risk-informed and performance-based approaches into its regulation and continues to revisit and update the approaches on a regular basis.

A major component to the overall safety of nuclear structures is the fracture behavior of the materials. Consensus codes and standards responsible for the design and analysis of such structures, such as ASME Boiler and Pressure Vessel code, typically rely on conservative fracture models with applied safety factors and conservative bounding inputs to account for the numerous uncertainties that may be present. Improving the reliability of such models by truly understanding the impacts of the assumptions and uncertainties becomes difficult because of the conservative nature of the models and inputs and the inadequate documentation of the basis for safety factors.

As a subset of PRA, probabilistic fracture mechanics (PFM) is an analysis technique that allows greater insight into the structural integrity of components than similar deterministic analyses. PFM allows the direct representation of uncertainties through the use of best-estimate models and distributed inputs. This analysis methodology permits determination of the direct impact of uncertainties on the results, which gives the user the ability to determine and possibly refine the specific drivers to the problem. However, PFM analyses can be more complicated and difficult to conduct than deterministic analyses. Determining validated best-estimate models, developing input distributions with limited data, characterizing and propagating input and model uncertainty, and understanding the impacts of problem assumptions on the adequacy of the results, can complicate the development and approval of PFM analyses in a regulatory application.

This paper provides some thoughts on how to improve confidence in structural analyses performed using PFM, by focusing on topics such as solution convergence, input distribution determination, uncertainty analyses, sensitivity analyses (to determine impact of uncertainties on result) and sensitivity studies (to determine impact of mean values on the results). By determining the main drivers to the probabilistic results and investigating the impacts of the assumption made to develop those drivers, the confidence in the overall results can be greatly improved.
The Effect of Crack Shape Idealisation on Leak-Before-Break Assessment
Authors: Bourga Renaud , Wang Bin , Moore Philippa , Janin Yin Jin
Published: December 2016

Based on detailed 3D finite element (FE) analyses, idealized and non-idealized axial through-wall flaws were evaluated in a cylinder under internal pressure. The key parameters (Stress Intensity Factor, Reference stress, and Crack Opening Area) from widely accepted structural integrity assessment procedures (BS 7910 and API 579-1/ASME FFS-1) were explored and compared between idealized (perpendicular straight-sided flaw) and non-idealized geometry. The effect of crack shape on the evolution of stress intensity factors and crack opening areas along the crack front were also investigated. Non-idealized crack shapes have been modelled assuming a straight crack front with different internal and external crack lengths. The influence of crack shape has been evaluated by varying the crack front location and lengths ratios. The current findings highlight the significance of assessing a more realistic crack shape and should be considered in a leak-before-break (LBB) analysis. A non-idealized crack has a significantly smaller crack opening area than the equivalent idealized through-wall crack. Therefore the leakage rate at this stage of crack growth will be lower than predicted by standard solutions. Stress intensity factor solutions should also take the crack shape variation into account with regards to fatigue crack growth as a surface flaw propagates through-thickness.
Root Cause Analysis and Characterisation of the Doel 3 and Tihange 2 Reactor Pressure Vessel Flaws
Authors: De Vroey Séverine , De Bruycker Evy , De Smet Michel , Stubbe Jacqueline
Published: December 2016

This paper presents the root cause analysis and characterisation of the indications discovered in two Belgian pressurized water reactor (PWR) pressure vessels (Doel 3 and Tihange 2), during in service inspections performed in 2012.

The only plausible mechanism at the origin of the detected indications is hydrogen flaking during fabrication. Flaking could occur because of the local combination of high hydrogen concentration, stresses and susceptible microstructure.

The phenomenology study performed on several materials including flaked materials provided precious information for the Safety Case: it confirmed the cause of the indications and evidenced that flaking exclusively occurs in segregated zones and that the ligament between flakes is sound.

The paper also briefly addresses the possibility of evolution of the indications during operation: low cycle fatigue during transients is identified as the only mechanism likely to induce flaw growth in operation. A particular attention has been paid to the potential hydrogen effects.
Probabilistic Non-Linear Cumulative Fatigue Damage of the P355NL1 Pressure Vessel Steel
Authors: Fonseca de Oliveira Correia José António , Jesus Abílio , Blasón Sergio , Calvente Miguel , Fernández-Canteli Alfonso
Published: December 2016

Miner’s rule for fatigue damage accumulation does not address conveniently the sequential effects of the fatigue loading due to underloads or overloads though such effects need to be taken into account for specific applications using a convenient model. Non-conservative (unsafe) or over-conservative (non-economic) fatigue predictions may result from such a linear damage analysis. To overcome these limitations, non-linear damage approaches are being proposed in the literature, as for instance, the double linear damage rule (DLDR). Further, advanced probabilistic models, as an alternative to deterministic ones, are being currently applied to fatigue damage assessment under variable (random) amplitude loading, though without including, up to present, sequential effects on the damage accumulation. In this paper, the synergetic effect of applying a non-linear fatigue damage model based on the DLDR in conjunction with a probabilistic approach based on the p-S-N field is pursued allowing the above mentioned sequential effects to be incorporated into a probabilistic damage prediction. The proposed approach was tested with existing fatigue block loading data available for the P355NL1 pressure vessel steel.
Hardened Pit Lid Design for High Pressure Extreme Temperature Pneumatic Gate Valve Testing
Authors: Wesevich James W. , Dunn Peter E. , Lawver Darell J. , Yeary Taylor J.
Published: December 2016

This paper discusses the design of a removable hardened test pit lid for conducting high pressure pneumatic testing under extreme temperature variations. The high pressure extreme temperature (HPET) pit configuration requires a robust lid to contain the energy release that could occur through testing a variety of oil services items placed within a frangible thermally insulated enclosure. The insulated and hardened enclosures include an inlet and outlet for airflow. These energetic release scenarios represent postulated test item failures resulting in significant fragment and shock loads within the insulated enclosure. A 618in3 gate valve charged with 20,000psi of compressed nitrogen under a temperature range of −100°F to 600°F was used to produce the worst-case energy release in the event of a catastrophic failure within the test pit.

In order to assess the structural response of the hardened pit lid, two sets of computational fluid dynamics (CFD) analyses were performed. A 2-dimensional axisymmetric CFD model of the gate valve was used to estimate the fragment velocity of its blind flange. A 3-dimensional CFD model of the test pit, insulated enclosure, and blast lid was used to estimate the applied blast loads. The test pit enclosure was assessed using non-linear dynamic finite element analysis using single-integration hexahedral continuum elements. The braces were modeled with layered shell elements and the bolts were explicitly modeled with beam and spring elements. All of the materials are modeled using a plasticity-based piecewise linear hardening constitutive model, with rate dependency and softening, fit to each material yield, tensile, and elongation limit.
Validation of Design Optimization Approach for Polymer Composite Piping
Authors: Harnischfeger Milan , Schatz Markus , Baier Horst , Mertiny Pierre
Published: December 2016

Excellent corrosion resistance and high specific properties make fiber-reinforced polymer composite piping an attractive choice for various industries. In previous research an optimization approach was developed in order to provide design guidance with respect to the composite piping fiber architecture and material system. The objective was to meet design specifications while maximizing performance and minimizing material usage. The research described in the present contribution seeks to validate this design optimization approach. Glass-fiber reinforced epoxy pipe samples were filament-wound in a conventional single-angle and an optimized multi-angle layup and tested applying monotonic internal pressurization. The experimental findings were used to discuss the preceding design optimization approach.
Examination of Fracture Toughness of Pipes to Satisfy Leak-Before-Break Conditions
Authors: Machida Hideo
Published: December 2016

This paper describes examinations of the requirements for fracture toughness of piping materials to establish Leak-Before-Break (LBB) behaviors. One of the important elements in establishing LBB is the fracture toughness of the materials. The fracture toughness might vary greatly due to inappropriate material management. Some representative fracture toughness properties of piping materials are plane strain fracture toughness (KIc or JIc) and fracture resistance curve (J-R curves). Requirements to establish LBB were examined focusing on these two properties. Although it is easy to obtain plane strain fracture toughness (it can, for example, be estimated using the Charpy impact test, etc.), trying to predict ductile fracture strength based only on plane strain fracture toughness will likely result in underestimating the strength. In the LBB Codes of the Japan Society of Mechanical Engineers (JSME), the elastic-plastic fracture mechanics (EPFM) have been defined for the material that shows ductile fracture behaviors. The LBB Codes set the ratio of the plastic collapse strength and ductile fracture strength (Pb′/Pb-cr) as 1.5 or less. Therefore, requirements for the fracture resistance of the piping materials to have the same fracture strength as the LBB Codes were examined. The examinations have shown that the slope of the fracture resistance curve is as important as the plane strain fracture toughness (JIc). In order to achieve the same ductile fracture strength with EPFM defined in the LBB Codes, the fracture resistance of the pipe materials should be controlled plane strain fracture toughness (JIc) and fracture resistance curve. Materials with high fracture toughness should be used, especially when employing thin-walled or high yield stress pipes.
Development and Application of Oxide Wedging Crack Growth Model for CANDU Zr-2.5Nb Pressure Tubes
Authors: Scarth Douglas A. , Doddihal Preeti , Ip Monique
Published: December 2016

Surface breaking and subsurface manufacturing flaws have been detected by in-service ultrasonic examination in a number of CANDU reactor Zr-2.5Nb pressure tubes. The manufacturing flaws are oriented in the circumferential direction in the Zr-2.5Nb pressure tube, and are axially aligned along the pressure tube. Metallographic examination of these flaws in an ex-service Zr-2.5Nb pressure tube revealed a series of parallel circumferentially oriented discontinuous features oriented at an angle of nominally 40 degrees relative to the axial direction in the pressure tube. Since the surface breaking flaws are exposed to the reactor coolant, it was considered prudent to evaluate potential growth of the flaws by an oxide wedging crack growth mechanism. Oxide wedging crack growth is a slow crack growth mechanism that can occur when zirconium oxide forms on the crack faces due to a corrosion reaction with the reactor coolant. An oxide wedging crack growth model was developed to predict crack growth rates and future flaw sizes as a part of the fitness-for-service evaluation of a Zr-2.5Nb pressure tube containing this type of manufacturing flaw. The model was then applied to predict crack growth from manufacturing flaws that were detected in an operating pressure tube, and the evaluation results were used as part of the justification for continued operation.
Study on Small-Scale Laminated Type Base Isolation Device Using Urethane Elastomer for Practical Application
Authors: Ishihana Kenta , Furuya Osamu , Goda Kengo , Omata Shohei
Published: December 2016

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material.

In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. The mechanical characteristics based on the loading test up to 500% shear strain using experimental specimen with 100 × 100 mm cross-sectional shape. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step.

In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.
Impact Toughness for PM HIP 316L at Cryogenic Temperatures
Authors: Berglund Tomas , Östlund Martin
Published: December 2016

It is well known throughout the PM HIP (Powder Metallurgy Hot Isostatic Pressing) industry that PM HIPed 316L material in general exhibit higher strength than conventional 316L. However, previous studies have shown an uncharacteristic behavior in impact toughness properties at cryogenic temperatures compared to conventional forged material. The uncharacteristic behavior consists of unexpectedly large drop in impact toughness at cryogenic temperatures which is not seen in the same extent in conventional material e.g. forged 316L. With the recent code case approval for PM HIPed 316L material, this behavior can be seen as an uncertainty regarding the performance of the material and its use in nuclear applications can therefore become limited. The behavior and underlying mechanisms is yet to be explained in detail. One possible explanation is that it is caused by oxides in the material, of which a large amount originates from oxygen picked up by the very large surface area of the powder during the manufacturing process. The correlation between impact toughness at room temperature and oxygen content is often referred to.

In this study the non-metallic inclusion content is correlated to the impact properties at −196°C (−321°F), and a suggested explanation for the behavior of PM HIP 316L/316LN vs. conventional 316L is presented. The size and number of inclusions constitutes a major difference between the PM HIPed and conventional material. The results show that the size of the inclusions is significantly smaller in the PM materials compared to the conventional material and as a consequence they are present in larger numbers in the PM materials. Furthermore, the results clearly show the correlation between inclusion content and the impact toughness at cryogenic temperatures. The correlation is not as clear at room temperature where the different materials behave more similar. The suggested explanation is further supported by literature on cryogenic properties of 316L/316LN, 316L weld material and PM HIP 316LN with greatly reduced oxygen content. The impact toughness testing was performed using instrumented test equipment capable of recording load vs. displacement during testing. From this data the crack propagation and crack initiation energy can be estimated.

Furthermore, it is known that grain size can influence mechanical properties. In this study no clear relationship between impact toughness and grain size could be observed. However, a correlation between the grain size and the amount of inclusions in the material was observed. It was found that larger amounts of inclusions in the PM HIPed material are correlated to a finer grain size. The results indicate that the inclusion particles inhibit grain growth during the HIP and heat treatment process by pinning of grain boundaries.
Examination of Various Bending Moments on the Run Side and on the Branch Side for the Stress Index C2 of ASME NB-3600 Class 1 Branch Connections
Authors: Faraz Umar , Gurdal Robert
Published: December 2016

Previous stress analyses have shown that the requirement of exclusively using the branch pipe cross-section properties for the NB-3600 Class 1 branch connection stress analyses can be very severe (conservative), when compared with using the branch nozzle cross-section properties. In the analyses performed for a 2015 PVP technical paper (Ref. 2), one of the questions raised was the fact that only two specified bending moments were used in those previous stress analyses: 1,000,000 in-lbf as the run bending moment and 20,000 in-lbf as the branch bending moment. In fact, that was the main question that was raised. Therefore, the purpose of this technical paper is to perform additional stress analyses, based on various bending moments on the run side and on the branch side. The impact of using these various bending moments will be evaluated.

The 2001 Edition of the ASME-Code removed a note at the bottom of the branch connection NB-3600 Figure. This note is required to be able to perform more accurate NB-3600 piping stress analyses of the branch connection. There is at this time a suggestion to restore that note.
Webinar | Characterizing the maternal immune environment during pregnancy: Implications for autism spectrum disorders
Authors: Jones Karen , Saporita Anthony
Published: December 2016

Under normal conditions, the maternal immune system is uniquely regulated during pregnancy to maintain a pathogen-free, yet noninflammatory environment for the developing fetus. However, factors such as cytokines and chemokines produced during gestation can have developmental consequences for the fetus. In particular, maternal immune dysregulation during pregnancy has been frequently associated with increased risk of autism spectrum disorders. This webinar will discuss the relationship between the maternal immune environment and autism risk, highlighting findings from the largest population-based prospective study to date to have examined the relationship between mid-gestational maternal cytokines and chemokines and risk for autism.

View the Webinar
Reforming the U.S. coal leasing program
Authors: Gillingham Kenneth , Bushnell James , Fowlie Meredith , Greenstone Michael , Kolstad Charles , Krupnick Alan , Morris Adele , Schmalensee Richard , Stock James
Published: December 2016

Royalty rates and auction practices do not reflect the social costs of coal
Double trouble: pelvi-ureteric junction obstruction and renal cell carcinoma in right to left crossed fused ectopia
Authors: Saini Sumit , Yadav Siddharth , Nayak Brusabhanu
Published: December 2016

Crossed renal ectopia is a rare occurrence. The majority of the crossed units are fused to their ipsilateral mate. Pelvi-ureteric junction obstruction (PUJO) in crossed fused moieties has been reported very rarely. Similarly, malignancy arising in the crossed over moieties is a rare occurrence too. Only a few cases have been reported earlier. We are here reporting an unusual case with coexistent PUJO and renal cell carcinoma in the crossed over moiety of right to left crossed fused ectopia. To the best of our knowledge, this is the first reported case with both these pathologies, coexisting, in the crossed over moiety. The patient underwent open radical nephrectomy of the right moiety via a lower midline incision. Surgery in this scenario is very challenging due to complex anatomy with aberrant vasculature, which needs for dissection within the renal parenchyma, similar to nephron-sparing surgery to separate from the normal moiety.
Internet-based cognitive–behavioural therapy for insomnia (ICBT-i): a meta-analysis of randomised controlled trials
Authors: Ye Yuan-yuan , Chen Ni-ka , Chen Jia , Liu Juan , Lin Ling , Liu Ya-zhen , Lang Ying , Li Xun-jun , Yang Xin-ju , Jiang Xiao-jiang
Published: December 2016

Objective

To evaluate the effectiveness of internet-based cognitive–behavioural therapy for insomnia (ICBT-i) in adults.

Design

A meta-analysis of ICBT-i.

Data sources

Systematic searches of randomised controlled trials of ICBT-i were performed in the PubMed, EMBASE, PsycINFO and Cochrane Library databases up to 19 June 2016.

Review method

2 reviewers independently performed study selection, quality assessment and data extraction. Outcomes of interest included sleep onset latency (SOL), total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of nocturnal awakenings (NWAK), and Insomnia Severity Index (ISI). RevMan 5.2 and Stata 13.0 meta-analysis software were used to perform statistical analysis.

Results

14 records for 15 studies (1013 experimental group participants, 591 waiting list group participants) were included. The meta-analysis indicated that, at the post-test time point, SOL decreased by 18.41 min (95% CI 13.60 to 23.21), TST increased by 22.30 min (95% CI 16.38 to 28.23), SE increased by 9.58% (95% CI 7.30% to 11.85%), WASO decreased by 22.31 min (95% CI 13.50 to 31.11), NWAK decreased by 0.52 (95% CI 0.28 to 0.76), and ISI decreased by 5.88 points (95% CI 4.29 to 7.46). Additionally SOL, TST, SE, and WASO exhibited statistically significant improvements at follow-up versus before treatment.

Conclusions

ICBT-i is an effective treatment for adults with insomnia. This conclusion should be verified in further studies.
Commonly prescribed drugs associate with cognitive function: a cross-sectional study in UK Biobank
Authors: Nevado-Holgado Alejo J , Kim Chi-Hun , Winchester Laura , Gallacher John , Lovestone Simon
Published: December 2016

Objective

To investigate medications associated with cognitive function.

Design

Population-based cross-sectional cohort study.

Setting

UK Biobank.

Participants

UK Biobank participants aged 37–73 years who completed cognitive tests at the baseline visit in 2006–2010.

Main outcome measures

Cognitive test outcomes on verbal–numerical reasoning test (n=165 493), memory test (n=482 766) and reaction time test (n=496 813).

Results

Most drugs (262 of 368) were not associated with any cognitive tests after adjusting for age, gender, education, household income, smoking, alcohol status, psychostimulant/nootropic medication use, assessment centre, and concurrent diagnoses and medications. Drugs used for nervous system disorders were associated with poorer cognitive performance (antiepileptics, eg, topiramate breasoning(score)−0.65 (95% CI −1.05 to −0.24), bmemory(score)−1.41 (−1.79 to −1.04); antipsychotics, eg, risperidone breaction time(ms)−33 (−46 to −20), negative values indicate poor cognitive performance and vice versa). Drugs used for non-nervous system conditions also showed significant negative association with cognitive score, including those where such an association might have been predicted (antihypertensives, eg, amlodipine breasoning−0.1 (−0.15 to −0.06), bmemory−0.08 (−0.13 to −0.03), breaction time−3 (−5 to −2); antidiabetics, eg, insulin breaction time−13 (−17 to −10)) and others where such an association was a surprising observation (proton pump inhibitors, eg, omeprazole breasoning−0.11 (−0.15 to −0.06), bmemory−0.08 (−0.12 to −0.04), breaction time−5 (−6 to −3); laxatives, eg, contact laxatives breaction time−13 (−19 to −8)). Finally, only a few medications and health supplements showed association towards a positive effect on cognitive function (anti-inflammatory agents, eg, ibuprofen breasoning0.05 (0.02 to 0.08), breaction time4 (3, 5); glucosamine breasoning0.09 (0.03 to 0.14), breaction time5 (3 to 6)).

Conclusions

In this large volunteer study, some commonly prescribed medications were associated with poor cognitive performance. Some associations may reflect underlying diseases for which the medications were prescribed, although the analysis controlled for the possible effect of diagnosis. Other drugs, whose association cannot be linked to the effect of any disease, may need vigilance for their implications in clinical practice.
Keeping Weight Off: study protocol of an RCT to investigate brain changes associated with mindfulness-based stress reduction
Authors: Fulwiler Carl , Siegel Julia A , Allison Jeroan , Rosal Milagros C , Brewer Judson , King Jean A
Published: December 2016

Introduction

Obesity is a growing epidemic fuelled by unhealthy behaviours and associated with significant comorbidities and financial costs. While behavioural interventions produce clinically meaningful weight loss, weight loss maintenance is challenging. This may partially be due to failure to target stress and emotional reactivity. Mindfulness-based stress reduction (MBSR) reduces stress and emotional reactivity and may be a useful tool for behaviour change maintenance. This study seeks to provide a mechanistic understanding for clinical trials of the benefits of MBSR for weight loss maintenance by examining changes in functional connectivity (FC) and the association of these changes with clinical outcomes.

Methods and analysis

Community-dwelling individuals (n=80) who intentionally lost ≥5% of their body weight in the past year will be recruited and randomised to an MBSR programme or educational control. FC using resting-state functional MRI will be measured at baseline and 8 weeks. Psychological factors, health behaviours, body mass index and waist circumference will be measured at baseline, 8 weeks and 6 months post intervention. A 12-month telephone follow-up will assess self-reported weight. Analyses will characterise FC changes in response to MBSR in comparison with a control condition, assess the relationship between baseline FC status and pre–post MBSR changes in FC and investigate the association of FC change with changes in psychological factors and weight loss maintenance.

Ethics and dissemination

The University of Massachusetts Medical School Institutional Review Board has approved this study, Declaration of Helsinki protocols are being followed, and patients will give written informed consent. The Independent Monitoring Committee will monitor protocol adherence. Results from the study will be disseminated to the medical community at conferences and submitted for publication in peer-reviewed journals when the last patient included has been followed up for 12 months.

Trial registration number

NCT02189187.
Leveraging ongoing research to evaluate the health impacts of South Africa's salt reduction strategy: a prospective nested cohort within the WHO-SAGE multicountry, longitudinal study
Authors: Charlton Karen , Ware Lisa J , Menyanu Elias , Biritwum Richard Berko , Naidoo Nirmala , Pieterse Chiné , Madurai Savathree (Lorna) , Baumgartner Jeannine , Asare George A , Thiele Elizabeth , Schutte Aletta E , Kowal Paul
Published: December 2016

Introduction

Attempting to curb the rising epidemic of hypertension, South Africa implemented legislation in June 2016 mandating maximum sodium levels in a range of manufactured foods that contribute significantly to population salt intake. This natural experiment, comparing two African countries with and without salt legislation, will provide timely information on the impact of legislative approaches addressing the food supply to improve blood pressure in African populations. This article outlines the design of this ongoing prospective nested cohort study.

Methods and analysis

Baseline sodium intake was assessed in a nested cohort of the WHO Study on global AGEing and adult health (WHO-SAGE) wave 2 (2014–2015), a multinational longitudinal study on the health and well-being of adults and the ageing process. The South African cohort consisted of randomly selected households (n=4030) across the country. Spot and 24-hour urine samples are collected in a random subsample (n=1200) and sodium, potassium, creatinine and iodine analysed. Salt behaviour and sociodemographic data are captured using face-to-face interviews, alongside blood pressure and anthropometric measures. Ghana, the selected control country with no formal salt policy, provided a nested subsample (n=1200) contributing spot and 24-hour urine samples from the SAGE Ghana cohort (n=5000). Follow-up interviews and urine collection (wave 3) in both countries will take place in 2017 (postlegislation) to assess change in population-level sodium intake and blood pressure.

Ethics and dissemination

SAGE was approved by the WHO Ethics Review Committee (reference number RPC149) with local approval from the North-West University Human Research Ethics Committee and University of the Witwatersrand Human Research Ethics Committee (South Africa), and University of Ghana Medical School Ethics and Protocol Review Committee (Ghana). The results of the study will be published in peer-reviewed international journals, presented at national and international conferences, and summarised as research and policy briefs.
Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment in groin pain in athlete
Authors: Bisciotti G N , Volpi P , Zini R , Auci A , Aprato A , Belli A , Bellistri G , Benelli P , Bona S , Bonaiuti D , Carimati G , Canata G L , Cassaghi G , Cerulli S , Delle Rose G , Di Benedetto P , Di Marzo F , Di Pietto F , Felicioni L , Ferrario L , Foglia A , Galli M , Gervasi E , Gia L , Giammattei C , Guglielmi A , Marioni A , Moretti B , Niccolai R , Orgiani N , Pantalone A , Parra F , Quaglia A , Respizzi F , Ricciotti L , Pereira Ruiz M T , Russo A , Sebastiani E , Tancredi G , Tosi F , Vuckovic Z
Published: December 2016

The nomenclature and the lack of consensus of clinical evaluation and imaging assessment in groin pain generate significant confusion in this field. The Groin Pain Syndrome Italian Consensus Conference has been organised in order to prepare a consensus document regarding taxonomy, clinical evaluation and imaging assessment for groin pain. A 1-day Consensus Conference was organised on 5 February 2016, in Milan (Italy). 41 Italian experts with different backgrounds participated in the discussion. A consensus document previously drafted was discussed, eventually modified, and finally approved by all members of the Consensus Conference. Unanimous consensus was reached concerning: (1) taxonomy (2) clinical evaluation and (3) imaging assessment. The synthesis of these 3 points is included in this paper. The Groin Pain Syndrome Italian Consensus Conference reached a consensus on three main points concerning the groin pain syndrome assessment, in an attempt to clarify this challenging medical problem.
Development and evaluation of a habitat suitability model for young lake sturgeon (Acipenser fulvescens) in the North Channel of the St. Clair River, Michigan
Authors: Krieger Joseph R. , Diana James S.
Published: December 2016

We evaluated the quantity, quality, and spatial distribution of riverine nursery habitat for larval, young-of-year (YOY), and juvenile (<500 mm) lake sturgeon (Acipenser fulvescens) in the North Channel of the St. Clair River (SCR), Michigan, using habitat suitability modeling (HSM) and fish collections. This HSM was developed using georeferenced habitat information on substrates, invertebrate densities, benthic flow velocities, and water depth. High-quality habitat comprised 29.1% of the study area, primarily in river bends and other areas where water velocities were highly varied. In all, 283 larval lake sturgeon were collected, with the majority found in high-quality habitat (81%) and heavily clustered in three locations (91.2% of total catch). Substrate composition and benthic flow velocity were the best indicators of observed larval catch-per-unit-effort (CPUE) patterns. Available data on captured YOY and juveniles were used to corroborate modeled habitat output and revealed strong associations between modeled habitat conditions and young lake sturgeon presence. An abundance of suitable habitat for young lake sturgeon within the North Channel of the SCR suggests that lack of suitable spawning habitat or high mortality early in life limits recruitment success in this system.
An evaluation of acceptable biological catch (ABC) harvest control rules designed to limit overfishing
Authors: Wiedenmann John , Wilberg Michael , Sylvia Andrea , Miller Thomas
Published: December 2016

In this paper we developed a simulation model to evaluate a range of acceptable biological catch (ABC) control rules to determine their relative performance at achieving common fishery management objectives. We explored a range of scenarios to determine robustness of a control rule to different situations and found that across scenarios the control rules that used a buffer to account for scientific uncertainty when setting the ABC were able to limit the frequency of overfishing. Modest buffers when setting the ABC were generally effective at limiting overfishing, but larger buffers resulted in higher average biomass, similar long-term benefits to the fishery (high yield, low variability in yield), more rapid recovery of depleted populations, and a lower risk of the population being overfished, and these results were robust to the level of uncertainty in the assessment model estimates. In addition, fixing the ABC over the interval between assessments and having a short interval between assessments was generally more effective at meeting management objectives than using projections and having a long assessment interval.