bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesh Convergence Studies for Hexahedral Elements Developed by the ASME Special Working Group on Computational Modeling
Authors: Tso Chi-Fung , Molitoris David P. , Yaksh Michael , Snow Spencer , Ammerman Doug , Bjorkman Gordon S. 
Published: January 2014

The ASME Special Working Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of element convergence studies that can aid designers in establishing the mesh refinement requirements necessary to achieve accurate results for a variety of different element types in regions of high plastic strain. These convergence studies will also aid reviewers in evaluating the quality of a finite element model and the apparent accuracy of its results.
In this paper, the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA hexahedral elements using both reduced and selectively reduced integration. Three loading levels are considered; the first maintains strains within the elastic range, the second induces moderate plastic strains, and the third produces large deformations and large plastic strains.
Guidelines for Managing the Integrity of Bolted Joints: Developments in European Standards
Authors: Noble Robert 
Published: January 2014

The Energy Institute Guidelines for the Management of Integrity of Bolted Joints in pressurized systems [1] was first introduced in 2002 in response to a drive to reduce Hydrocarbon leakage in the UK Offshore Industry. This was a successful initiative and the guidelines were updated in 2007 assisting with a further push to reduce Hydrocarbon leakage — at that time the guidelines were extended to the onshore industry.
The guidelines are now under review again with a target publication in 2013 to ensure they remain current best practice, which has a high relevance in 2013 the 25th Anniversary Year of the Piper Alpha disaster.
This paper will give an overview of the Guidelines — and discuss the key changes on the previous versions and alignment with ASME PCC-1-2010.[2]
The paper will also discuss developments in other key bolted joint standards in Europe including: En1591-1[3] and En1591-4[4].
Study of Crack Extension Effects on a Weld-Induced Residual Stress Field
Authors: Hong Jeong K. , Forte Thomas P. 
Published: January 2014

For many applications, welding is the best manufacturing process for joining two separate components. However, the welding process with its highly localized heating and cooling results in the residual stresses both along the surface and through the thickness of the joint. These residual stresses will affect the rate of growth of a fatigue crack as it propagates through the joint and therefore will affect the service life. Therefore, service life predictions must consider the residual stresses as well as their redistribution that occurs as the crack grows.
Analytical approaches to assess fitness-for-service such as API 579 are available to evaluate the effect of weld-induced residual stresses. However, current industry practices calculate stress intensity factors (SIFs) for fracture and fatigue crack growth life estimates without considering the redistribution of the residual stresses as the crack propagates, and thus tend to be very conservative.
In this paper, Battelle’s weld residual stress modeling methods are combined with a procedure for calculating the SIF using local crack tip displacements that accounts for the redistribution of the residual stresses due to crack extension. In addition, the finite element model used to determine the weld residual stresses is also used to determine the SIF. Therefore, the complete mechanical response to the welding, including residual stress, deformed geometry, elastic and plastic strains, etc. are available for the crack growth analysis. This new unified procedure is demonstrated for simple joints and is compared to a “simplified” crack growth analysis that uses stress mapping. The unified procedure clearly characterizes mixed mode crack behavior at the crack tip. In this paper the procedure is presented in terms of how the crack affects the weld-induced residual stress field; it is equally well suited for practical design use to assess structural integrity in the presence of a weld-induced residual stress field with or without external service loading.
Standards, Specifications, Test Methods and Technical Reports for GRP Water, Drainage and Sewerage Piping
Authors: Marques António Torres 
Published: January 2014

Many end-users, specifiers, governmental agencies and testing facilities, are not fully aware of the wealth of standards available for GRP piping products and the continuing work being done in CEN &ISO and other standards developing organizations. As a result the introduction of Ad-Hoc test methods, standards and obsolete requirements is, unfortunately, not uncommon.
The paper will list and comment available GRP Standards that has been prepared as a reference guide to assist in the proper specification and use of GRP piping products. The primary focus is on EN and ISO standards. The work being done in CEN and ISO is closely linked, with ISO taking the lead in test method development and ISO test methods being referenced in EN standards. The work in CEN is conducted in CEN TC 155 WG14 and the work in ISO in ISO TC138 SC6. However, important standards are issued by other standards organizations and these will be also covered in the paper.
Criteria for High Frequency Cutoff Based on ABWR Reactor Building Vibratory Loads
Authors: Ulku Evren , Ozgur Cagri , Ozkan Mustafa Kemal , Vaidya Nish , Srivastava Hari , Tanoue Tetsuharu 
Published: January 2014

In the seismic analysis practice, the calculation of modal response has traditionally been limited to a cutoff frequency of about 33 Hz based on United States Nuclear Regulatory Commission (US NRC) Regulatory Guide (RG) 1.60 [1] response spectra. The structural response in higher modes is calculated as a missing mass correction by static analysis.
Seismic ground motions at several sites (such as Central and Eastern United States) exhibit high frequency content, up to about 100 Hz. Additionally, the reactor building vibratory (RBV) loads that result from the suppression pool hydrodynamic loads due to loss of coolant accident (LOCA), and the annulus pressurization (AP) load from a postulated pipe break at the reactor pressure vessel (RPV) safe ends and shield wall generate peaks at frequencies in excess of 100 Hz. The qualification of safety equipment supported in the reactor building needs to reflect these high frequency motions. Extracting frequencies and mode shapes up to zero period acceleration (ZPA) frequencies in these cases may not be practical or economical. Therefore, the cutoff frequency criteria for these types of high frequency loads need to be evaluated so that the analysis produces a representative and a reasonably conservative response.
In this study, the equipment response is described in terms of stress quantities, member forces, and moments resulting from the solution up to a cutoff frequency. The responses are compared to the full solution up to the ZPA frequency under hydrodynamic and AP loads using the Response Spectrum Method. The cutoff frequency is deemed adequate if the ratio of the truncated response considering missing mass to the full response is 90% or greater. The internal strain energy (or its surrogate kinetic energy) for all modes with frequencies below the cutoff is also studied to assess the missing strain energy in modes in excess of the cutoff. The evaluation presented also examines how well the strain energy correlates with calculated stresses.
Latest Developments in Optimizing Reformer Tube Life Through Advanced Inspection and Remaining Life Assessment
Authors: Shannon Brian , Jaske Carl E. 
Published: January 2014

Steam methane reformer tubes must withstand high temperature and pressures during operation and are made from centrifugally cast austenitic materials, typically HK-40, HP Modified, and Micro-Alloy materials. Since operating conditions can result in various forms of damage, the identification and quantification of damage is of vital importance if tube life is to be predicted accurately.
This paper describes the recent developments in an integrated inspection system which uses multiple NDT techniques to provide a most comprehensive assessment of current tube condition. This system is coupled with a sophisticated remaining life assessment software model which predicts the remaining life of each tube in a furnace.
Ratchet Boundary of a Beam With Arbitrary Cross Section
Authors: Adibi-Asl R. , Reinhardt W. 
Published: January 2014

The classical approaches in shakedown analysis are based the assumption that the stresses are eventually within the elastic range of the material everywhere in a component (elastic shakedown). Therefore, these approaches are not very useful to predict the ratcheting limit (ratchet limit) of a component/structure in which the magnitude of stress locally exceeds the elastic range at any load, although in reality the configuration will certainly permit plastic shakedown.
In recent years, the “Non-Cyclic Method” (NCM) was proposed by the present authors to predict the entire ratchet boundary (both elastic and plastic) of a component/structure by generalizing the static shakedown theorem (Melan’s theorem). The fundamental idea behind the proposed method is to (conservatively) determine the stable and unstable boundary without going through the cyclic history.
The method is used to derive the interaction diagrams for a beam subjected to primary membrane and bending with secondary bending loads. Various cross-sections including rectangular, solid circular and thin pipe are investigated.
The Shakedown Boundary for Parabolic Stress Distribution in NB-3222.5
Authors: Reinhardt W. , Asadkarami A. 
Published: January 2014

The rules for the prevention of thermal stress ratchet in NB-3222.5 address the interaction of general primary membrane stress with two types of cyclic thermal loading. The first is a linear through-wall temperature gradient, for which the shakedown boundary is given by the well-known Bree diagram. The Code provides a second shakedown boundary for the interaction of general primary membrane stress with a “parabolic” temperature distribution. The corresponding ratchet boundary is fully defined in the elastic range, but only three points are given in the elastic-plastic regime. The range of validity of this ratchet boundary in terms of the thermal stress distribution (does “parabolic” mean second-order in the thickness coordinate or any polynomial of degree greater than one? If it is second-order, are there any further restrictions?) is not well defined in NB-3222.5.
Using a direct lower bound method of shakedown analysis, the non-cyclic method, an exact analytical solution is derived for the shakedown boundary corresponding to the interaction of general primary membrane stress with a cyclic “parabolic” temperature distribution. By comparison to what is given in NB-3222.5, the thermal condition for which the Code equation is valid is defined and its range of validity is established. To study the transition behavior to the steady state and to confirm the analytical solution, numerical results using an FE model are also obtained.
Fatigue Life Estimation in Notched Geometries
Authors: Cravero Sebastian , Ernst Hugo 
Published: January 2014

The fatigue failure in components is divided in two stages: an initiation stage that defines the number of cycles that it takes for a crack to appear in the material and a second stage that estimates the number of cycles where the crack grows until it becomes unstable.
Usual fatigue life estimation procedures (in crack free components) only consider the initiation stage and assume that the crack propagation period is relatively small compared with the total life. However, in the case of severely notched geometries like threaded connections, the propagation stage can be an important part of the component fatigue life and must be evaluated.
A fundamental issue in the calculation of initiation plus propagation fatigue life is the definition of the initial crack size after the initiation stage. In the present study techniques for crack initiation and crack growth are described. Also the procedure to combine the two techniques and define an initial crack size is presented. The study is based on previous work of C. Navarro, et al. [1]. Additionally, validation against experimental tests on notched specimens is provided.
Development of a Technical Bases Document to Support the IAEA Regulations for Safe Transport of Radioactive Material
Authors: Bajwa Christopher S. , Pope Ronald B. 
Published: January 2014

The International Atomic Energy Agency (IAEA) is entrusted by the Social and Economic Council of the United Nations with developing safety requirements for the safe transport of radioactive material. These requirements were first published as “Regulations for the Safe Transport of Radioactive Material”, Safety Series No. 6, 1961 edition (The Regulations). At the same time, the Director General of the IAEA indicated that these regulations would be revised at appropriate intervals, in consultation with Member States, and with input from other relevant organizations, as appropriate.
After 50 years, over 10 revisions of the Regulations have been published. These revisions have been taking into account experiences in transport, newly identified issues, new technologies, best practices, the demand for safer transport, and harmonization. Problems, challenges, the demand for improvements, and the need to provide biennial inputs to international dangerous goods model transport regulations have driven the transport community and the IAEA in particular, to facilitate the regular review and revision of the Regulations.
With the passage of time, the scientific and technical heritage of several decades of development in transport safety has begun to fade, and the requirement to capture valuable knowledge which needs to be preserved for future reference has become clear.
In general, every requirement in the regulations was developed based on an appropriate technical basis. The technical basis exists in a decentralized manner in many Member States with mature nuclear programs. Easier access to the existing technical bases for the Regulations could lead to a more comprehensive understanding of the Regulations and could inform proposals for change that were previously considered but not accepted for various technical (or political) reasons. Knowledge capture and transfer can contribute to the development of and innovations in, transport safety.
This paper provides an overview of the efforts to date that have been undertaken to develop a technical basis document for supporting the current transport regulations and will highlight the future plans for the development of this document.
Impact of New Imaging Non Destructive Methods in Testing and Monitoring of Composite and Metallic Components
Authors: Walaszek Henri 
Published: January 2014

The non-destructive testing techniques (NDT) are now undergoing significant changes associated with the development of new sensors and digital techniques for storing and processing information.
Thus, new ultrasonic methods now provide a view of the entire component in the form of a traceable image. These new methods include ultrasonic TOFD methods (to inspect metal products), and the Phased Array method (metallic and composite products), which can image the inside of components. The simulation of ultrasonic testing brings a strong contribution in ultrasonic inspection preparation.
Another major trend of the development of NDT methods is the rise of active thermal infrared methods, enabling high resolution imaging of surface and near surface defects of components.
A remarkable application of new radiographic technology consists also in Computed Tomography, which now allows 3D imaging within the mechanical components.
These technologies are now available in the market with affordable prices, to test more reliably and faster the health of mechanical components. Thus, it helps to increase the quality of components, especially in the Pressure Vessel and piping industry, and to improve the safety of industrial pressure equipment.
Developments in the more advanced testing methods are presented, with examples of applications on pressure vessel and piping components.
Condensation Induced Waterhammer in District Steam Distribution Systems
Authors: Sinha Sri K. , Vecchio Robert S. , Bruck Paul M. , Esselman Thomas C. , Zysk Gregory , Somrah Dowlatram 
Published: January 2014

Condensation induced waterhammer in district steam distribution systems can cause catastrophic rupture of piping and inflict severe damage to personnel, property, and environment. On July 18, 2007, a 20-in. diameter underground steam pipe in New York City ruptured at 5:56 p.m. at the intersection of 41st Street and Lexington Avenue in midtown Manhattan. At the time of rupture, the steam system was in service delivering steam to the customers at an operating pressure of approximately 160 psig and a steam temperature of approximately 370°F. The incident opened a large cavity measuring approximately 32 ft × 32 ft × 18 ft deep at the intersection of 41st Street and Lexington Avenue. The pipe rupture released steam, condensate, water, pipe insulation and various construction materials to the environment.
Consolidated Edison Co. of New York, Inc. (Con Edison) and LPI (Lucius Pitkin, Inc.) investigated the event. Based on detailed metallurgical and engineering evaluations of the steam system configuration and operating conditions, it was concluded that the steam pipe ruptured as a result of excessive pressure caused by condensation-induced waterhammer.
This paper presents a summary of the engineering evaluation, root cause, and conditions leading to the pipe rupture and provides measures which can be taken to reduce the likelihood of such a failure and enhance public safety.
Digital holographic interferometry: A novel optical calorimetry technique for radiation dosimetry
Authors: Cavan Alicia , Meyer Juergen 
Published: January 2014

Purpose:To develop and demonstrate the proof‐of‐principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium.Methods:The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature‐induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach.Results:The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ±3.45 Gy (corresponding to an uncertainty in the temperature value of ±8.3 × 10−4 K). The relative dose fall off was in agreement with treatment planning system modeled data.Conclusions:First results with a prototype optical setup and a Brachytherapy source demonstrate the proof‐of‐principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10−5 m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.
Draft Genome Sequence of
Rhodobacter
sp. Strain CACIA 14H1, a Heterotrophic Bacterium Obtained from a Nonaxenic Culture of a
Cyanobium
Species
Authors: Lima Alex Ranieri Jerônimo , Siqueira Andrei Santos , dos Santos Bruno Garcia Simões , da Silva Fábio Daniel Florêncio , Inada Davi Toshio , Lima Clayton Pereira , Cardoso Jedson Ferreira , Vianez-Júnior João Lídio S. G. , Nunes Márcio Roberto Teixeira , Gonçalves Evonnildo Costa 
Published: January 2014

ABSTRACT

Despite their prominent importance, few efforts have been paid to the genomic analysis of heterotrophic bacteria associated with cyanobacteria. Thus, this work presents the draft genome sequence (~3.9 Mbp) of a heterotrophic bacterium (
Rhodobacter
sp. strain CACIA 14H1) recovered from a nonaxenic culture of a
Cyanobium
species.
Genome Sequence of the Relapsing Fever Borreliosis Species Borrelia hispanica
Authors: Elbir Haitham , Larsson Pär , Upreti Mukunda , Normark Johan , Bergström Sven 
Published: January 2014

ABSTRACT

Borrelia hispanica
is the etiological pathogen of tick-borne relapsing fever, transmitted to humans by infected
Ornithodoros erraticus
ticks. Here we present the 1,783,846-bp draft genome sequence, with an average G+C content of 28%. It has 2,140 open reading frames, 3 ribosomal RNAs, and 32 transfer RNAs.
Genome Sequence of Lactococcus lactis subsp.
lactis
bv. diacetylactis LD61
Authors: Falentin Hélène , Naquin Delphine , Loux Valentin , Barloy-Hubler Frédérique , Loubière Pascal , Nouaille Sébastien , Lavenier Dominique , Le Bourgeois Pascal , François Patrice , Schrenzel Jacques , Hernandez David , Even Sergine , Le Loir Yves 
Published: January 2014

ABSTRACT

Lactococcus lactis
is widely used in the dairy industry. We report the draft genome sequence of
L. lactis
subsp.
lactis
bv. diacetylactis LD61, an industrial and extensively studied strain. In contrast to the closely related and plasmidless strain IL1403, LD61 contains 6 plasmids, and the genome sequence provides additional information related to adaptation to the dairy environment.
Complete Genome Sequence of Sterol-Transforming Mycobacterium neoaurum Strain VKM Ac-1815D
Authors: Shtratnikova Victoriya Y. , Bragin Eugeny Y. , Dovbnya Dmitry V. , Pekov Yury A. , Schelkunov Mikhail I. , Strizhov Nicolai , Ivashina Tanya V. , Ashapkin Vasily V. , Donova Marina V. 
Published: January 2014

ABSTRACT

Mycobacterium neoaurum
strain VKM Ac-1815D produces 4-androstene-3,17-dione as a major compound from phytosterols. Here, we report the complete genome sequence of the strain. The genome consists of a single circular 5,438,190-bp chromosome, with a G+C content of 66.88%, containing 5,318 putative open reading frames (ORFs), 46 tRNAs, and 6 rRNAs. Arrays of cholesterol metabolism genes are randomly clustered throughout the chromosome.
Genomic Sequencing of Two Coffee-Infecting Strains of Xylella fastidiosa Isolated from Brazil
Authors: Alencar Valquíria C. , Barbosa Deibs , Santos Daiene S. , Oliveira Ana Cláudia F. , de Oliveira Regina C. , Nunes Luiz R. 
Published: January 2014

ABSTRACT

Here, we describe the draft genome sequences of two
Xylella fastidiosa
strains:
Xf
6c and
Xf
32, which have been obtained from infected coffee plants in Brazil, and are associated with the disease known as coffee leaf scorch (CLS).