bluuebunny/crossref_metadata_2025 huggingface dataset:
Progressive Fatigue Life Prediction of Composite Materials Based on Residual Material Property Degradation Model
Authors: Nakai-Chapman J. , Park Y. H. , Sakai J.
Published: October 2020

Anisotropic composite materials have been extensively utilized in mechanical, automotive, aerospace and other engineering areas due to high strength-to-weight ratio, superb corrosion resistance, and exceptional thermal performance. As the use of composite materials increases, determination of material properties, mechanical analysis and failure of the structure become important for the design of composite structure. In particular, the fatigue failure is important to ensure that structures can survive in harsh environmental conditions. The non-homogeneous character of composites induces diverse failure modes of the constituent including fiber fracture, matrix cracking, fiber-matrix interface failure, and delamination. Non-homogeneity of composite materials makes their fatigue behavior very complex in comparison with traditional engineering materials. In this study, a progressive damage theory is extended to simulate fatigue failure of composite laminates under fatigue loading conditions. A residual material property degradation model was employed to predict fatigue damage due to arbitrary stress ratio without performing excessive quantities of testing. This generalized residual material property degradation rule is implemented into user subroutine USDFLD in ABAQUS through which material degradation states are updated over the progressive fatigue loading. The present computational method is verified by comparing the simulated results with the experimental data available in the literature.
Maintenance Optimization: Finding the Best Frequencies of Maintenance Activities
Authors: Cluever Joseph , Esselman Thomas , Bruck Paul
Published: October 2020

The nuclear industry has recently been shifting to value-based maintenance in order to keep nuclear power competitive in the power generation market. A key challenge in value-based maintenance is the optimization of a maintenance schedule. With most components having ten to fifteen available maintenances, the complexity of the optimization grows quite quickly. This paper presents a methodology for combining maintenance effectiveness, cost estimates, failure impacts, and overall reliability data to estimate an expected life cycle cost (LCC) for a component. The maintenance types are categorized into three types: monitoring, wear-rate reducing (e.g. oil change), or life-restoring (e.g. refurbishment). Each maintenance type has a different effect on problem detection, degradation rate, and future life expectancy. A Markov model uses the maintenance effects to estimate the distribution of what state of degradation a component is in at a specific time and concurrently, the component failures, maintenance costs, and failure impacts are tallied up in order to provide an expected life cycle cost for a given maintenance schedule. Optimization of the maintenance schedule is performed using the genetic algorithm where multiple maintenance schedules are simultaneously calculated, compared, and evolved in order to find the lowest expected life cycle costs. The genetic algorithm was selected as a suitable optimization algorithm for its ability to find relatively close approximations to the global optimum with relative ease while concurrently being able to handle non-smooth objective functions.
Damage Detection Using Multiphysics Guided Wave Propagation
Authors: Dana J. , Park Y. H. , Gonzales C.
Published: October 2020

In order to improve the safety, reliability, and life of diverse structures, the development of effective methodologies for structural health monitoring is critical. Among damage detection techniques, guided ultrasonic Lamb waves are particularly suitable for damage detection applications for plate-like and shell-like structures, such as aircraft wing-box structures, heat exchanger tubing, stiffened panels, and nuclear steam generator tubing, due to their sensitivity to damage. Computational models can play a critical role to study wave propagation for monitoring structural health and develop a technique to detect structural damage. Due to complexity of guided wave behavior, efficient and accurate computation tools are essential to study the mechanisms that account for coupling, dispersion, and interaction with damage. In this study, a numerical technique is presented for guided waves propagation in metallic structure by employing co-simulation using ABAQUS Standard module and ABAQUS Explicit module simultaneously to simulate transient wave propagation from an PZT actuator into a metallic plate. The present co-simulation analysis couples multiphysics (piezoelectric) analysis with transient dynamics (wave propagation) analysis. A numerical test is conducted using a PZT actuator for exciting planar Lamb waves and a sensor for acquiring wave signals. The signals achieved from defected and pristine models by FEA are then compared to identify and detect damage in the structure.
General Criteria and Evaluations for the Selection of ASME Section VIII, Division 1 or 2 for New Construction Pressure Vessels
Authors: Barkley Nathan , Riley Matt
Published: October 2020

For new ASME pressure vessel designs that have a design pressure less than 10,000 psi (70 MPa), it is commonly questioned whether Section VIII, Division 1 or Division 2 should be used as the code of construction. Each code offers specific advantages and disadvantages depending on the specific vessel considered. Further complicating the various considerations is the new Mandatory Appendix 46 of Division 1 which allows the design rules of Division 2 to be used for Division 1 designs. With the various options available, determining the best approach can be challenging and is often more complex than only determining which code provides the thinnest wall thickness.

This paper attempts to address many of the typical considerations that determine the use of Division 1 or Division 2 as the code of construction. Items to be considered may include administrative burden, certification process, design margins, design rules, and examination and testing requirements. From the considerations presented, specific comparisons are made between the two divisions with notable differences highlighted. Finally, sample evaluations are presented to illustrate the differences between each code of construction for identical design conditions. Also, material and labor estimates are compiled for each case study to provide a realistic comparison of the expected differential cost between the construction codes.
Influence of Elastic-Plastic Bending on the Relationship Between Applied Load and Maximum Bending Stress for Straight and Curved Bars
Authors: Metzger Don
Published: October 2020

Bending capacity in excess of the load required to cause yielding is due to a combination of work hardening and the effect of the plastic zone spreading toward the neutral axis. For materials of sufficiently high ductility, a fully developed plastic zone is achieved and the bulk of the section is stressed beyond yield. For lower ductility materials, failure may occur prior to full development of the plastic zone such that only a fraction of the cross section is at or above the yield stress. In such cases, the relationship between applied load and maximum bending stress becomes sensitive to the shape of the stress-strain curve near the yield point. This relationship is examined for straight and curved bars of rectangular and trapezoidal cross-section for tensile stress-strain curves characterized by nonlinear functions. The stress distribution as a function of applied load is determined analytically by enforcing moment equilibrium across the section. The strain distribution is determined through the classical condition of “planes remain plane” during deformation.

The solutions provide analytically smooth load curves such that maximum stress can be directly plotted as a function of applied load. These plots exhibit three distinct regimes of response: 1) elastic, 2) development of plastic zone, and 3) fully developed plastic zone. Since the response is analytically smooth, the detailed relationship through the knee of the tensile curve can be examined. The results indicate that bending capacity is influenced significantly by the development of small amounts of plastic strain prior to reaching a yield point defined by the usual 0.2% plastic strain offset method. The results also show how loss of ductility with respect to tensile elongation translates into reduced bending load capacity in a non-linear relationship.
VistaDam: A Physics Based Ductile Fracture Model for Pressurized Pipe Failure
Authors: Mobasher Mostafa E. , Londono Juan G. , Woelke Pawel B.
Published: October 2020

We present VistaDam, a physics-based ductile fracture material model that is tailored to predict failure in thin metal sheets. VistaDam is based on a three invariant plasticity model in which metal fracture is dependent on the combined evolution of the triaxial stresses as well as the third invariant of deviatoric stress. Thus, VistaDam can predict damage due to combined volumetric void growth and shear dilation; which provides VistaDam with a superior capability to describe and predict fracture in a wide range of loading ranges. VistaDam relies on three independent material parameters that can be calibrated from experimental data at different triaxiality. Calibration is achieved through the automated calibration tool VistaCal. The calibrated VistaDam material card can be readily used in explicit FEM packages such as Abaqus and LS-DYNA. In addition, the calibrated VistaDam model can be used as a virtual testing platform that can generate data required by data-driven models such as GISSMO and Johnson-Cook. This process is currently automated within VistaCal’s graphical user interface. VistaDam and VistaCal have been developed for Navy applications and have been deployed successfully to predict pressurized pipes and vessel deformation and fracture under extreme loading conditions.
A 3D Parallel High-Order Solver With Curved Local Mesh Refinement for Predicting Arterial Flow Through Varied Degrees of Stenoses
Authors: Chen Kuangxu , Zhang Bin , Liang Chunlei
Published: October 2020

A 3D parallel high-order spectral difference (SD) solver with curved local mesh refinement is developed in this research to simulate flow through stenoses of varied degrees (50%, 60%, 65%, 70% and 75%) of radius constriction at inlet Reynolds number of 500. This solver employs high-order curved mesh in the vicinity of arterial wall and the local mesh refinement technique reduces the overall computational cost by distributing more elements in critical regions. In simulation of flow through stenosis of 50% radius constriction, velocity profiles predicted from the SD solver agree well with previous DNS results and experimental data. Mesh independency study shows that numerical results from a conforming and a non-conforming mesh agree well with each other. When the constriction degree is larger than 50%, visualizations through iso-surfaces of Q-criterion show that vortex rings are ejected from the stenosis throat, advecting downstream before they hit the vessel walls and they finally break down and merge into a large bulk region of small-scale turbulence. The observation is consistent with the vorticity contour which is characterized by development of the Kelvin-Helmholtz instability when shear layers are formed, rolled up and advected downstream between the central jet and the recirculation region. When the constriction degree turns to 75%, the flow transitions rapidly downstream of stenosis throat and dramatic pressure drop is witnessed. This provides a fluid-dynamic explanation for clinical definition of critical stenosis (i.e. over 75% luminal radius narrowing). Furthermore, pressure drop across a stenosis is found to be proportional to square of ratio of non-stenosed area to minimum area at the stenosis throat with a linear correlation coefficient equal to 0.9998. Finally, this solver is proven to have excellent scalability on massively parallel computers when multi-level refinement of meshes is performed to capture small-scale structures in the turbulence region.
Environmental Fatigue Screening for Subsequent License Renewal
Authors: Walker Adam P. , Imbrogno Gregory M. , Gray Mark A. , Tomes Charles A.
Published: October 2020

Nuclear Regulatory Commission (NRC) guidance for Subsequent License Renewal (SLR) applicants is provided in the NUREG-2191. Specifically, Section X.M1 of the NUREG-2191 includes guidance for aging management programs (AMP) which has two aspects related to fatigue analyses, one that verifies the continued acceptability of existing analyses through cycle counting and the other that provides periodically updated evaluations of the fatigue analyses to demonstrate that they continue to meet the appropriate limits. In addition, the NUREG-2191 provides requirements to account for reactor water environment by deriving cumulative fatigue usage (CUF) including environmental effects (CUFen) in component fatigue analyses for a set of sample critical components for the plant outlined in NUREG/CR-6260. Furthermore each applicant is required to determine plant-specific component locations in the reactor coolant pressure boundary that may be more limiting than those considered in NUREG/CR–6260. This paper presents a methodology to identify plant-specific primary equipment component locations that are potentially more limiting than the locations identified in NUREG/CR-6260, through a detailed review and ranking of the analyses of record (AORs) for a plant. The ranking approach implemented in this methodology assesses the level of technical rigor required to derive the CUF values and provides a means to appropriately compare CUF values within the same transient section. This paper also illustrates how this methodology was applied for a recent license renewal application.
Preload Assurance in Bolted Flanges With a Model and Test Based Optimized Assembly Procedure
Authors: Du Michael , Song Fei , Li Haoming , Li Ke
Published: October 2020

Bolted flanges are widely used to connect pipelines in many industries. To assure sealability of a flange, generation of proper preloads in the bolts during the assembly process is critical. However, in the existing standard practice, identical torques are typically applied to all bolts to assemble the flange. Due to elastic interactions between the bolts, tightening one bolt can alter the tensile loads in the other bolts. Hence, the resultant preloads can vary significantly. Even with an improved makeup sequence, the variation in the bolt preloads can be still substantial, as high as 60%. This could pose a risk of leakage. When the bolted flange works under non-benign conditions, such as vibration, pressure and temperature variation, the risk could become even higher.

This paper introduces a new methodology to greatly enhance the preload assurance in bolted flanges with an optimized assembly procedure, which is enabled with advanced numerical modeling. A significantly improved uniform distribution of bolt preloads is achieved by optimizing the makeup torques, which is implemented by using physical test data as input and uniformly distributed preloads as the target function. The complexity of the elastic interactions between the flange, the sealing gasket, and the bolts presents uncertainties for the numerical model for quantitative prediction of the torque distribution that is required to yield uniform resultant bolt preloads. This paper resolves this modeling limitation through iterations between modeling and testing. These iterations calibrate and finally validate the model to generate the optimized makeup torque distribution which then leads to improved bolt preload uniformity. Based on the tests conducted on two different sizes of API flanges, 3-API-15K and 5-API-10K, the final preload distribution variation has been reduced to around 30% by utilizing the optimized makeup torque distributions.
Analysis of Spent Nuclear Fuel Multipurpose Canister Dynamics During Rail Transportation
Authors: Kadooka Kevin , Klymyshyn Nicholas
Published: October 2020

The primary mode of spent nuclear fuel transportation within the United States will be by railcar. One such system is the Atlas railcar, which is designed to transport 17 different spent nuclear fuel cask systems, including bare fuel systems and canister fuel systems. In the latter configuration, multipurpose canisters containing spent nuclear fuel may be placed within an overpack for storage, or within a cask for transportation. Compared to bare fuel systems, canister fuel systems have additional degrees of freedom for motion during transportation, because clearance between the cask and canister allows for some motion of the canister to occur relative to the cask. This work investigates the effect of canister motion on the shock and vibration imparted to the spent nuclear fuel within. Structural dynamic analyses have been conducted to identify the effects of canister to cask clearance, presence and type of dunnage, and loading direction and frequency. This modeling study calculates anticipated cask motion, canister motion, and spent nuclear fuel structural dynamic response to normal conditions of transportation railcar motion using finite element analysis methods that were developed to model the rail segment of the ENSA/DOE (Equipos Nucleares S.A., U.S. Department of Energy) multimodal transportation test of 2017.
Microscopic Deformation of Thin Sheet of Polycrystalline Pure Titanium Under Tension
Authors: Tada Naoya , Kishimoto Kentaro , Uemori Takeshi , Sakamoto Junji
Published: October 2020

Commercial pure titanium has been widely used in aerospace, chemical, and biomedical industries for its lightweight, high corrosion resistance, high strength, high heat resistance and good biocompatible properties. The market of pure titanium thin sheets is expected to increase in medical, dental, civil engineering, and acoustical engineering fields. On the other hand, pure titanium takes hexagonal closed-pack structure with anisotropic elasticity and plasticity. Inhomogeneous microscopic deformation always occurs by mechanical loading from the elastic condition. The inhomogeneity brings about various damages such as localized plastic deformation, microcracking, necking, and so on. Since the inhomogeneity is significant in thin sheets, it is important to investigate its deformation behavior. In this study, a tensile test was carried out using a thin sheet specimen of polycrystalline pure titanium, and the microscopic deformation of grains was measured by the digital holographic microscope. During the test, the height distribution of grains was measured in a fixed area on the front and back surfaces of the specimen at each tensile load step and the results at different load steps were compared. It was found from the measurement results that inhomogeneous deformation began at the small load due to anisotropic elasticity of crystal grains and expanded with the load by their anisotropic plasticity. Grain heights at grain center and those along grain boundaries were related with each other, and the grain heights on the front surface were inversely correlated with those on the back surface.
Overview of EASICS Weldment Assessment Route Development Through Inelastic Analysis
Authors: May S. , Bate S. , Chevalier M. , Dean D.
Published: October 2020

Structural integrity assessment of weldments within metal structures is key to substantiate any nuclear reactor design. The assessment of weldments should consider the localised strain enhancement due to weldment geometry and material mismatch. For high temperature plant designs (operating within the creep regime), R5 Volume 2/3 Appendix A4 provides a procedure for the assessment of creep-fatigue initiation in austenitic and ferritic steel weldments, which accounts for the associated strain enhancement using a Weld Strain Enhancement Factor (WSEF). The current austenitic Type 1 WSEFs in R5 Volume 2/3 have been defined by data attained primarily for plate butt weldments under applied bending loads, and this factor is used for all butt weldments. It has been proposed that the weld strain enhancement may be dependent on loading, geometric and material mismatch conditions, and that adopting a single factor in an assessment may introduce varying levels of conservatism, which are unquantified.

This work has included reviewing the current R5 Type 1 WSEF against existing validation data, previous inelastic Finite Element Analysis (FEA) studies and the use of inelastic material models in the FEA of weldments subject to cyclic loading.
Evaluation of Susceptibility to Thermal Fatigue Cracking in High Temperature Alloys for Refinery Olefin Applications
Authors: Zhang Yuxiang , Buntain Ryan , Edwards Jacob , Alexandrov Boian , Penso Jorge A.
Published: October 2020

High carbon, Cr – Ni alloys are used for tubing in refinery olefin furnaces. During furnace operation, such tubes might be exposed to thermal shock and fatigue loading, which may result in cracking and/or complete rupture. The objective of this study was to develop and validate a testing procedure for evaluation and ranking the susceptibility to thermal fatigue cracking in tubing of such Cr – Ni alloys.

The proposed thermal fatigue testing procedure utilizes the Gleeble™ thermo-mechanical simulator and was developed to closely match extreme service conditions. Test samples with notched gauge section were subjected to repeating thermal cycles under fixed displacement to restrict the sample expansion and contraction, during heating and cooling, and simulate high level of structural restraint. The temperature range of thermal cycling was between 1110°F (600°C) and 2040°F (1115°C) with heating rate of 10,000°F/hr (1.54°C/s) and cooling rate of 83,462°F/hr (12.88°C/s).

The following parameters were recorded and used for ranking the thermal fatigue cracking susceptibility: number of cycles to failure, stress vs. time integral, maximum experienced tensile and compressive stresses, and change in gauge section area. All failed test samples were subjected to fracture surface analysis using scanning electron microscopy. The non-failed samples were examined for notch cracks using binocular microscope at up to x100 magnification. The gauge section of all tested samples was characterized with light optical and scanning electron microscopy to correlate crack nucleation and propagation to susceptible microstructural constituents.
A Multi-Dimensional Approach to Design and Execution of Modifications, Refurbishments, and Beyond for Existing Nuclear Power Plants
Authors: Malekzadeh Omid , Monid Matthew , Huang Michael
Published: October 2020

Three-Dimensional (3D) CAD models are utilized by many designers; however, they are rarely utilized to their full potential. The current mainstream method of design process and communication is through design documentation. They are limited in depth of information, compartmentalized by discipline, fragmented into various segments, communicated through numerous layers, and finally, printed onto an undersized paper by the stakeholders and end-users. Large nuclear projects, such as refurbishments and decommissioning, suffer from spatial, interface, and interreference challenges, unintentional cost and schedule overruns, and quality concerns that can be rooted to the misalignments between designed and in-situ or previously as-built conditions that tend to stem from inaccessibility and lack of adequate data resolution during the transfer of technical information.

This paper will identify the technologies and the methodology used during several piping system modifications of existing nuclear power plants, and shares the lessons learned with respect to the benefits and shortcomings of the approach. Overall, it is beneficial to leverage available multi-dimensional technologies to enhance various engineering and execution phases.

The utilization and superposition of various spatial models into 3D and 4D formats, enabled the modification projects to significantly reduce in-person plant walkdown efforts, provide highly accurate as-found data, and enable stakeholders of all disciplines and trades to review the as-found, as-designed, and simulated as-installed modification; including the steps in between without requiring significant plant visits. This approach will therefore reduce the field-initiated changes that tend to result in design/field variations; resulting in less reliance on Appendix T of ASME BPVC Section III, reduction in the design registration reconciliations efforts, and it aligns with the overarching goal of EPRI guideline NCIG-05.

Beyond the benefits to design and execution, the multidimensional approach will provide highly accurate inputs to some of the nuclear safety’s Beyond Design Basis Assessments (BDBA) and allowed for the incorporation of actual design values as input and hence removing the unnecessary over-conservatisms within some of the inputs.
CISCC Experiment of a Large Plate Sectioned From a Spent Nuclear Fuel Canister
Authors: Duncan Andrew J. , Lam Poh-Sang , Sindelar Robert L.
Published: October 2020

As a long-term demonstration of chloride-induced stress corrosion cracking (CISCC) driven by welding residual stress (WRS), a large section (approximately 51 × 46 cm with thickness 16 mm and weight about 30 kg), which contains a circumferential weld, was cut from a full-size mockup canister. Through-wall and part-through-wall (surface) starter cracks, either parallel or perpendicular to the weld, were fabricated with electrical discharge machining (EDM) in the weld region. The stress intensity factors (KI) for each machined starter crack under canister WRS were estimated so as to provide insight into the propensity for crack initiation and growth. Dry salt was applied over these machined cracks on the surface of the large plate and natural deliquescence was allowed to take place at room temperature and 75% RH. This test has been on-going for ten months and the evolution of general corrosion near the starter cracks is monitored and documented; no CISCC has been observed. Two EDM starter cracks have been isolated for five months for a simultaneous experiment with extra salt loading; additional deliquescence and significant corrosion activity have been observed.
Effects of Post-Manufacturing Process on Material Properties of 3D Printed Vessels
Authors: Eberl Brandon , Mikolanis Christopher , Eberl K. , McKeel C. , Ketusky E. , Krentz T.
Published: October 2020

With the advancing capabilities for fabricating metal components using Additive Manufacturing (AM) (3D-Printing), designers are looking for ways to utilize the AM capabilities in new applications. A potential application for AM is the fabrication of pressure-retaining components or fittings with complex geometries that are difficult to fabricate using traditional methods (e.g., machining and welding). Using AM parts for pressure-retaining components presents new challenges to ensure the material will perform reliably and predictably to meet the specifications of the design. This paper summarizes work performed on 316L stainless steel vessels fabricated by AM. The AM vessels were evaluated before and after Hot Isostatic Pressing (HIP) post-processing, including destructive examination to evaluate the grain structure and strength. Tensile tests on baseline samples and samples subjected to HIP were compared to a test sample machined from conventional stainless material and leak tests were performed on an AM vessel using helium as a tracer gas. The role of the HIP post-processing is to reduce the metal porosity and other defects inherent in the 3D-metal printing process. HIP post-processing allows the finished product to achieve the strength, reliability and leak tightness requirements of national consensus standards, such as the American Society of Mechanical Engineers Boiler and Pressure Vessel Code.
The Role of Grain Boundary Orientation and Secondary Phases in Creep Cavity Nucleation of a 316H Boiler Header
Authors: Martin Tomas L. , He Siqi , Warren Alexander D. , Shang Hao , Knowles David M. , Flewitt Peter E. J.
Published: October 2020

Cavity formation during creep of steels at high temperatures and stresses is closely related to the original and evolved microstructure, particularly the orientation between grains and precipitation at the grain boundaries. Understanding the initiation, growth and coalescence of creep cavities is critical to determining the operational life of components in high temperature, high stress environments such as an advanced gas-cooled nuclear reactor. However, accelerated laboratory-based testing frequently shows another kind of void within the microstructure, caused by plastic damage and ductile failure, particularly if a specimen fails during a test. This paper compares the type of voids and cavities observed in an AISI 316 stainless steel after extensive service in a gas-cooled nuclear reactor boiler header and after uniaxial creep testing of a similar material at higher stresses. The differences between the features observed and their potential mechanistic origins are discussed.
Design of Acoustic Metamaterials for Cabin Noise Reduction and Pressure Sensing in Propfan Aircrafts
Authors: Abdudeen Asarudheen , Abu Qudeiri Jaber , Ziout Aiman , Ahammed Thanveer
Published: October 2020

This research is about to address the main challenge related to newly emerging airplane engines, namely open rotor (propfan). Though these engines show high efficiency, yet the noise generated is very high. This research focuses on designing a new class of ‘Acoustic Metamaterial’ to overcome the noise reaching the passenger cabin. An acoustic metamaterial is a complex composite structured material that exhibits negative density and negative bulk modulus either individually or simultaneously. The objective of this research is to design an acoustic fuselage using a combination of Negative density acoustic material (NDAM) and Negative bulk modulus acoustic material (NBAM) to reduce the noise transmission into the passenger cabin. Furthermore, the developed acoustic metamaterial structure can be used for pressure sensing application. Based on the literature reviews, experiments pertaining to the combination of NBAM and NDAM are limited. Hence, an integration of both structures is very appealing to be developed. Accordingly, the research will design a combination of two types of Helmholtz resonators (Conventional with one inner membrane and two inner membranes) of negative bulk modulus acoustic metamaterial. This filter can be embedded in a sandwich structure to obtain a new type of cabin wall. Hence the design and development of such acoustic metamaterial are expected to reduce the noise inside the cabin to a minimum. Also, the designed structure will be able to sense pressure at selected locations inside the cabin.
The Process of Creating and Reviewing a Transient Surge Model
Authors: Marroquin Amy
Published: October 2020

Transient surge modeling remains to be a specialized task and therefore quite unfamiliar to many engineers and designers. The process for discerning when to conduct a model can be vague. The process for how to conduct a model can be even more unclear and quite daunting. This paper serves as an introductory guide to an engineer or reviewing project manager new to surge modeling. The content within covers a brief overview of the physics behind transients, what information is required to create a computer surge model, the content within a surge report and how to interpret it.

Included within this paper are several references and detailed plots derived from actual projects.
Corrosion Behavior of Pipeline Steel With Stray Current Interference at Coating Defects
Authors: Li Ming , Wang Xiaolin , Yan Maocheng , Shi Lei , Wang Jianan , Zhao Wei , Li Xue
Published: October 2020

With rapid development of the economy, more and more power transmission, railway systems and oil/gas pipelines have been constructed in recent years. There have been many cases of pipelines crossing or paralleling to adjacent high-voltage transmission lines or railways. Corrosion caused by AC or DC interference is increasingly prominent and has received increasing attention for buried pipelines.

In this work, a crevice cell was constructed to simulate the local environment on the surface of pipeline steel under disbonded coating in a soil environment. Corrosion behavior of X80 pipeline steel under stray current interference is investigated in the crevice cell. The results show that the AC interference shifts the local potential to the negative direction and markedly increases anodic dissolution of the steel. The attack of pipeline steel at the coating defect is the most serious, while corrosion attack slightly alleviates under the coating disbondment. Influence of stray current interference on corrosion behavior of pipeline steel under the coating defect was discussed from aspects of the commutation effect of AC interference, the irreversibility of anode reaction and effect of AC on the double layer structure at steel/solution interface.
Simplified Procedure to Assess Hot Spots in Pressure Vessels
Authors: Adibi-Asl R. , Rana M. , Seshadri R. , Joshi C.
Published: October 2020

In many instances, pressure vessels and piping system designed for high temperature applications are exposed to localized hot spots. Hot spots usually occur as the refractory lining degrades over time during operation or process changes causing the surface temperature of the localized region to exceed Code allowable metal temperature. These localized overheating can reduce the overall structural integrity of the pressurized components due to lower yield and or ultimate tensile strength of the damaged region. If hot spots are left undetected, they can lead to catastrophic failure of the components.

This paper provides a simplified procedure to assess the effect of the hot spots on the pressure strength of the vessel. The procedure presented in this paper is applicable for hot spot temperatures in non-creep regime.
Ductile Tearing and Plastic Collapse Competition
Authors: Ancelet O. , Gilles Ph. , Le Delliou P. , Perez G.
Published: October 2020

Structures containing large cracks and made in ductile materials may experience two types of failure mechanisms: ductile tearing or plastic collapse. Under displacement controlled loading ductile tearing is a stable crack growth mechanism. Plastic collapse leads to a much faster damage evolution.

Ductile tearing is the result of void growth and coalescence ahead of the crack front under the high strain concentration. This mechanism is slowed down by a high material hardening and under a high constraint. The global deformation of the structure is limited.

Plastic collapse is induced by plastic strain accumulation along slip lines. Slip lines depend on the geometry of the cracked structures and of the type of loading. Therefore plastic collapse produces large deformations of the structure.

Several studies (Nicak, 2009; Gilles, 2010; Le Delliou, 2017) on large ductile crack growth have been performed by Framatome, and EDF on deeply surface cracked plates made in Nickel base alloy 600. The tests were performed on Centre Cracked Tension specimens with a semi-elliptical surface crack. In this very tough material, the crack grew in its plane, but for large load levels, the plate was extremely deformed and a collapse mechanism appeared.

More recently, Tests on Fixed Grip SE(T) specimens in Nickel base alloy 600 were performed by CEA showing a different type of transition between ductile tearing to collapse in function of the crack length. The paper analyzes these experiments and simulates the ductile tearing using node release methodology. The prediction of the apparition of the collapse is obtained by determining collapse load with large displacement modeling.

From these results, a reconciliation of curves J-R of the CCT et SE(T) specimen will be done.
Transesophageal endoscopic ultrasound fine needle aspiration of vertebral body osteolytic tumors – a novel diagnostic approach. Case series.
Authors: Chira Romeo Ioan , Florea Alina , Ichim Vlad , Rogojan Liliana , Chira Alexandra , Crisan Doinita
Published: October 2020

Aims: Vertebral lesions, either primary or more frequently metastasis, are difficult targets for percutaneous guided biopsies and surgical biopsies and are associated with greater risks of complications. We investigated the feasibility of endoscopic ultrasound (EUS) fine needle aspiration (FNA) biopsy in the assessment of vertebral osteolytic tumors as an alternative to CT guided biopsy which is the technique currently used.Material and methods: Four patients with osteolytic tumors of the vertebral bodies identified by imaging methods (CT or MRI) – 3 patients, and one with a tumor detected primarily during EUS procedure were included in order to evaluate the feasibility of the procedure. The lesions were located either at the dorsal or lumbar vertebrae. In all cases we performed EUS FNA of the osteolytic vertebral body lesions with 22G needles using the transesophageal or transgastric approach.Results: In all cases EUS FNA provided enough tissue for an accurate histopathological report, with no procedural complication. We diagnosed lung adenocarcinoma, hepatocarcinoma and a pancreatic adenocarcinoma vertebral metastasis and one case of lymphoma.Conclusions: EUS FNA is a valuable technique which should be considered in selected cases, when a “traditional approach” is not applicable or associated with a higher risk. Treatment guidelines are based on the histology of the tumor, histopathological examination being nowadays mandatory. Therefore, we propose for selected cases a feasible technique, with significantly lower procedural risks, as an alternative for open surgical biopsies or computed tomography guided biopsies
Exponential increase of plastic burial in mangrove sediments as a major plastic sink
Authors: Martin C. , Baalkhuyur F. , Valluzzi L. , Saderne V. , Cusack M. , Almahasheer H. , Krishnakumar P. K. , Rabaoui L. , Qurban M.A. , Arias-Ortiz A. , Masqué P. , Duarte C. M.
Published: October 2020

Exponentially increasing burial rates of microplastics since the 1950s confirm mangrove sediments as long-term sinks.
Homeoprotein transduction in neurodevelopment and physiopathology
Authors: Di Nardo Ariel A. , Joliot Alain , Prochiantz Alain
Published: October 2020

The homeobox gene transcription factor family has non-cell-autonomous functions and an unconventional transfer mechanism.
Rapidly declining body temperature in a tropical human population
Authors: Gurven Michael , Kraft Thomas S. , Alami Sarah , Adrian Juan Copajira , Linares Edhitt Cortez , Cummings Daniel , Rodriguez Daniel Eid , Hooper Paul L. , Jaeggi Adrian V. , Gutierrez Raul Quispe , Suarez Ivan Maldonado , Seabright Edmond , Kaplan Hillard , Stieglitz Jonathan , Trumble Benjamin
Published: October 2020

Body temperature in tropical forager-farmers declined as much in the past two decades as among Americans in the past 150 years.
Twofold improved tumor-to-brain contrast using a novel T1 relaxation-enhanced steady-state (T
1
RESS) MRI technique
Authors: Edelman R. , Leloudas N. , Pang J. , Bailes J. , Merrell R. , Koktzoglou I.
Published: October 2020

T
1
RESS is a novel MRI method that provides twofold improved tumor-to-brain contrast and enables modulation of vascular signal.
Metabolic reprogramming of donor T cells enhances graft-versus-leukemia effects in mice and humans
Authors: Uhl Franziska M. , Chen Sophia , O’Sullivan David , Edwards-Hicks Joy , Richter Gesa , Haring Eileen , Andrieux Geoffroy , Halbach Sebastian , Apostolova Petya , Büscher Jörg , Duquesne Sandra , Melchinger Wolfgang , Sauer Barbara , Shoumariyeh Khalid , Schmitt-Graeff Annette , Kreutz Marina , Lübbert Michael , Duyster Justus , Brummer Tilman , Boerries Melanie , Madl Tobias , Blazar Bruce R. , Groß Olaf , Pearce Erika L. , Zeiser Robert
Published: October 2020

Bicarbonate boosts metabolic fitness of T cells challenged with leukemia-derived lactic acid.
Epigenetic Compound Screening Uncovers Small Molecules for Reactivation of Latent HIV-1
Authors: Zutz Ariane , Chen Lin , Sippl Franziska , Humpe Andreas , Schölz Christian
Published: October 2020

During infection with the human immunodeficiency virus type 1 (HIV-1), latent reservoirs are established that circumvent full eradication of the virus by antiretroviral therapy (ART) and are the source for viral rebound after cessation of therapy. As these reservoirs are phenotypically indistinguishable from infected cells, current strategies aim to reactivate these reservoirs, followed by pharmaceutical and immunological destruction of the cells. Here, we employed a simple and convenient cell-based reporter system, which enables sample handling under biosafety level (BSL)-1 conditions, to screen for compounds that were able to reactivate latent HIV-1.
Lack of Specificity of Phenotypic Screens for Inhibitors of the Mycobacterium tuberculosis FAS-II System
Authors: Grzegorzewicz Anna E. , Lelièvre Joël , Esquivias Jorge , Angala Bhanupriya , Liu Jiuyu , Lee Richard E. , McNeil Michael R. , Jackson Mary
Published: October 2020

Phenotypic screening of inhibitors of the essential
Mycobacterium tuberculosis
FAS-II dehydratase HadAB led to the identification of GSK3011724A, a compound previously reported to inhibit the condensation step of FAS-II. Whole-cell-based and cell-free assays confirmed the lack of activity of GSK3011724A against the dehydratase despite evidence of cross-resistance between GSK3011724A and HadAB inhibitors. The nature of the resistance mechanisms is suggestive of alterations in the FAS-II interactome reducing access of GSK3011724A to KasA.
Bacillus thuringiensis Cry1Ab Domain III β-16 Is Involved in Binding to Prohibitin, Which Correlates with Toxicity against Helicoverpa armigera (Lepidoptera: Noctuidae)
Authors: Sena da Silva Igor Henrique , Gómez Isabel , Pacheco Sabino , Sánchez Jorge , Zhang Jie , Luque Castellane Tereza Cristina , Aparecida Desiderio Janete , Soberón Mario , Bravo Alejandra , Polanczyk Ricardo Antônio
Published: October 2020

Helicoverpa armigera
is a polyphagous pest that feeds on important crops worldwide. This insect pest is sensitive to different Cry1 toxins from
Bacillus thuringiensis
. In this study, we analyzed the potential role of PHB-2 as a Cry1 toxin receptor in comparison to CAD. We show that different Cry1 toxins bound to HaPHB-2 and HaCAD-TBR similarly and identify β-16 from domain III of Cry1Ab as a binding region involved in the interaction with HaPHB-2 and in toxicity. This report characterized HaPHB-Cry1 binding interaction, providing novel insights into potential target sites for improving Cry1 toxicity against
H. armigera
.
The Auxiliary NADH Dehydrogenase Plays a Crucial Role in Redox Homeostasis of Nicotinamide Cofactors in the Absence of the Periplasmic Oxidation System in Gluconobacter oxydans NBRC3293
Authors: Sriherfyna Feronika Heppy , Matsutani Minenosuke , Hirano Kensuke , Koike Hisashi , Kataoka Naoya , Yamashita Tetsuo , Nakamaru-Ogiso Eiko , Matsushita Kazunobu , Yakushi Toshiharu
Published: October 2020

Nicotinamide cofactors NAD
+
and NADP
+
mediate redox reactions in metabolism.
Gluconobacter oxydans
, a member of the acetic acid bacteria, oxidizes glucose incompletely in the periplasmic space—outside the cell. This incomplete oxidation of glucose is independent of nicotinamide cofactors. However, if the periplasmic oxidation of glucose is abolished, the cells oxidize glucose in the cytoplasm by reducing nicotinamide cofactors. Reduced forms of nicotinamide cofactors are reoxidized by NADH dehydrogenase (NDH) on the cell membrane. We found that two kinds of NDH in
G. oxydans
have different substrate specificities: the primary enzyme is NADH specific, and the auxiliary one oxidizes both NADH and NADPH. Inactivation of the latter enzyme in
G. oxydans
cells in which we had induced cytoplasmic glucose oxidation resulted in elevated intracellular levels of NAD(P)H, limiting cell growth on glucose. We suggest that the auxiliary enzyme is important if
G. oxydans
grows independently of the periplasmic oxidation system.
Dilution-to-Stimulation/Extinction Method: a Combination Enrichment Strategy To Develop a Minimal and Versatile Lignocellulolytic Bacterial Consortium
Authors: Díaz-García Laura , Huang Sixing , Spröer Cathrin , Sierra-Ramírez Rocío , Bunk Boyke , Overmann Jörg , Jiménez Diego Javier
Published: October 2020

The significance of our study mainly lies in the development of a combined top-down enrichment strategy (i.e., dilution to stimulation coupled to dilution to extinction) to build a minimal and versatile lignocellulolytic microbial consortium. We demonstrated that mainly two selectively enriched bacterial species (
Pseudomonas
sp. and
Paenibacillus
sp.) are required to drive the effective degradation of plant polymers. Our findings can guide the design of a synthetic bacterial consortium that could improve saccharification (i.e., the release of sugars from agricultural plant residues) processes in biorefineries. In addition, they can help to expand our ecological understanding of plant biomass degradation in enriched bacterial systems.
Draft Genome Sequences of Cronobacter muytjensii Cr150, Cronobacter turicensis Cr170, and Cronobacter sakazakii Cr611
Authors: Zizelski Valenci Gal , Rubinstein Mor , Afriat Reuven , Rosencwaig Shira , Dveyrin Zeev , Rorman Efrat , Nissan Israel
Published: October 2020

The sequencing and bioinformatics analyses of isolates Cr150, Cr170, and Cr611 from powdered infant formula indicate that the three strains represent new members in the
Cronobacter muytjensii
,
Cronobacter turicensis
, and
Cronobacter sakazakii
groups, respectively.
Chromosomal Sequence of Lactobacillus brevis Oregon-R-modENCODE Strain BDGP6, a Lactic Acid Bacterium Isolated from the Gut of Drosophila melanogaster
Authors: Wan Kenneth H. , Yu Charles , Park Soo , Hammonds Ann S. , Booth Benjamin W. , Celniker Susan E.
Published: October 2020

Lactobacillus brevis
Oregon-R-modENCODE strain BDGP6 was isolated from the gut of
Drosophila melanogaster
for functional host-microbial interaction studies. The bacterial chromosome is a single circular DNA molecule of 2,785,111 bp with a G+C content of 46%.
Whole-Genome Sequence of an African Swine Fever Virus Isolate from the Czech Republic
Authors: Forth Jan H. , Forth Leonie F. , Václavek Petr , Barták Pavel , Höper Dirk , Beer Martin , Blome Sandra
Published: October 2020

Between June 2017 and April 2018, an outbreak of African swine fever (ASF) affected wild boar in the southeast of the Czech Republic. Here, we present the whole-genome sequence of the causative ASF virus. It belongs to genotype II and shows very high identity with other strains from Eastern Europe.
Genome Sequence of Clinical Strain Pseudomonas aeruginosa NRD619
Authors: Sisk-Hackworth Laura , Sue Andrew , Aslam Saima , Roach Dwayne
Published: October 2020

Here, we report the complete genome sequence of the multidrug-resistant (MDR) strain
Pseudomonas aeruginosa
NRD619, assembled via long- and short-read hybrid assembly.
P. aeruginosa
is a Gram-negative bacterial pathogen that is a significant public health burden. NRD619 was isolated from a left ventricular assist device (LVAD) draining sinus tract.