bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Ultimate Strength of a Ellipsoidal Dished Head Plate Under Pressure on Convex Surface
Authors: Yada Hiroki , Ando Masanori , Tsukimori Kazuyuki , Ichimiya Masakazu , Anoda Yoshinari
Published: December 2016

Containment vessel is an important structure to prevent a significant and sudden radioactive release, however, the safety margin of the containment vessel against the internal or external pressure are not numerically clarified. Namely, the safety margins due to the relationship of the ultimate toughness of containment vessel structures and maximum design pressure is not clear. Indeed, to clarify the progress of events under the beyond design basis events (BDBE) and to design the BDBE countermeasure equipment, it is necessary to evaluate the pressure toughness of containment vessel adequately. The containment vessel of fast reactor is composed of the various structures. The head plate that forms the boundary between primary and secondary coolant in intermediate heat exchanger has an important role when the progress of the BDBE is considered. In this study, in order to develop the evaluation method of the pressure toughness of the head plate under the BDBE, the ultimate pressure test of the head plate test specimen subjected to convex side pressure was performed, and also FEM analysis was performed for discussion.
On the Equivalent Mechanical Properties of Spiral Wound Gaskets
Authors: Attoui Hocine , Bouzid Abdel-Hakim
Published: December 2016

Spiral wound gaskets are generally used to seal bolted joints working under high pressure and high temperature. The mechanical properties of the sealing element composed of the filler and the windings play important roles in the sealing performance and buckling strength of these gaskets. The proper modeling of a bolted joint that uses a spiral wound gasket requires the knowledge of the mechanical properties of the sealing element. The elastic modulus and Poisson’s ratio are often required in order to be used in any simplified analytical or numerical modelling of the gasket. A hybrid technique based on an analytical approach and experimental tests is developed to characterize the equivalent mechanical properties of spiral wound gaskets.

In this paper, an analytical model supported with numerical Finite Element Method (FEM) based simulation and experimental investigation is presented to characterize the mechanical properties of spiral wound sealing element. The results of the analytical model that are based on the theory of Lamé and consideration on the compatibility conditions between components, has an acceptable agreement with numerical simulation and experimental investigations.
A Hydrogen Compatibility and Suitability Evaluation of the Seamless Steel Tube 4130X
Authors: Zhai Jian-ming , Shou Bi-nan , Wang Hong-xia , Xu Tong , Ma Guang-qing , Gui Le-le
Published: December 2016

In recent years, hydrogen has been increasingly used as a clean energy source. Accordingly, the manufacturing and safety detection of hydrogen storage and transportation equipment is also becoming more and more important. To evaluate the hydrogen compatibility and suitability of 4130X seamless steel tube, CT and WOL specimen are used to evaluate its resistance of the hydrogen induced cracking by referring ISO 11114-4: 2005. The specimens were placed at 90 °C in 90 MPa high-pressure hydrogen environment for 1000 h after loading. The CT test results show that the 4130X materials have a good resistance to hydrogen-induced cracking under the standard required loading condition. The WOL test show that no crack occurs when the stress intensity factor KI of 4130X-A, 4130X-B is about 100–120 MPa•m1/2. The 4130X-C material exhibit the hydrogen-induced crack in the high-pressure hydrogen environment, the critical stress intensity factor KIH is about 87.81 MPa•m1/2. The study proves that the 4130X seamless steel tube has a good resistance to hydrogen embrittlement.
Testing and Numerical Simulation of Elastomeric Seals Under Consideration of Time Dependent Effects
Authors: Weber Mike , Kömmling Anja , Jaunich Matthias , Wolff Dietmar , Zencker Uwe , Völzke Holger , Schulze Dietmar
Published: December 2016

Due to delays in the siting procedure to establish a deep geological repository for spent nuclear fuel and high level waste and in construction of the already licensed Konrad repository for low and intermediate level waste, extended periods of interim storage will become more relevant in Germany. BAM is involved in most of the cask licensing procedures and is responsible for the evaluation of cask-related long-term safety issues. Elastomeric seals are widely used as barrier seals for containers for low and intermediate level radioactive waste. In addition they are also used as auxiliary seals in spent fuel storage and transportation casks (dual purpose casks (DPC)).

To address the complex requirements resulting from the described applications, BAM has initiated several test programs for investigating the behavior of elastomeric seals. These include experiments concerning the hyperelastic and viscoelastic behavior at different temperatures and strain rates, the low temperature performance down to −40°C, the influence of gamma irradiation and the aging behavior.

The first part of the paper gives an overview of these tests, their relevant results and their possible impact on BAM’s work as a consultant in the framework of approval and licensing procedures.

The second part presents an approach of the development of a finite element model using the finite element code ABAQUS®. The long-term goal is to simulate the complex elastomeric behavior in a complete lid closure system under specific operation and accident conditions.
Surface Crack Detection in Welded Stainless Steel Canisters Using Shear Horizontal Waves
Authors: Choi Sungho , Cho Hwanjeong , Lissenden Cliff J. , Lindsey Matthew S.
Published: December 2016

Ultrasonic inspection methodologies for welded stainless steel canisters in spent nuclear fuel dry storage casks are investigated for detection of stress corrosion cracking (SCC) in the heat affected zone (HAZ) of a weld. Shear horizontal (SH) waves having 3D wave motion, which are actuated and received by periodic permanent magnet electromagnetic acoustic transducers (EMATs), are used to detect cracks perpendicular or parallel to the weld line. Due to the limited accessibility to the welds in the stainless steel canister, three different types of sensor layouts amenable to robotic delivery are proposed that use either through-transmission or pulse-echo sensor configuration. A stainless steel welded plate having artificial surface breaking notches near the weld is inspected to demonstrate the performance of the methods. Two dimensional ultrasonic images showing the notch locations are obtained by scanning a pair of EMATs in the direction parallel to the weld line. The feasibility of detecting cracks normal to, and along, the weld line using pulse-echo mode is demonstrated. Thus, robotically delivered SH-wave EMATs will be effective for inspecting the entirety of the weld lines in the stainless steel canister, even in the presence of guide channels.
Robotic Inspection of Dry Storage Casks for Spent Nuclear Fuel
Authors: Lissenden C. J. , Choi S. , Cho H. , Motta A. , Hartig K. , Xiao X. , Le Berre S. , Brennan S. , Reichard K. , Leary R. , McNelly B. , Jovanovic I.
Published: December 2016

Extended dry storage of spent nuclear fuel makes it desirable to assess the structural integrity of the storage canisters. Stress corrosion cracking of the stainless steel canister is a potential degradation mode especially in marine environments. Sensing technologies are being developed with the aim of detecting the presence of chloride-bearing salts on the surface of the canister as well as whether cracks exist. Laser induced breakdown spectroscopy (LIBS) methods for the detection of Chlorine are presented. Detection of a notch oriented either parallel or perpendicular to the shear horizontal wave vector is demonstrated using the pulse-echo mode, which greatly simplifies the robotic delivery of the noncontact electromagnetic acoustic transducers (EMATs). Robotic delivery of both EMATs and the LIBS system is necessary due to the high temperature and radiation environment inside the cask where the measurements need to be made. Furthermore, the space to make the measurement is very constrained and maneuverability is confined by the geometry of the storage cask. In fact, a large portion of the canister surface is inaccessible due to the presence of guide channels on the inside of the cask’s overpack, which is strong motivation for using guided waves for crack detection. Among the design requirements for the robotic system are: to localize and track where sensor measurements are made to enable return to those locations, to avoid wedging or jamming of the robot, and to tolerate high temperatures and radiation levels.
Comparison of Internal and External Hydrogen on Fatigue-Life of Austenitic Stainless Steels
Authors: Gibbs Paul J. , San Marchi Chris , Nibur Kevin A. , Tang Xiaoli
Published: December 2016

The degradation of stress-controlled fatigue-life (stress-life) of notched specimens was measured in the presence of internal and in external hydrogen for two strain-hardened austenitic stainless steels: 316L and 21Cr-6Ni-9Mn. To assess the sensitivity of fatigue performance to various hydrogen conditions fatigue tests were performed in four environments: (1) in air with no added hydrogen, (2) in air after hydrogen pre-charging to saturate the steel with internal hydrogen, and in external gaseous hydrogen at pressure of (3)10 MPa (1.45 ksi), or (4) 103 MPa (15 ksi). The fatigue performance of the strain-hardened 316L and 21Cr-6Ni-9Mn steels in air was indistinguishable for the tested conditions. Decreases in the fatigue-life at a given stress level were measured in the presence of hydrogen and depended on the hydrogen environment. Testing in 103 MPa (15 ksi) external gaseous hydrogen always resulted in a clear decrease in the fatigue-life at a given maximum stress. Alloy dependent reductions in the observed life at a given maximum stress were observed in the presence of internal hydrogen or in gaseous hydrogen at a pressure of 10 MPa (1.45 ksi). The measured fatigue-life of hydrogen pre-charged specimens was comparable to the life with no intentional hydrogen additions. Accounting for the increased flow stress resulting from the supersaturation of hydrogen after pre-charging results in consistency between the measured fatigue-life of the pre-charged condition and measurements in 103 MPa (15 ksi) external hydrogen. The current results indicate that internal hydrogen may be an efficient method to infer hydrogen-assisted fatigue degradation of stainless steels in high-pressure gaseous hydrogen.
Development of Gaskets and its Accessories for Electrical Insulation of Pipelines
Authors: Araujo Roberto H. G. , Romano Luiz P. , Veiga José C. , Silva Ana C.
Published: December 2016

Insulation gasket kits are used to prevent electrochemical corrosion often observed in metal pipe system with dissimilar flanges materials or in buried pipelines. This insulation kit is typically used in refineries, pipelines, chemical plants and especially in offshore installations, such as oil platforms.

The market offers a great range of materials to meet these applications, which are based in phenolic resin, epoxy, rubber, etc. However, end users, frequently, do not have a complete understanding of all the requirements to do a proper specification of the insulation kit to meet their needs. A correct selection of the insulation kit requires knowledge about its physical as well as its electrical features in order to avoid a potential failure in the field.

Therefore, this paper proposes an overview of the main physical and electrical parameters for a reliable insulation kit, as well as alternative materials.
Unified Viscoplasticity Modeling Features Needed for Simulation of Grade 91 Creep and Fatigue Responses
Authors: Islam Nazrul , Dewees Dave , Hassan Tasnim
Published: December 2016

Chaboche unified viscoplasticity model and uncoupled plasticity and creep models (nonunified) are evaluated for their capability in simulating low-cycle fatigue, creep and creep-fatigue responses of Grade 91 steel. The primary objective of this study is to develop a constitutive model incorporating various advanced modeling features for design-by-analysis of elevated temperature power plant components. For validation of the model a broad set of experimental responses of Grade 91 in the temperature range 20–600°C are collected from literature. Performance of the models is demonstrated against simulating these experimental responses. It is demonstrated that the unified Chaboche model simulation capability can be improved through implementing strain range dependence, cyclic hardening through kinematic hardening rule and static recovery modeling features.
Short-Term and Long-Term Mechanical Testing to Evaluate the Effect of Flaws in Butt Fusion Joints in Polyethylene Pipes
Authors: Troughton Mike , Khamsehnezhad Amir
Published: December 2016

The use of non-destructive examination (NDE) for assessing the quality of butt fusion joints in polyethylene (PE) pipes has been included in the draft Mandatory Appendix XXVI to Section III of the ASME Boiler and Pressure Vessel Code (Rules for construction of Class 3 buried polyethylene pressure piping). However, currently, there are no acceptance criteria for flaws in butt fusion joints in PE pipes. There is an ASME Task Group on flaw evaluation for PE pipe, which is developing a code case using linear elastic fracture mechanics (LEFM) to determine critical flaw sizes. However, the initial experimental crack growth data generated suggests that linear elastic fracture mechanics is not able to adequately describe slow crack growth in PE materials. In addition, this work is only considering planar lack of fusion flaws in the joint; it is not considering other critical flaw types that can occur in butt fusion joints, such as particulate contamination and cold fusion.

TWI has developed procedures using mechanical testing to develop flaw acceptance criteria for butt fusion joints in PE pipes. This is based on inserting lack of fusion flaws of known size and particulate contamination flaws of known concentrations into butt fusion joints and determining the effect of these flaws on both the short-term and long-term integrity of the joints. An important aspect of this work is to determine which of the wide array of mechanical tests available for assessing the integrity of butt fusion joints in PE pipes are the most discriminating.

This paper describes the procedures developed for inserting simulated flaws into butt fusion joints in PE pipes, the experimental work to compare the results from different standard short-term and long-term tests on flawed and unflawed joints and the procedures developed to determine flaw acceptance criteria.

Results have shown that the most discriminating short-term test for butt fusion joints in PE pipes is a tensile test using a waisted specimen, such as those defined in EN 12814-2, EN 12814-7 and ISO 13953, and the most discriminating property is the energy to break the specimen. The most appropriate long-term test for butt fusion joints in PE pipes is the whole pipe tensile creep rupture test, as defined in EN 12814-3; this is the only long-term whole pipe test that consistently generates slow crack growth in the fused joint, even if it contains no flaws.
Long-Term Investigations of Metal Seals for Storage Casks of Radioactive Materials
Authors: Nagelschmidt Sven , Probst Ulrich , Völzke Holger , Wolff Dietmar
Published: December 2016

The Bundesanstalt für Materialforschung und –prüfung (BAM) is a federal institute for materials research and testing in Germany and has been involved in the qualification and safety evaluation procedures of metal seals from the early beginning of the interim storage licensing procedures for radioactive materials, stored in dual purpose casks. Regarding this subject, BAM investigates the long-term behavior of metal seals under the influence of temperature using experimental data and analytical approaches. The development of numerical models is in progress as well. Systematic experimental investigations performed by BAM indicate a continuous decrease of the remaining seal force and the usable resilience considering the leak tightness. Hence, there is a fundamental interest of describing time and temperature dependency to gain predictable values for the long-term behavior and to achieve reliable results with help of short-term tests.

The paper gives an overview about the sealing principle, test program and test results of metal seals of the type HELICOFLEX® HN200. The aging effect, respectively the long-term behavior in dependency of time and temperature, are introduced for two different outer liner materials, aluminum and silver.
Methods to Determine Low-Constraint Fracture Toughness: Review and Progress
Authors: Zhu Xian-Kui
Published: December 2016

Fracture toughness is often described by the J-integral or crack-tip opening displacement (CTOD) for ductile materials. ASTM, BSI and ISO have developed their own standard test methods for measuring fracture initiation toughness and resistance curves in terms of the J and CTOD using bending dominant specimens in high constraint conditions. However, most actual cracks are in low constraint conditions, and the standard resistance curves may be overly conservative.

To obtain more realistic fracture toughness for actual cracks in low-constraint conditions, different fracture test methods have been developed in the past decades. To facilitate understanding and use the test standards, this paper presents a critical review on commonly used fracture toughness test methods using standard and non-standard specimens in reference to the fracture parameters J and CTOD, including (1) ASTM, BSI and ISO standard test methods, (2) constraint correction methods for formulating a constraint-dependent resistance curve, and (3) direct test methods using the single edge-notched tension (SENT) specimen. This review discusses basic concepts, basic methods, estimation equations, test procedures, historical efforts and recent progresses.
Evaluation of Long-Term Behavior by the Size of Lead Rubber Bearings
Authors: Park Junhee , Choun Young-Sun , Kim Min Kyu
Published: December 2016

In the nuclear power plants (NPPs), the base isolators can be used to decrease the seismic force (acceleration, shear force, floor response spectra).

During the lifetime of isolation systems, the mechanical properties of rubber bearings will be constantly changed by the vulcanization and degradation of the rubber due to environmental and chemical factors such as the thermal oxidation, ultraviolet irradiation, and ozone. Usually, thermal oxidation is the most significant degradation factors during the lifetime of natural rubber. Thermal oxidation hardens the rubber and results in a significant decrease in performance. It was presented that the stiffness was increased and damping was decreased by the aging of lead rubber bearings (LRB). It can be observed that the horizontal stiffness of rubber bearings increases about 10% after 15 to 40 years. Considering aging effect of bearings at the design stage, AASHTO [1999] suggested an aging factor for the post-yield stiffness in LRBs. The aging of LRB may be proceeded from the surface to internal because the aging of rubber bearings mainly affected by the oxidation. Therefore, the long-term behavior of LRB can different according to the size. In this study, the horizontal stiffness and damping was evaluated by the size of LRB using the analytical model.

The LRBs with an outside diameter of 250 mm (D-250) and an outside diameter of 1,500 mm (D-1500) were selected as example model. In this study, Yeo model was used to model the properties of rubber material and ABAQUS was used as the analysis program. Aging depth of LRB was assumed to be 11 mm and 16 mm based on the accelerated thermal oxidation test.

From the analysis result, the effective stiffness of LRB of D-250 was increased about 15%∼22% while the effective stiffness of LRB of D-1500 was increased about 4%∼9%. Although the aging depth of LRB was equal, the ratio aging area to total area of LRB was different according to the size of bearings. Therefore, the mechanical properties factors should be proposed considering the size of LRB.
Critical Flaw Evaluation of Cast Austenitic Stainless Steel: Deterministic and Probabilistic Fracture Analyses
Authors: Uddin M. F. , Kurth R. E. , Sallaberry C. , Wilkowski G. M. , Brust F. W. , Rudland D.
Published: December 2016

Toughness reduction in cast austenitic stainless steels (CASS) due to thermal embrittlement is a growing concern for flaw tolerance evaluation in nuclear power plants. As the fracture toughness diminishes due to thermal-aging, some aged CASS materials have the potential to reach much lower toughness values than at the beginning of life. CASS also shows a high variability in toughness even for a given chemical composition, operating temperature, ferrite number or chrome equivalent. This is mainly due to the combined ferritic and austenitic microstructure and potentially large grain sizes. This variability in toughness needs to be used when developing flaw evaluation criteria in Section XI of the ASME Boiler and Pressure Vessel Code.

In this work, deterministic critical flaw size evaluations were conducted for one of the low-toughness CASS materials with a ferrite number (FN) lower than 25. Six different methods were used to evaluate the critical flaw sizes for circumferential surface flaws. In order to account for the large variability in CASS material properties, a probabilistic fracture mechanics (PFM) procedure was developed. Based on all deterministic analyses, the Dimensionless Plastic-Zone Parameter analysis was used to perform the probabilistic critical flaw evaluation. As an example calculation, an actual toughness distribution from a single US PWR plant chemical composition (using a thermal-aging model) was used to perform the probabilistic analysis. The probabilistic analysis provides the critical flaw sizes at various stress ratios for Service Level A (10−6) and Service Level B (10−5) probability of failure for this particular case.
Analytical Methodologies for Buried Pipeline Design in Geohazard Areas
Authors: Sarvanis Gregory C. , Karamanos Spyros A.
Published: December 2016

In geohazard areas, buried pipelines are subjected to permanent ground deformations, which constitute major threats for their structural safety. Geohazards include seismic fault movement, liquefaction-induced lateral spreading and slope instability, and the corresponding deformations induce severe strains in the pipeline. Calculation of these strains is necessary for assessing pipeline integrity. In the present paper, an analytical methodology is presented and compared with existing analytical and numerical methodologies for stress analysis of buried pipelines. The proposed methodology is also compared with full-scale available experimental results and offers significant intuition on the behavior of buried pipelines subjected to permanent ground deformations. Using the proposed analytical methodology, one may predict the strains developed in the pipeline wall quite efficiently and with good accuracy.
Comparison of BS 7910 and API 579-1/ASME FFS-1 Solutions With Regards to Leak-Before-Break
Authors: Bourga Renaud , Wang Bin , Moore Philippa , Janin Yin Jin
Published: December 2016

One of the ways to aid the decision whether or not to live with defects in pressurised components is through the demonstration of Leak-Before-Break (LBB). In this paper, three of the main solutions to carry out the LBB assessment, namely Stress Intensity Factor (SIF), Reference Stress (RS) and Crack Opening Area (COA) have been evaluated and compared for both BS 7910 and API 579/ASME FFS-1 standards. Differences with respect to the choice of solutions and boundary conditions are illustrated and discussed. The same applied loads and material properties have been used when applying each procedure. Different geometries for potential pressurised components which are of interest with regards to LBB have been considered for each solution. Focus is made on cylinders where axially and circumferentially oriented through-wall and surface cracks were analysed. While SIF solutions produce similar results for both standards, reference stress solutions show greater differences in the results. However, in LBB assessments it is the reference stress solution which is more relevant, since most LBB assessments pre-suppose the material to be ductile. In terms of COA, solutions are not given exactly equivalent, however they seem to agree well within the common range of applicability. Differences in the assessment route between the standards is also discussed. Experimental data from literature has also been compared to the different standard predictions, to illustrate the accuracy of the solutions for axially oriented surface cracks. The ability of solutions to predict the boundary between leak and break is discussed, in relation to how this shows the level of conservatism.
Numerical Simulation With a CFD-PBM Model of Hydrodynamics and Bubble Size Distribution of a Rectangle Bubble Column
Authors: Ding Yi-Gang , Lu Xia , Deng Fu-Li
Published: December 2016

A coupled CFD-PBM (population balance mode) model is adopted to investigate complex behavior in a rectangle bubble column. In this work The Euler–Euler (E–E) model was adopted for the liquid phase and gas phase, while accounting for bubble coalescence and breakup a PBM discrete model was employed. The total gas holdup for a range of superficial gas velocities were studied and compared with the literature and modest agreement was found. The simulation result shows that the superficial gas velocity has great effect on bubble size distribution, and a wider bubble size distribution is found at higher superficial gas velocity. This indicates an increasing of the superficial gas velocity increases the bubble coalescence and break-up rate.
Hubble uses galactic lens to study universe's first stars
Authors: Clery Daniel
Published: December 2016

Gravitational lensing aids search for source of radiation that ionized ancient cosmic gas.
A comprehensive nuclear test ban
Authors: Moniz Ernest J.
Published: December 2016

A permanent end to nuclear explosive testing, combined with sustained reliable deterrence, is in the national security interest of the United States and its allies and friends. The next U.S. Administration and the Congress should revisit the Comprehensive Nuclear Test Ban Treaty (CTBT) in view of current realities and work together toward enhanced security through ratification and an international push for entry into force.
Anterior chamber exudation in chronic myeloid leukaemia
Authors: Bypareddy Ravi , Takkar Brijesh , Azad Shorya Vardhan , Chawla Rohan
Published: November 2016

Anterior chamber leukaemic hypopyon is a rare occurrence in chronic myeloid leukaemia. We discuss two cases marked by rapid exudation inside the anterior chamber, which were subsequently diagnosed as chronic myeloid leukaemia. The hypopyon in both the cases resolved on induction of chemotherapy.
Omic-style statistical clustering reveals old and new patterns in the Gulf of Maine ecosystem
Authors: Record Nicholas R. , O’Brien John D. , Stamieszkin Karen , Runge Jeffrey A.
Published: November 2016

The burgeoning of omic technology has spawned a new subfield of statistics aimed at interpreting the complex information contained in omic data. Some of these statistical methods can be applied to any data set with taxonomic counts, and they have the potential to provide additional insights over traditional approaches. We test this potential by reanalyzing a well-studied zooplankton data set — the Gulf of Maine continuous plankton recorder series — using a modified Dirichlet-multinomial mixture (DMM) model. The data set has ∼50 years of approximately monthly samples along a transect from Boston, USA, to Yarmouth, Canada. The results from the DMM analysis were largely consistent with previous analyses but also provided new insights. Notably, the Calanus-dominated communities that returned following a reduction in the 1990s showed a loss of background diversity, suggesting a shift in sources and possibly higher vulnerability of these communities. The DMM analysis also revealed a breakdown of seasonal ecological succession in the 1990s. These changes could be a precursor to similar changes in other Calanus-dominated systems. The approach demonstrates a path toward linking traditional analyses with recent omic-style analyses.
Influence of species and hybrid status on induction of somatic embryogenesis in Castanea
Authors: Holtz C.T. , Tull A.R. , Merkle S.A.
Published: November 2016

The American chestnut (AC; Castanea dentata (Marsh.) Borkh.) once dominated the forests of eastern North America prior to the introduction of chestnut blight in the late 19th century. A somatic embryogenesis (SE) system developed for American chestnut is potentially applicable for clonally propagating blight-resistant trees produced by The American Chestnut Foundation’s hybrid backcross breeding program. In this program, AC trees are hybridized with blight-resistant Chinese chestnut (CC; Castanea mollissima Blume) trees, followed by multiple generations of backcrossing to AC trees. It is possible, however, that the proportion of CC parental contribution in the hybrid backcross material could affect the success of SE using the AC protocol. Over three years of culture initiations, we tested the effects of the relative parental contributions of AC and CC on the success of SE induction using our standard AC culture initiation protocol and, subsequently, a published protocol for SE in European chestnut (Castanea sativa Mill.). With our standard AC protocol, open-pollinated AC and open- and control-pollinated hybrid backcross BC3F3 seed explants, as well as open-pollinated BC2 seed explants, successfully produced embryogenic tissue, while CC, F1, and BC1 explants did not. The European chestnut protocol produced Chinese chestnut embryogenic tissue and, subsequently, somatic embryos. The first BC3F3 somatic seedlings are currently growing in field tests.
Restricted Boltzmann machines for the long range Ising models
Authors: Aoki Ken-Ichi , Kobayashi Tamao
Published: December 2016

We set up restricted Boltzmann machines (RBM) to reproduce the long range Ising (LRI) models of the Ohmic type in one dimension. The RBM parameters are tuned by using the standard machine learning procedure with an additional method of configuration with probability (CwP). The quality of resultant RBM is evaluated through the susceptibility with respect to the magnetic external field. We compare the results with those by block decimation renormalization group (BDRG) method, and our RBM clear the test with satisfactory precision.
A Very Simple Formula for Aggregation and Multicriteria Optimization
Authors: Zadeh Lotfi A.
Published: December 2016

Aggregation of data has many important applications in various fields, especially in economics, planning, optimization, decision-making and ranking of alternatives. There are many approaches to aggregation reflecting the fact that aggregation is application-depend and there are some considerations which are hard to quantify. The simple formula, FA, which is described in the following is easy to apply and lends itself to standardization and generalization. It is convenient to describe the formula in terms of a model in which the data relate to the grades g1, …, gn which a student, call him Robert, received for the collection of courses c1, …, cn . Assume that the data are of the form (c1, g1), (c2, g2), …, (cn, gn). The grades are on a scale from 0 to 100. Upon normalization they become numbers in the unit interval which may be interpreted as grades of membership or degrees. We propose two approaches.
Multi-Objective Cuckoo Search Under Multiple Archiving Strategies
Authors: Zeltni Kamel , Meshoul Souham
Published: November 2016

Cuckoo Search (CS) is a recent addition to the field of swarm-based metaheuristics. It has been shown to be an efficient approach for global optimization. Moreover, its application for solving Multi-objective Optimization (MOO) shows very promising results as well. In multi-objective context, a bounded archive is required to store the set of nondominated solutions. But, what is the best archiving strategy to use in order to maintain a bounded set with good characteristics is a critical issue that may lead to a questionable choice. In this work, the behavior of the developed multi-objective CS is studied under several archiving strategies. An extensive experimental study has been conducted using several test problems and two performance metrics related to convergence and diversity. A nonparametric test for statistical analysis is performed. In addition, we used a Multi-Objective Particle Swarm Optimization (MOPSO) for further analysis and comparison. The results revealed that archiving strategies play an important role as they can impact differently on the quality of obtained fronts depending on the problem’s characteristics. Also, this study confirms that the proposed MOCS algorithm is a very promising approach for MOPs compared to the widely used MOPSO.
A Novel Method for Classification of ECG Arrhythmias Using Deep Belief Networks
Authors: Wu Zhiyong , Ding Xiangqian , Zhang Guangrui
Published: November 2016

In this paper, a novel approach based on deep belief networks (DBN) for electrocardiograph (ECG) arrhythmias classification is proposed. The construction process of ECG classification model consists of two steps: features learning for ECG signals and supervised fine-tuning. In order to deeply extract features from continuous ECG signals, two types of restricted Boltzmann machine (RBM) including Gaussian–Bernoulli and Bernoulli–Bernoulli are stacked to form DBN. The parameters of RBM can be learned by two training algorithms such as contrastive divergence and persistent contrastive divergence. A suitable feature representation from the raw ECG data can therefore be extracted in an unsupervised way. In order to enhance the performance of DBN, a fine-tuning process is carried out, which uses backpropagation by adding a softmax regression layer on the top of the resulting hidden representation layer to perform multiclass classification. The method is then validated by experiments on the well-known MIT-BIH arrhythmia database. Considering the real clinical application, the inter-patient heartbeat dataset is divided into two sets and grouped into four classes (N, S, V, F) following the recommendations of AAMI. The experiment results show our approach achieves better performance with less feature learning time than traditional hand-designed methods on the classification of ECG arrhythmias.
Can we trust autonomous weapons?
Authors: Kirkpatrick Keith
Published: December 2016

Nations consider using defense systems that can make their own lethal decisions.
Nailing smoke
Authors: Anderson David P.
Published: December 2016

Curation at the bleeding edge of technology.
Spatiotopic coding during dynamic head tilt
Authors: Mikellidou Kyriaki , Turi Marco , Burr David C.
Published: December 2016

Humans maintain a stable representation of the visual world effortlessly, despite constant movements of the eyes, head, and body, across multiple planes. Whereas visual stability in the face of saccadic eye movements has been intensely researched, fewer studies have investigated retinal image transformations induced by head movements, especially in the frontal plane. Unlike head rotations in the horizontal and sagittal planes, tilting the head in the frontal plane is only partially counteracted by torsional eye movements and consequently induces a distortion of the retinal image to which we seem to be completely oblivious. One possible mechanism aiding perceptual stability is an active reconstruction of a spatiotopic map of the visual world, anchored in allocentric coordinates. To explore this possibility, we measured the positional motion aftereffect (PMAE; the apparent change in position after adaptation to motion) with head tilts of ∼42° between adaptation and test (to dissociate retinal from allocentric coordinates). The aftereffect was shown to have both a retinotopic and spatiotopic component. When tested with unpatterned Gaussian blobs rather than sinusoidal grating stimuli, the retinotopic component was greatly reduced, whereas the spatiotopic component remained. The results suggest that perceptual stability may be maintained at least partially through mechanisms involving spatiotopic coding.

NEW & NOTEWORTHY Given that spatiotopic coding could play a key role in maintaining visual stability, we look for evidence of spatiotopic coding after retinal image transformations caused by head tilt. To this end, we measure the strength of the positional motion aftereffect (PMAE; previously shown to be largely spatiotopic after saccades) after large head tilts. We find that, as with eye movements, the spatial selectivity of the PMAE has a large spatiotopic component after head rotation.
Postthoracotomy Ipsilateral Shoulder Pain: A Literature Review on Characteristics and Treatment
Authors: Yousefshahi Fardin , Predescu Oana , Colizza Melissa , Asenjo Juan Francisco
Published: November 2016

Context.Postthoracotomy Ipsilateral Shoulder Pain (IPS) is a common and sometimes intractable pain syndrome. IPS is different from chest wall pain in type, origin, and treatments. Various treatments are suggested or applied for it but none of them is regarded as popular accepted effective one.Objectives.To review data and collect all present experiences about postthoracotomy IPS and its management and suggest future research directions.Methods.Search in PubMed database and additional search for specific topics and review them to retrieve relevant articles as data source in a narrative review article.Results.Even in the presence of effective epidural analgesia, ISP is a common cause of severe postthoracotomy pain. The phrenic nerve has an important role in the physiopathology of postthoracotomy ISP. Different treatments have been applied or suggested. Controlling the afferent nociceptive signals conveyed by the phrenic nerve at various levels—from peripheral branches on the diaphragm to its entrance in the cervical spine—could be of therapeutic value. Despite potential concerns about safety, intrapleural or phrenic nerve blocks are tolerated well, at least in a selected group of patient.Conclusion.Further researches could be directed on selective sensory block and motor function preservation of the phrenic nerve. However, the safety and efficacy of temporary loss of phrenic nerve function and intrapleural local anesthetics should be assessed.
Exome Sequencing Identifies Compound Heterozygous Mutations inSCN5AAssociated with Congenital Complete Heart Block in the Thai Population
Authors: Thongnak Chuphong , Limprasert Pornprot , Tangviriyapaiboon Duangkamol , Silvilairat Suchaya , Puangpetch Apichaya , Pasomsub Ekawat , Sukasem Chonlaphat , Chantratita Wasun
Published: November 2016

Background. Congenital heart block is characterized by blockage of electrical impulses from the atrioventricular node (AV node) to the ventricles. This blockage can be caused by ion channel impairment that is the result of genetic variation. This study aimed to investigate the possible causative variants in a Thai family with complete heart block by using whole exome sequencing.Methods. Genomic DNA was collected from a family consisting of five family members in three generations in which one of three children in generation III had complete heart block. Whole exome sequencing was performed on one complete heart block affected child and one unaffected sibling. Bioinformatics was used to identify annotated and filtered variants. Candidate variants were validated and the segregation analysis of other family members was performed.Results. This study identified compound heterozygous variants, c.101G>A and c.3832G>A, in theSCN5Agene and c.28730C>T in theTTNgene.Conclusions. Compound heterozygous variants in theSCN5Agene were found in the complete heart block affected child but these two variants were found only in the this affected sibling and were not found in other unaffected family members. Hence, these variants in theSCN5Agene were the most possible disease-causing variants in this family.
Incidence of Prediabetes and Type 2 Diabetes among People Aged over 20 Years in Ahvaz: A 5-Year Perspective Study (2009–2014)
Authors: Latifi Seyed Mahmoud , Karandish Majid , Shahbazian Hajieh , Hardani Pasand Leila
Published: November 2016

Background. The present study is the fourth cohort study conducted in the Middle East on the evaluation of prediabetes and type 2 diabetes, implemented in Ahvaz, Iran.Methodology. The individuals aged over twenty years who had participated in a study on the prevalence of metabolic syndrome in 2009 (Phase 1) in Ahvaz were invited again in 2014. The questionnaires were completed via interview, and anthropometric parameters were measured by standard method. The logistic regression and chi-square test were used for data analysis.Results. In the median of five-year follow-up, a number of 593 people participated in reexamination from which 396 individuals were nondiabetic in Phase 1. The incidence of diabetes and prediabetes was 21.9 and 40.6 per 1000 person-years, respectively. Among Phase 1 prediabetics, 16.8% were diagnosed with diabetes in a five-year period. The factors affecting the incidence of prediabetes among the people younger than 65 years include age, family history of diabetes, and gender. The age factor plays an important role in the transformation of prediabetes to diabetes.Conclusion. The city of Ahvaz with type 2 diabetes incidence of 13.64 per 1000 person-years is one of the areas with high incidence of diabetes in Iran.
The Role of Hippocampal Estradiol Receptor‐α in a Perimenopausal Affective Disorders‐Like Rat Model and Attenuating of Anxiety by Electroacupuncture
Authors: Wang Xun , Huang Yongheng , Yuan Shiwen , Tamadon Amin , Ma Shulan , Feng Yi
Published: December 2016

Hormone replacement therapy is the principal treatment for perimenopausal affective disorders which can cause severe side effects. The present study compared the effects of electroacupuncture (EA) and estradiol treatment on perimenopausal affective disorders at the behavioral and cellular levels. In this randomized experimental in vivo study, adult female rats were divided into intact, ovariectomy, chronic unpredictable stress (CUS), and ovariectomy and CUS combination groups. After week 6, all groups were subdivided to three subgroups of control, EA, and estradiol treatment. The behavioral parameters in the open field and the elevated plus maze tests were assessed before and after treatments. Alterations of serum steroid hormones and changes of estradiol receptor‐α (ER‐α) immunofluorescence neurons in the hippocampus sections were evaluated. EA treatment caused more antianxiety effects than estradiol treatment in CUS group (P < 0.05). Notably, estradiol and EA treatments had better significant behavioral effects when the models were not estrogen‐deficient. Importantly, within each group, compared to the control group, the numbers of ER‐α‐positive neurons were significantly larger in EA subgroups. Therefore, EA had antianxiety effects on perimenopausal affective disorders caused by CUS but not by estrogen deficiency and upregulation of hippocampus ER‐α neurons may contribute to its mechanism of action.
Fatal Dengue Myocarditis despite the Use of Extracorporeal Membrane Oxygenation
Authors: Ku Yee-Huang , Yu Wen-Liang
Published: November 2016

Dengue is an important mosquitoes-borne viral disease which is endemic in tropics and subtropics region. Rapid spreading of disease to previously unaffected region was found in recent years. Atypical manifestations, such as myocarditis, were reported during large outbreak. There is a wide range of clinical manifestations of cardiac involvement in dengue, but rarely fatal. Here we reported a case of fulminant dengue myocarditis in fatal outcome despite cardiac mechanical support.
Clinical Comparison of Outcomes of Early versus Delayed Carotid Artery Stenting for Symptomatic Cerebral Watershed Infarction due to Stenosis of the Proximal Internal Carotid Artery
Authors: Liu Huakun , Chu Jianfeng , Zhang Lei , Liu Chaolai , Yan Zhongrui , Zhou Shengnian
Published: November 2016

The aim of this study was to compare the clinical outcomes of early versus delayed carotid artery stenting (CAS) for symptomatic cerebral watershed infarction (sCWI) patients due to stenosis of the proximal internal carotid artery. We retrospectively collected clinical data of those who underwent early or delayed CAS from March 2011 to April 2014. The time of early CAS and delayed CAS was within a week of symptom onset and after four weeks from symptom onset. Clinical data such as second stroke, the National Institutes of Health Stroke Scale (NHISS) score, and modified Rankin Scale (mRS) score and periprocedural complications were collected. The rate of second stroke in early CAS group is lower when compared to that of delayed CAS group. There was no significant difference regarding periprocedural complications in both groups. There was a significant difference regarding mean NHISS score 90 days after CAS in two groups. Early CAS group had a significant better good outcome (mRS score ≤ 2) than delayed CAS group. We suggest early CAS for sCWI due to severe proximal internal carotid artery stenosis as it provides lower rate of second stroke, comparable periprocedural complications, and better functional outcomes compared to that of delayed CAS.
Volar Locking Plate Breakage after Nonunion of a Distal Radius Osteotomy
Authors: Barrera-Ochoa Sergi , Rodríguez-Alabau Sergi , Sallent Andrea , Soldado Francisco , Mir Xavier
Published: November 2016

We report a 38-year-old male with a nonunion followed by plate breakage after volar plating of a distal radius osteotomy. Volar locking plates have added a new approach to the treatment of distal radius malunions, due to a lower morbidity of the surgical approach and the strength of the final construction, allowing early mobilization and return to function. Conclusion. Plate breakage is an uncommon complication of volar locking plate fixation. To our knowledge, few cases have been described after a distal radius fracture and no case has been described after a distal radius corrective osteotomy. In the present case, plate breakage appears to have occurred as a result of a combination of multiple factors as the large corrective lengthening osteotomy, the use of demineralized bone matrix instead of bone graft, and the inappropriate fixation technique as an unfilled screw on the osteotomy site, rather than the choice of plate.