bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of induced activity of 167Ho from different neutron capture paths
Authors: Morais T S L , Dias M S
Published: August 2019

The main purpose of this study is to predict the induced activity of 167Ho produced by 165Ho(n,γ)166mHo(n,γ)167Ho, 165Ho(n,γ)166Ho(n,γ)167Ho and 166mHo(n,γ)167Ho reactions to choose the best path to measure the cross section with lowest uncertainty. The activation and decay scheme was established starting from the 165Ho target and considering single, double and triple neutron capture reactions. The activity results were deduced from differential activation equations and decay rates for all reaction products. The calculations were performed considering samples which were taken from a stock solution supplied by the Electrotechnical Laboratory (Japan) for purposes of an international comparison.
Neutrino emission from neutron star crusts
Authors: Ramalho S V C , Vicente G S , Duarte S B
Published: August 2019

Neutrino production is the dominant cooling process in neutron stars. After the rapid cooling during the protoneutron star stage, the neutron star crust is formed. Neutrinos continue to be produced in the crust, which can escape from the surface. This neutrino production is an important process to the final cooling phase of the star. They are produced in the crystalline lattice formed by nuclei permeated by an electronic gas. Quantum oscillations of the electron density with respect to the lattice of nuclei generates plasmons, which decay in a pair of neutrinos. Many works have studied the plasma of the nucleus in the star, however, without incorporating the effect of the lattice in the crust of the neutron star. The objective of this work is to include the lattice in the calculation of the plasmon decay rate using quantum field theory at finite temperature. It is not common to find studies on the crystalline lattice of the star using quantum field theory and the calculations generally used for neutrino emissivity consider a homogeneous and isotropic medium, which can not be directly applied in the context of neutron star crust.
The gluonic halo of the nucleons
Authors: Trevisan L A , Mirez C , da Silva D I
Published: August 2019

On the scope of the nonextensive statistical model for the nucleon’s structure function, we propose that gluons may occupy a bigger volume than the quarks, in nucleons. This correction is needed to fit the carry out momentum of each kind of particle. At the end of the work, we notice that the radius was not the only variable to be changed to get the goal of momentum adjustment and the another constraints.
A Monte Carlo model of deuteron emission in pre-equilibrium nuclear reactions
Authors: Teixeira E A , Carlson B V
Published: August 2019

Nucleon-induced pre-equilibrium reactions are important in many applications of nuclear physics. About 20% of the particles emitted in such reactions are composites, such as deuterons and alpha particles. Deuterons are produced through emission from the compound nucleus, as well as through two important direct reaction mechanisms - “pick-up” and coalescence. Iwamoto and Harada developed a semi-classical pre-equilibrium model that describes both direct mechanisms as a generalization of coalescence. We have implemented the Iwamato and Harada unified model of deuteron emission in Blann and Chadwick’s hybrid Monte Carlo model. This implementation was made in order to analyse data of reactions of the type (p,d), that is, proton induced reactions having deuterons as emitted particles, but our previous results were not satisfactory. In order to find a new approach for the deuteron emission, we are investigating an eikonal approximation to the phase space of Iwamoto and Harada model. We are also comparing our angular distributions with the experimental ones using DWUCK4. Nevertheless, our results are not satisfactory yet and our work is under development.
Consistent Skyrme parametrization and its critical parameter values
Authors: Dutra M , Lourenço O , Delfino A
Published: August 2019

A new Skyrme parametrization was developed based on a shortlist of Skyrme forces. These selected parameterizations, 16 in total, were found in a comprehensive study involving 240 parametrizations submitted to constraints related to nuclear matter properties. The critical parameters associated with the liquid-gas phase transition, critical density, critical pressure, and critical temperature are calculated for this new parametrization as well as its flash point.
Consistent relativistic mean-field models: symmetry energy parameter
Authors: Lourenço O , Dutra M , Hen O , Piasetzky E , Menezes D P
Published: August 2019

In this work, we revisit the study published in [Dutra et al., Chinese Physics C 42, 064105 (2018)] where 34 consistent relativistic mean-field models were analyze at the nuclear matter constraints in relation to the role of short-range correlations in the calculation of the symmetry energy and its consequence on the value of the gamma parameter.
Single-event effects: experimental setup for power MOSFETs and diffusion model for cross section calculations in low-voltage MOSFETs
Authors: Alberton S G , Medina N H , Added N , Aguiar V A P , Menegasso R , Macchione E L A , Silveira M A G
Published: August 2019

MOSFETs are subject to different types of Single-Event Effects (SEEs) induced by heavy ions, with low-voltage MOSFETs being more susceptible to non-destructive effects, such as Single-Event Transients, than high-voltage MOSFETs which may also be susceptible to destructive effects. In this paper an experimental setup used to study SEEs in power MOSFETs at the São Paulo 8UD Pelletron accelerator and computational simulations for SEE cross section calculations in low-voltage MOSFETs are presented.
Damping Measurements on a Multi-Blade Cascade with Multiple Degrees of Freedom: A Francis-99 Test Case
Authors: Bergan C W , Tengs E O , Solemslie B W , Østby P , Dahlhaug O G
Published: August 2019

Due to thinner blades and higher demands for flexibility, the high-head Francis runners designed today face considerable challenges that severely affect the runners’ expected lifetime. For many high-head Francis runners, the leading cause of fatigue is blade cracking due to Rotor-Stator Interaction, which cause vibrations in the runner blades.

Accurate prediction of the vibration magnitudes in a turbine is paramount in designing a reliable Francis runner. The understanding of the interaction between the hydrodynamic forces and the internal stresses in the runner is not yet sufficient to make this prediction. Previous investigations have identified some key parameters that affect dynamic behaviour in water, such as added mass, as well as added stiffness and damping from moving water. These parameters affect the natural frequency and damping of a structure, which in the end will affect what vibrations magnitudes the runner will be subjected to for a given frequency of excitation. The behavior of these parameters have recently been investigated by several researchers, but the effect of neighboring blades is yet not understood.

A multi-blade cascade has been tested for four of its different modes of vibration. The results indicate that the slope of the damping with respect to the inverse Strouhal number is constant. This slope was found to be the same as for several single-blade tested performed, both in the same rig and in other works. The implication is that the product of added mass and mode shape does not change significantly.
Francis-99: Coupled simulation of the resonance effects in runner channels
Authors: Tengs Erik , Salvesen Fevåg Live , Storli Pål-Tore
Published: August 2019

A resonance phenomenon is observed experimentally in the runner channels of the Francis-99 model turbine runner. An incompressible CFD simulation is unable to simulate this. Two different coupled physics schemes are therefore presented to investigate if such effects can be replicated through simulations. The first procedure is a fully coupled acoustic-structural simulation, where the surrounding fluid is modelled using acoustic theory. This includes added mass effects and pressure propagation, but not advective and viscous effects. The second procedure is a quasi two-way coupled Fluid-Structure approach based on modal decomposition of the structural domain. In this procedure, the incompressible Navier-Stokes equations are solved along with the structural deformation.

The fully coupled acoustic-structural approach does successfully exhibit a magnification of the pressure through the runner channels, indicating a resonance effect. The exact values of the acoustic pressure amplitudes are highly sensitive to the damping, the blade connection to the shroud close to the trailing edge, and more.

The second procedure manages to simulate the structural deformation with the correct nodal diameters excited by the Rotor Stator Interaction, all inside the fluid solver. The pressure amplitudes however, does not exhibit the desired resonance effect, likely due to the assumption of incompressible fluid.
Influence of the guide vanes design on stress parameters of Francis-99 turbine
Authors: Lazarevikj M , Stojkovski F , Iliev I , Markov Z
Published: August 2019

The frequencies with predominant amplitudes in low specific speed Francis turbines are related to rotor-stator interaction and they are calculated on the basis of the runner rotational speed and the number of guide vanes and runner blades. Pressure pulsations in the blade channels can be a reason for noise and vibration in the turbine above allowed level. High pressure pulsations can be caused by certain combination of runner blades and guide vanes number and/or resonance with one of the runner’s natural frequencies. The stress parameters of the Francis-99 turbine guide vanes and their modifications are analysed in this paper. The main aim is to determine the impact of the geometry modification (thinner for increased efficiency) of the guide vanes on the Francis turbine stresses by performing numerical simulations. The original Francis-99 turbine guide vane geometry and three modifications consisting of new guide vane shapes are being considered. The numerical investigation of the flow field is based on the k-ω SST turbulence model with ‘frozen rotor’ approach selected, constituting a quasi-steady state analysis, without taking into account the physical rotation of the runner to obtain Rotor-Stator Interaction (RSI). Pressure distribution on one guide vane determined by a Computational Fluid Dynamics (CFD) simulation of the turbine is coupled to a Finite Element Method (FEM) simulation in order to analyse the stresses. The results from the one-way fluid-structure interaction analysis give the stresses distribution and deformations of the guide vanes. Moreover, modal-acoustics analysis is conducted to obtain the natural frequencies of the guide vanes in water and comparison is made with the calculated vortex shedding frequencies to estimate the risk of resonance.
Numerical investigation of hydroacoustic pressure pulsations due to rotor-stator interaction in the Francis-99 turbine
Authors: Platonov D , Minakov A , Sentyabov A
Published: August 2019

The paper deals with the numerical simulation of the flow in the Francis-99 hydraulic turbine at three different problem formulations, namely, the application of the method of rotating coordinate system, sliding mesh model, and consideration of a compressible fluid. The pulsations intensity and pressure pulsation spectra obtained by numerical simulation and experimentally are compared. It is shown that the simulation of a problem considering compressible fluid, and that conducted by the sliding mesh method gives significantly greater pressure amplitudes. It is also shown that the precessing vortex core is a source of pressure waves in the entire turbine flow path.
Identification and correlation analysis for performance shaping factors in flight crew operation
Authors: Wang Lijing , Wang Yanlong , Chen Yingchun , Dong Dayong
Published: August 2019

The dependency between PSFs (performance shaping factors) is gaining increasing attention in HRA (human reliability analysis). In this paper, 79 PSFs were identified through literature review and discussion of focus group, which is composed of human factors/HRA specialists and civil pilots. These PSFs were classified into 10 categories as cognitive characteristics, physiological and psychological characteristics, personal and social characteristics, procedures, task characteristics, human-machine interface, system state, phenomenology characteristics, physical working conditions team and organizational factors. Then a survey of 299 pilots was conducted. A self-rate scale was used to investigate how the pilots were influenced by these PSFs. Correlation analysis shows that the correlations between PSF subsets are moderate to strong. The result suggests further research on the dependency between PSFs and PSF interactions need to be included in future HRA efforts.
Runtime Contracts Checker: Increasing Robustness of Component-Based Software Systems
Authors: Illarramendi M , Etxeberria L , Elkorobarrutia X , Sagardui G
Published: August 2019

Software Systems are becoming increasingly complex leading to new Validation &Verification challenges. Model checking and testing techniques are used at development time while runtime verification aims to verify that a system satisfies a given property at runtime. This second technique complements the first one. This paper presents a runtime contract checker (RCC) which checks a component-based software system’s contracts defined at design phase. We address embedded systems whose software components are designed by Unified Modelling Language-State Machines (UML-SM) and their internal information can be observable in terms of model elements at runtime. Our previous research work, CRESCO (C++ REflective State-Machines based observable software COmponents) framework, generates software components that provide this observability. The checker uses software components’ internal status information to check system level safety contracts. The checker detects when a system contract is violated and starts a safeStop process to prevent the hazardous scenario. Thus, the robustness of the system is increased.
Effect of Process Parameters on Structure and Mechanical Properties of Friction Stir Welding Joint of 5052 Aluminum Alloy
Authors: Zhou Zejie , Huang Zhichao
Published: August 2019

2.5 mm thick sheets of AA5052 were welded using friction stir welding technology. The effects of welding speed, rotational speed of pin, length of pin, single-side and double-side welding process on the morphology, microstructure and mechanical properties of welded joints were studied and analyzed. The failure mode was studied. The results show that the joints with good mechanical properties and without welding defects can be welded when the rotational speed of pin is 500-1200r/min and the welding speed is 100-480mm/min. The microstructure of weld nugget is mainly composed of α phase solid solution and β phase particles. The process parameters of friction stir welding have great influence on the static strength of welded joints. The static strength increases with the increasing of rotational speed of pin, however decreases with the increasing of welding speed. The peak load of the double-side welding increases by 30% compared with the single-side welding. The length of pin has little effect on the tensile strength. The tensile fracture of the single-side welding is located in the weld nugget zone, whereas the fracture of double-side welding is located in the base material zone.
Effect of Heat Treatment on the Microstructure and Wear Resistance of NiCrMoV Steel
Authors: Wang Hongxing , Wang Zhangzhong , Xue Yajun , Wang Cangsheng , Lv Zhe , Yue Bao
Published: August 2019

The effect of an applied load within a 50-200 N range, speed of 10-45 mm/s, and sliding of 10-120 min on the wear behavior of a NiCrMoV low alloy steel quenched in air at 1123-1323 K, followed by tempering at 873 K, was investigated. The material’s microstructure was further studied. The wear was measured using a ball-on-disc type wear machine at room temperature under dry sliding conditions. The micromorphology, worn surface and debris were investigated using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results indicate that all the tempered specimens’ microstructure of the NiCrMoV low alloy steel consists of ferrite and carbide and that the grain size increases with an increase in quenching temperature. The friction coefficient and mass loss increased with an increase in the applied load, the sliding speed and time, as well an increase in quenching temperature. The friction coefficient and mass loss significantly increased at a load of 200 N. The worn surface of all the specimens revealed a discontinuous adherent layer. Furthermore, the microstrucure revealed that the specimens underwent a combination of delamination, plastic deformation, fatigue, and oxidation. The wear mechanism involves predominantly adhesion with a mixture mode of abrasive, adhesion, and oxidation.
Morphological Characterization and Chemical Bond Identification of Collagen-coated Native Silk Fibroin Fibers Using Chemical Method
Authors: Lu Yao , Hao Zhixiu
Published: August 2019

Native silk fibroin (SF) fiber has been widely researched as the materials for tissue engineering scaffolds for its robust mechanical properties. Collagen is the main component of extra cellular matrix (ECM) and has remarkable biocompatibility, so it is often utilized to coat native SF scaffolds for improving the cell adhesion. However, there is lack of feasible methodology for coating collagen on the native SF fibers. In this paper we coated collagen on the native SF fibers by creating amide bonds between the carboxyls from native SF and the amino groups from collagen. Morphological characterization (including 3D surface roughness S
q, S
pq and S
vq,) and chemical bond identification (including amide bond and carboxyl) of the native SF and collagen-coated SF fibers were performed. The results indicated the chemical method could integrally coat collagen on native SF fibers. The chemical modification on the surface and collagen concentration had no significant influence on the 3D roughness. The coated and uncoated groups had high similarity in position of characteristic peaks of chemical bonds.
The Evolution of Microstructures and Mechanical Properties of SnAgCu/Cu Weld Interface during Isothermal Aging
Authors: Chen Haiyan , Huang Liyang , Guo Li
Published: August 2019

Based on the model of the diffusion flux ratio of Cu and Sn at the Cu/Cu3Sn/Cu6Sn5/Sn interface, the evolution of microstructures, the behavior of formation and growth of intermetallic compound (IMC) for Sn95.5Ag3.8Cu0.7 solder aged at 150 °C were studied. The nano indentation was applied to measure the hardness and elastic modulus of the IMC. The tensile strength and the low cyclic fatigue properties of the weld joint were also measured. The results showed that the thickness increments of Cu3Sn and Cu6Sn5 phases of IMC are mainly controlled by diffusion mechanism. The growth rates of Cu3Sn and Cu6Sn5 are 7.86×10-19 m2/s and 7.80×10-17 m2/s, respectively. The hardness and elastic modulus of IMC enhance with increasing aging time. For 24h aging time, the microstructure of the Cu6Sn5 keeps scalloped shape and the elastic modulus of IMC layer are similar to the copper substrate, which result in high fatigue resistance of the welded joint and its tensile strength of 69.50 MPa. With the mechanical hardening cumulative effects resulting from aging and cyclic strain, the fatigue performance and tensile strength of the welded joint gradually worse with the further increase of the aging time.
Study on Stress-strain Constitutive Relationship of Super-long-age Plastic Concrete under Triaxial Compression
Authors: Hu Liangming , Zhu Junfu , Jia Xin , Zhang Changhui , Gao Danying
Published: August 2019

The triaxial stress-strain relationship of super long-aged (540d) plastic concrete mixed with clay and bentonite was studied. According to the test, the stress-strain curves of plastic concrete under different confining pressures are obtained. It is found that the stress-strain curves under the lateral confining pressure are basically the same (0.4 MPa, 0.6 MPa), (0.4 MPa, 0.8 MPa), and the slope of the rising section is basically the same. Compared with the peak pressure ratio (0.2 MPa, 0.4 MPa), the lateral confining pressure is larger. In addition, the calculation formula of the peak secant elastic modulus and the triaxial compressive stress-strain relationship in accordance with the lateral pressure of plastic concrete are also proposed. The fourth-order polynomial mathematical model. The establishment of the mathematical model provides a basis for the development of plastic concrete specifications and triaxial compression performance numerical analysis, and further promotes the engineering application of plastic concrete.
Research on Cost-effective New Alloy Cast Iron
Authors: Sun Dong , Zhang Lingfeng , Xiong Yi , Ren Fengzhang
Published: August 2019

Cast iron is the basic material of the manufacturing industry. It has excellent casting processability and good shock absorption and wear resistance, so it is widely used. With the awareness of energy conservation and environmental protection, the defects of low energy and high consumption of traditional materials are gradually revealed. They are gradually being replaced by new alloy cast iron. This paper introduces the latest developments in new alloy cast iron production technology in recent years in detail, involving iron purification, furnace selection, melt ratio, chemical composition control, inoculant type and application, and stress relief annealing. And this paper analyzes the strengthening mechanism of cast iron, puts forward the problems and solutions in the production process, and expounds the development trend of cast iron production technology and the prospect of China’s cast iron industry.
The Synthesis of Magnesium-aluminium Spinel for Catalytic Hydrolysis of Carbonyl Sulphur at the Middle Temperature
Authors: Shangguan Ju , Liu Yanxia , Wang Zexing , Xu Yikun
Published: August 2019

The influences of the physical and chemical properties for the catalyst materials on the hydrolysis catalytic activity of carbonyl sulphur (COS) and the anti-oxygen property will be crucial to removing COS from gas at moderate temperature. The magnesium-aluminium spinel for catalytic hydrolysis of COS was synthesized by the dry mixing of pseudo boehmite with MgO. The performances of the prepared catalyst were characterized by XRD, nitrogen isothermal adsorption (BET), CO2-TPD, and the COS hydrolysis activities were measured in fix-bed reactor with the change of space velocity, temperature, COS concentration and O2. The results showed that the MgAl2O4 synthesized by mixing of pseudo boehmite with MgO and then calcining at 873K is feasible. By comparison with γ-Al2O3 catalyst, the synthesized MgAl2O4 catalyst possesses more pore volume and diameter so as to improve the diffusion rate of reactant and product of COS hydrolysis. MgAl2O4 spinel catalyst showed the better catalytic activity of COS hydrolysis, combining the advantages of γ-Al2O3 and MgO. As a result, MgAl2O4 catalyst in itself not only helps to improve the catalytic activity of COS, but also helps to enhance the anti-oxygen poisoning property.
Development of High-voltage Standard Current Transformer with Three Phases in One Enclosure Based on Shielding and Balanced Winding
Authors: Liu Gang , Ai Bing , Zhang Jiefu , Liu Kun , Xiao Lingyue , Zhang Fuzhou
Published: August 2019

When three-phase testing method is applied to test errors of three-phase combined transformers on site, many testing devices are needed while laboratory space is limited. Therefore, narrowing down the space that testing devices occupied appears to be crucial. This article designed and developed the gas-insulated high-voltage standard current transformer with all three phases in one enclosure. Its characteristics is that double shielding and shielding combined with balancing winding are used separately to restrain the influence of leakage current and magnetic field on the error of standard current transformer. Moreover, the article carried out the effect of leakage current and magnetic field on the error of standard current transformer. The results show that the influence of leakage current on the error of standard current transformer is less than 1/10 of the error limit. The influence of adjacent phase current on standard current transformer is less than 1/10 of the error limit. The high voltage standard current transformer with three phases in one enclosure, designed and developed in this article, is capable of testing errors of 10 kV three-phase combined transformers for measurement on the field with three-phase testing method.
Analysis of Natural Mordant to B. mori Silk Fabrics Dyeing with Tea Extract
Authors: Huang Xiaocui , Liu Chen
Published: August 2019

Tea pigments as biological materials were extracted in this paper. Applications of turmeric and tannic acid during the silk dyeing with tea extract were studied. By changing mordant dyeing methods, concentration of mordant, dye solution pH value and dyeing concentration, we tried to study the effect of natural mordant. The results showed that two kinds of mordant were more suitable for pre-mordant. When the tannic acid was 5 g/L, the turmeric was 0.025 g/L, and the dye solution pH value was 5, the dyeing effect was optimal. Furthermore, when the dyeing concentration was diluted 5 times, the dyed fabric color was fuller. With the optimum mordant dyeing process conditions, the colors fastness to washing were acceptable.
Research on the Multi-factor Aging Resistance for the materials of Composite Poles
Authors: Li Panfeng , Wu Xiong , Feng Bing , Xie Fang
Published: August 2019

A multi-factor faster aging test with 5000h was carried to evaluate the aging resistance of running composite tower materials outdoor, which accelerates aging test includes different factors such as solar aging, mechanical aging, electrical aging, heat aging and environmental aging of materials. The flexural modulus retention rates of resin-based and resin-system composite samples decrease with aging time, except for the sample made of isophthalic unsaturated polyester, the flexural modulus retention rates of other composite samples are above 90%. Meanwhile, the modulus of the unsaturated polyester resin and E44 epoxy resin decreased significantly, the modulus retention of unsaturated polyester rate was 88% after aging test, and the damage flextural strength for E44 epoxy based glass fiber composite sample was 92%, while the bending strengh retention ratioes of other composite materials were higher than 96%. The multi-factor accelerated aging test results show that the modified polyurethane resin and vinyl resin have good aging resistance, and meet the application for composite materials’ poles and crossarms outdoor.
Design of Indoor Position System Based on DWM1000 Modules
Authors: Pan Dawei , Yu Yunhua
Published: August 2019

The traditional indoor position system is realized with laser scanners and cameras. The methods need complex calculation and have poor real-time and high cost. In this paper the UWB position technology is used to realize the indoor position system with TDOA. The platform of position system is based on DWM1000 modules, and the software and hardware are developed independently. The test result shows that the system has good reliability and feasibility and the position accuracy is within ±10cm.
Technical Study on the Rock Wool/Polyurethane Composite Insulation Board and Its External Insulation System for Ultra-low Energy Consumption Buildings
Authors: Lu Guozhong , Zheng Xuesong , Zhang Jiayang
Published: August 2019

Ultra-low energy consumption buildings refer to the buildings which adapt to the climate characteristics and natural conditions, use the envelope structure with high thermal insulation and air tightness performance as well as efficient fresh air heat recovery technology to minimize the heating and cooling demand of buildings, and make full use of renewable energy to provide comfortable indoor environment with less energy consumption. As a key part of the ultra-low energy consumption building technology system, the external wall heat transfer coefficient K value is much higher than the external wall heat transfer coefficient required by the current ordinary energy-saving buildings in China. In order to achieve the thermal insulation performance required by the ultra-low energy consumption buildings, higher requirements are put forward for the thermal insulation materials and external thermal insulation system of building envelope. In this research, a new type of thermal insulation material for external wall of buildings which combines rigid polyurethane and rock wool is developed, and its application technology in ultra-low energy consumption building external wall thermal insulation system is also studied.
Optimization of Technical Parameters of CO2 Inerting Goaf in 7271 Working Face of Yaoqiao Mine
Authors: Cheng Genyin , Liu Yifan , Si Junhong
Published: August 2019

Aiming at the problem of fire prevention and extinguishment in the 7271 working face of Yaoqiao Mine, the carbon dioxide inerting method was used to establish the influencing factors system, which combining injecting pipeline parameters, mining technical parameters and inerting gas physical parameters. Numerical simulation method was used to study the influence of different gas injection depth and different gas injection volume on the distribution of carbon dioxide flow field in the goaf. The range of gas injection parameters is determined by hierarchical simulation experiment; Taking comparative experiment between parameters obtain the optimal carbon dioxide fire prevention and inerting parameters for the 7271 working face to study injection depth and injection volume. Experiments show that the width of the oxidation zone reduced by 56m after inerting the goaf, and the width of the asphyxiation zone increased by 29m.
Reliability Assessment of RIC Neutron Flux Measurement System
Authors: Sun Lingyu , Liu Ce , Zhu Lili
Published: August 2019

Nuclear power core neutron flux measurement system is a special tool for real-time accurate measurement of nuclear reactors, which requires not only high technically demanding, but also has high requirements for reliability. Compared with the advanced level in foreign countries, there is still a certain gap between the reliability and stability of domestically produced products. Taking the prefabricated water level monitoring system as an example, this paper adopts the risk priority number method to carry out the failure mode and impact analysis, and divides the system into various agreements. Level, a detailed analysis of all possible failure modes, causes of failure, severity of consequences, probability of occurrence, and degree of damage. Meanwhile, the reliability prediction model is established to carry out quantitative analysis. According to the fmea result and the reliability prediction model, more serious failure modes and modules with higher failure rate are discussed. Based on this, the design improvement direction of the water level monitoring system of the core operation state monitor is proposed.
Structure and Protective Properties of Ti-containing Organic-inorganic Hybrid Film on Stainless Steel Surface
Authors: Lian Xueting , Gao Jin , Guo Feifei , Li Xiaogang
Published: August 2019

In this paper, a dense structure of Ti-containing organic-inorganic hybrid transparent film was prepared on the surface of 304 stainless steel by sol-gel method combined with organic-inorganic hybridization theory. The basic properties and corrosion resistance of the hybrid film showed a unimodal change with the increase of the precursor content. When the molar ratio of the precursor to tetrabutyl titanate was about 0.75, the hybrid film obtained had the best performance. The microstructure of the film was analyzed by SEM and AFM technology. The Ti-containing organic – inorganic hybrid film was denser than the Si-containing hybrid film and epoxy film, which resulted in better salt spray resistance and EIS performance.
High Resolution Sequence Stratigraphic Division and Isochronous Framework Establishment in Wuerxun-baer Sag
Authors: Wang Qi
Published: August 2019

High-resolution sequence stratigraphy and related technical methods have been widely used in the analysis of complex and changeable continental petroliferous basins in China in recent years. At present, the main fields of oil and gas exploration in Hailaer Basin have been transferred to lithologic reservoirs, so it is very important to find lithologic traps and analyze the favorable formation conditions of lithologic traps. The tectonic evolution, sequence stratigraphic framework and tectonic control over the sedimentary system of Nantun Formation have been studied in depth by predecessors. However, the division accuracy of Nantun Formation can only reach the level of system tract, and the distribution characteristics of sand bodies and source-reservoir allocation under high-resolution sequence framework are seldom studied. Therefore, on the basis of predecessors’research, the author synthetically uses the related technology and methods of high-resolution sequence stratigraphy, and according to the sequence boundary characteristics reflected by drilling, core, seismic and logging data, establishes the high-resolution sequence stratigraphic framework through fine division and correlation of base-level cycles at various levels. The distribution law of sand body under its control and the source-reservoir allocation relationship favorable to lithologic trap formation are studied in order to have important guiding significance for further tapping the potential of lithologic reservoir.
Properties of Gypsum Composites with Straw Fillers
Authors: Regulska K , Repelewicz A
Published: August 2019

Results of tests of physical and mechanical properties of gypsum composites with organic fillers, in the form of cut straw are presented at the paper. The conducted tests aimed at determining the influence of gypsum mixtures composition and the manner of filler’s preparation on the quality of composites. Strength and thermal properties, natural radioactivity and susceptibility to biological corrosion have been examined. The results were interesting. Moreover using straw as a component of gypsum mixtures is particularly friendly for natural environment.
Passive Adaptive Robot Obstacle Analysis and Optimization
Authors: Sun Lingyu , Liu Xiaoya , Li Zhilong
Published: August 2019

In order to improve the obstacle performance of robots in complex terrain environment, a crawler passive adaptive robot is proposed, which is mainly composed of car body module and track module. The link mechanism of the track module has a degree of freedom, and the carbon fiber material has the characteristics of light weight and high rigidity. The obstacle course of the crawler module is introduced, and the mathematical model is established. The obstacle obstacle ability is analyzed. On this basis, the optimization parameters and the objective function are proposed. The rod length parameters of the linkage mechanism are optimized by matlab. The analysis and simulation motion analysis of the optimized linkage mechanism verify the rationality of the obstacle performance and structural parameter design of the robot.
Research on Critical Technical Elements Recognition Method Based on AHP
Authors: Sun Lingyu , Zhu Lili , Liu Ce , Liu Xiaoya , Li Zhilong
Published: August 2019

The assessment of technology-readiness level is widely used in the multi-disciplinary manufacturing field. The identification of critical technical elements is a key step in the assessment of technology-ready level, and it is an important guarantee to reduce risks in the project or product development process and reduce development costs. The identification of traditional critical technical elements generally adopts the expert scoring method. Through discussion, the list of critical technical elements of final consistency is obtained. The results are subjective and uncertain, resulting in the loss or redundancy of critical technical elements, which directly affects the key to technical readiness. Quantitative identification of technical elements. To this end, this paper proposes a method for identifying critical technical elements using the AHP principle. Firstly, the judgment matrix is established according to the criterion and the importance degree scale. The consistency matrix is used to check and adjust the judgment matrix according to the consistency ratio. Then the summation method and the square root method are used to solve the importance of each sub-technical element. Finally, according to the importance degree. Quantitative evaluation results identify critical technical elements and validate their validity by example pairs. The results show that the method combines qualitative analysis with quantitative analysis and has good engineering application value.
Early-Life Predictors of Systolic Blood Pressure Trajectories From Infancy to Adolescence: Findings From Project Viva
Authors: Aris Izzuddin M , Rifas-Shiman Sheryl L , Li Ling-Jun , Belfort Mandy B , Hivert Marie-France , Oken Emily
Published: August 2019

Childhood blood pressure (BP) is a strong predictor of later risk of cardiovascular disease. However, few studies have assessed dynamic BP trajectories throughout the early-life period. We investigated the relationship between early-life factors and systolic BP (SBP) from infancy to adolescence using linear spline mixed-effects models among 1,370 children from Project Viva, a Boston, Massachusetts-area cohort recruited in 1999–2002. After adjusting for confounders and child height, we observed higher SBP in children exposed to gestational diabetes mellitus (vs. normoglycemia; age 3 years: β = 3.16 mm Hg (95% confidence interval (CI): 0.28, 6.04); age 6 years: β = 1.83 mm Hg (95% CI: 0.06, 3.60)), hypertensive disorders of pregnancy (vs. normal maternal BP; age 6 years: β = 1.39 mm Hg (95% CI: 0.10, 2.67); age 9 years: β = 1.84 mm Hg (95% CI: 0.34, 3.34); age 12 years: β = 1.70 mm Hg (95% CI: 0.48, 2.92)), higher neonatal SBP (per 10-mm Hg increase; age 3 years: β = 1.26 mm Hg (95% CI: 0.42, 2.09); age 6 years: β = 1.00 mm Hg (95% CI: 0.49, 1.51); age 9 years: β = 0.75 mm Hg (95% CI: 0.17, 1.33)), and formula milk in the first 6 months of life (vs. breast milk only; age 12 years: β = 2.10 mm Hg (95% CI: 0.46, 3.74); age 15 years: β = 3.52 mm Hg (95% CI: 1.40, 5.64); age 18 years: β = 4.94 mm Hg (95% CI: 1.88, 7.99)). Our findings provide evidence of programming of offspring SBP trajectories by gestational diabetes, hypertensive disorders of pregnancy, and formula milk intake and of neonatal BP being a potentially useful marker of childhood BP. These factors could be relevant in identifying children who are at risk of developing elevated BP.
Controlled substance diversion in health systems: A failure modes and effects analysis for prevention
Authors: Nolan Karen , Zullo Andrew R , Bosco Elliott , Marchese Christine , Berard-Collins Christine
Published: August 2019

Purpose

The purpose of this study was to demonstrate the utility of failure modes and effects analysis (FMEA) for systematically identifying potential sources of controlled substance diversion and developing solutions in an academic health system.

Methods

The FMEA was conducted by an 18-member cross-functional team from the department of pharmacy. The team developed scoring criteria specifically for controlled substance diversion, outlined the controlled substance processes from procurement to administration or disposal, and identified ways in which each step of the medication supply process might fail (failure modes) and result in diversion of controlled substances. Failure modes with a vulnerability score of 48 or 64 were considered highest risk and were immediately intervened on by the FMEA team.

Results

The FMEA outlined a total of 10 major steps and 30 substeps in the controlled substance supply process. From this, 103 potential failure modes were identified, with 24 modes (23%) receiving a vulnerability score of 48 or 64. Development of specific reports addressed 15 failure modes, while 9 involved pharmacy workflow alterations. Notable reports included controlled substance activity under temporary patients and discrepancy trends by user, medication, and patient care area. Notable workflow alterations included expanded use of cameras in high-risk areas and additional verification checks.

Conclusion

FMEA allowed for systematic identification of controlled substance diversion opportunities, prioritization by level of vulnerability, and the development of targeted strategies to reduce risk of diversion.
Adipose-Derived Stem Cells for Regenerative Wound Healing Applications: Understanding the Clinical and Regulatory Environment
Authors: Luck Joshua , Weil Benjamin D , Lowdell Mark , Mosahebi Afshin
Published: August 2019

There is growing interest in the regenerative potential of adipose-derived stem cells (ADSCs) for wound healing applications. ADSCs have been shown to promote revascularization, activate local stem cell niches, reduce oxidative stress, and modulate immune responses. Combined with the fact that they can be harvested in large numbers with minimal donor site morbidity, ADSC products represent promising regenerative cell therapies. This article provides a detailed description of the defining characteristics and therapeutic potential of ADSCs, with a focus on understanding how ADSCs promote tissue regeneration and repair. It summarizes the current regulatory environment governing the use of ADSC products across Europe and the United States and examines how various adipose-derived products conform to the current UK legislative framework. Advice is given to clinicians and researchers on how novel ADSC therapeutics may be developed in accordance with regulatory guidelines.
baerhunter: an R package for the discovery and analysis of expressed non-coding regions in bacterial RNA-seq data
Authors: Ozuna A , Liberto D , Joyce R M , Arnvig K B , Nobeli I
Published: August 2019

Standard bioinformatics pipelines for the analysis of bacterial transcriptomic data commonly ignore non-coding but functional elements e.g. small RNAs, long antisense RNAs or untranslated regions (UTRs) of mRNA transcripts. The root of this problem is the use of incomplete genome annotation files. Here, we present baerhunter, a coverage-based method implemented in R, that automates the discovery of expressed non-coding RNAs and UTRs from RNA-seq reads mapped to a reference genome. The core algorithm is part of a pipeline that facilitates downstream analysis of both coding and non-coding features. The method is simple, easy to extend and customize and, in limited tests with simulated and real data, compares favourably against the currently most popular alternative.

Availability and implementation

The baerhunter R package is available from: https://github.com/irilenia/baerhunter

Supplementary information

Supplementary data are available at Bioinformatics online.
On the frequency of northern and mountain genetic variants of widespread species: essential biodiversity information in a warmer world
Authors: Hedenäs Lars
Published: August 2019

Biodiversity studies and conservation management often neglect fundamental genetic diversity, even if biodiversity loss due to reduction in genetic diversity in declining, relatively common species is probably greater than the loss resulting from disappearing rare species. Climate models suggest that global warming will especially affect high latitudes due to a higher than average temperature increase towards the poles. In widespread Northern Hemisphere species, climate warming will therefore negatively affect especially northern and mountain genetic variants (NMGVs) in the same way that it will affect species with similar distributions. To explore whether NMGVs are frequent, they were searched for in ten widespread moss species based on a wide geographical sampling in Sweden and (two-) three (-four) molecular markers per species. NeighborNet split networks and jackknife analyses showed that eight of the studied species include one or more northern or, in most cases, mountain intraspecific genetic lineages or groups of related haplotypes. Analysis of molecular variance also showed that in the two species lacking such lineages or groups the genetic composition differs between different parts of Sweden or between lowlands and mountains of the north. Haplotype or nucleotide diversity is often higher in the north or mountains than in the south or lowlands. The high incidence of NMGVs, differences in genetic composition between the study regions and the frequent high diversity in the north or mountains show that conservation of the total biodiversity must also include the genetic diversity, not just the more obvious species-level taxa with restricted northern or mountain distributions.
Intermediate outcomes of right-to-left inverted living-donor lobar lung transplantation
Authors: Chen-Yoshikawa Toyofumi F , Tanaka Satona , Yamada Yoshito , Yutaka Yojiro , Nakajima Daisuke , Ohsumi Akihiro , Hamaji Masatsugu , Menju Toshi , Date Hiroshi
Published: August 2019

OBJECTIVES

Owing to the severe donor shortage in Japan, living-donor lobar lung transplantation (LDLLT) remains a valuable option. As only lobes are implanted in LDLLT, grafts may be too small, especially for adult recipients. To overcome this obstacle, we developed right-to-left inverted LDLLT. In this procedure, the right lower lobe, which is 25% bigger than the left lower lobe, is used as the left-side graft instead of the left lower lobe. This study aimed to investigate the characteristics and intermediate outcomes of right-to-left inverted LDLLT.

METHODS

Since the first right-to-left inverted LDLLT performed in 2014, 48 LDLLTs have been performed in our institution, of which 15 were right-to-left inverted LDLLTs. We reviewed their characteristics and intermediate outcomes.

RESULTS

The reasons for choosing an inverted procedure instead of the standard LDLLT were small-for-size graft in 11 cases and anatomical variation of donor vessels in 4 cases. The first patient underwent left single LDLLT using a right lower lobe graft, and the following 14 patients underwent bilateral LDLLT using 2 right lower lobe grafts. A native upper lobe-sparing procedure was additionally applied in 2 patients. No complications occurred in the bronchial and vascular anastomoses. No operative mortality occurred, and all the patients were discharged home after LDLLT. The 3-year survival was 92.3%, with a median follow-up time of 40 months. The donor postoperative course was uneventful, and all the donors returned to their regular routine postoperatively.

CONCLUSION

Right-to-left inverted LDLLT is a safe and useful option with encouraging intermediate outcome.
Anaerobic degradation of 2-chloro-4-nitroaniline by Geobacter sp. KT7 and Thauera aromatica KT9
Authors: Duc Ha Danh
Published: August 2019

2-chloro-4-nitroaniline is a nitroaromatic compound widely used in industrial and agricultural sectors, causing serious environmental problems. This compound and some of its analogs were utilized by two Fe3+-reducing microbial strains Geobacter sp. KT7 and Thauera aromatica KT9 isolated from contaminated sediment as sole carbon and nitrogen sources under anaerobic conditions. The anaerobic degradation of 2-chloro-4-nitroaniline by the mixed species was increased approximately by 45% compared to that of individual strains. The two isolates’ crossfeeding, nutrient sharing and cooperation in the mixed culture accounted for the increase in degradation rates. The determination of degradation pathways showed that Geobacter sp. KT7 transformed the nitro group in 2-chloro-4-nitroaniline to the amino group following by the dechlorination process, while T. aromatica KT9 dechlorinated the compound before removing the nitro group and further transformed it to aniline. This study provided an intricate network of 2-chloro-4-nitroaniline degradation in the bacterial mixture and revealed two parallel routes for the substrate catabolism.