scholarly journals Quantitative analysis of stability of 9%Cr steel microstructure after long-term ageing

2017 ◽  
Vol 62 (1) ◽  
pp. 263-271 ◽  
Author(s):  
G. Golański ◽  
J. Jasak ◽  
A. Zieliński ◽  
C. Kolan ◽  
M. Urzynicok ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Favorable Effect ◽  
Scanning Microscope ◽  
Steel Microstructure ◽  
Transmission Electron ◽  
The Matrix ◽  
The Mean ◽  
Analysis Of Stability ◽  
The Stability

Abstract The paper presents the results of research on the microstructure of martensitic X10CrMoVNb9-1 (P91) and X13CrMoCo- VNbNB9-2-1 (PB2) steel subject to long-term ageing at the temperature of 620°C and holding times up to 30 000 hours. The microstructural tests of the examined steel types were performed using a scanning microscope Joel JSM - 6610LV and a transmission electron microscope TITAN 80 - 300. The stability of the microstructure of the investigated steels was analyzed using a quantitative analysis of an image, including measurements of the following: the density of dislocations inside martensite/subgrain laths, the width of martensite laths, and the mean diameter of precipitates. It has been concluded that during long-term ageing, the microaddition of boron in PB2 steel significantly influenced the slowing of the process of degradation of the martensitic steel microstructure, as a result of slowing the process of coagulation of M23C6 carbides and Laves phase. It had a favorable effect on the stabilization of lath microstructure as a result of retardation of the processes of recovery and polygonization of the matrix.

scholarly journals A SLR Pre-Processing Algorithm Based on Satellite Signature Effect

2021 ◽  
Vol 11 (19) ◽  
pp. 8880
Author(s):  
Bowen Guan ◽  
Cunbo Fan ◽  
Ning An ◽  
Ricardo Cesar Podesta ◽  
Dra Ana Pacheco ◽  
...  
Keyword(s):  
Mean Value ◽  
Observation Data ◽  
Short Term ◽  
Error Sources ◽  
Effect Model ◽  
The Mean ◽  
The Stability ◽  
First Time ◽  
Satellite Signature Effect

As one of the major error sources, satellite signature effect should be reduced or even erased from the distribution of the post-fit residuals to improve the ranging precision. A simulation of satellite signature effect removal process for normal point algorithm is conducted based on a revised model of satellite response, which fully considers the structural and distribution characteristics of retroreflectors. In order to eliminate both long-term and short-term satellite signature effect, a clipping method for SLR data processing is proposed by defining the clipping location as 5.6 mm away from the mean value of the long-term fit residuals to select effective returns for normal points. The results indicate that, compared to normal points algorithm, the RMS per NP of LAGEOS-1 observation data processed by the clipping method is reduced from 62.90 ± 9.9 mm to 56.07 ± 4.69 mm, and the stability of RMS is improved 53%. This study improves the satellite signature effect model and simulates the fluctuation of normal points caused by satellite signature effect for the first time. The new method based on the simulation of satellite signature effect has stronger robustness and applicability, which can further minimize the influence of satellite signature effect on the SLR production and significantly improve the data property.

The performance of a two-stage SBR system in treating dye containing wastewater

2003 ◽  
Vol 47 (1) ◽  
pp. 291-296 ◽  
Author(s):  
X.-H. Wen ◽  
L.-Y. Fu ◽  
Y. Qian
Keyword(s):  
Pollutant Removal ◽  
Anaerobic Sludge ◽  
Scanning Microscope ◽  
Total Removal ◽  
Two Stage ◽  
Removal Rates ◽  
Operating Stability ◽  
Electron Scanning Microscope ◽  
The Stability

A two-stage SBR system treating the wastewater containing copper-phthalocyanin dye-Reactive Turquoise Blue KN-G (C. I. Reactive Blue 21, denoted by RTB) was investigated during a 200-cycle operation. The performance of the system, including pollutant removal rates, operating stability and sludge characteristics, may be a concern in the long-term run. The results shows that the system removed RTB efficiently despite the step-up RTB concentration from 13.1 to 107 mg/L in the influent. The average total removal rates of RTB were 81% to 92.5% due to the contribution of both anaerobic and aerobic stages, while stable effluent was produced with the help of the aerobic stage. The sludge in each reactor was in the steady state and of good activity on RTB removal. Moreover, the anaerobic sludge with the SVI value of 109.1 and the aerobic sludge with the SVI value of 103.2 had good settling properties, which was verified by hardly any presence of suspended solids in the effluent and an observation under an electron-scanning microscope. The adsorption and biodegradation were considered as the mechanism for the stability of the SBR system during the long-term run.

Influences of the Adding Manners of b on the Stability and the Soft Magnetic Properties of Amorphous Fe52Co34Hf7B6Cu1 Alloys

2013 ◽  
Vol 320 ◽  
pp. 83-87 ◽  
Author(s):  
Yue Gu ◽  
Yue Sheng Chao
Keyword(s):  
Activation Energy ◽  
Magnetic Properties ◽  
Amorphous State ◽  
Soft Magnetic Property ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Transmission Electron ◽  
The Matrix ◽  
Quenching Method ◽  
The Stability

The stability and the soft magnetic properties of amorphous Fe52Co34Hf7B6Cu1 alloys have been investigated in this paper. Amorphous Fe52Co34Hf7B6Cu1 alloys ribbons are prepared by single-roller-quenching method. The differential thermal analysis (DTA), X-ray diffraction (XRD), Mössbauer Spectroscopy, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) were used for characterizing microstructures, soft magnetic properties, and evaluating the influence of adding manners of B on the stability of as-quenched specimens. The XRD curve shows a wide dispersion of peak, the TEM diffraction ring was dispersed cyclic, the pattern of the matrix was homogeneous, and the Mössbauer spectrum of as-quenched alloy presents a typical broadened and overlapped sextet, which confirms the as-quenched alloy in fully amorphous state. The DTA results showed the activation energy of Fe52Co34Hf7B6Cu1 alloy is 299.7KJ/mol. When pure B is replaced by FeB in preparing amorphous Fe52Co34Hf7B6Cu1 alloys, the activation energy reduced to 293.3 KJ/mol,and the soft magnetic property is decline according VSM results.

scholarly journals Orthodontic treatment stability predictors: A retrospective longitudinal study

2016 ◽  
Vol 87 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Paloma González-Gil de Bernabé ◽  
José María Montiel-Company ◽  
Vanessa Paredes-Gallardo ◽  
Jose Luis Gandía-Franco ◽  
Carlos Bellot-Arcís
Keyword(s):  
Longitudinal Study ◽  
Orthodontic Treatment ◽  
Protective Factor ◽  
Peer Assessment ◽  
Anterior Segment ◽  
End Of Treatment ◽  
The Mean ◽  
The Difference ◽  
The Stability

ABSTRACTObjective: To examine medium- to long-term orthodontic treatment stability and its possible association with certain variables.Materials and Methods: In a retrospective longitudinal study of 70 postretention patients, the Peer Assessment Rating (PAR) index was measured at the start (T1) and end (T2) of treatment and between 4 and 10 years afterwards (T3). The stability was considered absolute when the T2 and T3 values were identical and relative when the difference was within the ±5 range.Results: Among the 70 patients, 65.8% were female and 34.2% were male. Their mean age was 14.5 years. The mean treatment length was 2.4 years. The mean retention phase was 3.3 years. The mean pre- and posttreatment PAR scores were 29.8 (T1) and 6.3 (T2). The mean T1–T2 difference was 23.6. The mean T2–T3 difference was −0.39.Conclusions: Within the study, 7.1% presented absolute stability and 68.6% presented relative stability. Lower anterior segment alignment and overbite were the most unstable occlusal features and tended to worsen. Fixed retainer (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.10–0.98) as a protective factor and years without retention (OR 1.32; 95% CI 1.03–1.68) as a risk factor are predictor variables of instability in the case of lower anterior segment alignment. The PAR value at the end of treatment (OR 1.29; 95% CI 1.08–1.54) and extractions (OR 4.76; 95% CI 1.05–21.6) before treatment are predictors for midline instability.

Ta2O5-Incorporated WO3 Nanocomposite Film for Improved Electrochromic Performance in an Acidic Condition

2006 ◽  
Vol 6 (11) ◽  
pp. 3572-3576 ◽  
Author(s):  
Hee-Sang Shim ◽  
Hyo-Jin Ahn ◽  
Youn-Su Kim ◽  
Yung-Eun Sung ◽  
Won Bae Kim
Keyword(s):  
Surface Roughness ◽  
Photoelectron Spectroscopy ◽  
Potential Cycling ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Continuous Potential ◽  
Chemical States ◽  
The Stability

We report electrochromic and electrochemical properties of a WO3-Ta2O5 nanocomposite electrode that was fabricated from co-sputtering. Transmission electron microscopy (TEM)images of the WO3-Ta2O5 nanocomposite electrode revealed that morphology of the WO3 film was changed by incorporation of Ta2O5 nanoparticles, and their chemical states were confirmed to be W6+ and Ta5+ oxides from X-ray photoelectron spectroscopy (XPS). The introduction of Ta2O5 to the WO3 film played a role in alleviating surface roughness increase during continuous potential cycling; whereas the surface roughness of the WO3 film was increased from ca. 3.0 nm to ca. 13.4 nm after 400 cycles, the roughness increase on the WO3-Ta2O5 was significantly reduced to 4.2 nm after 400 cycles, as investigated by atomic force microscopy (AFM). This improvement of the stability by adding Ta2O5 may be responsible for the enhanced electrochemical and optical properties over long-term cycling with the WO3-Ta2O5 nanocomposite electrode.

scholarly journals Prediction of rates of inbreeding in selected populations

1990 ◽  
Vol 55 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Naomi R. Wray ◽  
Robin Thompson
Keyword(s):  
Selective Advantage ◽  
Mass Selection ◽  
Effective Population ◽  
The Matrix ◽  
Mean And Variance ◽  
Unselected Population ◽  
The Mean ◽  
Number Of Individuals ◽  
The Relationship

SummaryA method is presented for the prediction of rate of inbreeding for populations with discrete generations. The matrix of Wright's numerator relationships is partitioned into ‘contribution’ matrices which describe the contribution of the Mendelian sampling of genes of ancestors in a given generation to the relationship between individuals in later generations. These contributions stabilize with time and the value to which they stabilize is shown to be related to the asymptotic rate of inbreeding and therefore also the effective population size, where N is the number of individuals per generation and μr and are the mean and variance of long-term relationships or long-term contributions. These stabilized values are then predicted using a recursive equation via the concept of selective advantage for populations with hierarchical mating structures undergoing mass selection. Account is taken of the change in genetic parameters as a consequence of selection and also the increasing ‘competitiveness’ of contemporaries as selection proceeds. Examples are given and predicted rates of inbreeding are compared to those calculated in simulations. For populations of 20 males and 20, 40, 100 or 200 females the rate of inbreeding was found to increase by as much as 75% over the rate of inbreeding in an unselected population depending on mating ratio, selection intensity and heritability of the selected trait. The prediction presented here estimated the rate of inbreeding usually within 5% of that calculated from simulation.

Evolution of Microstructure in Martensitic GX12CrMoVNbN9 – 1 Cast Steel after Low Cycle Fatigue

2013 ◽  
Vol 199 ◽  
pp. 418-423
Author(s):  
Grzegorz Golański ◽  
Joanna Kępa
Keyword(s):  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Total Strain Amplitude ◽  
Cycle Fatigue ◽  
Tempered Martensite ◽  
Transmission Electron ◽  
The Matrix ◽  
The Mean ◽  
Means Of Transmission ◽  
Evolution Of Microstructure

The paper presents the results of microstructural research on GX12CrMoVNbN91 cast steel in the as-received condition (after heat treatment) and after the process of low cycle fatigue at room temperature. The microstructural tests were carried out by means of transmission electron microscope and completed with quantitative study determining: the mean diameter of subgrains, density of dislocations and shape factor. Performed research has proved that in both states: the as-received one, as well as after fatigue, the investigated cast steel is characterized by lath microstructure of tempered martensite with numerous precipitations of the M23C6 and MX type. Fatigue in the low cycle scope leads to the processes of recovery and polygonization of the matrix, as a result of a decrease in the dislocation density and an increase in the subgrain width. Intensity of these processes depends not only on the temperature of testing, but also on the level of total strain amplitude εac. Stability of the substructure of the examined cast steel depends on the morphology of precipitates of M23C6, precipitated on the boundaries of grains/subgrains.

scholarly journals Cold fronts: probes of plasma astrophysics in galaxy clusters

2016 ◽  
Vol 82 (3) ◽  
Author(s):  
John A. ZuHone ◽  
E. Roediger
Keyword(s):  
Galaxy Clusters ◽  
Mean Free Path ◽  
Magnetized Plasma ◽  
X Ray ◽  
Gas Phases ◽  
Cold Fronts ◽  
The Mean ◽  
The Stability

The most massive baryonic component of galaxy clusters is the ‘intracluster medium’ (ICM), a diffuse, hot, weakly magnetized plasma that is most easily observed in the X-ray band. Despite being observed for decades, the macroscopic transport properties of the ICM are still not well constrained. A path to determine macroscopic ICM properties opened up with the discovery of ‘cold fronts’. These were observed as sharp discontinuities in surface brightness and temperature in the ICM, with the property that the denser side of the discontinuity is the colder one. The high spatial resolution of the Chandra X-ray Observatory revealed two puzzles about cold fronts. First, they should be subject to Kelvin–Helmholtz instabilities, yet in many cases they appear relatively smooth and undisturbed. Second, the width of the interface between the two gas phases is typically narrower than the mean free path of the particles in the plasma, indicating negligible thermal conduction. It was thus realized that these special characteristics of cold fronts may be used to probe the properties of the cluster plasma. In this review, we will discuss the recent simulations of cold fronts in galaxy clusters, focusing on those which have attempted to use these features to constrain ICM physics. In particular, we will examine the effects of magnetic fields, viscosity, and thermal conductivity on the stability properties and long-term evolution of cold fronts. We conclude with a discussion on what important questions remain unanswered, and the future role of simulations and the next generation of X-ray observatories.

Investigation on Shear Creep Mechanical Properties of Soft Rock

2011 ◽  
Vol 261-263 ◽  
pp. 1024-1028
Author(s):  
Yu Wang ◽  
Jian Lin Li
Keyword(s):  
Soil Mechanics ◽  
Testing Machine ◽  
Soft Rock ◽  
Underground Engineering ◽  
Shear Creep ◽  
Analysis Of Stability ◽  
The Stability ◽  
Argillaceous Siltstone ◽  
Rock And Soil

The construction of slope or underground engineering often encounters soft rocks, which control the stability of rock engineering, with obvious characteristics of rheology. Under step load conditon, the shear creep test of argillaceous siltstone is performed by using the RMT150c rock and soil mechanics testing machine. Testing results show that the amount of creep deformation for argillaceous siltstone is big enough, which should be taken into consideration for analysis of stability or design of slope or underground engineering. Based on testing results, the long-term shear strength parameters are determined to provide theory basis for engineering survey and design.

Analysis of the Stability of Synchronous Motor Driving without Sensor

2012 ◽  
Vol 429 ◽  
pp. 259-266
Author(s):  
Feng Xue ◽  
Guo Qing Shi
Keyword(s):  
Computer Simulation ◽  
Quantitative Analysis ◽  
Electromotive Force ◽  
Control Method ◽  
Sine Wave ◽  
Synchronous Motor ◽  
Equivalent Current ◽  
Analysis Of Stability ◽  
The Stability ◽  
Stable Control

The rotor’s position of brushless synchronous motor can only be got by windings’ currents, terminal voltages in the field where the sensors can not be installed. How to steadily drive the motor in the weak feedback becomes the key to the control method. Quantitative analysis of stability for control method is made for two kinds of motor which has trapezia wave and sine wave anti electromotive force， in which the concept of equivalent current bundle is brought forward. The computer simulation proves the results of analysis. Academic direction is made for the stable control of sensorless driving.

Sign in / Sign up

Export Citation Format

Share Document