scholarly journals DETERMINATION OF HARDENED METAL LAYER THICKNESS USING MAGNETIC METHOD

2019 ◽  
pp. 102-110 ◽  
Author(s):  
V. S. Bezkorovayniy ◽  
V. V. Yakovenko ◽  
Y. V. Livtsov
Keyword(s):  
Magnetic Field ◽  
Layer Thickness ◽  
Field Experiments ◽  
Metal Layer ◽  
Test Method ◽  
Rolling Stock ◽  
Magnetic Method ◽  
Method Error ◽  
Stray Magnetic Field ◽  
Before And After

The routine method to control metal surface layer is Vickers hardness test method. The existing nondestructive testing methods are based on measuring induction density and other magnetic quantities in magnetizer core. This causes the method error and restricts the ability to determine the structure of the processed material. The paper provides theoretical and experimental investigation of the method for controlling the hardened axis layer parameters by analyzing characteristics of stray magnetic field of the axis magnetized local surface area before and after rouletting. A method is proposed for determining the hardened metal layer thickness of the rolling stock axis, based on measuring the parameters of the magnetized local area stray magnetic field before and after processing. To justify the proposed method, mathematical modeling of stray magnetic field of the axis local magnetized section is performed before and after processing. Inspection for the hardened metal layer is performed using magnetization of the axis local segment with electromagnet, followed by measuring the stray magnetic field strength. The maximum value of the horizontal magnetic force is determined, which is an informative parameter. A mathematical model is developed for the magnetized section magnetic field, the results of numerical and field experiments are presented. The discrepancy between the experimental data and the results of theoretical calculations is estimated. The method makes it possible to control the thickness of the hardened metal layer and the quality of the hardening of the rolling stock axis.

DEVICE REALIZATION OF MAGNETIC METHOD FOR DEFINITION OF METAL STRENGTHENED LAYER THICKNESS IN ROLLING-STOCK AXLE

2021 ◽  
Vol 2021 (2) ◽  
pp. 28-37
Author(s):  
Yuriy Livcov ◽  
Vladimir Bezkorovaynyy ◽  
Andrey Kireev
Keyword(s):  
Magnetic Properties ◽  
Layer Thickness ◽  
Metal Layer ◽  
Rolling Stock ◽  
Magnetic Method ◽  
Cold Plastic Deformation ◽  
Natural Experiments ◽  
Micro Hardness ◽  
Scattering Field ◽  
Definition Of

The simplest and accessible method for rolling-stock axle surface strengthening is surface processing with cold plastic deformation by means of rolling. This process is one of the stages in manufacturing diesel locomotive and car axles of a rolling-stock. The basic parameters of rolling engineering process are micro-hardness of a metal surface strengthened layer and its depth, which at present are controlled by means of cutting out longitudinal polished specimens from the axle and in case of the deviation from the required value the whole set axles is rejected. That is why there is offered a method of the non-destruction control of micro-hardness and depth of axle strengthening the essence of which is not only in the control of a strengthening degree value, but in the instant correction of rolling equipment in case of the deviation from the parameter, as this device is integrated in the interface of a rolling machine. In such a way, an actual value of strengthened layer micro-hardness will be always within the specified limits. The principle of device operation is based on the topography changes in the scattering magnetic field of preliminary magnetized local volume of ferromagnetic material. There are shown numerical experiments for the dependence parameter definition of a scattering field of a magnetic mark from thickness and magnetic properties of a strengthened metal layer which had given a possibility to obtain the analytical dependences of a strengthened layer thickness and coercive force of the strengthened layer upon the parameters of a horizontal and vertical constituents of the scattering field strength of the magnetic mark. There are obtained results of natural experiments which allow defining magnetic properties of the upper metal layer in the axle and checking the correctness of data obtained at numerical computations, computation errors do not exceed 6%. The integration circuit of the mentioned structure-scope in the configuration of a rolling machine to obtain a feedback on a micro-hardness value of a surface strengthened layer.

MODEL MANAJEMEN PENDIDIKAN KARAKTER BERBASIS INTEGRASI NILAI-NILAI RELIGIUS DAN MULTIKULTURAL

2019 ◽  
Vol 20 (2) ◽  
pp. 227-266
Author(s):  
Rohmat Rohmat
Keyword(s):  
Character Education ◽  
Future Generation ◽  
T Test ◽  
Test Method ◽  
Intellectual Ability ◽  
Management Model ◽  
Education Management ◽  
Model Based ◽  
Before And After ◽  
Emotional Aspects

Securing religious and multicultural character values ​​is very important to be instilled as early as possible through education. This is due to education not only providing increased intellectual ability, but also is responsible for integrating character values ​​in students. At least there are some aspects that need to be developed in the education phase of school children including intellectual aspects, emotional aspects, social aspects, physical aspects, aspects of movement, aesthetic aspects, and moral aspects. Based on this opinion it can be seen that the cultivation of religious and multicultural character values ​​in madrasa ibtidaiyah level students needs to be done in order to realize a future generation of adults and character. On the other hand, the cultivation of multicultural values ​​is also an urgent matter to do.This study aims to find a character education management model based on the integration of religious and multicultural values ​​in MI Banyumas Regency. The research method with research and development methods. The results of the study of the character education management model based on the integration of religious and multicultural values ​​that were developed effectively for use in character education in Madrasah Ibtidaiyah. The results of the t test through the paired t test method showed that there were significant differences between the character values ​​before and after the implementation of character education in Madrasah Ibtidaiyah. These results reinforce that character education is effectively used in Madrasah Ibtidaiyah.

Two-dimensional oscillation of convection roll in a finite liquid metal layer under a horizontal magnetic field

2021 ◽  
Vol 911 ◽  
Author(s):  
Y. Tasaka ◽  
T. Yanagisawa ◽  
K. Fujita ◽  
T. Miyagoshi ◽  
A. Sakuraba
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Metal Layer ◽  
Two Dimensional ◽  
Horizontal Magnetic Field ◽  
Convection Roll

Abstract

scholarly journals A simulation study investigating potential diffusion-based MRI signatures of microstrokes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rafat Damseh ◽  
Yuankang Lu ◽  
Xuecong Lu ◽  
Cong Zhang ◽  
Paul J. Marchand ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Statistical Power ◽  
Barrel Cortex ◽  
Signal Loss ◽  
Nuclear Spins ◽  
Directional Diffusion ◽  
Ischemic Tissue ◽  
Significant Difference ◽  
Before And After ◽  
Experimental Validations

AbstractRecent studies suggested that cerebrovascular micro-occlusions, i.e. microstokes, could lead to ischemic tissue infarctions and cognitive deficits. Due to their small size, identifying measurable biomarkers of these microvascular lesions remains a major challenge. This work aims to simulate potential MRI signatures combining arterial spin labeling (ASL) and multi-directional diffusion-weighted imaging (DWI). Driving our hypothesis are recent observations demonstrating a radial reorientation of microvasculature around the micro-infarction locus during recovery in mice. Synthetic capillary beds, randomly- and radially-oriented, and optical coherence tomography (OCT) angiograms, acquired in the barrel cortex of mice (n = 5) before and after inducing targeted photothrombosis, were analyzed. Computational vascular graphs combined with a 3D Monte-Carlo simulator were used to characterize the magnetic resonance (MR) response, encompassing the effects of magnetic field perturbations caused by deoxyhemoglobin, and the advection and diffusion of the nuclear spins. We quantified the minimal intravoxel signal loss ratio when applying multiple gradient directions, at varying sequence parameters with and without ASL. With ASL, our results demonstrate a significant difference (p < 0.05) between the signal-ratios computed at baseline and 3 weeks after photothrombosis. The statistical power further increased (p < 0.005) using angiograms measured at week 4. Without ASL, no reliable signal change was found. We found that higher ratios, and accordingly improved significance, were achieved at lower magnetic field strengths (e.g., B0 = 3T) and shorter echo time TE (< 16 ms). Our simulations suggest that microstrokes might be characterized through ASL-DWI sequence, providing necessary insights for posterior experimental validations, and ultimately, future translational trials.

scholarly journals Experimental Study on the Water Selective Dense Membrane under an Absolute Pressure Difference with Simplified Test Method

2021 ◽  
Vol 11 (4) ◽  
pp. 1710
Author(s):  
Jinwook Lee ◽  
Hyo-Sun Kim ◽  
Donik Ku ◽  
Jihun Lim ◽  
Minkyu Jung ◽  
...  
Keyword(s):  
Measurement Methods ◽  
Test Method ◽  
Coefficient Of Performance ◽  
Absolute Pressure ◽  
Air Conditioner ◽  
Experimental Conditions ◽  
Simple Method ◽  
Performance Factors ◽  
Dense Membrane ◽  
Before And After

Membrane-based vacuum dehumidification technology is currently being actively studied. In most studies, the performance of the membrane-based systems is evaluated under the assumption that the membrane can achieve ideal separation, which results in ideal coefficient of performance (COP) values. However, the performance factors for membranes vary depending on the experimental conditions and measurement methods. Therefore, relevant values can only be calculated if the data are measured in an environment close to that of the application conditions. The cup measurement method is a simple method to measure the permeability, however, there are limitations regarding adding variables during the experiment. To overcome these limitations, a new experimental device was constructed that combines pressurized cell with the cup method. Using the device, the performance of polyethylene-amide-bonded dense membranes was evaluated under conditions where absolute pressure differentials occurred before and after the membrane, such as in air conditioner dehumidification systems.

scholarly journals Phase boundary dynamics of bubble flow in a thick liquid metal layer under an applied magnetic field

2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Mihails Birjukovs ◽  
Valters Dzelme ◽  
Andris Jakovics ◽  
Knud Thomsen ◽  
Pavel Trtik
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Phase Boundary ◽  
Applied Magnetic Field ◽  
Metal Layer ◽  
Bubble Flow ◽  
Boundary Dynamics

scholarly journals Diurnal variation effect in marine magnetometric surveys: clues from surveys in southeast Brazil

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Paula Possamai Sergipe ◽  
Yára Regina Marangoni ◽  
Roberto Paulo Zanon dos Santos ◽  
Denise Silva de Moura ◽  
Luigi Jovane
Keyword(s):  
Magnetic Field ◽  
Continental Shelf ◽  
Diurnal Variation ◽  
Brazilian Coast ◽  
Observatory Data ◽  
Before And After ◽  
Corrected Data ◽  
Well Correlation ◽  
The Magnetic Field ◽  
Magnetic Observatories

AbstractThe diurnal variation of the magnetic field cannot be predicted or modeled and for that reason, it is monitored during the magnetic surveys, usually by a stationary magnetometer. However, marine surveys have a practical issue with diurnal monitoring, owing to the distance between the survey, stationary magnetometers, and magnetic observatories. This work aims to verify the use of nearby magnetic observatories to estimate the diurnal variation correction in different marine surveys and evaluate its effectiveness. In this study, we selected surveys at the continental shelf near Santos city (Survey 1), continental slope next to the first survey location (Survey 2), continental shelf near Ubatuba city (Survey 3), and Mamanguá ria in the Paraty city (Survey 4), all southeast to the Brazilian coast. The crossing points were implemented to compare the magnetic field values at different times and days at the same measurement point, before and after the correction. Afterwards, we measure the Pearson’s Correlation of the raw data and the diurnal corrected data in all crossing points of each survey which showed an improvement after correction by the value approximating to 1, which indicates a very well correlation. The Ubatuba and Mamanguá surveys allowed comparing the observatory correction results with the base magnetometer results that were rather similar. Our analyses indicate a satisfactory diurnal correction using the observatory data and the crossing points approach, which can be used for every marine magnetometric survey worldwide placed near the coast (< 280 km) that do not have a stationary magnetometer available.

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