scholarly journals Measurement Distortion Analysis of Repetitive and Isolated Track Geometry Irregularities

2021 ◽  
Author(s):  
Csaba Ágh
Keyword(s):  
European Regulation ◽  
New Approach ◽  
Track Geometry ◽  
Pattern Change ◽  
Distortion Analysis ◽  
Band Pass ◽  
Lift Off ◽  
Railway Maintenance ◽  
Derivatives Of ◽  
Zero Points

Track geometry measurements are essential for day-to-day activities of railway maintenance and play an important role in vehicle-track simulations. The generally applied forms of longitudinal level and alignment recordings do not reflect the real shape of the track. Both the versine measurement method and the band-pass filters according to European regulation cause significant amplitude modification and pattern change. In addition, the distortion behavior of repetitive and isolated defects is fundamentally different. In this contribution, simulated measurements of various reference shapes, which represent repetitive and isolated track deformations, were investigated. Comprehensive functions for amplitude change and for other distortion factors were developed with analytical and numerical methods. For chord measurements, rules were found for zero points and distortion-free ranges. Regarding the standardized filters, a significant amplitude reduction of isolated defects was observed in all wavelength ranges. Since derailment and track degradation depend not only on the amplitude of the defect, also the derivatives of the original and filtered forms of reference shapes were investigated and, as a new approach, the defect features called 'hypothetical additional force', 'speed of hypothetical wheel lift-off', 'hypothetical deterioration impulse' and 'hypothetical deterioration energy' were introduced.

scholarly journals New approach in the application of lignin for the synthesis of hybrid materials

2017 ◽  
Vol 89 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Beata Podkościelna ◽  
Marta Goliszek ◽  
Olena Sevastyanova
Keyword(s):  
Suspension Polymerization ◽  
Nitrogen Adsorption ◽  
Experimental Protocol ◽  
New Approach ◽  
Surface Areas ◽  
Adsorption Data ◽  
Novel Method ◽  
Derivatives Of ◽  
Polymerization Method ◽  
Nitrogen Adsorption Data

AbstractIn this study, a novel method for the synthesis of hybrid, porous microspheres, including divinylbenzene (DVB), triethoxyvinylsilane (TEVS) and methacrylated lignin (L-Met), is presented. The methacrylic derivatives of kraft lignin were obtained by reaction with methacryloyl chloride according to a new experimental protocol. The course of the modification of lignin was confirmed by attenuated total reflectance (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy. The emulsion-suspension polymerization method was employed to obtain copolymers of DVD, TEVS and L-Met in spherical forms. The porous structures and morphologies of the obtained lignin-containing functionalized microspheres were investigated by low-temperature nitrogen adsorption data and scanning electron microscopy (SEM). The microspheres are demonstrated to be mesoporous materials with specific surface areas in the range of 430–520 m2/g. The effects of the lignin component on the porous structure, shape, swelling and thermal properties of the microspheres were evaluated.

Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Amino Alcohols

1996 ◽  
Vol 61 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý
Keyword(s):  
Amino Acids ◽  
Hydroxy Group ◽  
Building Blocks ◽  
Amino Alcohols ◽  
New Approach ◽  
Alternative Synthesis ◽  
Oxime Derivatives ◽  
A Chain ◽  
Derivatives Of

New approach to the preparation of steroids with connecting bridge, based on an O-carboxymethyloxime (CMO) structure, and with terminal hydroxy group, is presented. 17-CMO derivatives of 3β-acetoxy- and 3β-methoxymethoxyandrost-5-en-17-one were condensed with α,ω-amino alcohols to give derivatives with a chain of seven to nine atoms. After THP-protection, these compounds were converted to 3-keto-4-ene derivatives. An alternative synthesis consisted in transformation of 17-CMO derivatives with bonded amino acids by reduction of the terminal carboxyl. The resulting compounds were designed as building blocks for the preparation of bis-haptens for sandwich immunoassays.

scholarly journals POSI BOLA OF JAMI MOSQUE AS SPATIAL TRANSFORMATION SYMBOL

2019 ◽  
Vol 5 (4) ◽  
pp. 181-188
Author(s):  
Moh Sutrisno ◽  
Sudaryono Sastrosasmito ◽  
Ahmad Sarwadi
Keyword(s):  
Built Environment ◽  
Spatial Transformation ◽  
New Approach ◽  
South Sulawesi ◽  
Space Transformation ◽  
City Space ◽  
Islamic Religion ◽  
Zero Points ◽  
Horizontal Slice ◽  
Contextual Meaning

Palopo city space as the center of Tana Luwu cannot be separated from the significance of the oldest kingdom in South Sulawesi. The entry of the Islamic religion in Luwu was marked by the Jami Mosque, which is located at the zero points of Palopo city. The preservation of pre-Islamic heritage and after the entry of Islam in the present tends to not a dichotomy in two different meanings. The research is aimed to explore the semiotic meaning of the Jami Mosque, which has become an icon in Palopo City. The research used the ethnomethodology method within the framework of the semiotics paradigm to obtain contextual meaning as well as the application of a new approach in architecture semiotics study. The results show that the Jami Mosque keeps the complexity of meaning, which can be the foundation of conservation philosophy and planning of the built environment. The cosmos axis of Palopo city space and the territory of Luwu become the central point of religious civilization, especially in Islamic cosmology. The space transformation is represented by ‘posi bola’ (house pole). The symbolic ‘posi bola’ moves from the palace to the Jami mosque as the axis of Luwu space in the Islamic era. The horizontal slice of the pole has implications on the particular geometrical patterns of Luwu. The elements of structure and construction of buildings become a symbol of Islamic teachings.

THE QNDE USING IMAGE PROCESSING OF THE MAGNETIC CAMERA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4625-4630 ◽  
Author(s):  
JINYI LEE ◽  
JISEONG HWANG ◽  
SEHO CHOI
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Magnetic Hysteresis ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Second Derivatives ◽  
Crack Volume ◽  
Lift Off ◽  
Magnetic Camera ◽  
Derivatives Of

A scan type magnetic camera was proposed to satisfy the following demands: to obtain high speed quantitative magnetic flux leakage (MFL) distribution with homogeneous lift-off by using 2-dimensionally arrayed high sensitivity magnetic sensors; to concentrate the MFL; and to ignore the residual magnetization and magnetic hysteresis by using a magnetic fluid lens. The magnetic field distribution (MFD) image obtained by using the scan type magnetic camera is inclined to the scanning direction (x-direction) because of the poles of the magnetizer. Also, the image shows a homogeneous trend relative to the x-direction, but there are small waves in the distribution in the sensor arraying direction (y-direction). The crack information in the MFD image can be extracted using image processing. The first and second derivatives of both x and y are used in this processing. These are "1st derivative of x, ∂B/∂x", "1st derivative of y, ∂B/∂y", "2nd derivative of x, ∂2B/∂x2", "2nd derivative of y, ∂2B/∂y2", and "2nd derivative of x and y, ∂2B/∂x∂y". The ∂B/∂x distribution shows the existence of the crack. Also, the crack volume can be evaluated quantitatively, regardless of the crack direction, by using ∂B/∂x and a cross type magnetic coil.

A New Approach to the Synthesis of Functional Derivatives of 3-(4-Pyridinyl)-1H-indole and 4-(1H-Indol-3-yl)thieno[2,3-b]pyridine

2018 ◽  
Vol 88 (4) ◽  
pp. 682-688 ◽  
Author(s):  
V. V. Dotsenko ◽  
S. G. Krivokolysko ◽  
B. S. Krivokolysko ◽  
K. A. Frolov
Keyword(s):  
New Approach ◽  
Functional Derivatives ◽  
Derivatives Of

Rapid computation of rotary derivatives for subsonic and low transonic flows

2019 ◽  
Vol 36 (9) ◽  
pp. 3108-3121
Author(s):  
Jian-Ming Fu ◽  
Hai-Min Tang ◽  
Hong-Quan Chen
Keyword(s):  
Mach Number ◽  
Normal Velocity ◽  
New Approach ◽  
Content Type ◽  
Strip Theory ◽  
Model Aircraft ◽  
Computational Fluid Dynamics Cfd ◽  
Steady Solutions ◽  
State Pressure ◽  
Derivatives Of

Purpose The purpose of this paper is to develop a new approach for rapid computation of subsonic and low-transonic rotary derivatives with the available steady solutions obtained by Euler computational fluid dynamics (CFD) codes. Design/methodology/approach The approach is achieved by the perturbation on the steady-state pressure of Euler CFD codes. The resulting perturbation relation is established at a reference Mach number between rotary derivatives and normal velocity on surface due to angular velocity. The solution of the reference Mach number is generated technically by Prandtl–Glauert compressibility correction based on any Mach number of interest under the assumption of simple strip theory. Rotary derivatives of any Mach number of interest are then inversely predicted by the Prandtl–Glauert rule based on the reference Mach number aforementioned. Findings The resulting method has been verified for three typical different cases of the Basic Finner Reference Projectile, the Standard Dynamics Model Aircraft and the Orion Crew Module. In comparison with the original perturbation method, the performance at subsonic and low-transonic Mach numbers has significantly improved with satisfactory accuracy for most design efforts. Originality/value The approach presented is verified to be an efficient way for computation of subsonic and low-transonic rotary derivatives, which are performed almost at the same time as an accounting solution of steady Euler equations.

Evaluation of the effect of tamping on the track geometry condition: A case study

2016 ◽  
Vol 232 (2) ◽  
pp. 408-420 ◽  
Author(s):  
Iman Soleimanmeigouni ◽  
Alireza Ahmadi ◽  
Iman Arasteh Khouy ◽  
Christophe Letot
Keyword(s):  
Degradation Rate ◽  
Probabilistic Approach ◽  
Dominant Factor ◽  
Model Parameters ◽  
Track Geometry ◽  
Degradation Rates ◽  
Railway Maintenance ◽  
Long Term Prediction

Tamping is one of the major activities undertaken by railway maintenance managers to recover the track geometry condition. Modelling the effectiveness of tamping along with track geometry degradation is essential for long-term prediction of track geometry behaviour. The aim of this study is to analyse the effect of tamping on the different track geometry measurements, i.e. longitudinal level, alignment and cant, based on inspection car records from a part of the Main Western Line in Sweden. To model recovery after tamping, a probabilistic approach is applied. The track geometry condition before tamping was considered as the dominant factor for modelling the model parameters. Correlation analysis was performed to measure the linear relation between the recoveries of the different geometry measures. The results show a moderate correlation between the recovery of the longitudinal level and that of the cant, and a weak correlation between the recovery of the longitudinal level and that of the alignment. Linear regression and Wiener process were also applied to model track geometry degradation and to obtain degradation rates. The effect of tamping on degradation rate was analysed. It was observed that degradation rate increased after tamping.

scholarly journals An Efficient and Accurate Method for Different Configurations Railway Extraction Based on Mobile Laser Scanning

2019 ◽  
Vol 11 (24) ◽  
pp. 2929 ◽  
Author(s):  
Rong Zou ◽  
Xiaoyun Fan ◽  
Chuang Qian ◽  
Wenfang Ye ◽  
Peng Zhao ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Point Clouds ◽  
Accurate Method ◽  
Average Density ◽  
Railway Track ◽  
Track Geometry ◽  
Fitting Algorithm ◽  
Railway Maintenance ◽  
Night Period ◽  
Reflection Intensity

The precision of railway map is becoming a significant issue for autonomous train scheduling, monitoring and maintenance, related location-based service (LBS), and further ensuring travel safety. Mobile 3D laser scanning is an efficient method for making relative high-precision railway track maps, particularly during the night period of railway maintenance, for light detection and ranging (LiDAR) can work without ambient light. In this paper, we propose an efficient and accurate railway track vectorization method based on the LiDAR point clouds from the self-built train Mobile Laser Scanning (MLS) system. Our method takes full use of railway track geometry and reflection intensity feature of LiDAR, without any trajectory prior information. Firstly, clear track points are filtered by intensity; then, a K-means clustering fused Region-Grow Fitting algorithm is applied. It can not only extract the line vector of railway track, but also can tell the track branches apart, especially on bends and turnout. Experiments were carried on using point clouds with an average density of 490 points per square meter. The experimental results show that the method not only can quickly extract linear objects such as railway track and catenary, but also can detect the railways even in complex real-world topologies such as at bends and turnouts. The precision of the detection area in bends and turnouts are 90.32% and 81.31% respectively, the sensitivity is 83.27% and 83.33%, respectively. Moreover, it can identify the track networks.

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