scholarly journals Mathematical Description and Laboratory Study of Electrophysical Methods of Localization of Geodeformational Changes during the Control of the Railway Roadbed

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3164
Author(s):  
Artem Bykov ◽  
Anastasia Grecheneva ◽  
Oleg Kuzichkin ◽  
Dmitry Surzhik ◽  
Gleb Vasilyev ◽  
...  
Keyword(s):  
High Efficiency ◽  
Early Stage ◽  
Electrical Signal ◽  
Railway Track ◽  
Laboratory Modeling ◽  
Railway Tracks ◽  
Initial Stage ◽  
Phase Images ◽  
Harmonic Action ◽  
High Level

Currently, the load on railway tracks is increasing due to the increase in freight traffic. Accordingly, more and more serious requirements are being imposed on the reliability of the roadbed, which means that studies of methods for monitoring the integrity of the railway roadbed are relevant. The article provides a mathematical substantiation of the possibility of using seismoelectric and phasemetric methods of geoelectric control of the roadbed of railway tracks in order to identify defects and deformations at an early stage of their occurrence. The methods of laboratory modeling of the natural–technical system “railway track” are considered in order to assess the prospects of using the presented methods. The results of laboratory studies are presented, which have shown their high efficiency in registering a weak useful electrical signal caused by seismoacoustic effects against the background of high-level external industrial and natural interference. In the course of laboratory modeling, it was found that on the amplitude spectra of the output electrical signals of the investigated geological medium in the presence of an elastic harmonic action with a frequency of 70 Hz, the frequency of a harmonic electrical signal with a frequency of 40 Hz is observed. In laboratory modeling, phase images were obtained for the receiving line when simulating the process of sinking the soil base of the railway bed, confirming the presence of a transient process that causes a shift in the initial phase of the signal Δφ = 40° by ~45° (Δφ’ = 85°), which allows detection of the initial stage of failure formation.

scholarly journals Railway track design & degradation

2018 ◽  
Vol 211 ◽  
pp. 11006
Author(s):  
Mehran Sadri ◽  
Tao Lu ◽  
Arjen Zoeteman ◽  
Michaël Steenbergen
Keyword(s):  
Degradation Rate ◽  
Early Stage ◽  
Mechanical Energy ◽  
Measurement Data ◽  
Empirical Models ◽  
Railway Track ◽  
Structural Performance ◽  
Design Parameters ◽  
Railway Tracks

The long-term behaviour of railway track has attracted increasing attention in recent years. Improvements in long-term structural performance reduce demands for maintenance and increase the continuous availability of railway lines. The focus of this paper is on the prediction of the sensitivity of a track design to long-term deterioration in terms of track geometry. According to the state of the art literature, degradation is often investigated using empirical models based on field measurement data. Although a rough maintenance forecast may be made employing empirical models, the predictions are not generic, and the physical processes which govern track degradation under train operation remain unclear. The first aim of this study is to present a mathematical model to elucidate the underlying physics of long-term degradation of railway tracks. The model consists of an infinitely long beam which is periodically supported by equidistantly discrete sleepers and a moving unsprung mass which represents a travelling train. The mechanical energy dissipated in the substructure is proposed to serve as a measure of the track degradation rate. Secondly, parametric studies on energy dissipation are conducted to identify effects of various track design parameters on the susceptibility of the track to degradation, as well as the effect of the train speed. It has been shown that the track/subgrade stiffness is the most influential parameter on degradation whereas other system parameters do influence the degradation rate but at lower magnitudes. The conclusions can be used to optimise the track design in the early stage for better long-term structural performance of railway tracks.

Anisotropy of interfacial defects in the initial stage of MOVPE GaAs growth On Si

1990 ◽  
Vol 48 (4) ◽  
pp. 592-593
Author(s):  
C. Vannuffel ◽  
C. Schiller ◽  
J. P. Chevalier
Keyword(s):  
Early Stage ◽  
Threading Dislocations ◽  
Mbe Growth ◽  
Detailed Mechanism ◽  
Si Substrates ◽  
Initial Stage ◽  
Interfacial Defects ◽  
Interfacial Dislocations ◽  
Step Growth ◽  
Essential Problem

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.

A Study on Knowledge, Attitude, Awareness and Practice About HIV/AIDS among different age group of Karachi, Pakistan

2017 ◽  
Vol 3 (3) ◽  
pp. 328-333
Author(s):  
Safia Mehmood ◽  
Sheema Zia ◽  
Nida Aziz ◽  
Omama Sajid
Keyword(s):  
Hiv Transmission ◽  
Age Groups ◽  
World Population ◽  
Major Barrier ◽  
Initial Stage ◽  
Awareness Programs ◽  
And Gender ◽  
Strongly Agree ◽  
High Level ◽  
Lack Of Knowledge

The AIDS is one of the most complicated health problems of the 21st century and it threatens the world population. AIDS spread at an alarming rate. This was a descriptive study to determine the knowledge, awareness, and practice about HIV among different age groups. The study carried out in Karachi, Pakistan during the period of January 2016-april 2016, in which 82 peoples are participated; 65 peoples having age in between 18-30, people’s lies in 31-40 years, while only 4 peoples having age above 40. From which 91% peoples thought HIV is dangerous virus and 51% peoples having misconception that it cause AIDS on initial stage and does not have any effect on CD4+. Majority of peoples aware about transmission of AIDS through intercourse, and during pregnancy. But the study show the high level of misbelieve also in mode of transmission that HIV transmit through sweat, saliva etc. Majority of the peoples have knowledge that HIV-1 is the most common type found worldwide. Also large number of peoples have knowledge that HIV weak immune system by destroying CD4+ and require long exposure to progress AIDS. Less than 15% of peoples strongly agree that AIDS is common in women. This misconception reflex the lack of knowledge and awareness in the HIV transmission and gender relation. Also majority of peoples thought that lack of knowledge is major barrier in the proper cure of disease. So increasing knowledge by awareness programs; sexual prevention; by starting national testing resources and curing poverty will cured AIDS in Pakistan. Newly drugs are introduced which can stop the progression of AIDS.

COGNITIVIZATION — THE NEXT STAGE OF INFORMATIZATION OF EDUCATION

2018 ◽  
pp. 5-11
Author(s):  
A. S. Christochevskaya ◽  
S. A. Christochevsky
Keyword(s):  
Comparative Analysis ◽  
Learning Resources ◽  
Technical Base ◽  
Initial Stage ◽  
New Knowledge ◽  
Good Material ◽  
E Learning ◽  
New Material ◽  
High Level ◽  
Paper Method

Informatization of education has been going on for 30 years. During this time, a good material and technical base appeared in schools, there are repositories of e-learning resources to which teachers have access. However, it is difficult to use these e-learning resources due to their too large number and not always high level. It is advisable to introduce a system of reviews and recommendations, to conduct a comparative analysis, as well as to make reviews of resources on a particular subject/topic. In addition, the demand for e-learning resources is affected by the fact that education authorities encourage not so much the use of e-learning resources as their development by the teacher himself. In general, the load on teachers has increased instead of the promised saving of time and effort when using the e-learning resources. At the same time, many e-learning resources are not very effective, since they do not meet the requirements of cognitiveness (they contribute not to learning, but to simple memorization of the material). It is necessary to explore the process of learning new material: this will allow you to create cognitive e-learning resources and other resources that would help you with equal probability to successfully acquire new knowledge for students belonging to different psycho-types. At the initial stage of the study of any subject, it is more expedient to use the usual “paper” method, that is, a textbook and not overload the student’s brain with excessive information. Only when he has mastered the basic provisions, we can turn to e-learning resources, bearing in mind that they must be cognitive, that is, they are aimed at logical perception and rapid intuitive learning, only in this case e-learning resources can be considered effective. The conclusion is formulated that cognitiveness is the next stage of informatization of education after the stage of electronization.

scholarly journals Neighborhood Energy Modeling and Monitoring: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3716
Author(s):  
Francesco Causone ◽  
Rossano Scoccia ◽  
Martina Pelle ◽  
Paola Colombo ◽  
Mario Motta ◽  
...  
Keyword(s):  
High Performance ◽  
High Efficiency ◽  
Early Stage ◽  
Energy Performance ◽  
Monitoring Plan ◽  
Performance Targets ◽  
Carrier Energy ◽  
Zero Carbon ◽  
Energy Grid

Cities and nations worldwide are pledging to energy and carbon neutral objectives that imply a huge contribution from buildings. High-performance targets, either zero energy or zero carbon, are typically difficult to be reached by single buildings, but groups of properly-managed buildings might reach these ambitious goals. For this purpose we need tools and experiences to model, monitor, manage and optimize buildings and their neighborhood-level systems. The paper describes the activities pursued for the deployment of an advanced energy management system for a multi-carrier energy grid of an existing neighborhood in the area of Milan. The activities included: (i) development of a detailed monitoring plan, (ii) deployment of the monitoring plan, (iii) development of a virtual model of the neighborhood and simulation of the energy performance. Comparisons against early-stage energy monitoring data proved promising and the generation system showed high efficiency (EER equal to 5.84), to be further exploited.

scholarly journals The YadA Protein of Yersinia pseudotuberculosis Mediates High-Efficiency Uptake into Human Cells under Environmental Conditions in Which Invasin Is Repressed

2002 ◽  
Vol 70 (9) ◽  
pp. 4880-4891 ◽  
Author(s):  
Julia Eitel ◽  
Petra Dersch
Keyword(s):  
Extracellular Matrix ◽  
Mammalian Cells ◽  
Yersinia Pseudotuberculosis ◽  
High Efficiency ◽  
Environmental Parameters ◽  
Infection Process ◽  
Nutrient Concentrations ◽  
Integrin Receptors ◽  
Uptake Process ◽  
High Level

ABSTRACT The YadA protein is a major adhesin of Yersinia pseudotuberculosis that promotes tight adhesion to mammalian cells by binding to extracellular matrix proteins. In this study, we first addressed the possibility of competitive interference of YadA and the major invasive factor invasin and found that expression of YadA in the presence of invasin affected neither the export nor the function of invasin in the outer membrane. Furthermore, expression of YadA promoted both bacterial adhesion and high-efficiency invasion entirely independently of invasin. Antibodies against fibronectin and β1 integrins blocked invasion, indicating that invasion occurs via extracellular-matrix-dependent bridging between YadA and the host cell β1 integrin receptors. Inhibitor studies also demonstrated that tyrosine and Ser/Thr kinases, as well as phosphatidylinositol 3-kinase, are involved in the uptake process. Further expression studies revealed that yadA is regulated in response to several environmental parameters, including temperature, ion and nutrient concentrations, and the bacterial growth phase. In complex medium, YadA production was generally repressed but could be induced by addition of Mg2+. Maximal expression of yadA was obtained in exponential-phase cells grown in minimal medium at 37°C, conditions under which the invasin gene is repressed. These results suggest that YadA of Y. pseudotuberculosis constitutes another independent high-level uptake pathway that might complement other cell entry mechanisms (e.g., invasin) at certain sites or stages during the infection process.

Lung nodule classification using combination of CNN, second and higher order texture features

2021 ◽  
pp. 1-9
Author(s):  
Amrita Naik ◽  
Damodar Reddy Edla
Keyword(s):  
Malignant Tumors ◽  
Early Stage ◽  
Lung Nodule ◽  
Texture Features ◽  
Svm Classifier ◽  
Softmax Classifier ◽  
Spatial Features ◽  
High Level ◽  
Learning Architectures ◽  
Nodule Classification

Lung cancer is the most common cancer throughout the world and identification of malignant tumors at an early stage is needed for diagnosis and treatment of patient thus avoiding the progression to a later stage. In recent times, deep learning architectures such as CNN have shown promising results in effectively identifying malignant tumors in CT scans. In this paper, we combine the CNN features with texture features such as Haralick and Gray level run length matrix features to gather benefits of high level and spatial features extracted from the lung nodules to improve the accuracy of classification. These features are further classified using SVM classifier instead of softmax classifier in order to reduce the overfitting problem. Our model was validated on LUNA dataset and achieved an accuracy of 93.53%, sensitivity of 86.62%, the specificity of 96.55%, and positive predictive value of 94.02%.

scholarly journals Parametric Studies of a Mercury-Free DBD Lamp

Plasma ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 82-93
Author(s):  
Bruno Caillier ◽  
Laurent Therese ◽  
Philippe Belenguer ◽  
Philippe Guillot
Keyword(s):  
Indium Tin Oxide ◽  
High Efficiency ◽  
Barrier Discharge ◽  
Necessary Conditions ◽  
Electrical Signal ◽  
Major Interest ◽  
Xenon Mixture ◽  
Parametric Studies ◽  
Glass Plates ◽  
Alternative Solutions

Mercury discharge lamps are often used because of their high efficiency; however, the usage of mercury lamps will be restricted or forbidden for safety and environmental purposes. Finding alternative solutions to suppress mercury is of major interest. The aim of this work is to increase the luminous efficacy of a commercial-free mercury flat dielectric barrier discharge lamp (Planilum, St Gobain) in order to reach the necessary conditions for the lamp to be used as a daily lighting source. The lamp is made of two glass plates separated by a gap of 2 mm. The gap is filled by a neon xenon mixture. The external electrodes made of transparent ITO (indium tin oxide) are deposited on the lamp glass plates. The electrical signal applied to the electrodes generates a UV-emitting plasma inside the gap. Phosphors deposited on the glass allow the production of visible light. The original electrode geometry is plane-to-plane; this induces filamentary discharges. We show that changing the plane-to-plane geometry to a coplanar geometry allows the plasma to spread all over the electrode surface, and we can reach twice the efficacy of the lamp (32 lm/W) as compared to the original value. Using this new electrode geometrical configuration and changing the electrical signal from sinusoidal to a pulsed signal greatly improves the visual uniformity of the emitted light all over the lamp. Electrical and optical parametric measurements were performed to study the lamp characteristics. We show that it is possible to develop a free mercury lamp with an efficacy compatible with lighting purposes.

scholarly journals A Review of Different Aspects of Applying Asphalt and Bituminous Mixes under a Railway Track

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Kazem Jadidi ◽  
Morteza Esmaeili ◽  
Mehdi Kalantari ◽  
Mehdi Khalili ◽  
Moses Karakouzian
Keyword(s):  
High Speed ◽  
Review Paper ◽  
Railway Track ◽  
High Speed Train ◽  
Slab Track ◽  
Bituminous Mixtures ◽  
Railway Tracks ◽  
Potential Applications ◽  
Heavy Loads ◽  
Design And Construction

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate response under high-speed loads, especially in comparison to a rigid slab track. This review paper documents the literature related to the utilization of asphalt and bituminous mixes in railway tracks. This paper presents a critical review of the research in the application of asphalt and bituminous mixes in railway tracks. Additionally, this paper reviews the design and construction recommendations and procedures for asphalt and bituminous mixes in railway tracks as practiced in different countries. This paper also provides case studies of projects where asphalt and bituminous mixes have been utilized in railway tracks. It is anticipated that this review paper will facilitate (1) the exchange of ideas and innovations in the area of the design and construction of railway tracks and (2) the development of unified standards for the design and construction of railway tracks with asphalt and bituminous mixtures.

scholarly journals Micro-mechanical investigation of railway ballast behavior under cyclic loading in a box test using DEM: effects of elastic layers and ballast types

2019 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kumar ◽  
Bettina Suhr ◽  
Stefan Marschnig ◽  
Peter Dietmaier ◽  
Christof Marte ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Early Stage ◽  
Damage Model ◽  
Simulation Models ◽  
Railway Track ◽  
Maintenance Cost ◽  
Particle Movement ◽  
Railway Ballast ◽  
Elastic Layers ◽  
The Impact

Abstract Ballasted tracks are the commonly used railway track systems with constant demands for reducing maintenance cost and improved performance. Elastic layers are increasingly used for improving ballasted tracks. In order to better understand the effects of elastic layers, physical understanding at the ballast particle level is crucial. Here, discrete element method (DEM) is used to investigate the effects of elastic layers – under sleeper pad ($$\text {USP}$$USP) at the sleeper/ballast interface and under ballast mat ($$\text {UBM}$$UBM) at the ballast/bottom interface – on micro-mechanical behavior of railway ballast. In the DEM model, the Conical Damage Model (CDM) is used for contact modelling. This model was calibrated in Suhr et al. (Granul Matter 20(4):70, 2018) for the simulation of two different types of ballast. The CDM model accounts for particle edge breakage, which is an important phenomenon especially at the early stage of a tamping cycle, and thus essential, when investigating the impact of elastic layers in the ballast bed. DEM results confirm that during cyclic loading, $$\text {USP}$$USP reduces the edge breakage at the sleeper/ballast interface. On the other hand, $$\text {UBM}$$UBM shows higher particle movement throughout the ballast bed. Both the edge breakage and particle movement in the ballast bed are found to influence the sleeper settlement. Micro-mechanical investigations show that the force chain in deeper regions of the ballast bed is less affected by $$\text {USP}$$USP for the two types of ballast. Conversely, dense lateral forces near to the box bottom were seen with $$\text {UBM}$$UBM. The findings are in good (qualitative) agreement with the experimental observations. Thus, DEM simulations can aid to better understand the micro-macro phenomena for railway ballast. This can help to improve the track components and track design based on simulation models taking into account the physical behavior of ballast. Graphical Abstract

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