scholarly journals Scientific Substantiation of Thermal Leveling for Deformations in the Car Structure

2018 ◽  
Vol 7 (4.3) ◽  
pp. 125 ◽  
Author(s):  
Oleksiy Fomin ◽  
Oleksandr Logvinenko ◽  
Oleksiy Burlutsky ◽  
Andriy Rybin
Keyword(s):  
Rolling Stock ◽  
Railway Transport ◽  
Significant Deterioration ◽  
Rail Industry ◽  
Scientific Substantiation ◽  
Freight Car ◽  
The One ◽  
Welding Procedure ◽  
Transport Complex

Railway transport is the foundation of the transport complex and part of the transport network of logistics chains. However, significant deterioration of rolling stock units (especially freight cars accounting for the greater part of all transportation) is an urgent problem of the rail industry. Therefore, the problems of renovation of the existing freight car fleet by developing and introducing domestic models which can effectively compete in terms of the technical and economic and operational indexes are of crucial importance. But the car structure suffers from various deformations at all service stages (production, maintenance and operation). The main type of these deformations is residual ones developing during the welding procedure, due to the thermal effect. Therefore, the issues concerning elimination of these deformations in production and maintenance are becoming ever more urgent. In particular, the most recognized and economy-oriented approach in the field is the one based on the thermal leveling of welded structures. The implementation of this approach requires some research aimed at scientific substantiation of the thermal leveling, as well as, specification of forms and heating temperatures, determination of heating form sizes, thermal leveling simulation and experimental verification of the results, optical microscopy and determination of mechanical characteristics.  

scholarly journals MODEL FOR DETERMINATION OF CHARACTERISTICS OF RAILWAY TRAIN REGIME MAPS

2020 ◽  
pp. 132-142
Author(s):  
A. Falendysh ◽  
A. Gatchenko ◽  
O. Kletska ◽  
E. Kiritseva ◽  
M. Barybin
Keyword(s):  
Energy Efficient ◽  
Mechanical Energy ◽  
Technical Condition ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Railway Transport ◽  
Ecological Requirements ◽  
Methods Of Calculation ◽  
Methods Of Operation

The article considers the issues of determining rational approaches to the creation of train maps, the rational use of diesel modes and the use of automated computer simulation system. Based on the obtained results, an energy-efficient mode of train driving is proposed and a mathematical model of the locomotive operation character is created. There is a need to review obsolete regime and train locomotive crews in the latest methods of operation. The basic values and methods of calculation for specific operating conditions on the basis of the law of conservation of mechanical energy are established. It is proposed to create a passport of each locomotive to determine the rational weight norms on the existing service shoulders. After all, overloading or underutilization of the locomotive's resource is associated with loss of profit or the emergence of emergencies. The necessity of the offered methods within the limits of ecological requirements to traction rolling stock is proved. The possibility of forming a rational system of mileage between technical inspections and repairs for each locomotive as a whole on the basis of forecasting and statistics is determined. It is recommended to further implement mathematical modeling and digital means of monitoring the technical condition after repairs to achieve economic efficiency of railway transport.

scholarly journals SIMPLIFIED APPROACH OF DETERMINATION OF THE MEASURE TO INCREASE THE EFFICIENCY OF RAILWAY TRANSPORT OF THE METALLURGICAL PLANT

2021 ◽  
pp. 43-54
Author(s):  
Elena Kiritseva ◽  
Olha Kletska ◽  
Andrey Lyamzin ◽  
Anatoliy Falendysh
Keyword(s):  
Metallurgical Plant ◽  
Rolling Stock ◽  
Railway Transport ◽  
Metallurgical Enterprise ◽  
Simplified Approach ◽  
Scarce Resources ◽  
Industrial Enterprises ◽  
Stage Of Development ◽  
Standard Set ◽  
Freight Car

The article proposes the approach for determining the measure to increase the efficiency of railway transport of the metallurgical plant. The analysis of scientific and normative works on the efficiency of railway transport at industrial enterprises showed that this issue is not fully covered and requires more detailed study. The work of the railway shop of the metallurgical enterprise is considered, namely, the turnover off right cars of different owners and the time of their stay on the factory tracks are determined. An analysis of statistical data was made, which showed that the time difference between the standard set at the enterprise and the actual time of stay of the freight car at the planthas a large discrepancy. This requires spending additional funds for the use of cars of different owners. For this purpose, a model for determining measures to minimize costs at the metallurgical enterprise was developed. The algorithm for its solution involves five stages of calculations. It is based on the model of managements science, which is presented as the approach of linear programming to determine the optimal means of allocating scarce resources in the presence of competing needs. Calculations were made, thanks to which the first stage of development of the model for determining the measure to improve the performance of railway transport was performed and the indicators that characterize it were determined. The total time of rolling stock at the enterprise is determined. Based on this, it is established that it is necessary to separate from the total time the time spent at each station according to the operations performed with the cars. Costs are determined operationally due to the received analysis of the stay and turnover of the freight car at the metallurgical enterprise. Installed stations, which are the most time-consuming freight cars, is there is an excess of payment for the down time of cars at these stations. Based on this, it was decided that it is necessary to study in more detail the operations performed with cars at theses stations and to identify "weaknesses" in the turnover of the freight car at the metallurgical enterprise. 

INVESTIGATION OF TEMPERATURE OF BRAKE PADS WITH DIFFERENT EXTENT OF WEAR IN FRICTIONAL BRAKING

2020 ◽  
pp. 27-34
Author(s):  
P. Yu. Ivanov ◽  
◽  
A. M. Khudonogov ◽  
E. Yu. Dulskiy ◽  
A. A. Korsun ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Flow Distribution ◽  
Rolling Stock ◽  
Finite Element Models ◽  
Brake Pads ◽  
Coefficient Increase ◽  
Engineering Drawings ◽  
Freight Car ◽  
Full Stop

The issue of railway rolling stock brake pad heating is examined under frictional braking within a freight car with unilateral push, equipped with castiron brake pads. Foreign and domestic experience of studies of heat cycles caused by friction has been examined, mechanism of heat release in the contact zone between a pad and wheel during braking with consideration of a heat flow distribution coefficient is described, mathematical modeling choice as a way to refine temperature measurements in the process of experimental studies is grounded, the results of estimated determination of the thermal flow affecting the pad in braking of a loaded freight car weighing 93 ts with 5 ts push upon the axle from 60 km/h to full stop are shown. Dynamics of thermal energy change emitting in frictional braking with consideration of wheel rotation decelerating speed and friction coefficient increase is emulated. Finite element models of pads with even wear, wedgelike wear and with no wear having geometry of relevant engineering drawings are described. The results of investigation of heating of brake pads with different wear types in the process of braking until full stop are given.

СORRUPTION COMPONENT IN RAILWAY TRANSPORT ACTIVITIES: ROLE SEGMENT AND CONCEPTUAL ASPECT

2021 ◽  
Vol 2 (2) ◽  
pp. 132-140
Author(s):  
Vitaliy Kadala ◽  
◽  
Olena Guzenko ◽  
Keyword(s):  
Small Businesses ◽  
Cash Flows ◽  
Legal Framework ◽  
Influential Factors ◽  
Rolling Stock ◽  
Transport Sector ◽  
Railway Transport ◽  
Transport Services ◽  
The One ◽  
High Level

Domestic railway transport suffers from a number of problems that hinder its development. At the same time, the manifestations of corruption intensified, which resulted in the violation of the planned development plans for the future. As a rule, railway transport must function safely, combine the interests of the country with the interests of persons using transport services, promote competition, ensure equal access to its strategic infrastructure, as well as sustainable operation in a special period. However, every year the problems of transport industry development deepen, on the one hand, low level of fixed assets renewal, high level of rolling stock wear, low density of railways, low coefficient of electrification of railways, low speed of cargo delivery, technical and technological backwardness of infrastructure; on the other hand - a high level of transport capacity of GDP, transport services, low share of wages in the provided transportation service, air pollution and a high level of final energy consumption. Only these factors indicate the need for immediate implementation of measures that can ensure the reform of the system of organization of operation and management of the railway transport sector. One of the rather influential factors in slowing down the process of renewing the transport sector is corruption, which reduces cash flows for this type of work, as well as a certain level of imperfection of the legal framework, which should provide tools for anti-corruption actions. Studying the problem of corruption, scholars have drawn attention to different positions on the interpretation of it as a conceptual category. The research emphasizes the expediency and need to clarify the conceptual framework from the standpoint of corruption, which will allow politicians, scientists, top management of large, medium and small businesses operating in the railway sector to make decisions on a more substantive basis. Attention is drawn to the existing scientific positions on the interpretation of the definition of “corruption” with coverage of existing regulations aimed at overcoming it. The author's vision of the essential characteristic of the definitions “corruption in the field of railway transport” and “corruption event on the railway” is offered.

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

1969 ◽  
Vol 61 (2) ◽  
pp. 219-231 ◽  
Author(s):  
V. H. Asfeldt
Keyword(s):  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Cushing's Syndrome ◽  
Dexamethasone Suppression Test ◽  
Clinical Value ◽  
Suppression Test ◽  
The One ◽  
Steroid Excretion ◽  
Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

A Validated 2D-LC-UV Method for Simultaneous Determination of Imatinib and N-demethylimatinib in Plasma and Its Clinical Application for Therapeutic Drug Monitoring with GIST Patients

2020 ◽  
Vol 17 ◽  
Author(s):  
Houli Li ◽  
Di Zhang ◽  
Xiaoliang Cheng ◽  
Qiaowei Zheng ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
One Dimension ◽  
Therapeutic Drug ◽  
Plasma Samples ◽  
Column Temperature ◽  
Injection Volume ◽  
Target Analytes ◽  
The One ◽  
Middle Column

Background: The trough concentration (Cmin) of Imatinib (IM) is closely related to the treatment outcomes and adverse reactions of patients with gastrointestinal stromal tumors (GIST). However, the drug plasma level has great interand intra-individual variability, and therapeutic drug monitoring (TDM) is highly recommended. Objective: To develop a novel, simple, and economical two-dimensional liquid chromatography method with ultraviolet detector (2D-LC-UV) for simultaneous determination of IM and its major active metabolite, N-demethyl imatinib (NDIM) in human plasma, and then apply the method for TDM of the drug. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Conclusion: The novel 2D-LC-UV method is simple, stable, highly automated and independent of specialized technicians, which greatly increases the real-time capability of routine TDM for IM in hospital.

Tribology of rail bogie

2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov
Keyword(s):  
Contact Fatigue ◽  
Basic Element ◽  
Difficult Problem ◽  
Railway Track ◽  
Rolling Stock ◽  
Kinematic Parameters ◽  
Approximate Estimation ◽  
Railway Bogie ◽  
Classical Calculation

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.

Coordination of technology of railway operation of the Republic of Tajikistan and organization of railways in international traffic

2018 ◽  
Vol 77 (4) ◽  
pp. 211-217 ◽  
Author(s):  
P. N. Pulatov
Keyword(s):  
Rolling Stock ◽  
Railway Transport ◽  
Transport Services ◽  
Railway Infrastructure ◽  
External Conditions ◽  
The Republic ◽  
Railway Operation ◽  
Required Quality

Current geopolitical and economic conditions for the functioning of railway transport in most post-Soviet states are such that it is extremely difficult to provide required quality of transport services and break-even operations at high expenses for maintaining the railway infrastructure and rolling stock. Dynamics of transportation of the Tajik Railway (TSR) is shown, which displays that most of its sections are classified as low-intensity ones. The paper proposes methodical principles, setting and qualitative analysis of the task of rationalization of operational work and organization of car flows for international transportation, taking into account the specifics of the Tajik Railway. There is a problem of complex maintenance of the efficiency of operational work in modern conditions based on the synthesis of the tasks of self-management (rational internal operational technology of the Tajik Railway) and coordination tasks (technological interaction with railway administrations of other states). Author substantiated the necessity of solving this problem. Proposed classification of technological restrictions and controlled variables in the performance of transport takes into account methods for changing external conditions for the functioning of the railway landfill and methods for increasing internal efficiency of its operation. The search for the solution of the problem involves direct search of variants along its ordered set with clipping of groups of variants that do not correspond to constraints, with the subsequent finding of compromise control over a set of effective alternatives.

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