scholarly journals Measurements of railway welded rail joints with a laser device

2020 ◽  
Vol 92 (6) ◽  
pp. 37-43
Author(s):  
Andrzej Aniszewicz ◽  
Mariusz Fabijański
Keyword(s):  
Mechanical Processing ◽  
Noise Emission ◽  
Laser Device ◽  
Measuring Device ◽  
Rail Head ◽  
Advantages And Disadvantages ◽  
Wheel Rolling ◽  
Railway Rail ◽  
The Given ◽  
Stable Connection

One of the methods of joining rails is welding with termite, which guarantees a secure and stable connection of two sections of the rail without the need to use additional connecting elements and supporting the welded place. After joining (making a weld), appropriate mechanical processing of the joint is required in order to obtain the given rail head profile. The quality and diligence of the connection made has a major impact on safety, noise emission during the journey (wheel rolling) and the comfort of travelers. This article describes selected methods of making railway rail joints and presents the results of measurements with a portable laser measuring device Calipri C40 of the rail head within the welded rail joint made by thermite welding. An attempt to use this device for measurements of welded rail joints is shown, advantages and disadvantages as well as conclusions from the performed measurements are described.

scholarly journals Determination of the classification-based tactics for treating meniscus lesions in children

2020 ◽  
Vol 24 (3) ◽  
pp. 194-197
Author(s):  
Daria D. Pavlova ◽  
S. M. Sharkov ◽  
M. A. Petrov ◽  
E. M. Krainova
Keyword(s):  
Modern Literature ◽  
Advantages And Disadvantages ◽  
New Approaches ◽  
Current Trends ◽  
Meniscus Lesions ◽  
The Given

New approaches to the treatment of meniscus lesions is currently a hot topic in traumatology and orthopedics. Meniscus resection and suture issues are widely discussed and studied in modern literature. Current trends in the care of meniscus pathologies are aimed to restore the structure of the damaged segment by stitching it using various techniques. A classification scale plays an important role in the treatment of any disease because it allows to uniformly describe the main criteria of pathology and to define a treatment tactics. The given review describes modern classifications of meniscus lesions with their advantages and disadvantages.

scholarly journals The Method for Product Design Selection with Incomplete Linguistic Weight Information Based on Quality Function Deployment in a Fuzzy Environment

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ming Li
Keyword(s):  
Product Design ◽  
Quality Function Deployment ◽  
Design Development ◽  
Quality Function ◽  
Advantages And Disadvantages ◽  
Fuzzy Environment ◽  
Design Requirements ◽  
Design Selection ◽  
The Given ◽  
The Relationship

The selection of a design for the given product is a critical problem in product design development. Focuses of the designers and customers on the design are not identical. In order to bridge the gap and provide a more relaxing way to select the design, a new method based on quality function deployment (QFD) is proposed. In such a method, customers are required to give their linguistic preferences on the design with respect to the customer requirements (CRs). In the rating of the weight of CRs, they are allowed to provide incomplete linguistic weight information and the objective optimization model is proposed to derive the exact linguistic weight information. Designers are required to rate the correlation between design requirements (DRs) and the relationship between the CRs and DRs to construct the house of quality. Opinions given by the customers are translated into the opinions with respect to the DRs based on the QFD. Afterwards, the priorities of the designs and design requirements are determined. The assessment results not only show the contribution of each design requirement to the customer satisfaction but also show the advantages and disadvantages of each design from the designers’ perspective clearly and directly. An example is provided to validate the applicability of the proposed method.

Implications of Using Corpus Tools in Primary and Secondary Education

2020 ◽  
pp. 179-190
Keyword(s):  
Secondary Education ◽  
Primary School ◽  
Language Learning ◽  
Secondary School Teachers ◽  
School Teachers ◽  
Primary School Teachers ◽  
Educational Levels ◽  
Teaching Activities ◽  
Advantages And Disadvantages ◽  
The Given

This chapter will give a comparison of using computer corpora in primary and in secondary schools. It will compare information that was collected from primary school teachers and secondary school teachers about using computer corpora for language subjects on primary and secondary educational levels. Based on the given information, the chapter will provide an explanation of the advantages and disadvantages of using computer corpora in language learning on those two educational levels. The chapter will explore which educational levels have more possibilities for incorporating computer corpora in their teaching activities and how it can be used in the classroom with students.

PERMAFROST SOILS THAWING UNDER BUILDINGS IN NORILSK

2018 ◽  
Vol 8 (2) ◽  
pp. 65-70
Author(s):  
Svetlana S. POROSHINA
Keyword(s):  
Economic Costs ◽  
Mass Destruction ◽  
Advantages And Disadvantages ◽  
Permafrost Soils ◽  
The Given ◽  
The City

The experience of the construction of buildings on permafrost in the city of Norilsk is considered, the main methods of construction under the given conditions are indicated, their advantages and disadvantages are revealed. The study of the localization of deformations in the building, the nature of the deformations shows their consequences. It is revealed that the main cause of mass destruction of buildings is the fi ssion of the soil under the building. The main possible causes of this process are indicated. The economic costs associated with the elimination of the consequences of destruction caused by the ground-breaking have been analyzed, and methods for solving this problem have been proposed.

ON ECONOMIC ASSESSMENT OF BALLASTLESS TRACK STRUCTURE EFFICIENCY

2017 ◽  
pp. 63-69
Author(s):  
Ludmila Andreyeva ◽  
Yevgeniy Svintsov ◽  
Yelena Tarasevich
Keyword(s):  
Comparative Analysis ◽  
Practical Importance ◽  
Economic Assessment ◽  
Track Structure ◽  
Advantages And Disadvantages ◽  
Ballastless Track ◽  
Study Results ◽  
Ballast Track ◽  
The Given

Objective: To describe the regulation of railroad traffic parameters in modern conditions, that lead to the necessity of putting into operation the new systems of track design, relevant for regulations in question. Methods: The method of matching, as well as the method of comparative analysis was applied in the study. Results: The advantages and disadvantages of ballastless track structure and conventional ballast track design were compared. The possibility of extensive application of ballastless track structure on modern railroads was analyzed. Practical importance: Ballastless track structure implementation will make it possible to solve practical tasks of using the given type of track design in transport construction.

Stress Relaxation Modelling

2015 ◽  
Author(s):  
Andrea Riva ◽  
Maurizio Maldini
Keyword(s):  
Stress Relaxation ◽  
Gas Turbine ◽  
Initial Stress ◽  
Experimental Tests ◽  
Material Model ◽  
Time Range ◽  
Creep Tests ◽  
Operational Conditions ◽  
Advantages And Disadvantages ◽  
The Given

Modern gas turbine bolts experience severe operational conditions due to high temperatures and elevated axial stresses, generated by the tightening couple applied during the turbine assembly. In such conditions the relaxation of the initial stress due to viscous phenomena has to be taken into account in order to guarantee the proper operation of the turbine. Relaxation modelling can either be based on strain controlled relaxation tests or load controlled creep tests. Both solutions present difficulties: relaxation tests entail critical experimental issues, whereas creep tests may not be significant for the given strain controlled operational condition of a gas turbine bolt. Some of these problems will be described in the paper and solutions will be provided. The performances of several models for stress relaxation quantification will be compared, highlighting advantages and disadvantages of each approach. In particular, great emphasis will be given to those aspects which are relevant for bolt design or tightening load calculation. For instance, some important requirements are: firstly, the possibility to implement the given model easily in finite element calculations; secondly, the possibility to accurately calculate the relaxation in the second life of a serviced bolt after re-tightening; lastly, the possibility to reduce as much as possible the time required for the experimental tests. In order to evaluate the coefficients of the different models considered in the study, creep tests were performed at 450°C and 475°C with applied stresses producing a strain ε = 1% in a time range of 1000–10000h and stress relaxation tests were performed at the same temperatures with initial strain in the range of 0.2%. After some stress relaxation, the specimens were reloaded at the initial stress several times in order to simulate the aforesaid service conditions of bolts. In the paper it will be shown how a valid model, capable of predicting the stress relaxation with acceptable accuracy, can be fed either by creep or relaxation tests, provided that the experimental tests and the related data elaboration are conducted with the proper methodology. This scenario provides the engineer responsible for material model creation with a remarkable flexibility, essential to fulfill the requirements of modern GT design, in terms of accuracy, promptness of data collection and possibility of FEM implementation.

The Research on Metal Milling about down Milling and Inverse Milling for Application

2015 ◽  
Vol 733 ◽  
pp. 526-530
Author(s):  
Shi Min Wang ◽  
Dong Quan Zhao ◽  
Rong Qi Deng
Keyword(s):  
Production Efficiency ◽  
Work Piece ◽  
Mechanical Processing ◽  
Milling Machine ◽  
Forward Movement ◽  
Milling Cutter ◽  
Advantages And Disadvantages ◽  
Future Production ◽  
Cutting Direction

Milling is a rule in milling machine using the rotation of the milling cutter movement, the movement of the work piece forward movement to machining of cutting method. In processing, the direction of rotation of the milling cutter is generally the same, but the cutting direction of tool is changing. In milling of common two phenomena: down milling and inverse milling. In order to improve the surface quality of machining and reduce tool wear, and thus improve the production efficiency and economic benefit, this paper expounded from different angles and compared the advantages and disadvantages of two types of milling, In order to the future production mechanical processing industry provides the theoretical basis and technical support.

scholarly journals Assessment of the Summer Thermal Stability of the Attic Room Using Two Different Software

2020 ◽  
Vol 16 (2) ◽  
pp. 360-369
Author(s):  
Kateřina Stejskalová ◽  
Nikola Vavřínová
Keyword(s):  
Thermal Stability ◽  
Internal Temperature ◽  
Summer Period ◽  
Advantages And Disadvantages ◽  
The Given ◽  
Thermal Stability Of

AbstractThis paper presents the calculations of the summer thermal stability of a critical room of the given building. In this case, the critical room of the building is an attic room. Using two different software (SIMULACE and DesignBuilder), the summer thermal stability of the attic room was evaluated according to the Czech standard ČSN 73 0540-2 [1]. This standard compares the calculated and required value of the maximum internal temperature in the summer period. The results from both software were compared with the Czech standard and also with each other. The resulting temperature courses in the interior differ by a few Celsius degrees. In conclusion, the causes of different results are discussed as well as the advantages and disadvantages of both software.

scholarly journals CALCULATION OF PARAMETERS OF CHANNEL THROTTLING OF EXPENSIVE ELEMENTS OF FIRMWARE

2020 ◽  
pp. 50-53
Author(s):  
V. A. Saninsky ◽  
E. A. Fedyanov ◽  
E. N. Nesterenko
Keyword(s):  
Flow Rate ◽  
Economic Efficiency ◽  
Outer Surface ◽  
Coolant Flow ◽  
Mechanical Processing ◽  
Liquid Coolant ◽  
Calculation Of Parameters ◽  
Advantages And Disadvantages ◽  
Processing Modes ◽  
Pipe Blanks

The article considers possible options for supplying coolant to the cutting and deforming teeth of multi-pronged firmware for processing deep holes. The advantages and disadvantages of each scheme are indicated. It is noted that when the lubricant-cooling liquid (coolant) is pushed through straight or screw slotted grooves made on the outer surface of the mandrel teeth, "damping pads" are created on the surface to be processed, which improve the mandrel process and reduce wear of the stitches for processing deep holes. For each of the schemes, a method for calculating the coolant flow rate is described, depending on the parameters of the slotted grooves for the coolant flow and the pressure of its supply. The ability to calculate the consumption of coolant through the cutting and deforming teeth of multi-toothed stitches allows you to correctly assign processing modes and, thereby, increase the technical and economic efficiency of mechanical processing of long pipe blanks.

Novel Cycles Deployment Study for a Silent Aircraft

2008 ◽  
Author(s):  
L. Nettis ◽  
F. De Bellis ◽  
A. Javed ◽  
G. Doulgeris ◽  
S. O. T. Ogaji ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
New Technologies ◽  
Point Of View ◽  
Theoretical Point ◽  
The Novel ◽  
Noise Emission ◽  
Environmental Laws ◽  
Consumption Reduction ◽  
Noise Shielding ◽  
The Given

Aircraft noise is nowadays considered a pollutant like exhaust gases. Moreover, future requirements for aircraft certification impose a remarkable reduction in noise emission in the next 20 years. Since current technologies are insufficient to achieve the target, new technologies have to be developed, both for engines and airframes. In this paper, three novel engine cycles have been studied from a preliminary and theoretical point of view, considering noise and fuel consumption reduction as key design drivers. The innovative cycles analysed are: Variable Fan Nozzle Area (VFNA), Constant Volume Combustor (CVC) and Inter Cooled Recuperated (ICR). A parametric analysis has been performed for each one of them in order to select the best cycle; then, the three optimums have been compared. The designed VFNA engine provides the largest reduction in jet noise (64%) in comparison to the baseline, whilst the CVC has the lowest fuel consumption. However, both use two fans per engine, with weight and drag penalties. A further noise reduction is obtained installing the engines upon the wings, and not beneath them as in conventional designs. Obtained results show that noise shielding technique is responsible for a 20 dB decrease in OASPL, leading to a noise level, perceived on the ground, lower than 60 dB. This value implies a full satisfaction of the new environmental laws. Finally, the three propulsion systems have been installed on a medium range, twin engine aircraft and its flight performance has been evaluated. Simulations establish the superiority of the novel cycles against the baseline, in terms of reduced fuel consumption for the given mission.

Sign in / Sign up

Export Citation Format

Share Document