Influence of Dropper Spacing on Quality of Pantograph-Catenary Current Collection

2014 ◽  
Vol 654 ◽  
pp. 78-81 ◽  
Author(s):  
Mei Li Yu ◽  
Wen Zheng Liu ◽  
Jian Zhang ◽  
Cai Ying Yan
Keyword(s):  
Contact Force ◽  
Analysis Method ◽  
Key Factors ◽  
Element Analysis ◽  
Factors Affecting ◽  
Contact Wire ◽  
Current Collection ◽  
Negative Effect ◽  
The Stability

Elasticity variations in railway overhead contact line would lead to the fluctuation of contact force between pantograph and contact wire and produce a negative effect on the stability of current collection. Dropper distribution is one of the key factors affecting the elasticity of the contact wire. In this paper, the influence of dropper spacing on elasticity and quality of current collection have been studied using finite element analysis method by simulation. By analyzing the changes of elasticity value and contact force under different conditions of dropper distribution, the effect laws of dropper spacing on the contact wire elasticity and the quality of current collection under the speeds of 300km/h, 350km/h and 400km/h have been obtained.

Impact of overhead line irregularity on current collection and diagnostics based on the measurement of pantograph dynamics

2007 ◽  
Vol 221 (4) ◽  
pp. 547-559 ◽  
Author(s):  
A Collina ◽  
F Fossati ◽  
M Papi ◽  
F Resta
Keyword(s):  
Direct Measurement ◽  
Contact Force ◽  
Estimation Procedure ◽  
Overhead Line ◽  
Large Database ◽  
Contact Wire ◽  
Current Collection ◽  
Train Speed ◽  
The One

As train speed increases, contact wire irregularity affects the quality of current collection more and more. The possibility of achieving the maximum operating speed depends also on the maintenance level of the overhead line (OHL). In the present paper, the influence of contact wire irregularity (in terms of vertical deviation of its position) is investigated both experimentally and by means of numerical simulation of the dynamic interaction of pantograph and catenary. In a first step, the capability of the simulation to reproduce the effect of a singularity in the contact wire height along the line has been tested by comparison with available experimental results. The same model has been subsequently used to perform numerical experiments concerning the effects of several types of distributed defects on the catenary. Afterwards, considering the data generated with the simulation as experimental data, a procedure to find the signature in terms of the contact force of the considered distributed defects on the OHL has been proposed. In this procedure, the contact force is not measured, but estimated from the motion of the pantograph, by means of an application of the extended Kalman filter. The adoption of an estimation procedure for the contact force, instead of a direct measurement, would allow the installation of a measurement system that is much simpler than the one required for the direct measurement of contact force. For this feature, it could be installed, at least in principle, on ordinary trains, allowing to perform an extensive monitoring and diagnostic activity with a large database.

scholarly journals Drought and Salinity in Citriculture: Optimal Practices to Alleviate Salinity and Water Stress

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1283
Author(s):  
Vasileios Ziogas ◽  
Georgia Tanou ◽  
Giasemi Morianou ◽  
Nektarios Kourgialas
Keyword(s):  
Agricultural Sector ◽  
Review Paper ◽  
Cell Metabolism ◽  
High Water ◽  
Crop Productivity ◽  
Fruit Tree ◽  
Key Factors ◽  
Negative Effect

Among the various abiotic stresses, drought is the major factor limiting crop productivity worldwide. Citrus has been recognized as a fruit tree crop group of great importance to the global agricultural sector since there are 140 citrus-producing countries worldwide. The majority of citrus-producing areas are subjected to dry and hot summer weather, limited availability of water resources with parallel low-quality irrigation water due to increased salinity regimes. Citrus trees are generally classified as “salt-intolerant” with high water needs, especially during summer. Water scarcity negatively affects plant growth and impairs cell metabolism, affecting the overall tree growth and the quality of produced fruit. Key factors that overall attempt to sustain and withstand the negative effect of salinity and drought stress are the extensive use of rootstocks in citriculture as well as the appropriate agronomical and irrigation practices applied. This review paper emphasizes and summarizes the crucial role of the above factors in the sustainability of citriculture.

scholarly journals Factors Affecting the Initial Engagement of Older Adults in the Use of Interactive Technology

2021 ◽  
Vol 18 (6) ◽  
pp. 2847
Author(s):  
Lina Lee ◽  
Mary Lou Maher
Keyword(s):  
Older Adults ◽  
Interactive Technology ◽  
Key Factors ◽  
Group Discussions ◽  
Interactive Technologies ◽  
Factors Affecting ◽  
Diary Studies ◽  
User Focus ◽  
Depth Interviews

Smart environments and the use of interactive technology has the potential to improve the quality of life for the senior community as well as to support the connections among the senior community and the world outside their community. In addition to the increasing number of studies in the field of aging and technologies, research is needed to understand the practical issues of user focus, adoption, and engagement for older adults to accept interactive technologies in their lives. In this study, we use two commercial technological interventions (uDraw and GrandPad) to understand technology-related perceptions and behaviors of older adults. We present five case studies that emerge from empirical observations of initial engagement with technology through research methods such as focus group discussions, in-depth interviews, observations, and diary studies. The contributions of this study are identification of the key factors that influence the initial engagement with interactive technology for older adults.

Grain Refinement and Hot Tearing of Aluminium Alloys - How to Optimise and Minimise

2009 ◽  
Vol 630 ◽  
pp. 213-221 ◽  
Author(s):  
Mark Easton ◽  
David H. StJohn ◽  
Lisa Sweet
Keyword(s):  
Grain Refinement ◽  
Aluminium Alloys ◽  
Hot Tearing ◽  
Key Factors ◽  
Grain Refiner ◽  
Factors Affecting ◽  
Equiaxed Grains

Grain refinement and hot tearing are important key factors affecting the quality of castings. There have been substantial advances in the understanding of both of these phenomena over the last two decades. The paper discusses strategies for obtaining the lowest cost grain refiner addition and provides an explanation for how the refinement of equiaxed grains leads to a reduction in hot tear susceptibility. However, it also provides a warning that adding more grain refiner may not be better for reducing hot tear susceptibility. Alloy factors affecting hot tearing are also discussed. Finally, a list of six key considerations is provided to help casthouse and foundry engineers when trying to optimise grain refinement and reduce hot tearing.

scholarly journals The factors influencing technological entrepreneurship in nanotechnology businesses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tayebeh Nikraftar ◽  
Elahe Hosseini ◽  
Elham Mohammadi
Keyword(s):  
Analysis Method ◽  
Business Managers ◽  
Key Factors ◽  
Content Type ◽  
Factors Affecting ◽  
Confirmatory Factor ◽  
Technological Entrepreneurship ◽  
Executive Managers ◽  
Economic Modernization ◽  
Vital Factor

PurposeTechnological entrepreneurship has been a very significant topic in recent decades. It has a crucial role in economic modernization and growth. The need for technological entrepreneurship is because technology-based industries are expanding rapidly and are replacing traditional industries. Therefore, this study aimed at identifying the factors affecting the success of technological entrepreneurship in Iranian nanotechnology businesses.Design/methodology/approachThe research was conducted through mixed method. The participants in the qualitative section included 17 university experts and executive managers in the field of nanotechnology in Iran, and 75 nanotechnology business managers participated in the quantitative section. The interview and questionnaire were used to collect information. In order to measure and fit the models, the confirmatory factor analysis method and PLS3 software were used.FindingsThe results indicated that the key factors affecting the success of the technological entrepreneurship process in nanotechnology were classified into five general categories: organizational, environmental, institutional, individual and technology factors. Moreover, it was shown that all these dimensions had a positive and significant effect on technological entrepreneurship. In addition, the organizational dimension has an essential role.Originality/valueCompanies' ability to engage technological entrepreneurship is a vital factor in human resource management and strategic management. However, technological entrepreneurship in Iranian nanotechnology businesses has not been involved integrally in the context of companies.

MODELING THE INFLUENCE OF THE STRUCTURE AND QUALITY OF ASSETS ON THE PROFITABILITY OF A COMMERCIAL BANK

2021 ◽  
pp. 10-18
Author(s):  
Alena S. Kudriavtseva ◽  
Olga G. Arkadeva
Keyword(s):  
Economic Analysis ◽  
Commercial Banks ◽  
Financial Stability ◽  
Banking System ◽  
Factors Affecting ◽  
Correlation And Regression Analysis ◽  
The Stability ◽  
Classical Economic ◽  
Sound Management

In modern conditions, the methods of classical economic analysis are not enough to solve the problem of bank stability. This requires the development of methods and tools to analyze the current situation in the bank and to develop sound management decisions aimed at ensuring the stability of the bank. The article notes that the analysis of the influence of the structure and quality of assets on the profitability of commercial banks is an important step for assessing the financial position and reliability of a bank, and a method is proposed for constructing a model of the dependence of bank’s profitability on the factors that determine it. The scientific sources were the works of Russian and foreign researchers in the field of modeling and characteristics of the banking system, financial stability of credit institutions, assessment of the creditworthiness of potential borrowers, system organization and information technology. The article uses the methods of economic analysis, differential calculus and mathematical statistics, as well as the achievements of the main scientific schools dealing with the problems of economic and mathematical modeling and economic analysis of banking. In order to determine the most significant economic factors affecting the profitability of commercial banks, generalization of the theoretical, methodological and applied aspects of studies devoted to the study of the influence of the structure and quality of assets on the profitability of commercial banks was carried out, and a correlation and regression analysis was made. The model presented in the article can be used to predict changes in the profitability of Russian commercial banks and to predict promising directions for growth in profit and profitability of the bank.

ANALYSIS OF KEY TRENDS OF THE INTERNATIONAL COAL MARKET (ON THE EXAMPLE OF THE COUNTRIES OF NORTH-EASTERN ASIA)

2021 ◽  
pp. 96-105
Author(s):  
Andrey V. Cherechukin ◽  
Keyword(s):  
Raw Materials ◽  
Northeast Asia ◽  
Primary Energy ◽  
Key Factors ◽  
Factors Affecting ◽  
North Eastern ◽  
The World ◽  
Coal Market ◽  
National Economies

The article provides an analysis of key trends in the international market, using the example of the countries of Northeast Asia. In 2019, the world coal market amounted to 1,424.5 million tons, of which 78.1% are energy grades to produce electricity and heat, and 21.9% are in metallurgy, the reserves of which are significantly less. The import coal market of the countries of Northeast Asia in 2019 was already 680 million tons, covering 48% of the entire world coal market. The paper provides an overview of the key importers and exporters of coal in the world, the quantitative and qualitative characteristics of the supplied raw materials, and analyzes the key factors affecting the pricing of coal. In the conclusions, the main trends in the international coal market of the countries of Northeast Asia are presented, including "geographical" — the shift of the center of world trade from Europe to Asia, and "types and quality of imported coal" — an increase in the share of high-quality premium energy and coking (metallurgical). Trends can be clearly seen in the countries of Northeast Asia, which actively use coal, and are making efforts to decarbonize their national economies, while intensifying inter-fuel competition with other primary energy sources.

scholarly journals Neighborhood Influence: A Qualitative Study in Cáceres, an Aspiring Age-Friendly City

2019 ◽  
Vol 8 (6) ◽  
pp. 195 ◽  
Author(s):  
Lidia Domínguez-Párraga
Keyword(s):  
Successful Aging ◽  
Daily Life ◽  
Urban Sociology ◽  
Well Being ◽  
The Elderly ◽  
Key Factors ◽  
Social And Emotional ◽  
Negative Effect ◽  
Neighborhood Influence

The aim of this study is to understand the perspective of elderly residents on their neighborhood and how the composition of the neighborhood influences their daily life. The study took place in the city of Cáceres (Spain) that aspires to become an age-friendly city. This study focused on the intangible elements of the neighborhood related to feelings of safety, well-being, loneliness, belonging to the community and development of trusting relationships. The research was based on the sociology of aging, specifically referencing the theory of the activity of aging, and also urban sociology, which assumes the environment as a conditioning agent of daily life. Using a qualitative approach, 32 in-depth interviews were conducted with individuals over 65. The interviews were analyzed according to grounded theory. The results show how social aspects are key factors for the elderly in their perception of the neighborhood. Therefore, psychological, social and emotional dimensions of the neighborhood influence elderly residents and could have a positive or negative effect on successful aging. These findings also suggest that a crucial aspect of the positive perceptions of the environment lies in the quality of social interactions that take place inside the neighborhood.

Effect of the particulate morphology of resin on the gelation process of PVC plastisols

2017 ◽  
Vol 37 (8) ◽  
pp. 757-764 ◽  
Author(s):  
Yubi Ji ◽  
Zhao Yang ◽  
Min Shi ◽  
Hong Tan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Key Factors ◽  
Factors Affecting ◽  
Gelation Process ◽  
Secondary Particles ◽  
Poly Vinyl Chloride ◽  
Opposite Behavior

Abstract The gelation process of poly(vinyl chloride) (PVC) plastisol is very important to ensure the quality of the product and is affected by the type of resins, plasticizers, and other additives. In this study, the gelation process of the as-prepared PVC plastisol was characterized by measuring the evolution of vibrational viscosity with temperature or time using a vibrational viscometer. Furthermore, the effect of some commercial resins with different particulate morphologies on the gelation process was investigated by synchronously combining scanning election microscopy and laser particle size analyses. The results of this study proved that the particle size distribution and the aggregation degree of the secondary particles of a resin are the key factors affecting the gelation process. For the resin with bimodal particle size distribution, the closer the aggregation of the secondary particles, the slower the gel speed; however, an opposite behavior was observed for the resins with unimodal particle size distribution.

Research on the Forming Path for Fabricating the Sheet-Metal Part with Non-Horizontal End Face Using CNC Incremental Forming

2014 ◽  
Vol 599-601 ◽  
pp. 413-416 ◽  
Author(s):  
Hu Zhu ◽  
Jin Ju ◽  
Yi Bo Liu
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Analysis Method ◽  
Metal Part ◽  
Element Analysis ◽  
Sheet Metal Parts ◽  
Cnc Incremental Forming ◽  
Forming Technology ◽  
The Finite Element Analysis

For the purpose of the fabrication of the sheet-metal parts with non-horizontal end face using the sheet metal CNC incremental forming technology, two kinds of path generating methods, namely the level path perpendicular to Z axis method and the equidistant path parallel to sheet metal are proposed in this paper. Both of the paths are generated by Visual C++ and OpenGL graphics library, the effect of the two kinds of forming paths to the forming quality of the sheet part with non-horizontal end face is researched using the finite element analysis method in this paper.

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