Sand drift potential impacts within desert railway corridors: a case study of the Sarakhs-Mashhad railway line

2021 ◽  
Vol 14 (9) ◽  
Author(s):  
Mohammad Reza Rahdari ◽  
Yeboah Gyasi-Agyei ◽  
Jesus Rodrigo-Comino
2016 ◽  
Vol 2 (320) ◽  
Author(s):  
Paulina Tobiasz-Lis ◽  
Marcin Wójcik

The research presented in this article focuses on the urban region of Novosibirsk, which is one of the most industrialized part of Siberia and the Asian part of Russian Federation. To show relationships between the city as the core of the region and its peripheral area a case study analysing territorial units within the southern settlement belt along the Novosibirsk–Cherepanovo regional railway line over a distance of approx. 100 km. This belt was chosen because of the continuity of the settlement and due to the presence of different functional types of edge towns. The adopted system, from the core to the area of weakening direct links to Novosibirsk, helped to define the directional profile of the urban region as relating to the demographic and economic characteristics. The research was based on two methods of determining the functions of cities in the national settlement system: a research programme concerning the genesis of functional development and a research programme of specialised functions, the purpose of which is to determine the economic base (exogenous functions) of territorial units. The presented results have shown general tendencies in the transformations of the Novosibirsk urban region’s spatial structure, both in long-term perspective (the generic view of function development) and under contemporary circumstances related to the economic transformation of Russia.


2012 ◽  
Vol 253-255 ◽  
pp. 1235-1240
Author(s):  
Hua Li ◽  
Bao Ming Han ◽  
Fang Lu ◽  
Xiao Juan Li

Train-set circulation problem is an important issue in operations of high-speed passenger trains in the world. On the basis of characteristics of the train-set circulation problem in China, an integer programming model is presented without considering distinct train-set types. With redefinitions of some basic mathematical objects and operations, an improved particle swarm optimization algorithm is proposed to solve the model. The algorithm is applied in a real-life case study based on the timetable of the Wuhan-Guangzhou High-speed Railway Line. The results show that the proposed algorithm is effective to find the optimized train-set circulation plan.


Author(s):  
Ido Prasetio ◽  
Andri Irfan Rifai

Increasing the number of population and the development of activities will cause a growing need for space every day, this will result in physical changes and urban land use and can cause increased intensity of population movement from Megapolitan cities such as Bekasi, Bogor and Tangerang to the Metropolitan city (DKI Jakarta). Some people have now started to move from private vehicles to use public (mass) transportation such as buses, transjakarta, and electric rail trains or commonly known as KRL Commuter Line that serve Jabodetabek routes. The impact of crossing also causes buildup at each station. Train track with a single track (single track) is considered ineffective and inefficient and vulnerable to train accidents due to human error. It is necessary to develop or develop a double track to become a double-double track Bekasi Station km 26 + 652 - Jatinegara Station km 12 + 050. The research location is on the railway line from Bekasi Station to Jatinegara Station. The length of the train track is around 16 km and has 7 stations that are traversed, 5 of which are active (stop) and 2 passive stations.


2018 ◽  
Vol 244 ◽  
pp. 03002 ◽  
Author(s):  
Iwona Rybicka ◽  
Ondrej Stopka ◽  
Vladimír Ľupták ◽  
Mária Chovancová ◽  
Paweł Droździel

At present, the impact of transport on the environment constitutes a serious problem. This mainly concerns energy consumption and production of greenhouse gases (GHG) that via their participation in greenhouse effect intensification contribute to global warming. In this paper, the calculations provided by the EN 16258: 2012 methodology will be applied to two modes of transport: railway and road transport. Subsequently, the methodology will be applied to a case study of a selected nonelectrified railway line in comparison with parallel road transport. In particular, energy consumption and production of greenhouse gases will be monitored depending on traveling the distance between selected cities in the Czech Republic.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4781
Author(s):  
Szymon Haładyn

This article deals with the new challenges facing modernising railways in Poland. We look at the problem of the efficiency of the power supply system (3 kV DC) used in the context of the increasing use of electric vehicles, which have a higher demand for electricity than the old type. We present and characterise the power supply system in use, pointing out its weaknesses. We consider a case study. The load of the power supply network generated by the rolling stock used in Poland was examined using a microsimulation. A real train timetable was taken into account on a fragment of one of the most important railway line sections in one of the urban agglomerations. Then the results were compared with the results of a microsimulation in which old units were replaced by new trains. These tests were carried out in several variants. We found critical points in the scheduling of railway system use. Our results indicate that it is becoming increasingly necessary to take into account the permissible load capacity of the supply network in certain traffic situations in the process of timetable construction.


2021 ◽  
Vol 181 ◽  
pp. 775-783
Author(s):  
Lívia Macêdo de Alencar ◽  
Rosária de F. Segger Macri Russo ◽  
Cláudia Terezinha Kniess

2021 ◽  
Vol 13 (16) ◽  
pp. 9050
Author(s):  
Mohammad Reza Rahdari ◽  
Andrés Rodríguez-Seijo

Aeolian sediments cover about 6% of the earth’s surface, of which 97% occur in arid regions, and these sediments cover about 20% of the world’s lands. Sand drifts can harm sensitive ecosystems; therefore, this research has aimed to study wind regimes and the monitoring of sand drift potential and dune mobility in the Khartouran Erg (NE Iran). The study investigated 30 years of wind speed and direction to better understand sand dune mobility processes using the Fryberger and Tsoar methods. The results of the wind regime study showed that the eastern (33.4%) and northeastern (14.3%) directions were more frequent, but the study of winds greater than the threshold (6 m/s) in winter, spring, and autumn indicated the dominance of eastern and northern wind directions. Findings of calm winds showed that winters (40.4%) had the highest frequency, and summers (15%) had the lowest frequency; the annual frequency was 30%. The average wind speed in summers was the highest (4.38 m/s), and, in the winters, it was the lowest (2.28 m/s); the annual average wind speed was 3.3 m/s. The annual drift potential (DP = 173 VU) showed that it was categorized as low class, and the winds carried sand to the southwest. The monitoring of drift potential showed that there was a sharp increase between 2003 and 2008, which could have been attributed to a change in wind speeds in the region. Unite directional index, the index of directional variability, has been alternating from 0.3 to 0.6 for 30 years. Furthermore, monitoring of sand mobility recorded a value from 0.1 to 0.4, and the lowest and highest values were registered from 0.08 to 0.9, with an average of 0.27. Finally, it can be concluded that sand dunes have been fixed for a long time, and the intensity of the mobility index is affected by climate changes.


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