13 research outputs found
Rolling stock doorways compatibility with platforms at Serbian Railways
Rad prikazuje neke poteÅ”koÄe koje imaju putnici pri ulasku u voz. Prikazane su i razmotrene visine perona prema meÄunarodnim železniÄkim propisima. Dat je pregled visine perona na srpskim prugama i visine poda putniÄkih kola, dizel i elektriÄnih viÅ”edelnih jedinica za prigradski i regionalni saobraÄaj. Rad se fokusira na razlikama izmeÄu politike nabavke, u odnosu na kompatibilnost ulaziÅ”ta sa peronima, dizel i elektriÄnih viÅ”edelnih jedinica Železnice Srbije i posledicama ovih nabavki.This paper shows some of the passenger difficulties when boarding trains. Overview of platform heights is discussed in accordance with international railway regulation. An overview of platform heights at Serbian railway lines and floor heights of passenger coaches, diesel units and electric multiple units for suburban and regional railway transport are shown. This paper is focused on the differences between procurement policy, regarding doorway compatibility with platforms, of diesel and electric multiple units for Serbian Railways and consequences of these acquisitions
Experimental research of the tube absorbers of kinetic energy during collision
Razvoj elemenata za apsorbciju energije sudara je sastavni deo pasivne zaÅ”tite putniÄkih vagona. Pasivna zaÅ”tita ima zadatak da posledice sudara svede na minimum. Apsorber prikazan u radu napravljen je od standardne beÅ”avne cevi u kvalitetu P235T1 i konusnog prstena kvaliteta C45E. Predstavljeno reÅ”enje se zasniva na koriÅ”Äenju specijalnih elemenata koji apsorbuju odreÄenu koliÄinu kinetiÄke energije sudara putem kontrolisane plastiÄne deformacije, Äime se znaÄajno smanjuje deo energije koji se prenosi na noseÄu strukturu vozila. Pri sudaru dolazi do sabijanja-provlaÄenja cevi kroz konusni prsten. TežiÅ”te rada je na eksperimentalnim istraživanjima radi odreÄivanja stvarnih karakteristika apsorbera ovog tipa. Na osnovu analize dobijenih rezultata ispitivanja, predloženo je konaÄno konstruktivno reÅ”enje apsorbera, kao elementa buduÄe konstrukcije Äeonog dela postolja vagona.Development of collision energy absorbing elements is a constituent part of passive protection of passenger coaches. The target of passive protection is to minimize the collision consequences. The absorber, described in this paper, is constructed from a standard seamless tube of the quality P235T1 and conical ring of the quality C45E. The solution presented is based on the application of special elements that absorb a certain amount of collision kinetic energy by means of controlled plastic deformation, significantly decreasing the part of the energy which is transferred to the vehicle bearing structure. The tube is compressed - pushed through the conical ring in collision. The paper focuses on the quasi-static and dynamics experimental research. Based on the analysis of the results obtained in the research, a final design of the absorber is suggested as a part of the future front part of vehicle bearing structure
Experimental research of the tube absorbers of kinetic energy during collision
Razvoj elemenata za apsorbciju energije sudara je sastavni deo pasivne zaÅ”tite putniÄkih vagona. Pasivna zaÅ”tita ima zadatak da posledice sudara svede na minimum. Apsorber prikazan u radu napravljen je od standardne beÅ”avne cevi u kvalitetu P235T1 i konusnog prstena kvaliteta C45E. Predstavljeno reÅ”enje se zasniva na koriÅ”Äenju specijalnih elemenata koji apsorbuju odreÄenu koliÄinu kinetiÄke energije sudara putem kontrolisane plastiÄne deformacije, Äime se znaÄajno smanjuje deo energije koji se prenosi na noseÄu strukturu vozila. Pri sudaru dolazi do sabijanja-provlaÄenja cevi kroz konusni prsten. TežiÅ”te rada je na eksperimentalnim istraživanjima radi odreÄivanja stvarnih karakteristika apsorbera ovog tipa. Na osnovu analize dobijenih rezultata ispitivanja, predloženo je konaÄno konstruktivno reÅ”enje apsorbera, kao elementa buduÄe konstrukcije Äeonog dela postolja vagona.Development of collision energy absorbing elements is a constituent part of passive protection of passenger coaches. The target of passive protection is to minimize the collision consequences. The absorber, described in this paper, is constructed from a standard seamless tube of the quality P235T1 and conical ring of the quality C45E. The solution presented is based on the application of special elements that absorb a certain amount of collision kinetic energy by means of controlled plastic deformation, significantly decreasing the part of the energy which is transferred to the vehicle bearing structure. The tube is compressed - pushed through the conical ring in collision. The paper focuses on the quasi-static and dynamics experimental research. Based on the analysis of the results obtained in the research, a final design of the absorber is suggested as a part of the future front part of vehicle bearing structure
Modern trends in designing high-speed trains
PoveÄanje konkuretnosti železniÄkih transportnih sistema u odnosu na druge vidove transportnih sistema u poslednjih Å”ezdeset godina rezultat je intenzivnog razvoja novih generacija brzih vozova. Ove vrste vozova ne samo da zadovoljavaju potrebe za poveÄanom brzinom prevoza, a tako i kraÄe vreme putovanja, veÄ i zahteve za poveÄanje pouzdanosti, sigurnosti i direktne primene energetske efikasnosti na sam sistem transporta. Sa poveÄanjem brzine vozova, poveÄavaju se i otpori kretanja, pri Äemu pri brzinama veÄim od 200 km/h udeo otpora vazduha postaje najdominantniji Älan. Jedna od najefikasnijih mera za smanjenje otpora vazduha, kao i ostalih negativnih posledica koje nastaju pri kretanju velikim brzinama, je razvoj aerodinamiÄkog oblika voza. U ovom radu su predstavljena neka od konstrukcionih reÅ”enja koja utiÄu na aerodinamiÄke karakteristike vozova velikih brzina, pre svega oblik Äeonog dela, kao i sliÄnosti i razlike pojedinih podsistema neophodnih za funkcionisanje savremenih železniÄkih sisteme vozova velikih brzina. Analizirana su dva pristupa reÅ”avanja problema aerodinamiÄkog oblika voza i odgovarajuÄe infrastructure na primeru Japana i Francuske. Razmatrana su dva modela voza velikih brzina, Shinkansen (Japan) i TGV odnosno AGV (Francuska.).Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself. Along with increased train speed, the motion resistance is increased as well, whereby at speeds over 200 km/h the proportion of air resistance becomes the most dominant member. One of the most efficient measures for reducing air resistance, as well as other negative consequences of high-speed motion, is the development of the aerodynamic shape of the train. This paper presents some construction solutions that affect the aerodynamic properties of high-speed trains, first and foremost, the nose shape, as well as the similarities and differences of individual subsystems necessary for the functioning of modern high-speed rail systems. We analysed two approaches to solving the problem of the aerodynamic shape of the train and the appropriate infrastructure using the examples of Japan and France. Two models of high-speed trains, Shinkansen (Japan) and TGV, i.e. AGV (France), have been discussed
Modern trends in designing high-speed trains
PoveÄanje konkuretnosti železniÄkih transportnih sistema u odnosu na druge vidove transportnih sistema u poslednjih Å”ezdeset godina rezultat je intenzivnog razvoja novih generacija brzih vozova. Ove vrste vozova ne samo da zadovoljavaju potrebe za poveÄanom brzinom prevoza, a tako i kraÄe vreme putovanja, veÄ i zahteve za poveÄanje pouzdanosti, sigurnosti i direktne primene energetske efikasnosti na sam sistem transporta. Sa poveÄanjem brzine vozova, poveÄavaju se i otpori kretanja, pri Äemu pri brzinama veÄim od 200 km/h udeo otpora vazduha postaje najdominantniji Älan. Jedna od najefikasnijih mera za smanjenje otpora vazduha, kao i ostalih negativnih posledica koje nastaju pri kretanju velikim brzinama, je razvoj aerodinamiÄkog oblika voza. U ovom radu su predstavljena neka od konstrukcionih reÅ”enja koja utiÄu na aerodinamiÄke karakteristike vozova velikih brzina, pre svega oblik Äeonog dela, kao i sliÄnosti i razlike pojedinih podsistema neophodnih za funkcionisanje savremenih železniÄkih sisteme vozova velikih brzina. Analizirana su dva pristupa reÅ”avanja problema aerodinamiÄkog oblika voza i odgovarajuÄe infrastructure na primeru Japana i Francuske. Razmatrana su dva modela voza velikih brzina, Shinkansen (Japan) i TGV odnosno AGV (Francuska.).Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself. Along with increased train speed, the motion resistance is increased as well, whereby at speeds over 200 km/h the proportion of air resistance becomes the most dominant member. One of the most efficient measures for reducing air resistance, as well as other negative consequences of high-speed motion, is the development of the aerodynamic shape of the train. This paper presents some construction solutions that affect the aerodynamic properties of high-speed trains, first and foremost, the nose shape, as well as the similarities and differences of individual subsystems necessary for the functioning of modern high-speed rail systems. We analysed two approaches to solving the problem of the aerodynamic shape of the train and the appropriate infrastructure using the examples of Japan and France. Two models of high-speed trains, Shinkansen (Japan) and TGV, i.e. AGV (France), have been discussed
The comparison of gamma-radiation and electrical stress influences on oxide and interface defects in power VDMOSFET
The behaviour of oxide and interface defects in n-channel power vertical
double-diffused metal-oxide-semiconductor field-effect transistors, firstly
degraded by the gamma-irradiation and electric field and subsequently
recovered and annealed, is presented. By analyzing the transfer
characteristic shifts, the changes of threshold voltage and underlying
changes of gate oxide and interface trap densities during the stress
(recovery, annealing) of investigated devices, it is shown that these two
types of stress influence differently on the gate oxide and the SiO2-Si
interface. [Projekat Ministarstva nauke Republike Srbije, br. OI171026
Early identification of children with developmental delay and behavioural problems according to parents concerns in the Republic of Serbia
The main goal of this research was to describe the type and level of parents' concerns about child development and behaviour according to the PEDS test (Parents' Evaluation of Developmental Status). The sample included 289 parents of children from three to seven years of age, from two preschool institutions in Serbia. A significantly high correlation was determined between parents' general concerns and expressed concerns with regard to behaviour ((2)=17.86, df=2, p lt .001) and getting along with others ((2)=22.57, df=2, p lt .000). A marginally significant correlation was determined between parents' general concerns and manifested concerns with regard to fine motor skills ((2)=5.90, df=2, p=.052), as well as expressive language ((2)=5.858, df=2, p=.053). According to the criteria of PEDS test, this research identified 56.4% of children whose development needed to be monitored, 27.7% of children who needed to be referred for detailed diagnostic procedures, and 1.7% who needed to be included in treatment or special education support.This is the peerāreviewed version of the article: IliÄ, S. B.; NikoliÄ, S. J.; IliÄ-StoÅ”oviÄ, D. D.; GoluboviÄ, Å . S. Early Identification of Children with Developmental Delay and Behavioural Problems According to Parents Concerns in the Republic of Serbia. Early Child Development and Care 2020, 190 (16), 2605ā2611. [https://doi.org/10.1080/03004430.2019.1595610
Determining the influence of an air wave caused by a passing train on the passengers standing at the platform
This paper presents the results of research on the influence of an air wave, caused by a passing train on a person standing on the station platform. The tests were conducted in a real environment, at a railroad, on a doll and in a subsonic wind tunnel, on a 1 : 20 scale model of a high speed passenger train. Also, simulations of airflow, induced under the same conditions, were performed using the fluent software tool. At the end, the stability of a female with predefined biomechanical characteristics, exposed to an aerodynamic shock while standing on the platform, was estimated
Determining the influence of an air wave caused by a passing train on the passengers standing at the platform
This paper presents the results of research on the influence of an air wave, caused by a passing train on a person standing on the station platform. The tests were conducted in a real environment, at a railroad, on a doll and in a subsonic wind tunnel, on a 1 : 20 scale model of a high speed passenger train. Also, simulations of airflow, induced under the same conditions, were performed using the fluent software tool. At the end, the stability of a female with predefined biomechanical characteristics, exposed to an aerodynamic shock while standing on the platform, was estimated