Instrumentation for real time monitoring of the overhead contact line acceleration

In any railway power supply system, the contact line is considered one of the most important component influencing the life cycle of the system. The analyses, which estimates the wearing of the contact line but also of the pantograph contact strips, are based on the value of the contact force, which defines the interaction between pantograph, as external component, and overhead contact line. The instrumentation solutions, developed in time of the same project, provide two systems focused for acquisitioning the acceleration and displacement information of the overhead contact line."br" The first developed system uses sensor devices hanging by the contact line, having as objective to collect acceleration information at the contact point of the moving pantograph; the system is described in this paper."br" The second developed system uses one high speed video camera, placed aside the rail track, which register the movements of the contact line. Being a very different technology this system will make subject of other article."br" The both systems have main focus to determine, indirectly, the value of the contact force, but also to optimise a list of controllable factors

Low-cost radio network based system for monitoring mechanical and electromechanical rail interlocking equipment

This paper describes an innovative implementation of digital solutions for rail infrastructure aiming at enhancing the traditional electromechanical rail interlocking equipment. The research sources from the outputs of the NeTIRail-INFRA European project that gravitates around the continental trend to move the majority of passenger and merchandise transport to rail. Growing train traffic leads to the increased use of secondary rail lines that, in various countries in Europe, are still equipped with old mechanical and electromechanical interlocking systems having inappropriate safety levels. This paper presents the principle, general structure and early tests of a new digital system, based on current electronic and computer technologies, that is able to increase the utility and safety of existing mechanical and electromechanical rail interlocking equipment by using low-cost wireless control of two-position elements. Tests conducted thus far validated the system’s features and indicated that possible further developments and upgrades will have additional beneficial effect

Poly(2,5-diphenylgermole): incorporation of a germole ring into a conjugated polymer

The intramolecular zirconocene coupling of 4,4-bis(hexyloxymethyl)-1,7-bis-p-halophenyl-1,6-heptadiynes provides 2,5-bis-p-halophenylzirconocyclopentadienes (bromo and chloro derivatives), which undergo efficient transmetalation reactions with GeBr4. Methylation of the resulting dihalogermoles with MeLi provided bis-p-halophenyl-2,5-germole monomers. These functionalized germoles were polymerized via nickel coupling to give oligo- and poly(2,5-diphenylgermole) materials (7). Investigations of optical properties reveal that the monomers and a model 2,5-bisphenylgermole are somewhat photoluminescent (Φ = 0.018-0.12), while the high molecular weight polymer (Mn ≈ 20000) exhibits very efficient photoemission (Φ = 0.79). Electrochemical studies indicate that delocalization in 7 is accompanied by a modest lowering of the LUMO level relative to that of the monomer

Dynamic thermal performance analysis of two solar air collectors with and without porous media

The paper presents the thermal performance comparison between two types of solar air collectors, with and without porous absorber material. In order to simulate the transient processes which occur in the collectors two mathematical models were developed. Each model consists of a set of time dependent equations which describe the energy balance for the main components of the collector considering time-dependent thermo-physical properties and heat transfer coefficients. The theoretical models were validated by experimental data obtained from measurements performed in different meteorological conditions characteristic to the city of Bucharest – Romania (latitude 44°26′ N, longitude 26°6′ E). Good agreement between the simulation results and experimental data was achieved

Dynamic thermal performance analysis of two solar air collectors with and without porous media

The paper presents the thermal performance comparison between two types of solar air collectors, with and without porous absorber material. In order to simulate the transient processes which occur in the collectors two mathematical models were developed. Each model consists of a set of time dependent equations which describe the energy balance for the main components of the collector considering time-dependent thermo-physical properties and heat transfer coefficients. The theoretical models were validated by experimental data obtained from measurements performed in different meteorological conditions characteristic to the city of Bucharest – Romania (latitude 44°26′ N, longitude 26°6′ E). Good agreement between the simulation results and experimental data was achieved