Search results for "business.product_category"
showing 10 items of 376 documents
Do the mobile-rich get richer? Internet use, travelling and social differentiations in Finland
2014
This article investigates the daily travelling practices that are related to mobile-only, fixed-only and combined mobile/fixed use of the Internet, and the social differentiations that are related to these three ways of accessing the Internet. Survey data ( N = 612) collected from Finland in 2011 are analysed. The article shows that mobile-only Internet use is not associated with particularly diverse or frequent daily travelling practices, whereas combined mobile/fixed use is. Mobile-only Internet users are, in fact, in a relatively disadvantaged position – compared with other users, they are more typically unemployed and their household income is lower. The mobility of Internet access as …
Forecasting the diffusion of hydrogen EV refuelling infrastructures in Italy
2019
In Italy the electric vehicle revolution is arrived but it still has difficulties to take off. At the moment hybrid technology would seem the most quoted, due especially to range anxiety. The aim of this work is to understand if the fuel cell technology can find place in Italy. The possibility to use fuel cell to storage electric energy is quite interesting: the charging times will be reduced, and heavy passenger transportation should be easily faced. Basing on the existing history and analysis of the information accessible, this paper addresses the existing e-mobility scenario in Italy and predicts the cities in which a hydrogen refuelling infrastructure should be more remunerative, in ord…
Dynamic Simulation of Worm Gears Using CAD Applications
2021
The new processes by plastic deformation of the gears eliminate some of the shortcomings of the old methods of their manufacture, at the same time reducing the production costs and the time of realization of the mass production. To carry out this research, the AutoDesk INVENTOR PROFESSIONAL application was chosen. A worm gear was designed, after which the calculations for the worm and worm wheel were performed. Of particular importance for gear, mechanisms are the research of dynamic loads. The use of modern calculation methods, which have wide possibilities for rapid optimization of prototypes, ensures the minimization or sometimes even exclusion of the execution of experimental samples. T…
Quantitative Characteristics of Information Society and ICT Industry in Latvia
2015
Abstract The article is devoted to statistical analysis of information and communication technology (ICT) industry in Latvia and the development of Information Society in the country. On the basis of statistical data comparison of Latvia with other European countries is made. This comparison shows that Latvia belongs to countries with very well developed Internet. On the other hand the statistical data points on the fact that it is necessary to increase the awareness of population regarding possibilities offered by using of ICT and e-Government.
Does the internet increase the job finding rate? Evidence from a period of expansion in internet use
2021
Abstract We examine the impact of household access to the internet on job finding rates in Germany during a period (2006–2009) in which the share of households with a broadband connection increased by 31 percentage points, and job-seekers increased their use of the internet as a search tool. During this period, household access to broadband internet was almost completely dependent on the availability of a particular technology (DSL). We therefore exploit the variation in DSL availability across municipalities as an instrument for household access to the internet. OLS estimates which control for differences in individual and local area characteristics suggest a job finding advantage of about…
Analysis and design of bi-directional DC-DC converters for ultracapacitors management in EVs
2018
The on-board energy-storage system of an electric vehicle (EV) should be able to collect large amounts of energy and to deal with fast load variations. The use of hybrid power sources as storage devices is an attractive solution, aiming at maximizing both energy and power density. The battery/ultracapacitors (UCs) combination promises to provide significant benefits. An accurate design of bi-directional converters, capable of proplery managing the charge/discharge of the UCs from/to a voltage bus, is essential. In this paper, a bi-directional DC-DC converter connected to a bank of UCs is described and the simulation results are given as well. The designed converter is a buck-boost type, abl…
Experimental Validation of a Novel Method for Harmonic Mitigation for a Three-Phase Five-Level Cascaded H-Bridges Inverter
2019
In modern high-power electrical drives, the efficiency of the system is a crucial constraint. Moreover, the efficiency of power converters plays a fundamental role in modern applications requiring also a limited weight, such as the electric vehicles and novel more electric aircraft. The reduction of losses pushes for systems with a dc bus and a high number of dc/ac converters, widespread in the vehicle, not burdened by a too expensive data processing system. The purpose of this article is to concur to reduce losses by proposing an innovative selective harmonic mitigation method based on the identification of the working areas where the reference harmonics present lower amplitudes. In partic…
Design and Test of a Thermomagnetic Motor Using a Gadolinium Rotor
2013
This paper presents a Thermomagnetic Motor, whose design of the motor is based on a thermal-magnetic coupled dynamic model, which models its magnetic as well thermal properties (magnetic permeability and thermal conductivity). The thermal processes are supposed to be influenced by the thermal conductivity, the convection and the advection. An analytical expression of the generated torque, which links this quantity to the magnetic, thermal and geometrical parameters of the generated torque is given. A design of a machine, based on this theory is proposed and the related performances are numerically simulated. An experimental verification of the performances is reported.
A dq axis theory of the magnetic, thermal, and mechanical properties of Curie motor
2011
A dq axis theory of a thermomagnetic Curie motor is presented. This theory allows one to estimate the performances of a Curie motor from its geometrical, magnetic, and thermal properties. The proposed approach shows that the thermomagnetic Curie motor is equivalent from a magnetic point of view to a dc electric machine. The physical meaning of the parameters used in the dq theory of Curie motor is explicated. The theory is validated by using experimental data.
The use of results of spectral analysis of synchronous generator output voltage for technical diagnostics.
2006
The method of technical diagnostics of ship diesel engine-generator installations is offered. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. On these parameters it is possible to judge quality of course of working processes in diesel engine cylinder, its technical condition. This method is applicable to piston compressor installations with the electric drive.