Search results for "Spar"
showing 10 items of 1739 documents
Design and Implementation of an Electronic Control Unit for a CFR Bi-Fuel Spark Ignition Engine
2017
In this work an Electronic Control Unit for the management of a CFR engine will be described. The engine, which is used both for fuel octane rating (both in terms of RON and MON) and for research purpose, is equipped with a double injection system, with the aim to independently operate both with liquid and gaseous fuels. The developed ECU, hence, is able to control the injections of both kind of fuel, together with the spark ignition. Furthermore the system is also able to measure fuel’s consumption, instantaneous engine speed of rotation and air-fuel ratio, showing all the running parameters both on a local LCD display and on a PC based graphical user interface.
Spark ignition feedback control by means of combustion phase indicators on steady and transient operation
2014
In order to reduce fuel cost and CO2 emissions, modern spark ignition (SI) engines need to lower as much as possible fuel consumption. A crucial factor for efficiency improvement is represented by the combustion phase, which in an SI engine is controlled acting on the spark advance. This fundamental engine parameter is currently controlled in an open-loop by means of maps stored in the electronic control unit (ECU) memory: such kind of control, however, does not allow running the engine always at its best performance, since optimal combustion phase depends on many variables, like ambient conditions, fuel quality, engine aging, and wear, etc. A better choice would be represented by a closed-…
A Study on the Use of Combustion Phase Indicators for MBT Spark Timing on a Bi-Fuel Engine
2007
The performance of a spark ignition engine strongly depends on the phase of the combustion process with respect to piston motion, and hence on the spark advance; this fundamental parameter is actually controlled in open-loop by means of maps drawn up on the test bench and stored in the Electronic Control Unit (ECU). Bi-fuel engines (e.g. running either on gasoline or on natural gas) require a double mapping process in order to obtain a spark timing map for each of the fuels. This map based open-loop control however does not assure to run the engine always with the best spark timing, which can be influenced by many factors, like ambient condition of pressure, temperature and humidity, fuel p…
Empirical relationships for monitoring water quality of lakes and reservoirs through multispectral images
2014
Remote sensing techniques can be used to estimate water quality variables such as chlorophyll ${\mbi a}$ , total suspended particles, and water transparency. This paper describes empirical algorithms for the estimation of these variables using Landsat Thematic Mapper (TM) data. Ground data were taken from several Spanish lakes covering a variety of trophic statuses, ranging from oligotrophic to hypereutrophic. The studied lakes were the Albufera de Valencia and lakes and ponds of the Southeast Regional Park in Madrid. Empirical equations were obtained to estimate chlorophyll ${\mbi a}$ from the ratio in reflectance values between bands 2 and 4 of TM ( $\bf{ R^2 \, {\mmb =}\, 0.66}$ , ${\bf …
Corporate e-Governance Disclosure in the Digital Age: An Empirical Study of Spanish Listed Companies
2005
Corporate governance research has focused mainly on the analysis of the information that firms ought to disclose and the effects of disclosure, basically without considering the media involved. This paper examines the relevance of technology, and particularly the internet, for the improvement of corporate governance and transparency in listed companies. The need for this study is clear in view of the increasing interest shown by supervisory authorities for the oversight of the European and US capital markets in regulating not only content but also the manner in which corporate governance information is disclosed over the internet. In this paper we have quantified three corporate governance …
Performance Outcomes of Turnover Intentions in Temporary Organizations: A Dyadic Study on the Effects at the Individual, Team, and Organizational Lev…
2017
This research examines the link between turnover intentions from temporary and permanent organizations and how both types of turnover intentions affect employee performance at an individual, temporary and permanent organizational level. Using dyadic data from 253 team members and their supervisors we find that turnover intentions from temporary organizations significantly enhance turnover intentions from permanent organizations, which leads to decreasing performance at all three levels. A moderation analysis suggests that companies can reduce detrimental effects of turnover intentions from temporary organizations by providing transparency and possibilities to participate in staffing process…
Transition and Constitution in School/Work Relations
2012
In every industrial society, there must exist some kind of a transitional mechanism between the demand for and supply of a labour force, that is, a mechanism that facilitates the transition from school to work and from job to job both inside and outside the labour force. There are at least two main ways of organising such a school-labour network. The first way follows the pattern of a marketplace, that is, the labour market process is an extension of the existing market of commodities. In this pattern, the fundamental question in the marketplace relates to buying and selling and to pricing. The second way in which a school-labour network can be organised is based on the idea of a social gua…
Inequalities in mortality in small areas of eleven Spanish cities (the multicenter MEDEA project)
2009
The objectives of this study are to identify inequalities in mortality among census tracts of 11 Spanish cities in the period 1996-2003 and to analyse the relationship between these geographical inequalities and socioeconomic deprivation. It is a cross-sectional ecological study where the units of analysis are census tracts. We obtained an index of socioeconomic deprivation and estimated SMR by each census tract using hierarchical Bayesian models which take into account the spatial structure. In the majority of the cities geographical patterns in total mortality were found in both sexes, which were similar to those for the index of socioeconomic deprivation. Among men, four specific causes …
Modulation of Neurological Deficits and Expression of Glutamate Receptors during Experimental Autoimmune Encephalomyelitis after Treatment with Selec…
2013
The aim of our investigation was to characterize the role of group I mGluRs and NMDA receptors in pathomechanisms of experimental autoimmune encephalomyelitis (EAE), the rodent model of MS. We tested the effects of LY 367385 (S-2-methyl-4-carboxyphenylglycine, a competitive antagonist of mGluR1), MPEP (2-methyl-6-(phenylethynyl)-pyridine, an antagonist of mGluR5), and the uncompetitive NMDA receptor antagonists amantadine and memantine on modulation of neurological deficits observed in rats with EAE. The neurological symptoms of EAE started at 10-11 days post-injection (d.p.i.) and peaked after 12-13 d.p.i. The protein levels of mGluRs and NMDA did not increase in early phases of EAE (4 d.p…
Misfire Detection System based on the Measure of Crankshaft Angular Velocity
2007
Misfire detection systems are becoming increasingly important in automotive market due to recent environmental issues (Euro rules). An early misfire diagnosis also allows to prevent damages to the exhaust emission system and consequent costs for the user. Today few low cost methods exists in order to precisely detect single misfires in real time, the majority in fact require the use of expensive sensors (e.g. pressure sensors) or dedicated circuits (e.g. ionization current sensing). This work describes a method and electronic system capable of detecting misfires with good accuracy, using parameters such as the speed sensor signal, already available in commercial engines. The proposed method…