Search results for "Engines"
showing 10 items of 31 documents
The Experimental Validation of a New Thermodynamic Method for TDC Determination
2007
In-cylinder pressure analysis is becoming more and more important both for research and development purpose and for control and diagnosis of internal combustion engines; directly measured by means of a combustion chamber pressure transducers or evaluated by analysing instantaneous engine speed [1,2,3,4], incylinder pressure allows the evaluation of indicated mean effective pressure (IMEP), combustion heat release, combustion phase, friction pressure, etc...It is well known to internal combustion engine researchers that for a right evaluation of these quantities the exact determination of Top Dead Centre (TDC) is of vital importance: a 1° error on TDC determination can lead to evaluation err…
Constraining the ship contribution to the aerosol of the central Mediterranean
2017
Particulate matter with aerodynamic diameters lower than 10 µm, (PM10) aerosol samples were collected during summer 2013 within the framework of the Chemistry and Aerosol Mediterranean Experiment (ChArMEx) at two sites located north (Capo Granitola) and south (Lampedusa Island), respectively, of the main Mediterranean shipping route in the Straight of Sicily. The PM10 samples were collected with 12 h time resolutions at both sites. Selected metals, main anions, cations and elemental and organic carbon were determined. The evolution of soluble V and Ni concentrations (typical markers of heavy fuel oil combustion) was related to meteorology and ship traffic intensity in the Straight of Sicily…
Extracting work from random collisions: A model of a quantum heat engine
2022
We study the statistical distribution of the ergotropy and of the efficiency of a single-qubit battery ad of a single-qubit Otto engine, respectively fuelled by random collisions. The single qubit, our working fluid, is assumed to exchange energy with two reservoirs, a non-equilibrium "hot" reservoir and a zero temperature cold reservoir. The interactions between the qubit and the reservoirs is described in terms of a collision model of open system dynamics. The qubit interacts with the non-equilibrium reservoir (a large ensemble of qudits all prepared in the same pure state) via random unitary collisions and with the cold reservoir (a large ensemble of qubits in their ground state) via a p…
Performance Prevision of a Turbocharged Natural Gas Fuelled S.I. Engine
2008
Natural gas represents today maybe the most valid alternative to conventional fuels for road vehicles propulsion. The main constituent of natural gas, methane, is characterized by a high autoignition temperature, which makes the fuel highly resistant to knocking: this allows a considerable downsizing of the engine by means of supercharging even under high compression ratio. Starting from these considerations, the authors realized a thermodynamic model of a 4-cilynder s.i. engine for the prevision of in-cylinder pressure, employing a two-zone approach for the combustion and adding sub-models to account for gas properties change and knocking occurrence. An extensive experimental campaign has …
A COMPARISON BETWEEN COMBUSTION PHASE INDICATORS FOR OPTIMAL SPARK TIMING
2008
The closed-loop control of internal combustion engine spark timing may be accomplished by means of a combustion phase indicator, i.e., a parameter, derived from in-cylinder pressure analysis, whose variation is mainly referable to combustion phase shift and assumes a fixed reference value under optimal spark timing operation. The aim of the present work is a comparison between different combustion phase indicators, focusing on the performance attainable by a feedback spark timing control, which uses the indicator as pilot variable. An extensive experimental investigation has been carried out, verifying the relationship between indicators’ optimal values and the main engine running parameter…
Sabiedrībā aktuālu tēmu vizualizācija, izmantojot sociālo tīklu un tīmekļa meklētāju datus
2015
Sabiedrībā risinās notikumi, kuri ir aktuāli un kuriem seko līdzi ikviens mūsdienīgs tīmekļa lietotājs. Pateicoties tieši moderno tehnoloģiju straujajai attīstībai, sabiedrībā aktuālo iespējams uzzināt praktiski vienlaicīgi ar tā risināšanās gaitu. Galvenie darba mērķi ir salīdzināt un izpētīt populārākos tīmekļu meklētājus un sociālos tīklus, kuri nodrošina informācijas piegādi lielākajai daļai lietotāju. Izmantojot tīmekļu meklētāju un sociālo tīklus, iegūtos datus, veikt analīzi par sabiedrībā aktuālo tēmu ieguves iespējām. Balstoties uz izdarītajiem secinājumiem, ievākt un attēlot pieejamo informāciju interneta vietnē. Galvenais uzsvars tiek likts uz vēsturisko datu pieejamību un inform…
A Conversational Agent Based on a Conceptual Interpretation of a Data Driven Semantic Space
2005
In this work we propose an interpretation of the LSA framework which leads to a data-driven “conceptual” space creation suitable for an “intuitive” conversational agent. The proposed approach allows overcoming the limitations of traditional, rule-based, chat-bots, leading to a more natural dialogue.
Ziņu diskurss un ziņu rakstu mašīntulkošana
2019
Pēdējā desmitgadē mašīntulkošana ir ievērojami attīstījusies un tiek plaši izmantota tulkošanas nozarē, lai izpildītu pieaugošo pieprasījumu pēc ātrākiem tulkojumiem un samazinātu izmaksas. Lai maksimāli palielinātu mašīntulkošanas efektivitāti un iegūtu augstas kvalitātes tulkojumu, mašīntulkošanas darbplūsmā parasti tiek iekļauti divi papildus procesi: rediģēšana pirms un pēc mašīntulkošanas. Pētījuma mērķis ir izpētīt gan latviešu, gan angļu ziņu diskursu, kā arī salīdzināt divu mašīntulkošanas rīku – Google Translate un Tilde Translator – efektivitāti, tulkojot ziņu rakstus no angļu valodas latviešu valodā. Darbā tiek pielietotas teorētiskas un praktiskas pētniecības metodes. Teorētiskā…
Yksityisyys ja luottamus hakukoneiden käytössä
2016
Tämä tutkimus käsittelee yksityisyyden ja luottamuksen merkitystä hakukoneissa. Tämä on tärkeää, sillä hakukoneista on muodostunut ihmisten pääsääntöinen tiedon lähde. Näin ollen hakukoneiden yleistyminen on johtanut siihen, että käyttäjistä kerätään yhä enemmän henkilökohtaisia tietoja. Tämän ansiosta käyttäjille on noussut hakukoneista paljon yksityisyyshuolia ja sitä kautta myös luottamus voi rikkoutua. Tämä tutkimus on toteutettu kirjallisuuskatsauksena ja pyrkii vastaamaan tutkimuskysymykseen: mitä käyttäjän yksityisyys ja luottamus tarkoittavat hakukoneiden käytön yhteydessä? Tutkimuksen tulosten mukaan käyttäjien tietoisuuden parantamisella voidaan vaikuttaa sekä kokemukseen yksityis…
Continuum: A spatiotemporal data model to represent and qualify filiation relationships
2013
International audience; This work introduces an ontology-based spatio-temporal data model to represent entities evolving in space and time. A dynamic phenomenon generates a complex relationship network between the entities involved in the process. At the abstract level, the relationships can be identity or topological filiations. The existence of an identity filiation depends on whether the object changes its identity or not. On the other hand, topological filiations are based exclusively on the spatial component, like in the case of growth, reduction, merging or splitting. When combining identity and topological filiations, six filiation relationships are obtained, forming a second abstrac…