1,720,958 research outputs found
Superautomobilio aerodinaminių savybių tyrimas.
No full textIn this modern world aerodynamics plays vital role in super cars and it predominantly used in Motorsports industry for achieving vehicle better performance.This master thesis portrays that can be viewed about the methods of aerodynamic characteristics and why aerodynamics plays a vital role in super cars in efficient way. By installing spoiler,splitter and drag reduction in super cars for achieving better performance of the vehicle. Propose a method of reducing the drag and increase the down force in efficient way for the better function.As this mainly uses aerodynamic devices to affect the flow, a conventional spoiler is used here to spoil the oncoming flow with different types of spoiler design.Even in today’s modern technique all the super cars are not able to reduce the drag in efficient way because of its overall weight of the vehicle.The most essential thing is replacing all the parts of vehicles metal body by current efficient material will put super cars in question mark because it cannot be used for commercial purpose.So here a proposed method is to trim the side body in design and installing wind splitter and spoiler to achieve better performance in similar geometry shape. Nowadays, all the super cars have independent working of front and rear spoilers, but in this thesis splitter and spoiler are collaborated towards each other in efficient way
ESP sistemos transporto priemonės tyrimas ir transporto priemonės dinamikos analizė imituojant vedyna.
No full textElectronic Stability programme is an active safety system which was introduced by Robert Bosch to improve the stability of the vehicle and prevent the vehicle from an emergency situation such as skidding, understeer, oversteer and rollover accident. With the increase in production of vehicle in developing countries like India, China and introduction of more sports variants by countries like Germany, Italy has lead to increase in number of accidents, so it is of utmost importance that active safety system like ESP must be implemented in all vehicle to protect the passengers from fatalities and reduce the road accidents. To study about the ESP system and analyze the various properties that influence skidding, understeer, oversteer, and rollover specific car model Lamborghini Aventador lp 700 – 4 was chosen and tested by using various regulations in modelling simulation software veDYNA. The testing regulations such as steer step, double lane change, slalom test, circle drive and mu-split was used with varied parameters to know about the limits of the vehicle in various conditions. The graphs generated in the plot - gui of veDYNA software was used to analyze the yaw rate, yaw angle, roll angle, sideslip angle, steering wheel angle and lateral acceleration of the vehicle. The aim of the research is to study about the effectiveness of ESP system using theoretical methods and apply various methods leading to skidding, understeer, oversteer, and rollover using vehicle simulation software veDYNA which is linked with Matlab/Simulink interface
Investigation on the characteristics of diesel engine running on microalgal oil
Get PDFMikrodumbliai išsiskiria iš visų žinomų biomasės rūšių savo galimybe atliepti ateities iššūkius, jei vertinsim jų prieinamumą, trumpą augimo periodą, greitą prieaugį, derliaus kiekį gaunamą iš ploto vieneto, konkurencijos nebuvimą su dirbama žeme. Šios savybės leidžia dumblių biomasę laikyti tinkamiausia žaliava gaminti biodegalus ir pridėtinę vertę kuriančius antrinius produktus naudojant biologinio perdirbimo technologijas. Šio darbo autorius iškėlė problemą, kad norint atsisakyti dalies iškastinių degalų naudojamų transporto sektoriuje, dalį suvartojamo dyzelino galima būtų sėkmingai pakeisti biodegalais, pagamintais iš mikrodumblių rūšies P.moriformis. Šis disertacinis darbas dedikuotas detaliam mikrodumblių aliejaus naudojamo transporte vertinimui, kuris apėmė mikrodumblių auginimo technologijos parinkimą, variklio degimo proceso skaitinį modeliavimą, pagamintų biodegalų fizikinių-cheminių charakteristikų nustatymą, išsamius dyzelinio variklio eksploatacinių ir aplinkosauginių charakteristikų tyrimus jam dirbant skirtingomis apkrovomis, paankstintais arba pavėlintais degalų įpurškimo kampais bei aktyviu /neaktyviu deginių recirkuliaciniu vožtuvu.
Disertaciją sudaro įvadas, trys skyriai, bendrosios išvados, naudotos litera-tūros sąrašas, autoriaus publikacijų sąrašas ir priedai.
Įvadinėje dalyje suformuluota problematika, aptartas darbo aktualumas ir tyrimų tikslai. Metodika ir įvardinti uždaviniai pabrėžia ir atspindi darbo aktualumą ir jo mokslinį naujumą. Taip pat šioje dalyje supažindinama su disertacinio darbo struktūra ir autoriaus publikacijomis tyrimų tematika.
Pirmasis skyrius skaitytojui leidžia pažvelgti į Lietuvos transporto sektorių ir jo kelių dešimtmečių kelią darnaus mobilumo link, vertinant oro taršos pokyčius. Mikrodumblių potencialo biodegalų gamybą, procesų inžinerijos svarbą ir įvairių sinergijų paiešką siekiant efektyvumo. Apžvelgti mokslininkų tyrimai slėginio suspaudimo varikliuose naudojant grynus augalinius aliejus bei jų mišiniu su mineraliniu dyzelinu. Antrajame skyriuje aprašyta tyrimų metodologija, naudota įranga, eksperimentų eiga, degalų terminės analizės rezultatai ir paklaidų skaičiavimas. Trečiame skyriuje pateikti eksperimentinių tyrimų rezultatai, kurie apima: mikrodumblių aliejaus degimo proceso dyzelinio variklio cilindruose skaitinį modeliavimą, naudojant AVL BOOST programinį paketą; Laboratorinio variklio energetinių ir ekologinių rodiklių pokyčius, priklausomai nuo apkrovos charakteristikos; Reguliavimo charakteristikos paankstinant ir/arba pavėlinant degalų įpurškimą ir jo įtaka dyzelinio variklio energetiniams ir ekologiniams rodikliams; Išorinę greičio charakteristiką varikliui veikiant mikrodumblių aliejaus ir dyzelino mišiniu.Disertacij
Algal Biodiesel in Lithuania: From Promise to Reality
No full textAbstractThe search for alternative fuel sources of organic origin, their adaptation and promotion emerged as one of the key focus areas worldwide, which could bring positive effect on lowering down the fossil fuel prices and solving the environmental problems. Algal biodiesel intended for use in the vehicles is among the solutions for the transport sector. In this article, we made an overview of biodiesel investigation in Lithuania over 11 years. Algae are the third generation biofuel form with high production perspective. This microorganism can be found almost everywhere even in Arctic. Algae can be counted as 55 000 species organism with great number of growth and quantities of biomass per unit. Possibilities and challenges of biodiesel from algae in Lithuania have been analysed. Application and compatibility of algae biodiesel in internal combustion engine has been investigated. Many advantages of biodiesel have been presented as well as some disadvantages were found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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