813 research outputs found
Teoreettinen monimittakaavamallinnus Al2O3 ja ZnO ohutkalvojen atomikerroskasvatuksesta
No full textThe rapid development of nanotechnology, especially in the field of microelectronics, and ever shrinking dimensions of device components set high requirements for the manufacturing of the necessary nanostructures. Many microscopic components, e.g. transistors, are constructed layer-by-layer from thin film. An important tool 21st century technique for the fabrication of such thin films is the atomic layer deposition. Atomic layer deposition, originally developed in Finland, is based on sequential self-limiting gas-pulses, resulting in a uniform, pin-hole free thin film, with thickness control at the atomic level.
Computational modeling is an important part of modern chemistry. Research can be conducted theoretically - without empirical parameters - with the application of quantum mechanics. With quantum mechanical calculations it is possible to model the electronic structure of molecules and to study the bonding and interactions of molecules as well as different molecular mechanisms. In this work, the deposition of aluminium and zinc oxides were studied using computational chemistry. Both oxides have wide range of applications e.g. in transistors and solar cells.
Aluminium oxide is usually deposited using a trimethylaluminium-water-process. The surface chemistry was studied on a realistic hydroxylated surface model and trimethylaluminium was observed to react rapidly with surface hydroxyl groups to produce monomethylaluminium. Monomethylaluminium was estimated to be relatively inert and to convert to aluminium only at high temperatures. Subsequent water pulse mechanisms were also studied at low methyl-coverage. Direct dimethylaluminium--water reactions were accessible at process conditions, but the elimination of monomethylaluminium by water requires a complex cooperative mechanism.
Zinc oxide is usually deposited using a diethylzinc-water-process. Diethylzinc was found to convert rapidly into monoethylzinc but the elimination of monoethylzinc was found to be a slow process. Based on the calculations, two ethyl-saturated surface structures were constructed, corresponding to low and high temperature estimations. These saturated surfaces were used in a subsequent study on the water pulse reactions, resulting in a reaction network for a complete ALD cycle.
The growth of the zinc oxide thin film was then modeled in macroscopic scale using a kinetic Monte Carlo model. The kinetic modelling enables a direct comparison with experimental measurements. The kinetic model, built upon the theoretical calculations, accurately predicted the temperature-dependency of the film growth. Also, the predicted growth per cycle is in good agreement with experimental data.Nanotekniikan, erityisesti pienelektroniikan, nopea kehitys ja alati kutistuvat komponentit ovat asettaneet kovia vaatimuksia laitekomponenttien valmistusmenetelmille. Monet mikroskooppiset laitteet, esimerkiksi transistorit, valmistetaan kasvattamalla päällekäin erilaisia materiaali-kerrostumia, ohutkalvoja. Atomikerroskasvatus, ALD, on noussut tärkeäksi ohutkalvojen kasvatusprosessiksi 2000-luvulla. Atomikerroskasvatus on perujaan suomalainen prosessi, jossa kaasumaisia itseäänrajoittavia reagenssipulsseja vuorottemalla saadaan kasvatettua yhtenäinen ja sileä ohutkalvo, jonka paksuutta voidaan säädellä atomin tarkkuudella.
Laskennallinen mallintaminen tärkeä osa nykyajan kemian tutkimusta. Tutkimusta voidaan tehdä teoreettisesti - ilman empiirisiä parametreja - soveltamalla kvanttimekaniikkaa. Kvantti-mekaniikalla päästään käsiksi molekyylien elektronirakenteeseen ja voidaan tutkia molekyylien sitoutumista, vuorovaikutusta sekä erilaisia reaktiomekanismeja. Tässä työssä on tutkittu laskennallisesti alumiini- ja sinkkioksidiohutkalvojen kasvatusta ALD:llä. Molemmilla oksideilla on lukuisia teollisia sovelluskohteita, mm. transistoreissa ja aurinkokennoissa.
Alumiinioksidia kasvatetaan yleisesti trimetyylialumiini-vesi-prosessilla. Prosessin pintakemiaa tutkittiin realistisella veden peittämällä pintamallilla ja trimetyylialumiinin havaittiin reagoivan nopeasti pinnalla monometyylialumiiniksi. Monometyylialumiinin arvioitiin reagoivan alumiiniksi vasta korkeissa lämpötiloissa. Veden todettiin voivan reagoida dimetyylialumiinin kanssa reaktori-olosuhteissa. Monometyylialumiinin eliminointi on sen sijaan mutkikkaampi ja vaatii yhtäaikaa useamman vesimolekyylin.
Sinkkioksidia kasvatetaan vastaavasti dietyylisinkki-vesi-prosessilla. Dietyylisinkin reagoi pinnalla nopeasti monoetyylisinkiksi, mutta monoetyylisinkin eliminoiti on kohtalaisen hidas prosessi. Reaktiomekanismien pohjalta rakennettiin kaksi etyylin peittämää pintarakennetta, jotka vastasivat pinnan saturoitumista matalassa ja korkeassa lämpötilassa. Näitä etyylin peittämiä pintoja hyödynnettiin vesipulssin reaktiomekanismeja tutkimiseen. Sinkkioksidin kasvulle saatiin näin rakennettua koko ALD kierroksen kattava reaktiomekanismiverkosto.
Sinkkioksidiohutkalvon kasvua mallinnettiin makroskooppisessa mittakaavassa kineettisen Monte Carlo -mallin avulla. Kineettinen malli mahdollistaa helpon vertailun kokeellisten mittausten kanssa. Teoreettisista reaktiolaskuista rakennettu kineettinen malli kykeni ennustamaan ohutkalvon kasvun lämpötila-riippuvuuden tarkasti. Myös mallista laskettu kierroskasvu vastaa hyvin kokeellisia tuloksia
The Spoken Wikipedia Corpora
No full textThe Spoken Wikipedia project unites volunteer readers of Wikipedia articles. Hundreds of spoken articles in multiple languages are available to users who are – for one reason or another – unable or unwilling to consume the written version of the article. Our resource, the Spoken Wikipedia Corpus, consolidates the Spoken Wikipediae, adding text segmentation, normalization, time-alignment and further annotations, making it accessible for research and fostering new ways of interacting with the material.
Timo Baumann and Arne Köhn and Felix Hennig. 2018. The Spoken Wikipedia Corpus Collection: Harvesting, Alignment and an Application to Hyperlistening, in Language Resources and Evaluation, Special Issue representing significant contributions of LREC 2016.
Arne Köhn, Florian Stegen, Timo Baumann. 2016. Mining the Spoken Wikipedia for Speech Data and Beyond, in Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC 2016).
CLARIN Metadata summary for The Spoken Wikipedia Corpora (CMDI-based)
Title: The Spoken Wikipedia Corpora
Description: The Spoken Wikipedia project unites volunteer readers of Wikipedia articles. Hundreds of spoken articles in multiple languages are available to users who are – for one reason or another – unable or unwilling to consume the written version of the article. Our resource, the Spoken Wikipedia Corpus, consolidates the Spoken Wikipediae, adding text segmentation, normalization, time-alignment and further annotations, making it accessible for research and fostering new ways of interacting with the material.
Publication date: 2017
Data owner: Timo Baumann - Universität Hamburg
Contributors: Timo Baumann (author), Arne Köhn (author), Florian Stegen (author)
Languages: English (eng), German (deu), Dutch (nld)
Size: 5397 article, 1005 hour
Segmentation units: other
Genre: encyclopedia
Modality: spoken
References: Timo Baumann; Arne Köhn; Felix Hennig (2018) The Spoken Wikipedia Corpus Collection: Harvesting, Alignment and an Application to Hyperlistening References: Arne Köhn; Florian Stegen; Timo Baumann (2016) Mining the Spoken Wikipedia for Speech Data and Beyon
Replication Data for: Efficient Application of Accelerator Cards for the Coupling Library preCICE
No full textThis dataset contains all testcase setup files and result files for the measurements presented in the Master's thesis with the title "Efficient Application of Accelerator Cards for the Coupling Library preCICE" (Author: Timo Pierre Schrader).
Furthermore, it contains the version of preCICE used throughout this thesis.
The thesis revolves around GPU acceleration of RBF data mapping in preCICE. See the README for more information how to build and run the testcase
Timo de Rijk: 'We plant the seed'; interview
No full textArt historian Timo de Rijk was appointed Professor of Design, Culture and Society in Delft and Leiden last September. He calls this combination ‘a real breakthrough’. ‘Leiden University studies the workings of culture, while TU Delft aims at creating new things. These are fundamentally different approaches. I am the bridge between the two.’Industrial Design Engineerin
Educación Artística Comunitaria en Finlandia: entrevista a Timo Jokela
No full textEste artículo presenta un estudio sobre la educación artística comunitaria en la Universidad de Laponia en Finlandia. En primer lugar se analizan las líneas principales de este modelo formativo y de su plan de estudios. En segundo lugar se presenta una entrevista con Timo Jokela, Decano de la Facultad de Arte y Diseño de la Universidad de Laponia y director del Departamento de Educación Artística en esa misma Facultad. En la entrevista Timo Jokela habla de las relaciones entre arte, medio ambiente, comunidad y educación partiendo de su propia experiencia como artista y centrado en el contexto finlandés. También sobre los aspectos sociales, culturales, artísticos y educativos que están implícitos en el modelo de educación artística comunitaria que se pone en práctica, como itinerario formativo, en la Universidad de Laponia.
This article presents a study on community-based art education at the University of Lapland in Finland. First, the main guidelines of this training model and its curriculum are analysed. Second, the author includes an interview with Timo Jokela, Dean of the Faculty of Art and Design of The University of Lapland in Finland and Director of the Department of Art Education at the same faculty. In the interview Timo Jokela draws upon his own experience as an artist in Finland to talk about the relationships between art, the environment, community and education. He also talks about the social, cultural, artistic and educational aspects, which are central to the community-based art education scheme in place at The University of Lapland
Modelling the growth reaction pathways of zincone ALD/MLD hybrid thin films : a DFT study
No full textALD/MLD hybrid thin films can be fabricated by combining atomic layer deposition (ALD) and molecular layer deposition (MLD). Even though this deposition method has been extensively used experimentally, the computational work required to acquire the reaction paths during the thin film deposition process is still in dire demand. We investigated hybrid thin films consisting of diethyl zinc and either 4-aminophenol or hydroquinone using both gas-phase and surface reactions to gain extensive knowledge of the complex phenomena occurring during the process of hybrid thin film deposition. We used density functional theory (DFT) to obtain the activation energies of these kinetic-dependent deposition processes. Different processes of ethyl ligand removal as ethane were discovered, and we found that the hydroxyl group of 4-aminophenol was more reactive than the amino group in the migration of hydrogen to an ethyl ligand within a complicated branching reaction chain.peerReviewe
Ei-ladattavan hybridiauton esilämmitys : vaikutukset järjestelmän toimintakykyyn
No full textTämän opinnäytetyön tarkoituksena oli tutkia ja selvittää sähköisen esilämmityksen vaikutuksia hybridijärjestelmän toimintaan. Työssä tarkasteltiin erityisesti vaikutuksia matkaan joka ajettiin pelkästään käyttämällä sähköä auton hybridiakustosta. Samalla seurattiin auton polttoaineen keskikulutuksen muutoksia. Nämä vaikutukset saatiin parhaiten näkyviin, ajamalla samoja reittejä esilämmitetyllä ja ilman esilämmitystä olevalla autolla sekä vertailemalla näistä saatuja tuloksia.
Työssä käytettävä hybridiauto on tekijän omistuksessa ja omassa käytössä. Autoa käytetään pääsääntöisesti taajamaliikenteessä, mutta myös maantie- ja moottoritienopeuksissa. Ajaminen koostuu tekijän normaalista auton käytöstä. Työhön kuuluu kolme eri vaihetta. Ensimmäisessä vaiheessa autoa esilämmitettiin ennen jokaista kotona suoritettua liikkeellelähtöä, työn tekemisen aikana voimassa olleiden suosituksien mukaisesti. Toisessa vaiheessa autoa ei esilämmitetty ennen ajoon lähtöä. Kolmannessa vaiheessa tulokset kirjattiin muistiin ja analysoitiin.
Hybridijärjestelmän käyttö vähentää polttoaineen kulutusta ja päästöjä verrattuna pelkästään polttomoottorilla varustettuun autoon. Auton esilämmitys parantaa sekä ajoturvallisuutta että mukavuutta, kun lämpötila on pakkasella tai lähellä nollaa. Esilämmitetty moottori saavuttaa nopeammin normaalin käyntilämpötilan verrattuna moottoriin, jota ei ole esilämmitetty ennen ajoon lähtöä. Kun moottori käy normaalilla käyntilämpötilallaan, päästöt ja polttoaineen kulutus pienentyvät verrattuna kylmänä käyvään moottoriin. Myös käynnistyksen päästöjä saadaan pienennettyä esilämmityksellä.
Autolla on ajettu pääsääntöisesti lyhyitä matkoja, jolloin järjestelmän polttomoottori ei ole saavuttanut normaalia käyntilämpötilaansa. Työn tuloksena havaittiin, että esilämmitys vaikuttaa myönteisesti hybridijärjestelmän kykyyn käyttää pelkästään sähkömoottoria auton liikuttamiseen. Tämä tulos on ennakko-odotusten mukainen.The purpose of the thesis was to study the effects of electronic preheating on the operation of a hybrid system. The impact of the trip, which was driven by using only electricity from the car hybrid battery, was specifically examined in this thesis. At the same time, changes in the average fuel consumption of the car were tracked. The effects were best noticed driving the same routes with a preheated car and the car without preheating, and comparing the results.
The hybrid car used in the work is owned and used by the author. The car is mainly used in urban area but also at highway speeds. Driving consists of the author´s normal car use. The work involved three different phases. In the first phase, the car was preheated before each start-up at home, in accordance with the recommendations in force at the time of the work. In the second phase, the car was not preheated before start-ups. In the third phase, the results were reported and analyzed.
Using a hybrid system in a car reduces fuel consumption and emissions compared to a car with an internal combustion engine only. Car preheating improves both driving safely and comfort when the temperature is low or near zero degrees. A preheated engine reaches faster its normal operating temperature compared to an engine that has not been preheated before driving. When the engine is running at its normal operating temperature, emissions and fuel consumption are reduced compared to a cold engine. Start-up emissions can also be reduced by preheating.
The car has been mainly driven for short distances, whereupon the internal combustion engine of the system has not reached its normal operating temperature. The study shows that preheating has a positive effect on the ability of the hybrid system to use only an electric motor to move the car. This result is in line with the expectations
Cittadinanza amministrativa e democrazia partecipativa
No full textThis paper examines the definition of participation focusing on the idea of
administrative participation and the concept of administrative democracy.
Therefore, the author analyses the alteration of citizenship notion as the result of the change in
the relationship between citizens and public administration: the adoption of the law 241/1990 –
together with other laws – and the gradual opening of administrative institutions give new tools to
citizens to create an administrative democracy
Tagging of Biomedical Articles on CiteULike: A Comparison of User, Author and Professional Indexing
No full textThis paper examines the context of online indexing from the viewpoint of three different groups: users, authors, and professional indexers. User tags, author keywords and descriptors were collected from academic journal articles, which were both indexed in Pubmed and tagged on CiteULike, and analysed. Descriptive statistics, informetric measures, and thesaural term comparison shows that there are important differences in the use of keywords between the three groups in addition to similarities which can be used to enhance support for search and browse. While tags and author keywords were found that matched descriptors exactly, other terms which did not match but provided important expansion to the indexing lexicon were found. These additional terms could be used to enhance support for searching and browsing in article databases as well as to provide invaluable data for entry vocabulary and emergent terminology for regular updates to indexing systems. Additionally, the study suggests that tags support organisation by association to task, projects and subject while making important connections to traditional systems which classify into subject categories
Design and commissioning of an Ultra-High-Resolution Time-of-Flight based isobar separator and mass spectrometer [05.11.2010]
No full textOnTEAM metadata: GDSID: DOC-2011-Mar-36; Attribute ID: LIBRARY-thesis_diss-2011-004; Title: [GSI Diss 2010-16] Design and commissioning of an Ultra-High-Resolution Time-of-Flight based isobar separator and mass spectrometer [05.11.2010]; Author(s): Dickel, Timo; Corporate author(s): ; Publication date: 20110309; Creator: manton; Creation date: 09.03.2011 16:13:48; Change date: 09.03.2011 16:28:32; Access: Welt; Attribute type: Text.Thesis.Diss; Directory path: ['GSI Publications', 'GSI as Publisher']; Attribute path: ['Infrastructure', 'Library and Documentation', 'thesis_diss', 'Added in 2011']; File name(s): ['DOC-2011-Mar-36-1.pdf']; File title(s): ['']; File access: ['nur berechtigte Gruppen'
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