Ruokohelven käytön lisääminen Joensuun voimalaitoksen kattilassa – käytettävyys, hyötysuhde ja taloudellisuus

Ruokohelpi soveltuu ympäristöystävällisyyden ja korkean lämpöarvon vuoksi hyvin energiantuotantoon. Fortumin Joensuun voimalaitoksella ruokohelpi on syötetty kattilaan tähän asti pääasiassa pääpolttoaineisiin, turpeeseen tai hakkeeseen seostettuna pieninä energiaosuuksina. Pääpolttoaineisiin verrattuna ruokohelvellä on alhaisempi irto- ja energiatiheys, korkeampi klooripitoisuus ja kattilaa likaavampi tuhka, mikä asettaa rajoitteita sen käytön lisäämiselle voimalaitoksella. Alhaisesta irto- ja energiatiheydestä johtuvan holvautumisen sekä tukoksien lisääntymisen ja Joensuun voimalaitoksen nykyisten kuljettimien kapasiteettiongelmien vuoksi ruokohelven osuuden lisääminen suuremmaksi kuin 5 % polttoaine-energiasisällöstä on riskialtista ja edellyttää täten investointia erilliseen ruokohelven käsittely- ja syöttöjärjestelmään. Yksi vaihtoehto on murskata ruokohelpipaalit joko sähkökäyttöisellä, puolikiinteällä ja nopeakäyntisellä Haybuster H1130 tilt -murskaimella tai kiinteällä ja hidaskäyntisellä Raumaster-murskaimella ja ohjata ruokohelpisilppu joko pitkän mekaanisen kuljettimen ja sen perässä olevien lyhyiden pneumalinjojen tai pelkkien pitkien pneumalinjojen kautta suoraan kattilapesään. Työssä tutkitut investoinnit ovat taloudellisesti sitä kannattavampia mitä enemmän ruokohelpeä voidaan vuositasolla polttaa voimalaitoksella. Ruokohelven käyttömäärää voimalaitoksella kannattanee lisätä kuljetusmatkaa pidentämällä. Investointien valinta ei ole itsestäänselvyys. Nopeakäyntinen murskain on hidaskäyntistä murskainta edullisempi investointi, tosin hidaskäyntisen murskaimen käyttövarmuus on parempi kuin nopeakäyntisen murskaimen. Kattilan käytettävyyden kannalta ruokohelven käytön lisääminen edellyttää kattilan palamistekniikan analysointia laskennallisesti virtausmallinnuksella ennen kuin lopullisia päätöksiä investointien suhteen voidaan tehdä.

Soodakattilan lentotuhkan uudentyyppisen analysaattorin arviointi

RBDA (Recovery Boiler Dust Analyzer) on soodakattilan savukaasujen hiukkasten määrää mittaava laite. Yksi laitteen mahdollisista sovelluskohteista on soodakattilan nuohouksen optimointi. Tämän työn tarkoituksena oli parantaa RBD-analysaattorin toimintaa ja erityisesti tutkia laitteen toimivuutta soodakattilan nuohouksen optimoinnis-sa. Soodakattilan nuohouksen optimoinnilla voidaan vähentää nuohoukseen kuluneen höyryn määrää ja näin saavuttaa taloudellisia säästöjä. RBD-analysaattorin toimivuutta testattiin toimivan soodakattilan avulla. Tutkimuksen tueksi testeissä käytetyn soodakattilan savukaasujen lämpötilat ja tuhkan tarttumisomi-naisuudet selvitettiin. Laitteen toimivuutta testattiin vertaamalla RBDA:n mittaustulosta standardin mukaiseen savukaasujen hiukkasmittausmenetelmään. Mittajärjestelmän soveltuvuutta soodakattilan nuohouksen optimointiin tutkittiin ajamalla nuohoimia käsin eri seisonta-aikojen jälkeen sekä mittaamalla soodakattilan normaalia nuohousjärjes-tystä. Mittausten perusteella todettiin, että RBDA havaitsee savukaasujen pölypitoisuuden ja sen muutokset luotettavasti. Nuohouksen optimointiin RBDA:n todettiin soveltuvan ny-kyisessä mallissaan vain vedenesilämmittimien osalta. Keittopinnan ja tulistimien nuo-hointen optimointiin ei saatu riittävän luotettavia mittaustuloksia. RBDA:n kehittäminen jatkotutkimuksilla todettiin mahdolliseksi.

Mobile learning and video experience in delivering digital content

In recent years, the worldwide distribution of smartphone devices has been growing rapidly. Mobile technologies are evolving fast, a situation which provides new possibilities for mobile learning applications. Along with new delivery methods, this development enables new concepts for learning. This study focuses on the effectiveness and experience of a mobile learning video promoting the key features of a specific device. Through relevant learning theories, mobile technologies and empirical findings, the thesis presents the key elements for a mobile learning video that are essential for effective learning. This study also explores how previous experience with mobile services and knowledge of a mobile handset relate to final learning results. Moreover, this study discusses the optimal delivery mechanisms for a mobile video. The target group for the study consists of twenty employees of a Sanoma Company. The main findings show that the individual experience of learning and the actual learning results may differ and that the design for certain video elements, such as sound and the presentation of technical features, can have an impact on the experience and effectiveness of a mobile learning video. Moreover, a video delivery method based on cloud technologies and HTML5 is suggested to be used in parallel with standalone applications.

Europeana content priorities

David Smithin esitys Europeana työpajassa 20.11.2012 Helsingissä.

Solids removal in pyrolysis

Pyrolysis is a process for turning biomass into liquid fuel. The process consists of heating the biomass in inert conditions and quenching the resulting vapors into oil. The oil has many potential uses, such as heating fuel in peak heating plants. In order to broaden the application base and improve the quality of the oil, solids removal has to be addressed. The solids may also increase the probability of plugging in downstream equipment. The purpose of this research was to gain an understanding of the formation of solids in the pyrolysis process and to assess options for reducing the solid content of the oil. From literature it is known that the solids can be removed either by hot vapor filtration, liquid treatment or multiple cyclones. Hot vapor filtration decreases yield, but improves the stability of the oil while simultaneously removing solids and ash. Liquid treatment techniques are good for removing large particles but involve losses of pyrolysis liquid. Cyclones are a traditional robust technique used regularly in pyrolysis. In the experimental part of this thesis, a 2 MWfuel pyrolysis setup with 2 cyclones in series was operated and monitored. Solid and liquid samples were collected from various parts of the process for further examination. Sampling and sample treatment techniques were developed. The chemical properties of the pyrolysis char were also analyzed and assessed as a function of reactor temperature and fluidizing velocity. By measuring the particle size distributions it was noticed that there were much smaller particles collected from the second cyclone than fed into pyrolysis. The solids in the pyrolysis oil were even smaller. This was most likely caused by attrition and shrinkage. Due to better separation efficiency of the cyclones in large particles, excess attrition should be avoided.

Content marketing and the significance of corporate branding

Tämän tutkielman tavoite on tutkia vahvan brandin merkitystä ja syitä, miksi yritykset käyttävät sisältömarkkinointia brandin rakentamisessa, sekä selvittää mitkä ovat yritysten sisältömarkkinointi-investointien tavoitteet, odotetut seuraukset ja koetut hyödyt ja tulokset. Teoriaosassa esitetään empiriaosaa varten tarvittava akateeminen taustatutkimustieto. Empiria on toteutettu puoli-struktroiduilla kahdenkeskisillä puhelinhaastatteuilla. Haastateltavina ovat työn toimeksiantajan Calcus Kustannus Oy:n viisi asiakasta. Näiden yritysten liikevaihto vaihtelee 23-75M€ välillä, ja yritykset toimivat pääosin suomen B2B yritysmarkkinoilla. Haastateltavat henkilöt ovat yrityksissä vastuussa markkinointipäätöksistä. Tulokset osoittavat, että vahvalla brandilla on erittäin suuri merkitys yrityksen kasvun ja menestyksen kannalta, ja että yritykset käyttävät sisältömarkkinointia brandin rakentamisessa, koska se kasvattaa brandipääomaa tehokkaasti. Sisältömarkkinoinnilla yritykset pyrkivät kasvttamaan heidän asiakkaidensa branditietoisuutta ja brandiuskollisuutta, sekä brandinsa uskottavuutta jakamalla aidosti kiinnostavaa ja lisäarvoa tuottavaa sisältöä. Lisäksi yrityksen asiantuntija-, sekä mielipidejohtajaroolin vahvistaminen koettiin erittäin tärkeäksi. Sisältömarkkinoinnin koetaan olevan brandin rakentamisessa tehokkaampaa kuin traditionaalinen markkinointi, minkä vuoksi yritykset tulevat kasvattamaan sen osuutta markkinointisuunnitelmissaan tulevaisuudessa.

The role of potassium in the corrosion of superheater materials in boilers firing biomass

Inhibition of global warming has become one of the major goals for the coming decades. A key strategy is to replace fossil fuels with more sustainable fuels, which has generated growing interest in the use of waste-derived fuels and of biomass fuels. However, from the chemical point of view, biomass is an inhomogeneous fuel, usually with a high concentration of water and considerable amounts of potassium and chlorine, all of which are known to affect the durability of superheater tubes. To slow down or reduce corrosion, power plants using biomass as fuel have been forced to operate at lower steam temperatures as compared to fossil fuel power plants. This reduces power production efficiency: every 10°C rise in the steam temperature results in an approximate increase of 2% in power production efficiency. More efficient ways to prevent corrosion are needed so that power plants using biomass and waste-derived fuels can operate at higher steam temperatures. The aim of this work was to shed more light on the alkali-induced corrosion of superheater steels at elevated temperatures, focusing on potassium chloride, the alkali salt most frequently encountered in biomass combustion, and on potassium carbonate, another potassium salt occasionally found in fly ash. The mechanisms of the reactions between various corrosive compounds and steels were investigated. Based on the results, the potassium-induced accelerated oxidation of chromia protected steels appears to occur in two consecutive stages. In the first, the protective chromium oxide layer is destroyed through a reaction with potassium leading to the formation of intermediates such as potassium chromate (K2CrO4) and depleting the chromium in the protective oxide layer. As the chromium is depleted, chromium from the bulk steel diffuses into the oxide layer to replenish it. In this stage, the ability of the material to withstand corrosion depends on the chromium content (which affects how long it takes the chromium in the oxide layer to be depleted) and on external factors such as temperature (which affects how fast the chromium diffuses into the protective oxide from the bulk steel). For accelerated oxidation to continue, the presence of chloride appears to be essential.

Assessment of Young Learners’ English Proficiency in Bilingual Content Instruction CLIL

This applied linguistic study in the field of second language acquisition investigated the assessment practices of class teachers as well as the challenges and visions of language assessment in bilingual content instruction (CLIL) at primary level in Finnish basic education. Furthermore, pupils’ and their parents’ perceptions of language assessment and LangPerform computer simulations as an alternative, modern assessment method in CLIL contexts were examined. The study was conducted for descriptive and developmental purposes in three phases: 1) a CLIL assessment survey; 2) simulation 1; and 3) simulation 2. All phases had a varying number of participants. The population of this mixed methods study were CLIL class teachers, their pupils and the pupils’ parents. The sampling was multi-staged and based on probability and random sampling. The data were triangulated. Altogether 42 CLIL class teachers nationwide, 109 pupils from the 3rd, 4th and 5th grade as well as 99 parents from two research schools in South-Western Finland participated in the CLIL assessment survey followed by an audio-recorded theme interview of volunteers (10 teachers, 20 pupils and 7 parents). The simulation experimentations 1 and 2 produced 146 pupil and 39 parental questionnaires as well as video interviews of volunteered pupils. The data were analysed both quantitatively using percentages and numerical frequencies and qualitatively employing thematic content analysis. Based on the data, language assessment in primary CLIL is not an established practice. It largely appears to be infrequent, incidental, implicit and based on impressions rather than evidence or the curriculum. The most used assessment methods were teacher observation, bilingual tests and dialogic interaction, and the least used were portfolios, simulations and peer assessment. Although language assessment was generally perceived as important by teachers, a fifth of them did not gather assessment information systematically, and 38% scarcely gave linguistic feedback to pupils. Both pupils and parents wished to receive more information on CLIL language issues; 91% of pupils claimed to receive feedback rarely or occasionally, and 63% of them wished to get more information on their linguistic coping in CLIL subjects. Of the parents, 76% wished to receive more information on the English proficiency of their children and their linguistic development. This may be a response to indirect feedback practices identified in this study. There are several challenges related to assessment; the most notable is the lack of a CLIL curriculum, language objectives and common ground principles of assessment. Three diverse approaches to language in CLIL that appear to affect teachers’ views on language assessment were identified: instrumental (language as a tool), dual (language as a tool and object of learning) and eclectic (miscellaneous views, e.g. affective factors prioritised). LangPerform computer simulations seem to be perceived as an appropriate alternative assessment method in CLIL. It is strongly recommended that the fundamentals for assessment (curricula and language objectives) and a mutual assessment scheme should be determined and stakeholders’ knowledge base of CLIL strengthened. The principles of adequate assessment in primary CLIL are identified as well as several appropriate assessment methods suggested.

A distributed, cloud-ready, digital content processing and transformation platform and a specific use case

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Repository content - lost in Discovery?

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Packaging Content for Aggregated and Federated Repositories through APTrust

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Preserve your content with LOCKSS-O-Matic

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014