Lightweight, liquid-cooled, direct-drive generator for highpower wind turbines: motivation, concept, and performance

Thesis: A liquid-cooled, direct-drive, permanent-magnet, synchronous generator with helical, double-layer, non-overlapping windings formed from a copper conductor with a coaxial internal coolant conduit offers an excellent combination of attributes to reliably provide economic wind power for the coming generation of wind turbines with power ratings between 5 and 20MW. A generator based on the liquid-cooled architecture proposed here will be reliable and cost effective. Its smaller size and mass will reduce build, transport, and installation costs. Summary: Converting wind energy into electricity and transmitting it to an electrical power grid to supply consumers is a relatively new and rapidly developing method of electricity generation. In the most recent decade, the increase in wind energy’s share of overall energy production has been remarkable. Thousands of land-based and offshore wind turbines have been commissioned around the globe, and thousands more are being planned. The technologies have evolved rapidly and are continuing to evolve, and wind turbine sizes and power ratings are continually increasing. Many of the newer wind turbine designs feature drivetrains based on Direct-Drive, Permanent-Magnet, Synchronous Generators (DD-PMSGs). Being low-speed high-torque machines, the diameters of air-cooled DD-PMSGs become very large to generate higher levels of power. The largest direct-drive wind turbine generator in operation today, rated just below 8MW, is 12m in diameter and approximately 220 tonne. To generate higher powers, traditional DD-PMSGs would need to become extraordinarily large. A 15MW air-cooled direct-drive generator would be of colossal size and tremendous mass and no longer economically viable. One alternative to increasing diameter is instead to increase torque density. In a permanent magnet machine, this is best done by increasing the linear current density of the stator windings. However, greater linear current density results in more Joule heating, and the additional heat cannot be removed practically using a traditional air-cooling approach. Direct liquid cooling is more effective, and when applied directly to the stator windings, higher linear current densities can be sustained leading to substantial increases in torque density. The higher torque density, in turn, makes possible significant reductions in DD-PMSG size. Over the past five years, a multidisciplinary team of researchers has applied a holistic approach to explore the application of liquid cooling to permanent-magnet wind turbine generator design. The approach has considered wind energy markets and the economics of wind power, system reliability, electromagnetic behaviors and design, thermal design and performance, mechanical architecture and behaviors, and the performance modeling of installed wind turbines. This dissertation is based on seven publications that chronicle the work. The primary outcomes are the proposal of a novel generator architecture, a multidisciplinary set of analyses to predict the behaviors, and experimentation to demonstrate some of the key principles and validate the analyses. The proposed generator concept is a direct-drive, surface-magnet, synchronous generator with fractional-slot, duplex-helical, double-layer, non-overlapping windings formed from a copper conductor with a coaxial internal coolant conduit to accommodate liquid coolant flow. The novel liquid-cooling architecture is referred to as LC DD-PMSG. The first of the seven publications summarized in this dissertation discusses the technological and economic benefits and limitations of DD-PMSGs as applied to wind energy. The second publication addresses the long-term reliability of the proposed LC DD-PMSG design. Publication 3 examines the machine’s electromagnetic design, and Publication 4 introduces an optimization tool developed to quickly define basic machine parameters. The static and harmonic behaviors of the stator and rotor wheel structures are the subject of Publication 5. And finally, Publications 6 and 7 examine steady-state and transient thermal behaviors. There have been a number of ancillary concrete outcomes associated with the work including the following. X Intellectual Property (IP) for direct liquid cooling of stator windings via an embedded coaxial coolant conduit, IP for a lightweight wheel structure for lowspeed, high-torque electrical machinery, and IP for numerous other details of the LC DD-PMSG design X Analytical demonstrations of the equivalent reliability of the LC DD-PMSG; validated electromagnetic, thermal, structural, and dynamic prediction models; and an analytical demonstration of the superior partial load efficiency and annual energy output of an LC DD-PMSG design X A set of LC DD-PMSG design guidelines and an analytical tool to establish optimal geometries quickly and early on X Proposed 8 MW LC DD-PMSG concepts for both inner and outer rotor configurations Furthermore, three technologies introduced could be relevant across a broader spectrum of applications. 1) The cost optimization methodology developed as part of this work could be further improved to produce a simple tool to establish base geometries for various electromagnetic machine types. 2) The layered sheet-steel element construction technology used for the LC DD-PMSG stator and rotor wheel structures has potential for a wide range of applications. And finally, 3) the direct liquid-cooling technology could be beneficial in higher speed electromotive applications such as vehicular electric drives.

Uni-portaalin kehitys käytettävyystutkimuksen pohjalta

Tässä työssä tutkitaan Lappeenrannan teknillisen yliopiston Uni-portaalia ja sen käytettävyyttä käytettävyystutkimuksen avulla. Työn tavoitteena on saada palveluun parannusehdotuksia tutkimuksen tuloksien pohjalta. Työssä tarkastellaan vain palvelun ”Opinnot ja palvelut” -sivua ja sen suomenkielistä näkymää. Työn tuloksina kävi ilmi palvelun sisältävän huonosti nimettyjä linkkejä, liian pitkiä linkkipolkuja sekä epäloogisia paikkoja eri tiedoille. Tuloksien pohjalta palvelulle on esitetty parannuksia juuri näihin epäkohtiin.

Making home rules for mother tongues : the legal implications of linguistic diversity in the design of autonomy regimes

Principen om nationalismen där det politiska och det nationella är samspelt kan vara av markant betydelse för uppbyggande av autonomiska regimer. Likaså tillåter decentralicering och delegering av befogenheter för språk och utbildning (officiellt erkännande av språk, standardisering av språk, undervisningsspråk och relaterade läroplaner) formning av identiteter inom dessa autonomiska regimer. Resultatet är en ofullkomlig cirkulär relation där språk, samfund och politiska institutioner ömsesidigt och kontinuerligt formar varandra: lingvistiskt mångfald prägar och formger autonomiska ordningar och vice-versa. De juridiska implikationerna av territoriella och icke-territoriella former av autonomi är dock av en annan art. Emedan territoriell autonomi bygger på idéen om ett eventuellt inkluderande hemland för lingvistiska grupper, vars vistelseort är avgörande, förstärker den icke-territoriella autonomin idéen om ett exclusivt samfund bestående av själv-identifierade medlemmar som är kapabla till självstyre oavsett territoriella gränser. Denna avhandling utgör an analys av sådana juridiska implikationer genom komparativa och institutionella analyser. Avhandlingen föreslår som resultat en serie av normativa och pragmatiska rekommendationer inriktade på att främja demokratiseringsprocesser i linje med principer om multikulturalism.

Improving oral healthcare in Scotland with special reference to sustainability and caries prevention

Brett Duane Improving oral healthcare in Scotland with special reference to sustainability and caries prevention University of Turku, Faculty of Medicine, Institute of Dentistry, Community Dentistry, Finnish Doctoral Program in Oral Sciences (FINDOS-Turku), Turku, Finland Annales Universitatis Turkuensis, Sarja- Ser. D, Medica-Odontologica. Painosalama Oy, Turku, Finland, 2015. Dentistry must provide sustainable, evidence-based, and prevention-focused care. In Scotland oral health prevention is delivered through the Childsmile programme, with an increasing use of high concentration fluoride toothpaste (HCFT). Compared with other countries there is little knowledge of xylitol prevention. The UK government has set strict carbon emission limits with which all national health services (NHS) must comply. The purpose of these studies was firstly to describe the Scottish national oral health prevention programme Childsmile (CS), to determine if the additional maternal use of xylitol (CS+X) was more effective at affecting the early colonisation of mutans streptococci (MS) than this programme alone; secondly to analyse trends in the prescribing and management of HCFT by dentists; and thirdly to analyse data from a dental service in order to improve its sustainability. In all, 182 mother/child pairs were selected on the basis of high maternal MS levels. Motherswere randomly allocated to a CS or CS+X group, with both groups receiving Childsmile. Theintervention group consumed xylitol three times a day, from when the child was 3 months until 24 months. Children were examined at age two to assess MS levels. In order to understand patterns of HCFT prescribing, a retrospective secondary data analysis of routine prescribing data for the years 2006-2012 was performed. To understand the sustainability of dental services, carbon accounting combined a top-down approach and a process analysis approach, followed by the use of Pollard’s decision model (used in other healthcare areas) to analyse and support sustainable service reconfiguration. Of the CS children, 17% were colonised with MS, compared with 5% of the CS+X group. This difference was not statistically significant (P=0.1744). The cost of HCFT prescribing increased fourteen-fold over five years, with 4% of dentists prescribing 70% of the total product. Travel (45%), procurement (36%) and building energy (18%) all contributed to the 1800 tonnes of carbon emissions produced by the service, around 4% of total NHS emissions. Using the analytical model, clinic utilisation rates improved by 56% and patient travel halved significantly reducing carbon emissions. It can be concluded that the Childsmile programme was effective in reducing the risk for MS transmission. HCFT is increasing in Scotland and needs to be managed. Dentistry has similar carbon emissions proportionally as the overall NHS, and the use of an analytic tool can be useful in helping identify these emissions. Key words: Sustainability, carbon emissions, xylitol, mutans streptococci, fluoride toothpaste, caries prevention.

The nature and role of trust in temporary virtual problem-solving teams

The objective of this study is to increase understanding of the nature and role of trust in temporary virtual problem-solving teams engaged in real-life co-creation activities, while much of previous research has been conducted in student settings. The different forms and bases of trust, possible trust barriers and trust building actions, and perceived role of trust in knowledge sharing and collaboration are analyzed. The study is conducted as a qualitative case study in case company. Data includes interviews from 24 people: 13 from 3 different project teams that were going on during the study, 8 from already finalized project teams, and 3 founders of case company. Additional data consists of communication archives from three current teams. The results indicate that there were both knowledge-based and swift trust present, former being based on work-related personal experiences about leaders or other team members, and latter especially on references, disposition to trust and institution-based factors such as norms and rules, as well as leader and expert action. The findings suggest that possible barriers of trust might be related to lack of adaptation to virtual work, unclear roles and safety issues, and nature of virtual communication. Actions that could be applied to enhance trust are for example active behavior in discussions, work-related introductions communicating competence, managerial actions and face-to-face interaction. Finally, results also suggest that trust has a focal role as an enabler of action and knowledge sharing, and coordinator of effective collaboration and performance in temporary virtual problem-solving teams.

Adopting the Vaadin Java framework to rebuild VTT’s Web Interfaces and Database Applications

With the growth in new technologies, using online tools have become an everyday lifestyle. It has a greater impact on researchers as the data obtained from various experiments needs to be analyzed and knowledge of programming has become mandatory even for pure biologists. Hence, VTT came up with a new tool, R Executables (REX) which is a web application designed to provide a graphical interface for biological data functions like Image analysis, Gene expression data analysis, plotting, disease and control studies etc., which employs R functions to provide results. REX provides a user interactive application for the biologists to directly enter the values and run the required analysis with a single click. The program processes the given data in the background and prints results rapidly. Due to growth of data and load on server, the interface has gained problems concerning time consumption, poor GUI, data storage issues, security, minimal user interactive experience and crashes with large amount of data. This thesis handles the methods by which these problems were resolved and made REX a better application for the future. The old REX was developed using Python Django and now, a new programming language, Vaadin has been implemented. Vaadin is a Java framework for developing web applications and the programming language is extremely similar to Java with new rich components. Vaadin provides better security, better speed, good and interactive interface. In this thesis, subset functionalities of REX was selected which includes IST bulk plotting and image segmentation and implemented those using Vaadin. A code of 662 lines was programmed by me which included Vaadin as the front-end handler while R language was used for back-end data retrieval, computing and plotting. The application is optimized to allow further functionalities to be migrated with ease from old REX. Future development is focused on including Hight throughput screening functions along with gene expression database handling

Minkä nuorena hallitsee sen aikuisena taitaa? Liikehallinnan pysyvyys kouluiästä aikuisikään – 24 vuoden seurantatutkimus

Tässä 24 vuoden pitkittäistutkimuksessa tutkitaan liikehallinnan kehitystä ja pysyvyyttä kouluiästä aikuisikään. Lisäksi ennustetaan ja selitetään aikuisiän liikehallintaa kouluiän liikehallinnan perusteella. Tutkimukseen osallistui 44 miestä ja 44 naista eri puolilta Suomea, joiden liikehallintaa mitattiin kouluiässä 1985 ja 1988 (9–16-vuotiaina) sekä aikuisiässä 2009 (33−39-vuotiaina). Liikehallintaa mitattiin kuudella liiketehtävämittarilla (flamingoseisonta, tarkkuusheittokiinniotto, kahdeksikkokuljetus, edestakaisinhyppely, vauhditon 5-loikka ja kärrynpyörä) sekä niistä lasketulla summamuuttujalla. Miesten ja naisten liikehallintaa vertailtiin varianssianalyysilla. Kouluiässä pojat menestyivät välineenkäsittelytehtävissä ja tytöt tasapaino- ja voimistelutehtävissä, mutta kokonaisuutena sukupuolten välillä ei ollut eroa. Aikuisena miehet olivat naisia parempia lähes kaikissa tehtävissä. Kovarianssianalyysissä havaittiin, että kehonrakenteeltaan (BMI) erilaisten ryhmien liikehallinnassa oli vain yksittäisiä eroja koulu- ja aikuisiässä. Toistettujen mittausten varianssianalyysissa ilmeni, että kouluiässä molempien sukupuolten liikehallinnan kehitys oli samanlaista. Kouluiän jälkeen kevyiden ja keskipainoisten poikien liikehallinta parani, mutta painavien tulokset eivät muuttuneet. Kevyiden tyttöjen tuloksissa ei tapahtunut muutosta, mutta keskipainoisten ja painavien tulokset heikkenivät. Koululiikunnan tehostus- ja vertailuryhmien välille kouluiässä muodostuneet erot kaventuivat tai katosivat aikuisena. Kouluiän liikehallinnaltaan eritasoisten ryhmien väliset erot kaventuivat, mutta eivät poistuneet kouluiän jälkeen. Klusterianalyysissa tutkittavat jakaantuivat kouluiässä neljään liikehallintatyyppiin (yleishyvät, tasapainoiset, pallotaitajat ja yleisheikot), jotka säilyivät myös aikuisiässä, mutta niiden väliset erot kaventuivat. Ristiintaulukointi ja khiin neliö -testi osoittivat, että tasoryhmän ja liikehallinnan monipuolisuuden pysyvyys oli vahvaa kouluiästä aikuisikään. Koulu- ja aikuisiän liikehallintatulosten välinen korrelaatio oli naisilla (0.69) vahvempaa kuin miehillä (0.48). Yksittäiset mittaustulokset kouluiässä selittivät keskimäärin 33 % aikuisiän tuloksista (korrelaation neliö). Regressioanalyysissa miesten aikuisiän liikehallintaa selittivät kouluiän muuttujista parhaiten liikehallinnan monipuolisuus sekä liikkuvuus (61 %), mutta naisilla vain liikehallinnan monipuolisuus (37 %). Miesten ja naisten erot liikehallinnassa syntyivät kouluiän jälkeen, mikä johtunee erilaisista liikuntatavoista ja -harrastuksista. Kouluiän liikehallinta määritti vahvasti varsinkin tytöillä aikuisiän liikehallintaa sekä yksilö- että ryhmätasolla, mikä korostaa monipuolisen koululiikunnan merkitystä. Yksilölliset muutokset olivat mahdollisia. Kouluiän jälkeen erityisesti naiset ja kehonrakenteeltaan painavat tarvitsisivat hermolihasjärjestelmää monipuolisesti kuormittavaa ja liikesuunniltaan moniulotteista liikuntaa liikehallinnan kehittämiseksi ja ylläpitämiseksi. Naisten liikehallinnan taantuminen varsinkin tasapainotehtävissä voi altistaa kaatumistapaturmille ja rajoittaa fyysistä toimintakykyä.

ATTITUDES TOWARD RUSSIAN CUSTOMERS IN THE FINNISH RETAIL TRADE SECTOR – A salesperson’s point of view

The amount of Russian tourists in Finland has increased significantly in the past years. The impact of Russian tourism to the Finnish retail trade sector is enormous, since Russian tourists often spend a lot of money particularly on shopping. Shopping tourism is mainly focused in the near border cities, such as Imatra and Lappeenranta, and in addition in Helsinki metropolitan area. The purpose of this study is to map the attitudes and perceptions of the sales personnel who are working in the Finnish retail trade sector towards Russian customers and to discover which elements affect these attitudes. The theories in this study are based on cultural elements and elements related to sales behavior and performance. Cultural differences between Finland and Russia, cultural distance and cultural intelligence form the cultural aspect of this study. Customer orientation vs. sales orientation (SOCO), adaptive selling, selling skills and job competency, salesperson’s affect and empathy toward customers, and job autonomy form the elements concerning sales behavior and performance. Furthermore, the attitude – behavior link, based on social psychology is addressed. A survey was conducted in two retail trade chains operating in Finland. These retail companies have stores and department stores in different geographical areas in Finland and the survey was conducted in altogether 19 cities. In addition to the theories that were discussed, two expert interviews were conducted in order to get a deeper understanding of the phenomenon at hand. Moreover the interviews helped in the formulation of the hypotheses and the questionnaire design. The questionnaires were sent directly to the stores, where they were placed so that they were available for the sales personnel. Altogether 487 usable responses were collected. The returned questionnaires were analyzed with IBM SPSS 21 statistics program. The results of this study indicated that the attitudes toward Russian customers are more negative compared to other foreign customers. However, the respondents’ attitudes toward and perceptions of Russian customers varied a lot. From the background variables age, education level, length of employment in current workplace, and length of experience in customer service had an effect on the attitudes of the respondents. In addition, the perceptions of Russian customers were more positive in the Eastern Finland compared to Helsinki metropolitan area. The cultural elements; cultural knowledge, cultural distance and cultural intelligence all affected the attitudes of the respondents. From the elements related to sales behavior and performance customer orientation, salesperson’s affect and empathy toward customers, and perceived job autonomy had an effect on the attitudes