Wind turbine operation in cold climate

The goal of the master‘s thesis is to determine and estimate ice accretion influence on the wind turbine blade performance. The thesis describes the technique of ice accretion calculation on the wind turbine blade and determination characteristics of the turbine with ice accreted. The methodology of the classic Blade Element Moment Theory was used. Iced blade experimental data was investigated in order to calculate blade with ice characteristics. The obtained results shows that iced blade power coefficient is lower than clean blade one. The heating system implementation shows that in the particular site in the Lapland region it is efficient.

Es war ein alter König

Myös Gramophone GC-2-42786.

Research on Latvian Herrnhutism in the inter-war period

Kirjallisuusarvostelu

Spin-Dynamics in Cold Gases of 87Rb and Atomic Hydrogen. The spins they are a-changin’

In this thesis the dynamics of cold gaseous atoms is studied. Two different atomic species and two different experimental techniques have been used. In the first part of the thesis experiments with Bose-Einstein condensates of Rb-87 are presented. In these experiments the methods of laser cooling and magnetic trapping of atoms were utilized. An atom chip was used as the experimental technique for implementation of magnetic trapping. The atom chip is a small integrated instrument allowing accurate and detailed manipulation of the atoms. The experiments with Rb-87 probed the behaviour of a falling beam of atoms outcoupled from the Bose-Einstein condensate by electromagnetic field induced spin flips. In the experiments a correspondence between the phases of the outcoupling radio frequency field and the falling beam of atoms was found. In the second part of the thesis experiments of spin dynamics in cold atomic hydrogen gas are discussed. The experiments with atomic hydrogen are conducted in a cryostat using a dilution refrigerator as the cooling method. These experiments concentrated on explaining and quantifying modulations in the electron spin resonance spectra of doubly polarized atomic hydrogen. The modifications to the previous experimental setup are described and the observation of electron spin waves is presented. The observed spin wave modes were caused by the identical spin rotation effect. These modes have a strong dependence on the spatial profile of the polarizing magnetic field. We also demonstrated confinement of these modes in regions of strong magnetic field and manipulated their spatial distribution by changing the position of the field maximum.

War barmhertig!

12 x 18 cm

Battled nerves : Finnish soldiers' war experience, trauma, and military psychiatry, 1941–44

I min avhandling undersöker jag av kriget framkallade psykiska störningar hos finländska soldater under fortsättningskriget. Vilka var de psykiskt invalidiserade soldaterna och hurudana var deras traumatiska erfarenheter? Vilken var den bredare upplevelsevärlden vid fronten där störningarna uppstod, och hur kan man förklara att majoriteten av soldaterna ändå klarade sig utan mentala rubbningar i denna av våld präglade miljö? Hur förhöll sig Finlands armé i allmänhet och den krigspsykiatri som utvecklades under kriget specifikt till soldaternas psykiska störningar? Som Matti Ponteva redan 1977 utredde, det totala antalet psykiatriska soldatpatienter under fortsättningskriget var ca 15 700 män. I min undersökning betonar jag att den siffran omfattar endast en del av fenomenet: långt ifrån alla finländska soldater som uppvisade psykiska symptom förpassades från fronten i psykiatrisk vård. De finländska psykiatrerna hade före vinterkriget inte kommit i direkt kontakt med av krig orsakade psykiska störningar. Deras kunskaper kom nästan uteslutande från den tyska krigspsykiatrin, där den ledande tanken framför allt efter första världskriget var att förklara psykiska störningar med soldaternas personliga brister och svagheter. Slutligen resonerar jag, varför synen på soldaternas psykiska störningar på ett så markant sätt skilde sig från synen på andra krigsskador. Att soldater stupade eller sårades fysiskt kunde framställas som yttringar av manligt hjältemod och offervillighet. Att brytas ner psykiskt av kriget blev däremot en tom symbol för våldet och saknade annat innehåll än uttryckligen en meningslöshet. Psykiska störningar associerades med ett moraliskt fördömande och ett stigma av skam, och förutom att man tenderade att förneka och marginalisera deras existens försökte man göra en skillnad mellan dem och den egentliga krigsupplevelsen. Det har varit problematiskt att inkludera de psykiskt rubbade soldaterna i den nationella historieskrivningen fram till våra dagar.

From War Pigs to Unsung Heroes: The Criticism and Justification of War in Metal Lyrics

Tässä tutkimuksessa käsitellään heavy metal -kappaleiden sanoitusten sisältöä. Tutkimusmateriaaliin on valittu yksi teema, sota, jonka avulla avataan sanoitusten sisältöä ja merkitystä. Metallimusiikki alakulttuurina on tyylillisesti ja temaattisesti spesifi, ja sillä on omat musiikilliset tavoitteensa. Tässä tutkimuksessa tarkastellaan erityisesti sitä miten sotaa kritisoidaan tai perustellaan heavy rock -sanoituksissa. Tutkimusmateriaalini koostuu 29 englanninkielisen kappaleen sanoituksesta vuosilta 1970–2012. Edustettuina on useita ajanjaksoja sekä maita. Yhdistävänä tekijänä on englannin kielen lisäksi se, että kaikki sanoitukset käsittelevät modernia länsimaista sodankäyntiä. Tekstit valittiin sen perusteella, että niissä ilmeni positiivinen tai negatiivinen näkökulma sotaan. Tutkimus nojaa Theo van Leeuwenin legitimaatioteoriaan, joka puolestaan pohjautuu diskurssianalyysiin. Legitimaatioteoria käsittää neljä strategiaa, jotka voivat joko kritisoida tai perustella sosiaalisia käytänteitä. Ne ovat auktoriteetteihin vetoaminen, moraalinen arviointi, järkeistäminen ja mytopoeesi. Yksi tavoitteistani tutkimuksessani on selvittää legitimaatioteorian toimivuutta omassa materiaalissani. Käytän metodina lähilukua, joka mahdollistaa niiden sanojen ja ilmaisujen identifioimisen, jotka ovat näkökulmaltaan joko positiivisesti tai negatiivisesti sotaan suhtautuvia. Analyysini kannalta tärkeitä ovat sekä kieli- että kulttuurikonteksti, sillä ne määrittelevät sanojen merkityksen. Analyysin perusteella kävi ilmi, että esimerkit jakautuivat eri strategioiden välille hyvin epätasaisesti. Auktoriteetteihin vetoamisen strategiasta löytyi vain yksi esimerkki, kun taas moraalisen arvioinnin esimerkkejä oli neljätoista. Lisäksi kaikkia legitimaatioteorian alaryhmiä ei löytynyt materiaalista ollenkaan. Osalla alaryhmistä oli useita esiintymiä, mutta osalla vain yksi. Esimerkkien epätasaista jakautumista selittää mm. se, että tutkimuksen materiaalin kannalta kaikki alakategoriat eivät ole relevantteja. Jotta tutkimustuloksista saataisiin edustavampi, laajempi otanta olisi tarpeen. Legitimaatioteorian soveltuvuutta sanoituksien yhteydessä tulisi tutkia laajemmin.

The Global War on Terrorism in the Horn of Africa

Ever since Siad Barre’s regime was toppled in the beginning of the 1990’s Somalia has been without an effective central government. As a result Somalia has remained in an anarchic condition of state collapse for nearly two decades. This anarchy has often been put forward as a potential breeding ground for terrorism. As a response to this threat the United States has undertaken several policies, initiatives, and operations in the Horn of Africa generally and in Somalia specifically. In this descriptive study a twofold analysis has been undertaken. First, conditions in present day Somalia as well as Somali history have been analyzed to evaluate the potential Somalia holds as a terrorist base of operations or a recruiting- or staging area. Second, US strategies and actions have been analyzed to evaluate the adequacy of the US response to the threat Somalia poses in terms of terrorism. Material for the analyses have been derived from anthropological, political, and security studies dealing with Somalia. This material has been augmented by a wide range of news coverage, western and non-western. Certain different US policy documents from different levels have been chosen to represent US strategies for the Global War on Terrorism. Because Somali social institutions, such as the clan system, hold great weight in Somali society, Somalia is a difficult area of operations for terrorist networks. In addition the changing nature of Somali alliances and the tangled webs of conflict that characterize present day Somalia aggravate the difficulties that foreign terrorist networks would encounter in Somalia, would they choose to try to utilize it in any great extent. The US has taken potential terrorism threats in Africa and specifically Somalia very seriously. US actions in Somalia have mainly focused on apprehending or neutralizing terror suspects. Such policies, coupled with backing the Ethiopian invasion of Somalia may have actually turned out increasing Somalia’s terror potential.

Parameter optimization of AC rectangular wave outputs for aluminum cold wire GTAW

The objective of this work was to optimize the parameter setup for GTAW of aluminum using an AC rectangular wave output and continuous feeding. A series of welds was carried-out in an industrial joint, with variation of the negative and positive current amplitude, the negative and positive duration time, the travel speed and the feeding speed. Another series was carried out to investigate the isolate effect of the negative duration time and travel speed. Bead geometry aspects were assessed, such as reinforcement, penetration, incomplete fusion and joint wall bridging. The results showed that currents at both polarities are remarkably more significant than the respective duration times. It was also shown that there is a straight relationship between welding speed and feeding speed and this relationship must be followed for obtaining sound beads. A very short positive duration time is enough for arc stability achievement and when the negative duration time is longer than 5 ms its effect on geometry appears. The possibility of optimizing the parameter selection, despite the high inter-correlation amongst them, was demonstrate through a computer program. An approach to reduce the number of variables in this process is also presented.

Application of the finite element method in cold forging processes

The demand for more efficient manufacturing processes has been increasing in the last few years. The cold forging process is presented as a possible solution, because it allows the production of parts with a good surface finish and with good mechanical properties. Nevertheless, the cold forming sequence design is very empirical and it is based on the designer experience. The computational modeling of each forming process stage by the finite element method can make the sequence design faster and more efficient, decreasing the use of conventional "trial and error" methods. In this study, the application of a commercial general finite element software - ANSYS - has been applied to model a forming operation. Models have been developed to simulate the ring compression test and to simulate a basic forming operation (upsetting) that is applied in most of the cold forging parts sequences. The simulated upsetting operation is one stage of the automotive starter parts manufacturing process. Experiments have been done to obtain the stress-strain material curve, the material flow during the simulated stage, and the required forming force. These experiments provided results used as numerical model input data and as validation of model results. The comparison between experiments and numerical results confirms the developed methodology potential on die filling prediction.

“Ich habe gedacht, ich bin ihresgleichen und dann war ich immer ganz jemand anderes” : das Leben von Pfarrfrauen in der hannoverschen Landeskirche bis Anfang der 1970er Jahre im Licht sozialtechnischer Modernisierung

De protestantiska prästernas hustrur, prästfruarna, inom Landeskirche Hannover utgör en liten grupp konfessionellt bundna och troende kvinnor som jag undersökt ur kvinnohistoriskt och kulturvetenskapligt perspektiv. Jag belyser förändringarna i synen på prästgård, prästfruns värv och församling under mitten av 1900-talet då prästfruarna förlorade sin ställning i samhälle och församling. Prästfruarna framstår som vittnen över slutet på en epok som började med reformationen och som visat sig vara grundläggande för utformningen av moderniteten liksom också för övergången till senmoderna makt- och socialtekniker som lett till dagens emancipatoriska krav på självförverkligande med jaget som expert. Förändringarna ledde till kvinnopolitiska segrar, som bättre tillgång till arbetsmarknaden, men också till en hittills inte undersökt tragisk sida av denna modernisering, nämligen hur det självständiga handlingsutrymme försvann som prästfruarna hade i prästgård och församling just som kvinnor. Den protestantiska kyrkan bidrog så till en revolutionerande strukturomvandling för att referera till historikerna Lutz Raphael och Anselm Doering-Manteuffel.

[War es ein Traum?]

Soitinnus: lauluääni (tenori), orkesteri.

Letters from the War of Ecosystems – An Analysis of Independent Software Vendors in Mobile Application Marketplaces

The recent emergence of a new generation of mobile application marketplaces has changed the business in the mobile ecosystems. The marketplaces have gathered over a million applications by hundreds of thousands of application developers and publishers. Thus, software ecosystems—consisting of developers, consumers and the orchestrator—have emerged as a part of the mobile ecosystem. This dissertation addresses the new challenges faced by mobile application developers in the new ecosystems through empirical methods. By using the theories of two-sided markets and business ecosystems as the basis, the thesis assesses monetization and value creation in the market as well as the impact of electronic Word-of-Mouth (eWOM) and developer multihoming— i. e. contributing for more than one platform—in the ecosystems. The data for the study was collected with web crawling from the three biggest marketplaces: Apple App Store, Google Play and Windows Phone Store. The dissertation consists of six individual articles. The results of the studies show a gap in monetization among the studied applications, while a majority of applications are produced by small or micro-enterprises. The study finds only weak support for the impact of eWOM on the sales of an application in the studied ecosystem. Finally, the study reveals a clear difference in the multi-homing rates between the top application developers and the rest. This has, as discussed in the thesis, an impact on the future market analyses—it seems that the smart device market can sustain several parallel application marketplaces.