Jäänmurtaja Sisun viiden pääkoneen ja potkurilaakeroinnin huolto

Opinnäytetyön aiheena on Arctia Icebreakingin jäänmurtaja Sisun viiden pääkoneen ja potkurilaakeroinnin huolto. Työ sai alkunsa keväällä 2014 kun Arctia Icebreaking tilasi pääkone 2 haalauksen Marine Diesel Finland Oy:ltä. Kun ensimmäiset kiertokanget aukaistiin, niin huomattiin että laakerit ovat todella huonoja ja voiteluöljyn seassa on oltava joitain epäpuhtauksia. Kesäkuussa 2014 aloitettiin viiden pääkoneen ja akselilinjojen kannatinlaakereiden huolto. Potkurimoottoreiden painelaakerien voiteluöljykierrossa epäiltiin olevan myös epäpuhtauksia, joten olivat nekin tarkastettava. Olin tuolloin ensimmäisessä työharjoittelussani töissä Marine Diesel Finland Oy:ssä ja olin mukana aina kesäkuun alusta kun moottoreita ruvettiin purkamaan lokakuun loppuun kun merikoeajo ja koeajon jälkeiset laakeritarkistukset oli tehty. Työn tarkoituksena on käsitellä mitä kaikkea moottorista joudutaan purkamaan, tarkastamaan, uusimaan ja kuinka laaja operaatio saattaa tulla, kun voiteluöljyjärjestelmässä on epäpuhtauksia. Mitä ja miksi epäpuhtauksia on voiteluöljyjärjestelmään päässyt, ei tässä työssä kerrotaThe subject of my thesis is the servicing of the five main engines and the propeller bearings of icebreaker Sisu. The task was started in the spring of 2014, when Arctia Icebreaking ordered the overhauling of main engine number 2 from Marine Diesel Finland Ltd. When the first conrods were split, it became apparent that the bearings were in a sorry condition and the lubricating oil was sure to contain some impurities. The maintenance of the five main engines and the shaft line bearings began in June 2014. The lubricating oil circulating in the pressure bearings of the propeller engines was suspected to contain impurities, so they had to be checked, too. During that time I was completing my very first apprenticeship at Marine Diesel Ltd. I was involved from the early June, when the engines were taken apart, to the late October when the sea trials and the following bearing tests were completed. Also the grinding of the shafts took longer than what was initially anticipated. The main reason for this was the fact that the bearing surfaces had to be ground where conrod bearings, main bearings, thrust bearing, ice breaking bearing and shaft trunnion bearings were to be fitted

"Go forth and experiment" : A survey on primary school teachers' perceptions of their competence in teaching programming

Objectives. The aim of the present study is to identify factors influencing primary school teachers' perceptions of their own competence in teaching programming. Programming was included in the Finnish curriculum in 2016 and has consequently not yet been studied in depth. Thus, the factors influencing teachers' competence in this study were initially selected through discourse with teachers and from studies examining the problems in teaching ICT. In this study emotions affecting teaching (enthusiasm, fear/anxiety), previous experiences, other teachers and school administration are treated as factors potentially influencing teachers' competence. Methods. Teachers' evaluations of their attitudes and emotions towards teaching programming as well as background information were obtained using a web-based questionnaire with 7-point Likert and open-ended complementary items. A total of 253 participants completed the questionnaire. The data was analyzed using a mixed methods design which comprised i) conducting a multiple linear regression analysis and ii) qualitative examination of common themes found in open-ended questions. Conclusions. Seven significant predictors to teaching competence were found in multiple regression modelling. Regression analysis determined that the most influential variables to competence were enthusiasm, teacher's awareness of what teaching programming requires of her/him and previous experiences as trainings or trying programming with students. The open-ended questions revealed that teachers emphasized the importance of being able to try new teaching subjects and the need to be explained what is expected of them regarding new procedures as including programming in the curriculum. Importantly, teachers were largely unaware of what teaching programming required of them. Finally, the results indicate that offering possibilities to try programming at school and explaining teachers what it means to teach programming in practice increases teachers' competence.Tavoitteet. Tutkimuksen tarkoituksena on selvittää, millaiset tekijät ovat yhteydessä alakoulun opettajan arvioon omasta valmiudestaan opettaa ohjelmointia. Koska ohjelmoinnin opetus on tullut osaksi opetussuunnitelmaa vasta syksyllä 2016, on aihetta tutkittu vielä vähän. Ohjelmoinnin opetusvalmiuteen oletetaan tässä tutkimuksessa vaikuttavan opetuksen herättämät tunteet (innostus, mahdollinen pelko/jännitys), aiemmat kokemukset sekä muut opettajat. Menetelmät. Tutkimuksen data kerättiin selainpohjaisella ja 7-portaisella Likert- kyselylomakkeella, johon oli lisätty avoimia kysymyksiä. Tutkimukseen vastasi 253 vastaajaa. Vastausten analyysissä hyödynnettiin mixed methods -menetelmää, joka yhdistää sekä kvantitatiivista että kvalitatiivista tutkimusotetta. Kvantitatiivista dataa analysoitiin aineistoa kuvailemalla, korrelaatioita tarkastelemalla sekä suorittamalla usean muuttujan lineaarinen regressioanalyysi. Avoimiin vastauksiin hyödynnettiin sisällönanalyysia. Tulokset ja johtopäätökset. Regressioanalyysin avulla löydettiin seitsemän muuttujaa, jotka merkittävästi selittivät opettajan valmiutta opettaa ohjelmointia. Valmiutta selittivät voimakkaimmin opettajan käsitys siitä, mitä ohjelmointi häneltä edellyttää, opettajan kokema innostus sekä aiempi kokemus ohjelmoinnista joko opetuskokeilujen tai koulutuksen muodossa. Myös avoimissa vastauksissa korostuivat opetuskokeilujen sekä opetuksen tavoitteiden selkiyttämisen merkitys. Tulosten valossa näyttäisi siltä, että vielä toukokuussa 2016 tämän tutkimuksen opettajilla ei ollut selvää näkemystä ohjelmoinnin opetuksesta saatikka koulutason suunnitelmaa siihen, miten ohjelmointia lopulta opetetaan. Valmiutta näyttäisivät tämän tutkimuksen perusteella kuitenkin lisäävän koulussa tapahtuvat opetuskokeilut sekä opetusta koskevien tavoitteiden ja vaatimusten selkiyttäminen opettajille

Aineenvaihduntatuotteiden automaattinen kvantitointi virtsasta

Aineenvaihduntatuotteet kertovat paljon yksilön terveydentilasta ja niiden avulla on mahdollista tehdä riskiarvioita yksilöstä, kunhan populaatiotason vertailuarvot ovat tunnettuja. Aineenvaihduntatuotteiden laaja mittaaminen on usein työlästä, epätarkkaa sekä kallista, joten korkean suorituskyvyn omaaville automaattisille menetelmille on tarvetta. Automaattisen ydinmagneettiseen resonanssiin (NMR) perustuvan kvantitointimenetelmän kehittely vaatii hyvää teoreettista fysiikan ja matematiikan tuntemusta. Sen teoria on kuitenkin monimutkaista ja vaatii hyvää fysiikan ja matematiikan tuntemusta. Sitä pystytään onneksi havainnollistamaan riittävällä tasolla vektorimallilla. Vektorimallissa ytimien käyttäytymistä havainnollistetaan kokonaismagnetisaatiovektorilla. Tutkielmassa on tarkasteltu ydinmagneettisen resonanssin teoriaa energiatasoista vektorimalliin ja pyritty havainnollistamaan kvalitatiivisella tasolla mitä magneetin sisällä tapahtuu. Nykyään NMR-laitteet ovat erittäin monimutkaisia ja sisältävät suuren määrän erilaista teknologiaa. Tutkielman viimeisessä osassa on havainnollistettu yleisellä tasolla, että mistä nykyaikaiset NMR-laitteet koostuvat. Tutkielman kokeellisessa osuudessa identifioitiin virtsasta aineenvaihduntatuotteita, joista PERCH:in avulla kerättiin sijainti- ja intensiteetti-informaatiota. Tätä dataa käytettiin kehittämään yhdessä Nightingale Health Ltd:n muiden työntekijöiden kanssa automaattinen malli, jolla pystytään mittaamaan aineenvaihduntatuotteiden pitoisuuksia virtsasta korkealla suorituskyvyllä

Assessment of field monitoring of plant fluxes of oxidized nitrogen with two types of detectors

Peer reviewe

Technical note : Comparison of methane ebullition modelling approaches used in terrestrial wetland models

Emission via bubbling, i.e. ebullition, is one of the main methane (CH4) emission pathways from wetlands to the atmosphere. Direct measurement of gas bubble formation, growth and release in the peat-water matrix is challenging and in consequence these processes are relatively unknown and are coarsely represented in current wetland CH4 emission models. In this study we aimed to evaluate three ebullition modelling approaches and their effect on model performance. This was achieved by implementing the three approaches in one process-based CH4 emission model. All the approaches were based on some kind of threshold: either on CH4 pore water concentration (ECT), pressure (EPT) or free-phase gas volume (EBG) threshold. The model was run using 4 years of data from a boreal sedge fen and the results were compared with eddy covariance measurements of CH4 fluxes. Modelled annual CH4 emissions were largely unaffected by the different ebullition modelling approaches; however, temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence the ebullition modelling approach drives the temporal variability in modelled CH4 emissions and therefore significantly impacts, for instance, high-frequency (daily scale) model comparison and calibration against measurements. The modelling approach based on the most recent knowledge of the ebullition process (volume threshold, EBG) agreed the best with the measured fluxes (R-2 = 0.63) and hence produced the most reasonable results, although there was a scale mismatch between the measurements (ecosystem scale with heterogeneous ebullition locations) and model results (single horizontally ho-mogeneous peat column). The approach should be favoured over the two other more widely used ebullition modelling approaches and researchers are encouraged to implement it into their CH4 emission models.Peer reviewe

Does nitrate fertilization induce nox emission from scots pine (p. sylvestris) shoots?

Peer reviewe

Calibrating the sqHIMMELI v1.0 wetland methane emission model with hierarchical modeling and adaptive MCMC

Estimating methane (CH4) emissions from natural wetlands is complex, and the estimates contain large uncertainties. The models used for the task are typically heavily parameterized and the parameter values are not well known. In this study, we perform a Bayesian model calibration for a new wetland CH4 emission model to improve the quality of the predictions and to understand the limitations of such models. The detailed process model that we analyze contains descriptions for CH4 production from anaerobic respiration, CH4 oxidation, and gas transportation by diffusion, ebullition, and the aerenchyma cells of vascular plants. The processes are controlled by several tunable parameters. We use a hierarchical statistical model to describe the parameters and obtain the posterior distributions of the parameters and uncertainties in the processes with adaptive Markov chain Monte Carlo (MCMC), importance resampling, and time series analysis techniques. For the estimation, the analysis utilizes measurement data from the Siikaneva flux measurement site in southern Finland. The uncertainties related to the parameters and the modeled processes are described quantitatively. At the process level, the flux measurement data are able to constrain the CH4 production processes, methane oxidation, and the different gas transport processes. The posterior covariance structures explain how the parameters and the processes are related. Additionally, the flux and flux component uncertain-ties are analyzed both at the annual and daily levels. The parameter posterior densities obtained provide information regarding importance of the different processes, which is also useful for development of wetland methane emission models other than the square root HelsinkI Model of MEthane buiLd- up and emIssion for peatlands (sqHIMMELI). The hierarchical modeling allows us to assess the effects of some of the parameters on an annual basis. The results of the calibration and the cross validation suggest that the early spring net primary production could be used to predict parameters affecting the annual methane production. Even though the calibration is specific to the Siikaneva site, the hierarchical modeling approach is well suited for larger-scale studies and the results of the estimation pave way for a regional or global- scale Bayesian calibration of wetland emission models.Peer reviewe

Peat macropore networks – new insights into episodic and hotspot methane emission

Peatlands are important natural sources of atmospheric methane (CH4) emissions. The production and emission of CH4 are strongly influenced by the diffusion of oxygen into the soil and of CH4 from the soil to the atmosphere, respectively. This diffusion, in turn, is controlled by the structure of macropore networks. The characterization of peat pore structure and connectivity through complex network theory approaches can give conceptual insight into how the relationship between the microscale pore space properties and CH4 emissions on a macroscopic scale is shaped. The evolution of the pore space that is connected to the atmosphere can also be conceptualized through a pore network modeling approach. Pore regions isolated from the atmosphere may further develop into anaerobic pockets, which are local hotspots of CH4 production in unsaturated peat. In this study, we extracted interconnecting macropore networks from three-dimensional X-ray micro-computed tomography (µCT) images of peat samples and evaluated local and global connectivity metrics for the networks. We also simulated the water retention characteristics of the peat samples using a pore network modeling approach and compared the simulation results with measured water retention characteristics. The results showed large differences in peat macropore structure and pore network connectivity between vertical soil layers. The macropore space was more connected and the flow paths through the peat matrix were less tortuous near the soil surface than at deeper depths. In addition, macroporosity, structural anisotropy, and average pore throat diameter decreased with depth. Narrower and more winding air-filled diffusion channels may reduce the rate of gas transport as the distance from the peat layer to the soil–air interface increases. The network analysis also suggests that both local and global network connectivity metrics, such as the network average clustering coefficient and closeness centrality, might serve as proxies for assessing the efficiency of gas diffusion in air-filled pore networks. However, the applicability of the network metrics was restricted to the high-porosity near-surface layer. The spatial extent and continuity of the pore network and the spatial distribution of the pores may be reflected in different network metrics in contrasting ways. The hysteresis of peat water content between wetting and drying was found to affect the evolution of the volume of connected air-filled pore space in unsaturated peat. Thus, the formation of anaerobic pockets may occur in a smaller soil volume and methanogenesis may be slower when the peat is wetting compared to in drying conditions. This hysteretic behavior might explain the hotspots and episodic spikes of CH4 emissions, and therefore, it should be taken into account in biogeochemical models.Peer reviewe

Urinary metabolite profiling and risk of progression of diabetic nephropathy in 2670 individuals with type 1 diabetes

Aims/hypothesis This prospective, observational study examines associations between 51 urinary metabolites and risk of progression of diabetic nephropathy in individuals with type 1 diabetes by employing an automated NMR metabolomics technique suitable for large-scale urine sample collections. Methods We collected 24-h urine samples for 2670 individuals with type 1 diabetes from the Finnish Diabetic Nephropathy study and measured metabolite concentrations by NMR. Individuals were followed up for 9.0 +/- 5.0 years until their first sign of progression of diabetic nephropathy, end-stage kidney disease or study end. Cox regressions were performed on the entire study population (overall progression), on 1999 individuals with normoalbuminuria and 347 individuals with macroalbuminuria at baseline. Results Seven urinary metabolites were associated with overall progression after adjustment for baseline albuminuria and chronic kidney disease stage (p < 8 x 10(-4)): leucine (HR 1.47 [95% CI 1.30, 1.66] per 1-SD creatinine-scaled metabolite concentration), valine (1.38 [1.22, 1.56]), isoleucine (1.33 [1.18, 1.50]), pseudouridine (1.25 [1.11, 1.42]), threonine (1.27 [1.11, 1.46]) and citrate (0.84 [0.75, 0.93]). 2-Hydroxyisobutyrate was associated with overall progression (1.30 [1.16, 1.45]) and also progression from normoalbuminuria (1.56 [1.25, 1.95]). Six amino acids and pyroglutamate were associated with progression from macroalbuminuria. Conclusions/interpretation Branched-chain amino acids and other urinary metabolites were associated with the progression of diabetic nephropathy on top of baseline albuminuria and chronic kidney disease. We found differences in associations for overall progression and progression from normo- and macroalbuminuria. These novel discoveries illustrate the utility of analysing urinary metabolites in entire population cohorts.Peer reviewe