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Arabianmeren trooppiset syklonit ovat voimistuneet vuosien 1979 – 2010 aikana. Voimistumisen arvellaan johtuvan ilmakehän pystysuuntaisen tuuliväänteen heikkenemisestä Arabianmerellä. Trooppisen syklonin voimistumiseen vaikuttavia tekijöitä on kuitenkin useita ja osa niistä on huomioitu potentiaalisen voimakkuuden teoriassa. Potentiaalisella voimakkuudella kuvataan trooppisen syklonin voimakkuuden teoreettista ylärajaa. Teorian mukaan trooppisen syklonin potentiaalinen voimakkuus nousee keskimääräisen pintatuulennopeuden heiketessä, jos muut teorian huomioimat tekijät pysyvät muuttumattomina. Arabianmeren keskimääräisen pintatuulennopeuden muutoksia tarkastellaan 10 metrin korkeudella ja 850 hPa:n tasolla koko merialueella. Erityisesti keskitytään yleisimpiin trooppisten sykloneiden synty- ja esiintymisalueisiin sekä -ajankohtiin. NCEP-keskuksen laatimista uusanalyyseistä määritetään keskimääräisten pintatuulennopeuksien erotuksia ja suhteellisia muutoksia vuosijaksojen 1997 – 2010 ja 1979 – 1996 välille eripituisille ajanjaksoille. Keskimääräinen pintatuulennopeus on enimmäkseen heikentynyt Arabianmeren itä- ja pohjoisalueilla, jotka ovat yleisiä trooppisten sykloneiden esiintymisalueita. Voimakasta pintatuulennopeuden suhteellista heikkenemistä havaitaan erityisesti Intian länsirannikon lähistöllä. Meren itäosissa pintatuulennopeus on heikentynyt vähintään 5 % voimakkaimman heikkenemisen vaihdellessa 20 – 35 % välillä ajankohdasta riippuen. Pintatuulennopeuden heikkeneminen on suhteellisesti voimakkaampaa 10 metrin korkeudella kuin 850 hPa:n tasolla. Keskimääräisen pintatuulennopeuden heikkenemistä voidaan pitää potentiaalisen voimakkuuden teorian mukaisesti osittain syynä Arabianmeren trooppisten sykloneiden voimistumiseen vuosina 1979 – 2010.

Tämän tutkielman tarkoituksena on esitellä pintojen teoriaa ja johtaa Greenin kaavat. Pintojen tutkimiseen tarvitaan käänteiskuvauslausetta: ...

Pisin yhteinen jatke -ongelmassa tarkoituksena on selvittää tietorakenteen avulla merkkijonon kahden loppuosan pisimmän yhteisen alkuosan pituus. Ongelman nopea ratkaiseminen on tärkeää esimerkiksi monissa merkkijonoalgoritmeissa. Lisäksi tiedon määrän jatkuva kasvu lisää tarvetta minimoida tietorakenteen viemä tila. Tutkielmassa käsitellään pisin yhteinen jatke -ongelman ratkaisemista koodaavalla tietorakenteella. Tällöin alkuperäiseen merkkijonoon päästään käsiksi vain ennalta määriteltyjen kyselyjen avulla, eikä merkkijonoa tarvita kyselyissä. Tyypillisesti koodaava tietorakenne vie vähemmän tilaa ja sisältää vähemmän informaatiota kuin alkuperäinen tieto. Taustan antamiseksi käsitellään ensin pisin yhteinen jatke -ongelman perinteisiä ratkaisuja. Sen jälkeen tarkastellaan tiedon tilavaativuutta informaatioteoreettisen entropian avulla, mikä luo perustan arvioida tietorakenteiden tilavaativuuden optimaalisuutta ja aika - tila-vaihtokauppaa. Lisäksi annetaan esimerkkejä koodaavan tietorakenteen käytöstä ja ongelman tilaa säästävistä ratkaisuista. Yksityiskohtaisesti käsitellään pisin yhteinen jatke -ongelman ratkaisua, jossa käytetään koodaavaa tietorakennetta. Ratkaisussa on kaksi pääasiallista osaa, joiden avulla vastaus selvitetään. Toteutuksessa käytetään hyväksi useita tietorakenteita, esimerkiksi loppuosapuuta, de Bruijn -verkon muunnosta ja virittävää puuta. Algoritmin ja tietorakenteen toteutuksen lisäksi tarkastellaan tietorakenteen tilavaativuuden ylärajan parantamista ja puiden esittämistä toteutuksessa tilaa säästäen. Keskeiset johtopäätökset ovat seuraavat. Useita kyselyjä tehtäessä pisin yhteinen jatke -ongelma voi kannattaa ratkaista tietorakenteen avulla. Tiedon määrän kasvun ja tietorakenteiden kehityksen seurauksena ongelmaan on viime vuosina esitetty tilaa säästäviä ratkaisuja. Niissä optimoidaan aika- ja tilavaativuutta monin eri tavoin. Ongelmaan on olemassa muun muassa vakioaikainen, koodaavaa tietorakennetta hyödyntävä ratkaisu, jolla voidaan päästä alilineaariseen tilavaativuuteen ilman alkuperäisen merkkijonon korkeaa tiivistyvyyttä. Viimeaikaisten ratkaisujen suorituskyvystä sovelluksissa ei ole vertailutietoa.

This master's thesis examines the use of Geographical Information Systems (GIS ) for analysing archaeological sites in the Loita-Mara area, southwest Kenya. GIS oriented archaeological studies have been relatively scarce in the context of African archaeology, and one of my main aims is to start filling this research gap. Loita-Mara area is one of the most intensively archaeologically studied areas in whole East Africa, which offers a good starting point for testing GIS methods. The spatial setting and potential site-catchments of archaeological sites are examined with GIS analyses. Site catchment analysis (SCA) was aimed for examining a presented hypothesis of a mixed agro-pastoral economic base for the early pastoralists. This has been based on the idea that without plant food sources pastoralism alone cannot support human societies in a long term perspective. GIS predictive models are also tested in the thesis. These have been very little utilized in the African archaeology so far. GIS data for analyses is based on archaeological and historical information combined from various sources, and on the freely available spatial-environmental data. For SCA the agricultural potential of the study area was modeled based on FAO/IIASA recommendations. Examined SCA areas were based on cost-distance catchments calculated on the basis of topography and rivers. Carried out SCA might support the presented hypothesis of a mixed agro-pastoral economy for the early pastoralists, but more detailed research is needed e.g. on the dating of various sites before any definitive conclusions can be drawn. It has to be also remembered that the best agricultural soils provided also most likely good foraging areas for both the game and domestic animals. Predictive modelling techniques tested and compared in the thesis were Boolean models, Mahalanobis distance modelling, logistic regression (GLM) and GAM. Used modelling variables were selected cognitively (deductively) founded on theoretical bases. All tested modelling techniques gave useful results for locating sites in the area. The functionality of models was evaluated using various indexes, and based on these GAM models gave best results. Predictive models are preliminary, since their ground-proofing has not been possible during this work.

Pitkittyneet kuivuus-, sade- ja hellejaksot ovat erityisen haitallisia maanviljelylle, ja näin ollen on hyödyllistä tutkia, kuinka ilmastomallit tuottavat tällaisia jaksoja sekä havaittuun ilmastoon nähden että tulevaisuudessa RCP8.5-päästöskenaarion (Representative Concentration Pathways) mukaan. Tutkittavana ovat kolmen viikon kuivat- ja sadejaksot sekä kahden viikon hellejaksot. Tässä työssä käytettiin kuuden globaalin kolmiulotteisen kytketyn ilmakehä-valtamerimallin simulaatioiden tuloksia. Mallien simuloimat lämpötilat ja sademäärät alueellistettiin kolmella eri menetelmällä: deltamuutosmenetelmällä, jossa havaintoaineistoa muokataan ilmastomallin ennustamilla muutoksilla, ja kahdella eri harhankorjausmenetelmällä, missä ilmastomallien tuloksia muokataan havaintoaineiston avulla. Ilmastomallien mukaan huhti-syyskuun keskilämpötila nousee Suomessa keskimäärin noin viisi astetta kaudesta 1981-2010 kauteen 2071-2100 sademäärän kasvaessa noin kymmenen prosenttia. Osittain sademäärän kasvamisen johdosta pitkät kuivat kaudet näyttävät vähenevän tulevaisuudessa ja lämpötilan nousun vuoksi hellejaksojen määrä nousee. Erityisen sateisten jaksojen määrän muutoksesta ei näy selviä merkkejä. Vertailukaudella 1981-2010 harhankorjausmenetelmät tuottivat sekä alueellisesti että kuukausikeskiarvoiltaan havaintoaineistoa tasaisempia jakaumia. Toisaalta deltamuutosmenetelmään nähden harhankorjausmenetelmillä muutokset vertailukaudesta tulevaisuuden jaksoon 2071-2100 olivat alueellisesti ja kuukausikeskiarvoiltaan vaihtelevampia. Varsinkin muutosten suuruutta tarkasteltaessa ilmastomallien välinen hajonta on suurta ja peittää osittain alleen menetelmien välisiä eroja. Paikallisesti muutosten suunta voi olla menetelmästä riippuen eri, jos muutokset alueella ovat pieniä. Erot muutosten luonteessa johtuvat ainakin osittain siitä, että deltamuutosmenetelmissä alueelliset ja ajalliset korrelaatiot pysyvät vertailukauden mukaisina mutta harhankorjauksessa vertailukausi ja tulevaisuuden jakso ovat toisistaan riippumattomat. Menetelmien väliset erot olivat suurimmat kahden viikon hellejaksojen määrissä, jotka molemmat harhankorjausmenetelmät yliarvioivat reilusti vertailukaudella havaintoaineistoon verrattuna. Harhankorjausmenetelmät myös kasvattivat jaksojen määrää ilmaston lämmetessä enemmän kuin deltamuutosmenetelmä, joskin ero oli suhteessa pienempi kuin ero vertailukauden hellejaksojen määrässä.

This thesis concentrates on the place-based conservation and how its implementation suits the marine realm characterized by large-scale patterns and wrapped in scientific uncertainty. There is still great amount of information missing which affects the conservation design. Furthermore, as the science behind marine conservation lacks behind its terrestrial counterpart, the theoretical foundations on which marine conservation and MPAs are laid on is based greatly on terrestrial conservation practices and experiences with terrestrial species and habitats in mind. The social aspect of conservation and marine protected areas (MPAs) is often neglected in research. Also the incorporation of locals to the management is often lacking. For the long-term success of any given MPA, the social component should be a major part of managing MPAs as non-compliance to regulations often follows when the local communities are excluded or not fully incorporated. Furthermore, tensions between and among different stakeholders can weaken the functioning of any MPA. Part of this study aims to shed light on the perceptions and attitudes the fishermen have with respect to the management of Watamu MPA. The setting for the study is Watamu Marine National park and Reserve in Kenya to which I conducted a field trip in February-March 2016. Semi-structured interviews were conducted with fishermen in two landing sites - Watamu and Darakasi. In addition, a literature research was conducted to gain more holistic picture of the areas ecology and the outcomes of the marine park. Theoretical framework is based on political ecology and draws influence particularly from its Marxist roots of nature-society dialectics and materialist philosophy. Also emphasis is given to the concept of boundaries with 'power of maps' framework that questions the use of place-based conservation as the only valid approach to conservation. Most of the fishermen in both landing sites were favorable of conservation and understood the need to protect, but simultaneously did not perceive major benefits from the Watamu MPA. Especially with respect to the marine park, some division among the fishermen was detected. Many wished the park would be opened for seasonal use for fishing purposes. Still, the marine park has shown to be delivering tangible conservation outcomes which is why it should stay closed. Adaptive management is thus needed to find common ground between ecological factors and social needs.

This master’s thesis explores spatial and aesthetic experiences and placemaking in two public spaces in Malmi and Malminkartano in Helsinki. It focuses on two case studies through ethnographic fieldwork in order to evaluate the added value of placemaking in the urban planning practices of the City of Helsinki from the citizens’ perspective. The case studies shed light on the possibilities and risks of placemaking, especially in the context of Helsinki neighbourhoods that are subject to densification and suburban regeneration projects. This research was commissioned by the Strategic Urban Planning Department of the Urban Environment Division of the City of Helsinki. This thesis explores three research questions. It aims to understand how the observed placemaking projects affected the spatial and aesthetic experiences in the public spaces in question. It also examines what kind of attitudes arose among informants regarding public space, placemaking, densification and urban planning in the context of the studied neighbourhoods. Lastly, it assesses the potential of placemaking to improve the spatial and aesthetic experience of public spaces in neighbourhoods undergoing suburban regeneration projects. The theoretical framework of this research utilises theories and viewpoints of human geography and philosophy of urban aesthetics. Building on the study of place and space, it employs the concepts of spatial and aesthetic experience to examine sensory perceptions in public spaces. Additionally, it continues the culture and tradition of qualitative urban planning research. The data was gathered through ethnographic fieldwork during the span of the studied placemaking projects between July and October 2021. The fieldwork entailed participant observation, informal interviews and conversations with informants and autoethnographic observations of sensory, spatial and aesthetic experiences in public space. In addition to the ethnographic data, placemaking theory was utilised to formulate the analyses and results. Based on the data, the observed placemaking case studies had a moderate effect on the spatial and aesthetic experiences in the public spaces in question. However, they raised valuable discussions about local viewpoints and provided important place-based knowledge for urban planners. The ethnographic process revealed both accepting and antagonistic narratives within the local communities regarding densification and the urban planning practices of the City of Helsinki. The latter attitudes did not, however, seem to negatively affect the informants’ conceptions of the studied projects or placemaking generally. Instead, place-driven attempts at making public spaces greener, livelier and more engaging were almost unanimously accepted and welcomed. Consequently, placemaking is proposed here as a viable method to develop and improve the experience of public spaces among citizens in neighbourhoods undergoing suburban regeneration projects. Based on the gathered data and theoretical reasoning, this thesis argues that placemaking is an urban development approach, method and philosophy that can create added value to conventional urban planning practices in Helsinki. Placemaking can improve the experience of public space by vitalising its experiential and sensory qualities, and thus complement technocratic urban planning and construction processes. Placemaking can provide planners with place-based knowledge about local conditions and aspirations that is useful for long-term planning goals. Placemaking can be utilised as a participation method that gives citizens more agency and shows faster impact than other means of participation, further empowering them to reclaim public spaces for communal uses. Placemaking can make public spaces safer and more pluralistic by broadening their usership and increasing vulnerable groups’ presence. By engaging in community-driven placemaking, the City of Helsinki can improve its public spaces in multiple ways and develop its current participatory and urban design practices in alignment with its strategic goals of enhancing the quality of life for its citizens.

This thesis examines cross-sectoral interaction, the role of large actors and its implications to citizens as well as the institutional factors shaping the functioning of the planning sector in Helsinki. The aim is to understand the local planning climate and how it has been shaped by global ideas. Helsinki was chosen because the combination of municipal planning monopoly and vast land ownership makes it a unique case study. Research on large actors (referred to as planning machines and global intelligence corps) has illustrated that large actors and the traveling planning ideas introduced by them affect local planning climates. The resources of planning machines can exclude smaller actors from the field, and complicate the efforts of citizens to resist projects executed by them. International planning ideas on the other hand are adopted by planning officials and local politicians, resulting in a more managerial and entrepreneurial role of planning departments and city councils. Ecological planning is an example of a traveling planning idea discussed in the thesis. Both planning machines and traveling planning ideas have been associated with a post-political climate in which alternatives to current development are marginalised, having direct consequences for democracy. A total of nine professionals from public and private sectors were interviewed, and the semi-structured interviews were coded and analysed using computer assisted qualitative data analysis software. Figures and tables of the 20 most frequent codes and three codes with a highest co-occurrence with each of these codes were chosen for the analysis, as well as other codes with relevance to the research questions. The analysis shows that institutional factors place Helsinki in a strong position to negotiate with the private sector. In cross-sectoral cooperation the role of the public sector has become more managerial and the city has advanced its strategic goals concerning the attractiveness and competitiveness of the city region. However, the city has protected its interests in themes such as social mixing, slowing down negative development witnessed elsewhere. New forms of partnerships such as Allianssi model are examples of successful cross-sectoral cooperation where the power relations between sectors are more equal, but seem to favour large actors due to their resource-heavy nature. Procurement legislation also favours large actors for the same reason. Recommendations for further spatial, temporal and scalar research are proposed.

The development of active, stable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is paramount for the large-scale deployment of hydrogen based clean energy technologies. Despite its apparent simplicity, the HER serves as a bridge between fundamental electrocatalysis research and practical catalyst design. Water splitting, a highly efficient and environmentally friendly method for hydrogen production, necessitates a stable, active, and abundant catalysts. While platinum (Pt)-based materials reign supreme in acidic electrolytes for their exceptional HER efficiency and durability, their scarcity and high-cost limit their widespread application. This study introduces a strategy to decrease the Pt loading in the catalyst by developing nanoparticles containing an ultralow Pt loading supported on tungsten oxide (W18O49). Remarkably, the activity of this developed system approaches that of commercially available 20% (wt.) Pt/C catalysts, even with a noble metal content of less than 2 wt.%. Notably, the optimal sample, Pt1.6/W18O49 (containing 1.6 wt.% Pt), demonstrates a superior Tafel slope and requires a mere 46 mV overpotential to achieve a current density of 10 mA cm-2. This work suggests that catalyst design and controlled synthesis can promote the HER and facilitate faster electron transfer even at low Pt loadings. This system exhibits exceptional stability, maintaining its performance for over 24 hours without significant degradation. This synergistic approach, employing minimal Pt supported on a W18O49 matrix, paves the way for addressing real-world challenges in hydrogen production.

The impacts of dust aerosols on human health and climate change are increasing as the particulate matter (PM) mass concentrations and frequency of Sand and Dust Storm (SDS) episodes have shown an increasing trend in recent studies, especially for the Middle East and North Africa (MENA). In this thesis, particulate matter (PM10 and PM2.5) concentrations were measured during May 2018–March 2019 in the urban atmosphere of Amman, Jordan. The PM sampling was 24-hours every 6 days. The overall mean PM10 mass concentration was 64±39 μg/m3 with the median (+interquartile range) value of 49.2+53.5 μg/m3, the PM2.5 mass concentration varied between 15 μg/m3 and 190 μg/m3 with an annual average 47±32 μg/m3 and with the median (+interquartile range) value of 35.8+26.3 μg/m3. The PM2.5 / PM10 ratio was 0.8±0.2. According to the Jordanian Air Quality standards, the annual mean PM10 needs to be below a limit value of 120 μg/m3, which was true in this work. However, the PM2.5 mass concentration was three times higher the corresponding limit value (65 μg/m3). However, both exceeded the World Health Organization (WHO) air quality annual guideline of 20 μg/m3 for PM10 and 10 μg/m3 for PM2.5. The results show that the observed PM10 mass concentrations in Jordan were lower than what was reported in other cities in the Middle East but were higher when compared to other Mediterranean cities. During the measurement period, Jordan was affected by Sand and Dust Storms (SDS), which were observed on 14 sampling days. The source origins of these SDS were traced back to North Africa, the Arabian Peninsula, and the Levant. The 24-hour PM10 concentrations during these SDS episodes ranged between 108.1 μg/m3 and 187.3 μg/m3. In the future, measurements with a higher time resolution (one sample per day) are recommended for a more precise seasonal trend interpretation.